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chromium / native_client / pnacl-subzero / 32f9ccef8dee33110cc9ebdca2853d6a078752ed / . / src / IceTargetLoweringARM32.cpp
blob: a2f1123088419a65a05309c963764ab64acaac3a [file] [log] [blame]
//===- subzero/src/IceTargetLoweringARM32.cpp - ARM32 lowering ------------===//
//
// The Subzero Code Generator
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Implements the TargetLoweringARM32 class, which consists almost
/// entirely of the lowering sequence for each high-level instruction.
///
//===----------------------------------------------------------------------===//
#include "IceTargetLoweringARM32.h"
#include "IceCfg.h"
#include "IceCfgNode.h"
#include "IceClFlags.h"
#include "IceDefs.h"
#include "IceELFObjectWriter.h"
#include "IceGlobalInits.h"
#include "IceInstARM32.def"
#include "IceInstARM32.h"
#include "IceInstVarIter.h"
#include "IceLiveness.h"
#include "IceOperand.h"
#include "IcePhiLoweringImpl.h"
#include "IceRegistersARM32.h"
#include "IceTargetLoweringARM32.def"
#include "IceUtils.h"
#include "llvm/Support/MathExtras.h"
#include <algorithm>
#include <array>
#include <utility>
namespace ARM32 {
std::unique_ptr<::Ice::TargetLowering> createTargetLowering(::Ice::Cfg *Func) {
return ::Ice::ARM32::TargetARM32::create(Func);
}
std::unique_ptr<::Ice::TargetDataLowering>
createTargetDataLowering(::Ice::GlobalContext *Ctx) {
return ::Ice::ARM32::TargetDataARM32::create(Ctx);
}
std::unique_ptr<::Ice::TargetHeaderLowering>
createTargetHeaderLowering(::Ice::GlobalContext *Ctx) {
return ::Ice::ARM32::TargetHeaderARM32::create(Ctx);
}
void staticInit(::Ice::GlobalContext *Ctx) {
::Ice::ARM32::TargetARM32::staticInit(Ctx);
if (Ice::getFlags().getUseNonsfi()) {
// In nonsfi, we need to reference the _GLOBAL_OFFSET_TABLE_ for accessing
// globals. The GOT is an external symbol (i.e., it is not defined in the
// pexe) so we need to register it as such so that ELF emission won't barf
// on an "unknown" symbol. The GOT is added to the External symbols list
// here because staticInit() is invoked in a single-thread context.
Ctx->getConstantExternSym(Ctx->getGlobalString(::Ice::GlobalOffsetTable));
}
}
bool shouldBePooled(const ::Ice::Constant *C) {
return ::Ice::ARM32::TargetARM32::shouldBePooled(C);
}
::Ice::Type getPointerType() {
return ::Ice::ARM32::TargetARM32::getPointerType();
}
} // end of namespace ARM32
namespace Ice {
namespace ARM32 {
namespace {
/// SizeOf is used to obtain the size of an initializer list as a constexpr
/// expression. This is only needed until our C++ library is updated to
/// C++ 14 -- which defines constexpr members to std::initializer_list.
class SizeOf {
SizeOf(const SizeOf &) = delete;
SizeOf &operator=(const SizeOf &) = delete;
public:
constexpr SizeOf() : Size(0) {}
template <typename... T>
explicit constexpr SizeOf(T...)
: Size(__length<T...>::value) {}
constexpr SizeT size() const { return Size; }
private:
template <typename T, typename... U> struct __length {
static constexpr std::size_t value = 1 + __length<U...>::value;
};
template <typename T> struct __length<T> {
static constexpr std::size_t value = 1;
};
const std::size_t Size;
};
} // end of anonymous namespace
// Defines the RegARM32::Table table with register information.
RegARM32::RegTableType RegARM32::RegTable[RegARM32::Reg_NUM] = {
#define X(val, encode, name, cc_arg, scratch, preserved, stackptr, frameptr, \
isGPR, isInt, isI64Pair, isFP32, isFP64, isVec128, alias_init) \
{ \
name, encode, cc_arg, scratch, preserved, stackptr, frameptr, isGPR, \
isInt, isI64Pair, isFP32, isFP64, isVec128, \
(SizeOf alias_init).size(), alias_init \
} \
,
REGARM32_TABLE
#undef X
};
namespace {
// The following table summarizes the logic for lowering the icmp instruction
// for i32 and narrower types. Each icmp condition has a clear mapping to an
// ARM32 conditional move instruction.
const struct TableIcmp32_ {
CondARM32::Cond Mapping;
} TableIcmp32[] = {
#define X(val, is_signed, swapped64, C_32, C1_64, C2_64, C_V, INV_V, NEG_V) \
{ CondARM32::C_32 } \
,
ICMPARM32_TABLE
#undef X
};
// The following table summarizes the logic for lowering the icmp instruction
// for the i64 type. Two conditional moves are needed for setting to 1 or 0.
// The operands may need to be swapped, and there is a slight difference for
// signed vs unsigned (comparing hi vs lo first, and using cmp vs sbc).
const struct TableIcmp64_ {
bool IsSigned;
bool Swapped;
CondARM32::Cond C1, C2;
} TableIcmp64[] = {
#define X(val, is_signed, swapped64, C_32, C1_64, C2_64, C_V, INV_V, NEG_V) \
{ is_signed, swapped64, CondARM32::C1_64, CondARM32::C2_64 } \
,
ICMPARM32_TABLE
#undef X
};
CondARM32::Cond getIcmp32Mapping(InstIcmp::ICond Cond) {
assert(Cond < llvm::array_lengthof(TableIcmp32));
return TableIcmp32[Cond].Mapping;
}
// In some cases, there are x-macros tables for both high-level and low-level
// instructions/operands that use the same enum key value. The tables are kept
// separate to maintain a proper separation between abstraction layers. There
// is a risk that the tables could get out of sync if enum values are reordered
// or if entries are added or deleted. The following anonymous namespaces use
// static_asserts to ensure everything is kept in sync.
// Validate the enum values in ICMPARM32_TABLE.
namespace {
// Define a temporary set of enum values based on low-level table entries.
enum _icmp_ll_enum {
#define X(val, is_signed, swapped64, C_32, C1_64, C2_64, C_V, INV_V, NEG_V) \
_icmp_ll_##val,
ICMPARM32_TABLE
#undef X
_num
};
// Define a set of constants based on high-level table entries.
#define X(tag, reverse, str) \
static constexpr int _icmp_hl_##tag = InstIcmp::tag;
ICEINSTICMP_TABLE
#undef X
// Define a set of constants based on low-level table entries, and ensure the
// table entry keys are consistent.
#define X(val, is_signed, swapped64, C_32, C1_64, C2_64, C_V, INV_V, NEG_V) \
static_assert( \
_icmp_ll_##val == _icmp_hl_##val, \
"Inconsistency between ICMPARM32_TABLE and ICEINSTICMP_TABLE: " #val);
ICMPARM32_TABLE
#undef X
// Repeat the static asserts with respect to the high-level table entries in
// case the high-level table has extra entries.
#define X(tag, reverse, str) \
static_assert( \
_icmp_hl_##tag == _icmp_ll_##tag, \
"Inconsistency between ICMPARM32_TABLE and ICEINSTICMP_TABLE: " #tag);
ICEINSTICMP_TABLE
#undef X
} // end of anonymous namespace
// Stack alignment
const uint32_t ARM32_STACK_ALIGNMENT_BYTES = 16;
// Value is in bytes. Return Value adjusted to the next highest multiple of the
// stack alignment.
uint32_t applyStackAlignment(uint32_t Value) {
return Utils::applyAlignment(Value, ARM32_STACK_ALIGNMENT_BYTES);
}
// Value is in bytes. Return Value adjusted to the next highest multiple of the
// stack alignment required for the given type.
uint32_t applyStackAlignmentTy(uint32_t Value, Type Ty) {
// Use natural alignment, except that normally (non-NaCl) ARM only aligns
// vectors to 8 bytes.
// TODO(jvoung): Check this ...
size_t typeAlignInBytes = typeWidthInBytes(Ty);
if (isVectorType(Ty))
typeAlignInBytes = 8;
return Utils::applyAlignment(Value, typeAlignInBytes);
}
// Conservatively check if at compile time we know that the operand is
// definitely a non-zero integer.
bool isGuaranteedNonzeroInt(const Operand *Op) {
if (auto *Const = llvm::dyn_cast_or_null<ConstantInteger32>(Op)) {
return Const->getValue() != 0;
}
return false;
}
} // end of anonymous namespace
TargetARM32Features::TargetARM32Features(const ClFlags &Flags) {
static_assert(
(ARM32InstructionSet::End - ARM32InstructionSet::Begin) ==
(TargetInstructionSet::ARM32InstructionSet_End -
TargetInstructionSet::ARM32InstructionSet_Begin),
"ARM32InstructionSet range different from TargetInstructionSet");
if (Flags.getTargetInstructionSet() !=
TargetInstructionSet::BaseInstructionSet) {
InstructionSet = static_cast<ARM32InstructionSet>(
(Flags.getTargetInstructionSet() -
TargetInstructionSet::ARM32InstructionSet_Begin) +
ARM32InstructionSet::Begin);
}
}
namespace {
constexpr SizeT NumGPRArgs =
#define X(val, encode, name, cc_arg, scratch, preserved, stackptr, frameptr, \
isGPR, isInt, isI64Pair, isFP32, isFP64, isVec128, alias_init) \
+(((cc_arg) > 0) ? 1 : 0)
REGARM32_GPR_TABLE
#undef X
;
std::array<RegNumT, NumGPRArgs> GPRArgInitializer;
constexpr SizeT NumI64Args =
#define X(val, encode, name, cc_arg, scratch, preserved, stackptr, frameptr, \
isGPR, isInt, isI64Pair, isFP32, isFP64, isVec128, alias_init) \
+(((cc_arg) > 0) ? 1 : 0)
REGARM32_I64PAIR_TABLE
#undef X
;
std::array<RegNumT, NumI64Args> I64ArgInitializer;
constexpr SizeT NumFP32Args =
#define X(val, encode, name, cc_arg, scratch, preserved, stackptr, frameptr, \
isGPR, isInt, isI64Pair, isFP32, isFP64, isVec128, alias_init) \
+(((cc_arg) > 0) ? 1 : 0)
REGARM32_FP32_TABLE
#undef X
;
std::array<RegNumT, NumFP32Args> FP32ArgInitializer;
constexpr SizeT NumFP64Args =
#define X(val, encode, name, cc_arg, scratch, preserved, stackptr, frameptr, \
isGPR, isInt, isI64Pair, isFP32, isFP64, isVec128, alias_init) \
+(((cc_arg) > 0) ? 1 : 0)
REGARM32_FP64_TABLE
#undef X
;
std::array<RegNumT, NumFP64Args> FP64ArgInitializer;
constexpr SizeT NumVec128Args =
#define X(val, encode, name, cc_arg, scratch, preserved, stackptr, frameptr, \
isGPR, isInt, isI64Pair, isFP32, isFP64, isVec128, alias_init) \
+(((cc_arg > 0)) ? 1 : 0)
REGARM32_VEC128_TABLE
#undef X
;
std::array<RegNumT, NumVec128Args> Vec128ArgInitializer;
const char *getRegClassName(RegClass C) {
auto ClassNum = static_cast<RegARM32::RegClassARM32>(C);
assert(ClassNum < RegARM32::RCARM32_NUM);
switch (ClassNum) {
default:
assert(C < RC_Target);
return regClassString(C);
// Add handling of new register classes below.
case RegARM32::RCARM32_QtoS:
return "QtoS";
}
}
} // end of anonymous namespace
TargetARM32::TargetARM32(Cfg *Func)
: TargetLowering(Func), NeedSandboxing(SandboxingType == ST_NaCl),
CPUFeatures(getFlags()) {}
void TargetARM32::staticInit(GlobalContext *Ctx) {
RegNumT::setLimit(RegARM32::Reg_NUM);
// Limit this size (or do all bitsets need to be the same width)???
SmallBitVector IntegerRegisters(RegARM32::Reg_NUM);
SmallBitVector I64PairRegisters(RegARM32::Reg_NUM);
SmallBitVector Float32Registers(RegARM32::Reg_NUM);
SmallBitVector Float64Registers(RegARM32::Reg_NUM);
SmallBitVector VectorRegisters(RegARM32::Reg_NUM);
SmallBitVector QtoSRegisters(RegARM32::Reg_NUM);
SmallBitVector InvalidRegisters(RegARM32::Reg_NUM);
const unsigned EncodedReg_q8 = RegARM32::RegTable[RegARM32::Reg_q8].Encoding;
for (int i = 0; i < RegARM32::Reg_NUM; ++i) {
const auto &Entry = RegARM32::RegTable[i];
IntegerRegisters[i] = Entry.IsInt;
I64PairRegisters[i] = Entry.IsI64Pair;
Float32Registers[i] = Entry.IsFP32;
Float64Registers[i] = Entry.IsFP64;
VectorRegisters[i] = Entry.IsVec128;
RegisterAliases[i].resize(RegARM32::Reg_NUM);
// TODO(eholk): It would be better to store a QtoS flag in the
// IceRegistersARM32 table than to compare their encodings here.
QtoSRegisters[i] = Entry.IsVec128 && Entry.Encoding < EncodedReg_q8;
for (int j = 0; j < Entry.NumAliases; ++j) {
assert(i == j || !RegisterAliases[i][Entry.Aliases[j]]);
RegisterAliases[i].set(Entry.Aliases[j]);
}
assert(RegisterAliases[i][i]);
if (Entry.CCArg <= 0) {
continue;
}
const auto RegNum = RegNumT::fromInt(i);
if (Entry.IsGPR) {
GPRArgInitializer[Entry.CCArg - 1] = RegNum;
} else if (Entry.IsI64Pair) {
I64ArgInitializer[Entry.CCArg - 1] = RegNum;
} else if (Entry.IsFP32) {
FP32ArgInitializer[Entry.CCArg - 1] = RegNum;
} else if (Entry.IsFP64) {
FP64ArgInitializer[Entry.CCArg - 1] = RegNum;
} else if (Entry.IsVec128) {
Vec128ArgInitializer[Entry.CCArg - 1] = RegNum;
}
}
TypeToRegisterSet[IceType_void] = InvalidRegisters;
TypeToRegisterSet[IceType_i1] = IntegerRegisters;
TypeToRegisterSet[IceType_i8] = IntegerRegisters;
TypeToRegisterSet[IceType_i16] = IntegerRegisters;
TypeToRegisterSet[IceType_i32] = IntegerRegisters;
TypeToRegisterSet[IceType_i64] = I64PairRegisters;
TypeToRegisterSet[IceType_f32] = Float32Registers;
TypeToRegisterSet[IceType_f64] = Float64Registers;
TypeToRegisterSet[IceType_v4i1] = VectorRegisters;
TypeToRegisterSet[IceType_v8i1] = VectorRegisters;
TypeToRegisterSet[IceType_v16i1] = VectorRegisters;
TypeToRegisterSet[IceType_v16i8] = VectorRegisters;
TypeToRegisterSet[IceType_v8i16] = VectorRegisters;
TypeToRegisterSet[IceType_v4i32] = VectorRegisters;
TypeToRegisterSet[IceType_v4f32] = VectorRegisters;
TypeToRegisterSet[RegARM32::RCARM32_QtoS] = QtoSRegisters;
for (size_t i = 0; i < llvm::array_lengthof(TypeToRegisterSet); ++i)
TypeToRegisterSetUnfiltered[i] = TypeToRegisterSet[i];
filterTypeToRegisterSet(Ctx, RegARM32::Reg_NUM, TypeToRegisterSet,
llvm::array_lengthof(TypeToRegisterSet),
[](RegNumT RegNum) -> std::string {
// This function simply removes ", " from the
// register name.
std::string Name = RegARM32::getRegName(RegNum);
constexpr const char RegSeparator[] = ", ";
constexpr size_t RegSeparatorWidth =
llvm::array_lengthof(RegSeparator) - 1;
for (size_t Pos = Name.find(RegSeparator);
Pos != std::string::npos;
Pos = Name.find(RegSeparator)) {
Name.replace(Pos, RegSeparatorWidth, "");
}
return Name;
},
getRegClassName);
}
namespace {
void copyRegAllocFromInfWeightVariable64On32(const VarList &Vars) {
for (Variable *Var : Vars) {
auto *Var64 = llvm::dyn_cast<Variable64On32>(Var);
if (!Var64) {
// This is not the variable we are looking for.
continue;
}
// only allow infinite-weight i64 temporaries to be register allocated.
assert(!Var64->hasReg() || Var64->mustHaveReg());
if (!Var64->hasReg()) {
continue;
}
const auto FirstReg =
RegNumT::fixme(RegARM32::getI64PairFirstGPRNum(Var->getRegNum()));
// This assumes little endian.
Variable *Lo = Var64->getLo();
Variable *Hi = Var64->getHi();
assert(Lo->hasReg() == Hi->hasReg());
if (Lo->hasReg()) {
continue;
}
Lo->setRegNum(FirstReg);
Lo->setMustHaveReg();
Hi->setRegNum(RegNumT::fixme(FirstReg + 1));
Hi->setMustHaveReg();
}
}
} // end of anonymous namespace
uint32_t TargetARM32::getCallStackArgumentsSizeBytes(const InstCall *Call) {
TargetARM32::CallingConv CC;
RegNumT DummyReg;
size_t OutArgsSizeBytes = 0;
for (SizeT i = 0, NumArgs = Call->getNumArgs(); i < NumArgs; ++i) {
Operand *Arg = legalizeUndef(Call->getArg(i));
const Type Ty = Arg->getType();
if (isScalarIntegerType(Ty)) {
if (CC.argInGPR(Ty, &DummyReg)) {
continue;
}
} else {
if (CC.argInVFP(Ty, &DummyReg)) {
continue;
}
}
OutArgsSizeBytes = applyStackAlignmentTy(OutArgsSizeBytes, Ty);
OutArgsSizeBytes += typeWidthInBytesOnStack(Ty);
}
return applyStackAlignment(OutArgsSizeBytes);
}
void TargetARM32::genTargetHelperCallFor(Inst *Instr) {
constexpr bool NoTailCall = false;
constexpr bool IsTargetHelperCall = true;
switch (Instr->getKind()) {
default:
return;
case Inst::Arithmetic: {
Variable *Dest = Instr->getDest();
const Type DestTy = Dest->getType();
const InstArithmetic::OpKind Op =
llvm::cast<InstArithmetic>(Instr)->getOp();
if (isVectorType(DestTy)) {
switch (Op) {
default:
break;
case InstArithmetic::Fdiv:
case InstArithmetic::Frem:
case InstArithmetic::Sdiv:
case InstArithmetic::Srem:
case InstArithmetic::Udiv:
case InstArithmetic::Urem:
scalarizeArithmetic(Op, Dest, Instr->getSrc(0), Instr->getSrc(1));
Instr->setDeleted();
return;
}
}
switch (DestTy) {
default:
return;
case IceType_i64: {
// Technically, ARM has its own aeabi routines, but we can use the
// non-aeabi routine as well. LLVM uses __aeabi_ldivmod for div, but uses
// the more standard __moddi3 for rem.
RuntimeHelper HelperID = RuntimeHelper::H_Num;
switch (Op) {
default:
return;
case InstArithmetic::Udiv:
HelperID = RuntimeHelper::H_udiv_i64;
break;
case InstArithmetic::Sdiv:
HelperID = RuntimeHelper::H_sdiv_i64;
break;
case InstArithmetic::Urem:
HelperID = RuntimeHelper::H_urem_i64;
break;
case InstArithmetic::Srem:
HelperID = RuntimeHelper::H_srem_i64;
break;
}
Operand *TargetHelper = Ctx->getRuntimeHelperFunc(HelperID);
ARM32HelpersPreamble[TargetHelper] = &TargetARM32::preambleDivRem;
constexpr SizeT MaxArgs = 2;
auto *Call = Context.insert<InstCall>(MaxArgs, Dest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(Instr->getSrc(0));
Call->addArg(Instr->getSrc(1));
Instr->setDeleted();
return;
}
case IceType_i32:
case IceType_i16:
case IceType_i8: {
const bool HasHWDiv = hasCPUFeature(TargetARM32Features::HWDivArm);
InstCast::OpKind CastKind;
RuntimeHelper HelperID = RuntimeHelper::H_Num;
switch (Op) {
default:
return;
case InstArithmetic::Udiv:
HelperID = HasHWDiv ? RuntimeHelper::H_Num : RuntimeHelper::H_udiv_i32;
CastKind = InstCast::Zext;
break;
case InstArithmetic::Sdiv:
HelperID = HasHWDiv ? RuntimeHelper::H_Num : RuntimeHelper::H_sdiv_i32;
CastKind = InstCast::Sext;
break;
case InstArithmetic::Urem:
HelperID = HasHWDiv ? RuntimeHelper::H_Num : RuntimeHelper::H_urem_i32;
CastKind = InstCast::Zext;
break;
case InstArithmetic::Srem:
HelperID = HasHWDiv ? RuntimeHelper::H_Num : RuntimeHelper::H_srem_i32;
CastKind = InstCast::Sext;
break;
}
if (HelperID == RuntimeHelper::H_Num) {
// HelperID should only ever be undefined when the processor does not
// have a hardware divider. If any other helpers are ever introduced,
// the following assert will have to be modified.
assert(HasHWDiv);
return;
}
Operand *Src0 = Instr->getSrc(0);
Operand *Src1 = Instr->getSrc(1);
if (DestTy != IceType_i32) {
// Src0 and Src1 have to be zero-, or signed-extended to i32. For Src0,
// we just insert a InstCast right before the call to the helper.
Variable *Src0_32 = Func->makeVariable(IceType_i32);
Context.insert<InstCast>(CastKind, Src0_32, Src0);
Src0 = Src0_32;
// For extending Src1, we will just insert an InstCast if Src1 is not a
// Constant. If it is, then we extend it here, and not during program
// runtime. This allows preambleDivRem to optimize-out the div-by-0
// check.
if (auto *C = llvm::dyn_cast<ConstantInteger32>(Src1)) {
const int32_t ShAmt = (DestTy == IceType_i16) ? 16 : 24;
int32_t NewC = C->getValue();
if (CastKind == InstCast::Zext) {
NewC &= ~(0x80000000l >> ShAmt);
} else {
NewC = (NewC << ShAmt) >> ShAmt;
}
Src1 = Ctx->getConstantInt32(NewC);
} else {
Variable *Src1_32 = Func->makeVariable(IceType_i32);
Context.insert<InstCast>(CastKind, Src1_32, Src1);
Src1 = Src1_32;
}
}
Operand *TargetHelper = Ctx->getRuntimeHelperFunc(HelperID);
ARM32HelpersPreamble[TargetHelper] = &TargetARM32::preambleDivRem;
constexpr SizeT MaxArgs = 2;
auto *Call = Context.insert<InstCall>(MaxArgs, Dest, TargetHelper,
NoTailCall, IsTargetHelperCall);
assert(Src0->getType() == IceType_i32);
Call->addArg(Src0);
assert(Src1->getType() == IceType_i32);
Call->addArg(Src1);
Instr->setDeleted();
return;
}
case IceType_f64:
case IceType_f32: {
if (Op != InstArithmetic::Frem) {
return;
}
constexpr SizeT MaxArgs = 2;
Operand *TargetHelper = Ctx->getRuntimeHelperFunc(
DestTy == IceType_f32 ? RuntimeHelper::H_frem_f32
: RuntimeHelper::H_frem_f64);
auto *Call = Context.insert<InstCall>(MaxArgs, Dest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(Instr->getSrc(0));
Call->addArg(Instr->getSrc(1));
Instr->setDeleted();
return;
}
}
llvm::report_fatal_error("Control flow should never have reached here.");
}
case Inst::Cast: {
Variable *Dest = Instr->getDest();
Operand *Src0 = Instr->getSrc(0);
const Type DestTy = Dest->getType();
const Type SrcTy = Src0->getType();
auto *CastInstr = llvm::cast<InstCast>(Instr);
const InstCast::OpKind CastKind = CastInstr->getCastKind();
switch (CastKind) {
default:
return;
case InstCast::Fptosi:
case InstCast::Fptoui: {
if (DestTy != IceType_i64) {
return;
}
const bool DestIsSigned = CastKind == InstCast::Fptosi;
const bool Src0IsF32 = isFloat32Asserting32Or64(SrcTy);
Operand *TargetHelper = Ctx->getRuntimeHelperFunc(
Src0IsF32 ? (DestIsSigned ? RuntimeHelper::H_fptosi_f32_i64
: RuntimeHelper::H_fptoui_f32_i64)
: (DestIsSigned ? RuntimeHelper::H_fptosi_f64_i64
: RuntimeHelper::H_fptoui_f64_i64));
static constexpr SizeT MaxArgs = 1;
auto *Call = Context.insert<InstCall>(MaxArgs, Dest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(Src0);
Instr->setDeleted();
return;
}
case InstCast::Sitofp:
case InstCast::Uitofp: {
if (SrcTy != IceType_i64) {
return;
}
const bool SourceIsSigned = CastKind == InstCast::Sitofp;
const bool DestIsF32 = isFloat32Asserting32Or64(Dest->getType());
Operand *TargetHelper = Ctx->getRuntimeHelperFunc(
DestIsF32 ? (SourceIsSigned ? RuntimeHelper::H_sitofp_i64_f32
: RuntimeHelper::H_uitofp_i64_f32)
: (SourceIsSigned ? RuntimeHelper::H_sitofp_i64_f64
: RuntimeHelper::H_uitofp_i64_f64));
static constexpr SizeT MaxArgs = 1;
auto *Call = Context.insert<InstCall>(MaxArgs, Dest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(Src0);
Instr->setDeleted();
return;
}
case InstCast::Bitcast: {
if (DestTy == SrcTy) {
return;
}
Variable *CallDest = Dest;
RuntimeHelper HelperID = RuntimeHelper::H_Num;
switch (DestTy) {
default:
return;
case IceType_i8:
assert(SrcTy == IceType_v8i1);
HelperID = RuntimeHelper::H_bitcast_8xi1_i8;
CallDest = Func->makeVariable(IceType_i32);
break;
case IceType_i16:
assert(SrcTy == IceType_v16i1);
HelperID = RuntimeHelper::H_bitcast_16xi1_i16;
CallDest = Func->makeVariable(IceType_i32);
break;
case IceType_v8i1: {
assert(SrcTy == IceType_i8);
HelperID = RuntimeHelper::H_bitcast_i8_8xi1;
Variable *Src0AsI32 = Func->makeVariable(stackSlotType());
// Arguments to functions are required to be at least 32 bits wide.
Context.insert<InstCast>(InstCast::Zext, Src0AsI32, Src0);
Src0 = Src0AsI32;
} break;
case IceType_v16i1: {
assert(SrcTy == IceType_i16);
HelperID = RuntimeHelper::H_bitcast_i16_16xi1;
Variable *Src0AsI32 = Func->makeVariable(stackSlotType());
// Arguments to functions are required to be at least 32 bits wide.
Context.insert<InstCast>(InstCast::Zext, Src0AsI32, Src0);
Src0 = Src0AsI32;
} break;
}
constexpr SizeT MaxSrcs = 1;
InstCall *Call = makeHelperCall(HelperID, CallDest, MaxSrcs);
Call->addArg(Src0);
Context.insert(Call);
// The PNaCl ABI disallows i8/i16 return types, so truncate the helper
// call result to the appropriate type as necessary.
if (CallDest->getType() != Dest->getType())
Context.insert<InstCast>(InstCast::Trunc, Dest, CallDest);
Instr->setDeleted();
return;
}
case InstCast::Trunc: {
if (DestTy == SrcTy) {
return;
}
if (!isVectorType(SrcTy)) {
return;
}
assert(typeNumElements(DestTy) == typeNumElements(SrcTy));
assert(typeElementType(DestTy) == IceType_i1);
assert(isVectorIntegerType(SrcTy));
return;
}
case InstCast::Sext:
case InstCast::Zext: {
if (DestTy == SrcTy) {
return;
}
if (!isVectorType(DestTy)) {
return;
}
assert(typeNumElements(DestTy) == typeNumElements(SrcTy));
assert(typeElementType(SrcTy) == IceType_i1);
assert(isVectorIntegerType(DestTy));
return;
}
}
llvm::report_fatal_error("Control flow should never have reached here.");
}
case Inst::IntrinsicCall: {
Variable *Dest = Instr->getDest();
auto *IntrinsicCall = llvm::cast<InstIntrinsicCall>(Instr);
Intrinsics::IntrinsicID ID = IntrinsicCall->getIntrinsicInfo().ID;
switch (ID) {
default:
return;
case Intrinsics::Ctpop: {
Operand *Src0 = IntrinsicCall->getArg(0);
Operand *TargetHelper =
Ctx->getRuntimeHelperFunc(isInt32Asserting32Or64(Src0->getType())
? RuntimeHelper::H_call_ctpop_i32
: RuntimeHelper::H_call_ctpop_i64);
static constexpr SizeT MaxArgs = 1;
auto *Call = Context.insert<InstCall>(MaxArgs, Dest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(Src0);
Instr->setDeleted();
if (Src0->getType() == IceType_i64) {
ARM32HelpersPostamble[TargetHelper] = &TargetARM32::postambleCtpop64;
}
return;
}
case Intrinsics::Longjmp: {
static constexpr SizeT MaxArgs = 2;
static constexpr Variable *NoDest = nullptr;
Operand *TargetHelper =
Ctx->getRuntimeHelperFunc(RuntimeHelper::H_call_longjmp);
auto *Call = Context.insert<InstCall>(MaxArgs, NoDest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(IntrinsicCall->getArg(0));
Call->addArg(IntrinsicCall->getArg(1));
Instr->setDeleted();
return;
}
case Intrinsics::Memcpy: {
// In the future, we could potentially emit an inline memcpy/memset, etc.
// for intrinsic calls w/ a known length.
static constexpr SizeT MaxArgs = 3;
static constexpr Variable *NoDest = nullptr;
Operand *TargetHelper =
Ctx->getRuntimeHelperFunc(RuntimeHelper::H_call_memcpy);
auto *Call = Context.insert<InstCall>(MaxArgs, NoDest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(IntrinsicCall->getArg(0));
Call->addArg(IntrinsicCall->getArg(1));
Call->addArg(IntrinsicCall->getArg(2));
Instr->setDeleted();
return;
}
case Intrinsics::Memmove: {
static constexpr SizeT MaxArgs = 3;
static constexpr Variable *NoDest = nullptr;
Operand *TargetHelper =
Ctx->getRuntimeHelperFunc(RuntimeHelper::H_call_memmove);
auto *Call = Context.insert<InstCall>(MaxArgs, NoDest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(IntrinsicCall->getArg(0));
Call->addArg(IntrinsicCall->getArg(1));
Call->addArg(IntrinsicCall->getArg(2));
Instr->setDeleted();
return;
}
case Intrinsics::Memset: {
// The value operand needs to be extended to a stack slot size because the
// PNaCl ABI requires arguments to be at least 32 bits wide.
Operand *ValOp = IntrinsicCall->getArg(1);
assert(ValOp->getType() == IceType_i8);
Variable *ValExt = Func->makeVariable(stackSlotType());
Context.insert<InstCast>(InstCast::Zext, ValExt, ValOp);
// Technically, ARM has its own __aeabi_memset, but we can use plain
// memset too. The value and size argument need to be flipped if we ever
// decide to use __aeabi_memset.
static constexpr SizeT MaxArgs = 3;
static constexpr Variable *NoDest = nullptr;
Operand *TargetHelper =
Ctx->getRuntimeHelperFunc(RuntimeHelper::H_call_memset);
auto *Call = Context.insert<InstCall>(MaxArgs, NoDest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(IntrinsicCall->getArg(0));
Call->addArg(ValExt);
Call->addArg(IntrinsicCall->getArg(2));
Instr->setDeleted();
return;
}
case Intrinsics::NaClReadTP: {
if (SandboxingType == ST_NaCl) {
return;
}
static constexpr SizeT MaxArgs = 0;
Operand *TargetHelper =
SandboxingType == ST_Nonsfi
? Ctx->getConstantExternSym(
Ctx->getGlobalString("__aeabi_read_tp"))
: Ctx->getRuntimeHelperFunc(RuntimeHelper::H_call_read_tp);
Context.insert<InstCall>(MaxArgs, Dest, TargetHelper, NoTailCall,
IsTargetHelperCall);
Instr->setDeleted();
return;
}
case Intrinsics::Setjmp: {
static constexpr SizeT MaxArgs = 1;
Operand *TargetHelper =
Ctx->getRuntimeHelperFunc(RuntimeHelper::H_call_setjmp);
auto *Call = Context.insert<InstCall>(MaxArgs, Dest, TargetHelper,
NoTailCall, IsTargetHelperCall);
Call->addArg(IntrinsicCall->getArg(0));
Instr->setDeleted();
return;
}
}
llvm::report_fatal_error("Control flow should never have reached here.");
}
}
}
void TargetARM32::findMaxStackOutArgsSize() {
// MinNeededOutArgsBytes should be updated if the Target ever creates a
// high-level InstCall that requires more stack bytes.
constexpr size_t MinNeededOutArgsBytes = 0;
MaxOutArgsSizeBytes = MinNeededOutArgsBytes;
for (CfgNode *Node : Func->getNodes()) {
Context.init(Node);
while (!Context.atEnd()) {
PostIncrLoweringContext PostIncrement(Context);
Inst *CurInstr = iteratorToInst(Context.getCur());
if (auto *Call = llvm::dyn_cast<InstCall>(CurInstr)) {
SizeT OutArgsSizeBytes = getCallStackArgumentsSizeBytes(Call);
MaxOutArgsSizeBytes = std::max(MaxOutArgsSizeBytes, OutArgsSizeBytes);
}
}
}
}
void TargetARM32::createGotPtr() {
if (SandboxingType != ST_Nonsfi) {
return;
}
GotPtr = Func->makeVariable(IceType_i32);
}
void TargetARM32::insertGotPtrInitPlaceholder() {
if (SandboxingType != ST_Nonsfi) {
return;
}
assert(GotPtr != nullptr);
// We add the two placeholder instructions here. The first fakedefs T, an
// infinite-weight temporary, while the second fakedefs the GotPtr "using" T.
// This is needed because the GotPtr initialization, if needed, will require
// a register:
//
// movw reg, _GLOBAL_OFFSET_TABLE_ - 16 - .
// movt reg, _GLOBAL_OFFSET_TABLE_ - 12 - .
// add reg, pc, reg
// mov GotPtr, reg
//
// If GotPtr is not used, then both these pseudo-instructions are dce'd.
Variable *T = makeReg(IceType_i32);
Context.insert<InstFakeDef>(T);
Context.insert<InstFakeDef>(GotPtr, T);
}
GlobalString
TargetARM32::createGotoffRelocation(const ConstantRelocatable *CR) {
GlobalString CRName = CR->getName();
GlobalString CRGotoffName =
Ctx->getGlobalString("GOTOFF$" + Func->getFunctionName() + "$" + CRName);
if (KnownGotoffs.count(CRGotoffName) == 0) {
constexpr bool SuppressMangling = true;
auto *Global =
VariableDeclaration::create(Func->getGlobalPool(), SuppressMangling);
Global->setIsConstant(true);
Global->setName(CRName);
Func->getGlobalPool()->willNotBeEmitted(Global);
auto *Gotoff =
VariableDeclaration::create(Func->getGlobalPool(), SuppressMangling);
constexpr auto GotFixup = R_ARM_GOTOFF32;
Gotoff->setIsConstant(true);
Gotoff->addInitializer(VariableDeclaration::RelocInitializer::create(
Func->getGlobalPool(), Global, {RelocOffset::create(Ctx, 0)},
GotFixup));
Gotoff->setName(CRGotoffName);
Func->addGlobal(Gotoff);
KnownGotoffs.emplace(CRGotoffName);
}
return CRGotoffName;
}
void TargetARM32::materializeGotAddr(CfgNode *Node) {
if (SandboxingType != ST_Nonsfi) {
return;
}
// At first, we try to find the
// GotPtr = def T
// pseudo-instruction that we placed for defining the got ptr. That
// instruction is not just a place-holder for defining the GotPtr (thus
// keeping liveness consistent), but it is also located at a point where it is
// safe to materialize the got addr -- i.e., before loading parameters to
// registers, but after moving register parameters from their home location.
InstFakeDef *DefGotPtr = nullptr;
for (auto &Inst : Node->getInsts()) {
auto *FakeDef = llvm::dyn_cast<InstFakeDef>(&Inst);
if (FakeDef != nullptr && FakeDef->getDest() == GotPtr) {
DefGotPtr = FakeDef;
break;
}
}
if (DefGotPtr == nullptr || DefGotPtr->isDeleted()) {
return;
}
// The got addr needs to be materialized at the same point where DefGotPtr
// lives.
Context.setInsertPoint(instToIterator(DefGotPtr));
assert(DefGotPtr->getSrcSize() == 1);
auto *T = llvm::cast<Variable>(DefGotPtr->getSrc(0));
loadNamedConstantRelocatablePIC(Ctx->getGlobalString(GlobalOffsetTable), T,
[this, T](Variable *PC) { _add(T, PC, T); });
_mov(GotPtr, T);
DefGotPtr->setDeleted();
}
void TargetARM32::loadNamedConstantRelocatablePIC(
GlobalString Name, Variable *Register,
std::function<void(Variable *PC)> Finish) {
assert(SandboxingType == ST_Nonsfi);
// We makeReg() here instead of getPhysicalRegister() because the latter ends
// up creating multi-blocks temporaries that liveness fails to validate.
auto *PC = makeReg(IceType_i32, RegARM32::Reg_pc);
auto *AddPcReloc = RelocOffset::create(Ctx);
AddPcReloc->setSubtract(true);
auto *AddPcLabel = InstARM32Label::create(Func, this);
AddPcLabel->setRelocOffset(AddPcReloc);
auto *MovwReloc = RelocOffset::create(Ctx);
auto *MovwLabel = InstARM32Label::create(Func, this);
MovwLabel->setRelocOffset(MovwReloc);
auto *MovtReloc = RelocOffset::create(Ctx);
auto *MovtLabel = InstARM32Label::create(Func, this);
MovtLabel->setRelocOffset(MovtReloc);
// The EmitString for these constant relocatables have hardcoded offsets
// attached to them. This could be dangerous if, e.g., we ever implemented
// instruction scheduling but llvm-mc currently does not support
//
// movw reg, #:lower16:(Symbol - Label - Number)
// movt reg, #:upper16:(Symbol - Label - Number)
//
// relocations.
static constexpr RelocOffsetT PcOffset = -8;
auto *CRLower = Ctx->getConstantSymWithEmitString(
PcOffset, {MovwReloc, AddPcReloc}, Name, Name + " -16");
auto *CRUpper = Ctx->getConstantSymWithEmitString(
PcOffset, {MovtReloc, AddPcReloc}, Name, Name + " -12");
Context.insert(MovwLabel);
_movw(Register, CRLower);
Context.insert(MovtLabel);
_movt(Register, CRUpper);
// PC = fake-def to keep liveness consistent.
Context.insert<InstFakeDef>(PC);
Context.insert(AddPcLabel);
Finish(PC);
}
void TargetARM32::translateO2() {
TimerMarker T(TimerStack::TT_O2, Func);
// TODO(stichnot): share passes with other targets?
// https://code.google.com/p/nativeclient/issues/detail?id=4094
if (SandboxingType == ST_Nonsfi) {
createGotPtr();
}
genTargetHelperCalls();
findMaxStackOutArgsSize();
// Do not merge Alloca instructions, and lay out the stack.
static constexpr bool SortAndCombineAllocas = true;
Func->processAllocas(SortAndCombineAllocas);
Func->dump("After Alloca processing");
if (!getFlags().getEnablePhiEdgeSplit()) {
// Lower Phi instructions.
Func->placePhiLoads();
if (Func->hasError())
return;
Func->placePhiStores();
if (Func->hasError())
return;
Func->deletePhis();
if (Func->hasError())
return;
Func->dump("After Phi lowering");
}
// Address mode optimization.
Func->getVMetadata()->init(VMK_SingleDefs);
Func->doAddressOpt();
Func->materializeVectorShuffles();
// Argument lowering
Func->doArgLowering();
// Target lowering. This requires liveness analysis for some parts of the
// lowering decisions, such as compare/branch fusing. If non-lightweight
// liveness analysis is used, the instructions need to be renumbered first.
// TODO: This renumbering should only be necessary if we're actually
// calculating live intervals, which we only do for register allocation.
Func->renumberInstructions();
if (Func->hasError())
return;
// TODO: It should be sufficient to use the fastest liveness calculation,
// i.e. livenessLightweight(). However, for some reason that slows down the
// rest of the translation. Investigate.
Func->liveness(Liveness_Basic);
if (Func->hasError())
return;
Func->dump("After ARM32 address mode opt");
if (SandboxingType == ST_Nonsfi) {
insertGotPtrInitPlaceholder();
}
Func->genCode();
if (Func->hasError())
return;
Func->dump("After ARM32 codegen");
// Register allocation. This requires instruction renumbering and full
// liveness analysis.
Func->renumberInstructions();
if (Func->hasError())
return;
Func->liveness(Liveness_Intervals);
if (Func->hasError())
return;
// The post-codegen dump is done here, after liveness analysis and associated
// cleanup, to make the dump cleaner and more useful.
Func->dump("After initial ARM32 codegen");
// Validate the live range computations. The expensive validation call is
// deliberately only made when assertions are enabled.
assert(Func->validateLiveness());
Func->getVMetadata()->init(VMK_All);
regAlloc(RAK_Global);
if (Func->hasError())
return;
copyRegAllocFromInfWeightVariable64On32(Func->getVariables());
Func->dump("After linear scan regalloc");
if (getFlags().getEnablePhiEdgeSplit()) {
Func->advancedPhiLowering();
Func->dump("After advanced Phi lowering");
}
ForbidTemporaryWithoutReg _(this);
// Stack frame mapping.
Func->genFrame();
if (Func->hasError())
return;
Func->dump("After stack frame mapping");
postLowerLegalization();
if (Func->hasError())
return;
Func->dump("After postLowerLegalization");
Func->contractEmptyNodes();
Func->reorderNodes();
// Branch optimization. This needs to be done just before code emission. In
// particular, no transformations that insert or reorder CfgNodes should be
// done after branch optimization. We go ahead and do it before nop insertion
// to reduce the amount of work needed for searching for opportunities.
Func->doBranchOpt();
Func->dump("After branch optimization");
// Nop insertion
if (getFlags().getShouldDoNopInsertion()) {
Func->doNopInsertion();
}
}
void TargetARM32::translateOm1() {
TimerMarker T(TimerStack::TT_Om1, Func);
// TODO(stichnot): share passes with other targets?
if (SandboxingType == ST_Nonsfi) {
createGotPtr();
}
genTargetHelperCalls();
findMaxStackOutArgsSize();
// Do not merge Alloca instructions, and lay out the stack.
static constexpr bool DontSortAndCombineAllocas = false;
Func->processAllocas(DontSortAndCombineAllocas);
Func->dump("After Alloca processing");
Func->placePhiLoads();
if (Func->hasError())
return;
Func->placePhiStores();
if (Func->hasError())
return;
Func->deletePhis();
if (Func->hasError())
return;
Func->dump("After Phi lowering");
Func->doArgLowering();
if (SandboxingType == ST_Nonsfi) {
insertGotPtrInitPlaceholder();
}
Func->genCode();
if (Func->hasError())
return;
Func->dump("After initial ARM32 codegen");
regAlloc(RAK_InfOnly);
if (Func->hasError())
return;
copyRegAllocFromInfWeightVariable64On32(Func->getVariables());
Func->dump("After regalloc of infinite-weight variables");
ForbidTemporaryWithoutReg _(this);
Func->genFrame();
if (Func->hasError())
return;
Func->dump("After stack frame mapping");
postLowerLegalization();
if (Func->hasError())
return;
Func->dump("After postLowerLegalization");
// Nop insertion
if (getFlags().getShouldDoNopInsertion()) {
Func->doNopInsertion();
}
}
uint32_t TargetARM32::getStackAlignment() const {
return ARM32_STACK_ALIGNMENT_BYTES;
}
bool TargetARM32::doBranchOpt(Inst *I, const CfgNode *NextNode) {
if (auto *Br = llvm::dyn_cast<InstARM32Br>(I)) {
return Br->optimizeBranch(NextNode);
}
return false;
}
const char *TargetARM32::getRegName(RegNumT RegNum, Type Ty) const {
(void)Ty;
return RegARM32::getRegName(RegNum);
}
Variable *TargetARM32::getPhysicalRegister(RegNumT RegNum, Type Ty) {
static const Type DefaultType[] = {
#define X(val, encode, name, cc_arg, scratch, preserved, stackptr, frameptr, \
isGPR, isInt, isI64Pair, isFP32, isFP64, isVec128, alias_init) \
(isFP32) \
? IceType_f32 \
: ((isFP64) ? IceType_f64 : ((isVec128 ? IceType_v4i32 : IceType_i32))),
REGARM32_TABLE
#undef X
};
if (Ty == IceType_void) {
assert(unsigned(RegNum) < llvm::array_lengthof(DefaultType));
Ty = DefaultType[RegNum];
}
if (PhysicalRegisters[Ty].empty())
PhysicalRegisters[Ty].resize(RegARM32::Reg_NUM);
assert(unsigned(RegNum) < PhysicalRegisters[Ty].size());
Variable *Reg = PhysicalRegisters[Ty][RegNum];
if (Reg == nullptr) {
Reg = Func->makeVariable(Ty);
Reg->setRegNum(RegNum);
PhysicalRegisters[Ty][RegNum] = Reg;
// Specially mark a named physical register as an "argument" so that it is
// considered live upon function entry. Otherwise it's possible to get
// liveness validation errors for saving callee-save registers.
Func->addImplicitArg(Reg);
// Don't bother tracking the live range of a named physical register.
Reg->setIgnoreLiveness();
}
return Reg;
}
void TargetARM32::emitJumpTable(const Cfg *Func,
const InstJumpTable *JumpTable) const {
(void)Func;
(void)JumpTable;
UnimplementedError(getFlags());
}
void TargetARM32::emitVariable(const Variable *Var) const {
if (!BuildDefs::dump())
return;
Ostream &Str = Ctx->getStrEmit();
if (Var->hasReg()) {
Str << getRegName(Var->getRegNum(), Var->getType());
return;
}
if (Var->mustHaveReg()) {
llvm::report_fatal_error("Infinite-weight Variable (" + Var->getName() +
") has no register assigned - function " +
Func->getFunctionName());
}
assert(!Var->isRematerializable());
int32_t Offset = Var->getStackOffset();
auto BaseRegNum = Var->getBaseRegNum();
if (BaseRegNum.hasNoValue()) {
BaseRegNum = getFrameOrStackReg();
}
const Type VarTy = Var->getType();
Str << "[" << getRegName(BaseRegNum, VarTy);
if (Offset != 0) {
Str << ", #" << Offset;
}
Str << "]";
}
TargetARM32::CallingConv::CallingConv()
: GPRegsUsed(RegARM32::Reg_NUM),
GPRArgs(GPRArgInitializer.rbegin(), GPRArgInitializer.rend()),
I64Args(I64ArgInitializer.rbegin(), I64ArgInitializer.rend()),
VFPRegsUsed(RegARM32::Reg_NUM),
FP32Args(FP32ArgInitializer.rbegin(), FP32ArgInitializer.rend()),
FP64Args(FP64ArgInitializer.rbegin(), FP64ArgInitializer.rend()),
Vec128Args(Vec128ArgInitializer.rbegin(), Vec128ArgInitializer.rend()) {}
bool TargetARM32::CallingConv::argInGPR(Type Ty, RegNumT *Reg) {
CfgVector<RegNumT> *Source;
switch (Ty) {
default: {
assert(isScalarIntegerType(Ty));
Source = &GPRArgs;
} break;
case IceType_i64: {
Source = &I64Args;
} break;
}
discardUnavailableGPRsAndTheirAliases(Source);
if (Source->empty()) {
GPRegsUsed.set();
return false;
}
*Reg = Source->back();
// Note that we don't Source->pop_back() here. This is intentional. Notice how
// we mark all of Reg's aliases as Used. So, for the next argument,
// Source->back() is marked as unavailable, and it is thus implicitly popped
// from the stack.
GPRegsUsed |= RegisterAliases[*Reg];
return true;
}
// GPR are not packed when passing parameters. Thus, a function foo(i32, i64,
// i32) will have the first argument in r0, the second in r1-r2, and the third
// on the stack. To model this behavior, whenever we pop a register from Regs,
// we remove all of its aliases from the pool of available GPRs. This has the
// effect of computing the "closure" on the GPR registers.
void TargetARM32::CallingConv::discardUnavailableGPRsAndTheirAliases(
CfgVector<RegNumT> *Regs) {
while (!Regs->empty() && GPRegsUsed[Regs->back()]) {
GPRegsUsed |= RegisterAliases[Regs->back()];
Regs->pop_back();
}
}
bool TargetARM32::CallingConv::argInVFP(Type Ty, RegNumT *Reg) {
CfgVector<RegNumT> *Source;
switch (Ty) {
default: {
assert(isVectorType(Ty));
Source = &Vec128Args;
} break;
case IceType_f32: {
Source = &FP32Args;
} break;
case IceType_f64: {
Source = &FP64Args;
} break;
}
discardUnavailableVFPRegs(Source);
if (Source->empty()) {
VFPRegsUsed.set();
return false;
}
*Reg = Source->back();
VFPRegsUsed |= RegisterAliases[*Reg];
return true;
}
// Arguments in VFP registers are not packed, so we don't mark the popped
// registers' aliases as unavailable.
void TargetARM32::CallingConv::discardUnavailableVFPRegs(
CfgVector<RegNumT> *Regs) {
while (!Regs->empty() && VFPRegsUsed[Regs->back()]) {
Regs->pop_back();
}
}
void TargetARM32::lowerArguments() {
VarList &Args = Func->getArgs();
TargetARM32::CallingConv CC;
// For each register argument, replace Arg in the argument list with the home
// register. Then generate an instruction in the prolog to copy the home
// register to the assigned location of Arg.
Context.init(Func->getEntryNode());
Context.setInsertPoint(Context.getCur());
for (SizeT I = 0, E = Args.size(); I < E; ++I) {
Variable *Arg = Args[I];
Type Ty = Arg->getType();
RegNumT RegNum;
if (isScalarIntegerType(Ty)) {
if (!CC.argInGPR(Ty, &RegNum)) {
continue;
}
} else {
if (!CC.argInVFP(Ty, &RegNum)) {
continue;
}
}
Variable *RegisterArg = Func->makeVariable(Ty);
if (BuildDefs::dump()) {
RegisterArg->setName(Func, "home_reg:" + Arg->getName());
}
RegisterArg->setIsArg();
Arg->setIsArg(false);
Args[I] = RegisterArg;
switch (Ty) {
default: { RegisterArg->setRegNum(RegNum); } break;
case IceType_i64: {
auto *RegisterArg64 = llvm::cast<Variable64On32>(RegisterArg);
RegisterArg64->initHiLo(Func);
RegisterArg64->getLo()->setRegNum(
RegNumT::fixme(RegARM32::getI64PairFirstGPRNum(RegNum)));
RegisterArg64->getHi()->setRegNum(
RegNumT::fixme(RegARM32::getI64PairSecondGPRNum(RegNum)));
} break;
}
Context.insert<InstAssign>(Arg, RegisterArg);
}
}
// Helper function for addProlog().
//
// This assumes Arg is an argument passed on the stack. This sets the frame
// offset for Arg and updates InArgsSizeBytes according to Arg's width. For an
// I64 arg that has been split into Lo and Hi components, it calls itself
// recursively on the components, taking care to handle Lo first because of the
// little-endian architecture. Lastly, this function generates an instruction
// to copy Arg into its assigned register if applicable.
void TargetARM32::finishArgumentLowering(Variable *Arg, Variable *FramePtr,
size_t BasicFrameOffset,
size_t *InArgsSizeBytes) {
const Type Ty = Arg->getType();
*InArgsSizeBytes = applyStackAlignmentTy(*InArgsSizeBytes, Ty);
if (auto *Arg64On32 = llvm::dyn_cast<Variable64On32>(Arg)) {
Variable *const Lo = Arg64On32->getLo();
Variable *const Hi = Arg64On32->getHi();
finishArgumentLowering(Lo, FramePtr, BasicFrameOffset, InArgsSizeBytes);
finishArgumentLowering(Hi, FramePtr, BasicFrameOffset, InArgsSizeBytes);
return;
}
assert(Ty != IceType_i64);
const int32_t ArgStackOffset = BasicFrameOffset + *InArgsSizeBytes;
*InArgsSizeBytes += typeWidthInBytesOnStack(Ty);
if (!Arg->hasReg()) {
Arg->setStackOffset(ArgStackOffset);
return;
}
// If the argument variable has been assigned a register, we need to copy the
// value from the stack slot.
Variable *Parameter = Func->makeVariable(Ty);
Parameter->setMustNotHaveReg();
Parameter->setStackOffset(ArgStackOffset);
_mov(Arg, Parameter);
}
Type TargetARM32::stackSlotType() { return IceType_i32; }
void TargetARM32::addProlog(CfgNode *Node) {
// Stack frame layout:
//
// +------------------------+
// | 1. preserved registers |
// +------------------------+
// | 2. padding |
// +------------------------+ <--- FramePointer (if used)
// | 3. global spill area |
// +------------------------+
// | 4. padding |
// +------------------------+
// | 5. local spill area |
// +------------------------+
// | 6. padding |
// +------------------------+
// | 7. allocas (variable) |
// +------------------------+
// | 8. padding |
// +------------------------+
// | 9. out args |
// +------------------------+ <--- StackPointer
//
// The following variables record the size in bytes of the given areas:
// * PreservedRegsSizeBytes: area 1
// * SpillAreaPaddingBytes: area 2
// * GlobalsSize: area 3
// * GlobalsAndSubsequentPaddingSize: areas 3 - 4
// * LocalsSpillAreaSize: area 5
// * SpillAreaSizeBytes: areas 2 - 6, and 9
// * MaxOutArgsSizeBytes: area 9
//
// Determine stack frame offsets for each Variable without a register
// assignment. This can be done as one variable per stack slot. Or, do
// coalescing by running the register allocator again with an infinite set of
// registers (as a side effect, this gives variables a second chance at
// physical register assignment).
//
// A middle ground approach is to leverage sparsity and allocate one block of
// space on the frame for globals (variables with multi-block lifetime), and
// one block to share for locals (single-block lifetime).
Context.init(Node);
Context.setInsertPoint(Context.getCur());
SmallBitVector CalleeSaves = getRegisterSet(RegSet_CalleeSave, RegSet_None);
RegsUsed = SmallBitVector(CalleeSaves.size());
VarList SortedSpilledVariables;
size_t GlobalsSize = 0;
// If there is a separate locals area, this represents that area. Otherwise
// it counts any variable not counted by GlobalsSize.
SpillAreaSizeBytes = 0;
// If there is a separate locals area, this specifies the alignment for it.
uint32_t LocalsSlotsAlignmentBytes = 0;
// The entire spill locations area gets aligned to largest natural alignment
// of the variables that have a spill slot.
uint32_t SpillAreaAlignmentBytes = 0;
// For now, we don't have target-specific variables that need special
// treatment (no stack-slot-linked SpillVariable type).
std::function<bool(Variable *)> TargetVarHook = [](Variable *Var) {
static constexpr bool AssignStackSlot = false;
static constexpr bool DontAssignStackSlot = !AssignStackSlot;
if (llvm::isa<Variable64On32>(Var)) {
return DontAssignStackSlot;
}
return AssignStackSlot;
};
// Compute the list of spilled variables and bounds for GlobalsSize, etc.
getVarStackSlotParams(SortedSpilledVariables, RegsUsed, &GlobalsSize,
&SpillAreaSizeBytes, &SpillAreaAlignmentBytes,
&LocalsSlotsAlignmentBytes, TargetVarHook);
uint32_t LocalsSpillAreaSize = SpillAreaSizeBytes;
SpillAreaSizeBytes += GlobalsSize;
// Add push instructions for preserved registers. On ARM, "push" can push a
// whole list of GPRs via a bitmask (0-15). Unlike x86, ARM also has
// callee-saved float/vector registers.
//
// The "vpush" instruction can handle a whole list of float/vector registers,
// but it only handles contiguous sequences of registers by specifying the
// start and the length.
PreservedGPRs.reserve(CalleeSaves.size());
PreservedSRegs.reserve(CalleeSaves.size());
// Consider FP and LR as callee-save / used as needed.
if (UsesFramePointer) {
if (RegsUsed[RegARM32::Reg_fp]) {
llvm::report_fatal_error("Frame pointer has been used.");
}
CalleeSaves[RegARM32::Reg_fp] = true;
RegsUsed[RegARM32::Reg_fp] = true;
}
if (!MaybeLeafFunc) {
CalleeSaves[RegARM32::Reg_lr] = true;
RegsUsed[RegARM32::Reg_lr] = true;
}
// Make two passes over the used registers. The first pass records all the
// used registers -- and their aliases. Then, we figure out which GPRs and
// VFP S registers should be saved. We don't bother saving D/Q registers
// because their uses are recorded as S regs uses.
SmallBitVector ToPreserve(RegARM32::Reg_NUM);
for (SizeT i = 0; i < CalleeSaves.size(); ++i) {
if (NeedSandboxing && i == RegARM32::Reg_r9) {
// r9 is never updated in sandboxed code.
continue;
}
if (CalleeSaves[i] && RegsUsed[i]) {
ToPreserve |= RegisterAliases[i];
}
}
uint32_t NumCallee = 0;
size_t PreservedRegsSizeBytes = 0;
// RegClasses is a tuple of
//
// <First Register in Class, Last Register in Class, Vector of Save Registers>
//
// We use this tuple to figure out which register we should push/pop during
// prolog/epilog.
using RegClassType = std::tuple<uint32_t, uint32_t, VarList *>;
const RegClassType RegClasses[] = {
RegClassType(RegARM32::Reg_GPR_First, RegARM32::Reg_GPR_Last,
&PreservedGPRs),
RegClassType(RegARM32::Reg_SREG_First, RegARM32::Reg_SREG_Last,
&PreservedSRegs)};
for (const auto &RegClass : RegClasses) {
const uint32_t FirstRegInClass = std::get<0>(RegClass);
const uint32_t LastRegInClass = std::get<1>(RegClass);
VarList *const PreservedRegsInClass = std::get<2>(RegClass);
for (uint32_t Reg = FirstRegInClass; Reg <= LastRegInClass; ++Reg) {
if (!ToPreserve[Reg]) {
continue;
}
++NumCallee;
Variable *PhysicalRegister = getPhysicalRegister(RegNumT::fromInt(Reg));
PreservedRegsSizeBytes +=
typeWidthInBytesOnStack(PhysicalRegister->getType());
PreservedRegsInClass->push_back(PhysicalRegister);
}
}
Ctx->statsUpdateRegistersSaved(NumCallee);
if (!PreservedSRegs.empty())
_push(PreservedSRegs);
if (!PreservedGPRs.empty())
_push(PreservedGPRs);
// Generate "mov FP, SP" if needed.
if (UsesFramePointer) {
Variable *FP = getPhysicalRegister(RegARM32::Reg_fp);
Variable *SP = getPhysicalRegister(RegARM32::Reg_sp);
_mov(FP, SP);
// Keep FP live for late-stage liveness analysis (e.g. asm-verbose mode).
Context.insert<InstFakeUse>(FP);
}
// Align the variables area. SpillAreaPaddingBytes is the size of the region
// after the preserved registers and before the spill areas.
// LocalsSlotsPaddingBytes is the amount of padding between the globals and
// locals area if they are separate.
assert(SpillAreaAlignmentBytes <= ARM32_STACK_ALIGNMENT_BYTES);
assert(LocalsSlotsAlignmentBytes <= SpillAreaAlignmentBytes);
uint32_t SpillAreaPaddingBytes = 0;
uint32_t LocalsSlotsPaddingBytes = 0;
alignStackSpillAreas(PreservedRegsSizeBytes, SpillAreaAlignmentBytes,
GlobalsSize, LocalsSlotsAlignmentBytes,
&SpillAreaPaddingBytes, &LocalsSlotsPaddingBytes);
SpillAreaSizeBytes += SpillAreaPaddingBytes + LocalsSlotsPaddingBytes;
uint32_t GlobalsAndSubsequentPaddingSize =
GlobalsSize + LocalsSlotsPaddingBytes;
// Adds the out args space to the stack, and align SP if necessary.
if (!NeedsStackAlignment) {
SpillAreaSizeBytes += MaxOutArgsSizeBytes;
} else {
uint32_t StackOffset = PreservedRegsSizeBytes;
uint32_t StackSize = applyStackAlignment(StackOffset + SpillAreaSizeBytes);
StackSize = applyStackAlignment(StackSize + MaxOutArgsSizeBytes);
SpillAreaSizeBytes = StackSize - StackOffset;
}
// Combine fixed alloca with SpillAreaSize.
SpillAreaSizeBytes += FixedAllocaSizeBytes;
// Generate "sub sp, SpillAreaSizeBytes"
if (SpillAreaSizeBytes) {
// Use the scratch register if needed to legalize the immediate.
Operand *SubAmount = legalize(Ctx->getConstantInt32(SpillAreaSizeBytes),
Legal_Reg | Legal_Flex, getReservedTmpReg());
Sandboxer(this).sub_sp(SubAmount);
if (FixedAllocaAlignBytes > ARM32_STACK_ALIGNMENT_BYTES) {
Sandboxer(this).align_sp(FixedAllocaAlignBytes);
}
}
Ctx->statsUpdateFrameBytes(SpillAreaSizeBytes);
// Fill in stack offsets for stack args, and copy args into registers for
// those that were register-allocated. Args are pushed right to left, so
// Arg[0] is closest to the stack/frame pointer.
Variable *FramePtr = getPhysicalRegister(getFrameOrStackReg());
size_t BasicFrameOffset = PreservedRegsSizeBytes;
if (!UsesFramePointer)
BasicFrameOffset += SpillAreaSizeBytes;
materializeGotAddr(Node);
const VarList &Args = Func->getArgs();
size_t InArgsSizeBytes = 0;
TargetARM32::CallingConv CC;
for (Variable *Arg : Args) {
RegNumT DummyReg;
const Type Ty = Arg->getType();
// Skip arguments passed in registers.
if (isScalarIntegerType(Ty)) {
if (CC.argInGPR(Ty, &DummyReg)) {
continue;
}
} else {
if (CC.argInVFP(Ty, &DummyReg)) {
continue;
}
}
finishArgumentLowering(Arg, FramePtr, BasicFrameOffset, &InArgsSizeBytes);
}
// Fill in stack offsets for locals.
assignVarStackSlots(SortedSpilledVariables, SpillAreaPaddingBytes,
SpillAreaSizeBytes, GlobalsAndSubsequentPaddingSize,
UsesFramePointer);
this->HasComputedFrame = true;
if (BuildDefs::dump() && Func->isVerbose(IceV_Frame)) {
OstreamLocker _(Func->getContext());
Ostream &Str = Func->getContext()->getStrDump();
Str << "Stack layout:\n";
uint32_t SPAdjustmentPaddingSize =
SpillAreaSizeBytes - LocalsSpillAreaSize -
GlobalsAndSubsequentPaddingSize - SpillAreaPaddingBytes -
MaxOutArgsSizeBytes;
Str << " in-args = " << InArgsSizeBytes << " bytes\n"
<< " preserved registers = " << PreservedRegsSizeBytes << " bytes\n"
<< " spill area padding = " << SpillAreaPaddingBytes << " bytes\n"
<< " globals spill area = " << GlobalsSize << " bytes\n"
<< " globals-locals spill areas intermediate padding = "
<< GlobalsAndSubsequentPaddingSize - GlobalsSize << " bytes\n"
<< " locals spill area = " << LocalsSpillAreaSize << " bytes\n"
<< " SP alignment padding = " << SPAdjustmentPaddingSize << " bytes\n";
Str << "Stack details:\n"
<< " SP adjustment = " << SpillAreaSizeBytes << " bytes\n"
<< " spill area alignment = " << SpillAreaAlignmentBytes << " bytes\n"
<< " outgoing args size = " << MaxOutArgsSizeBytes << " bytes\n"
<< " locals spill area alignment = " << LocalsSlotsAlignmentBytes
<< " bytes\n"
<< " is FP based = " << UsesFramePointer << "\n";
}
}
void TargetARM32::addEpilog(CfgNode *Node) {
InstList &Insts = Node->getInsts();
InstList::reverse_iterator RI, E;
for (RI = Insts.rbegin(), E = Insts.rend(); RI != E; ++RI) {
if (llvm::isa<InstARM32Ret>(*RI))
break;
}
if (RI == E)
return;
// Convert the reverse_iterator position into its corresponding (forward)
// iterator position.
InstList::iterator InsertPoint = reverseToForwardIterator(RI);
--InsertPoint;
Context.init(Node);
Context.setInsertPoint(InsertPoint);
Variable *SP = getPhysicalRegister(RegARM32::Reg_sp);
if (UsesFramePointer) {
Variable *FP = getPhysicalRegister(RegARM32::Reg_fp);
// For late-stage liveness analysis (e.g. asm-verbose mode), adding a fake
// use of SP before the assignment of SP=FP keeps previous SP adjustments
// from being dead-code eliminated.
Context.insert<InstFakeUse>(SP);
Sandboxer(this).reset_sp(FP);
} else {
// add SP, SpillAreaSizeBytes
if (SpillAreaSizeBytes) {
// Use the scratch register if needed to legalize the immediate.
Operand *AddAmount =
legalize(Ctx->getConstantInt32(SpillAreaSizeBytes),
Legal_Reg | Legal_Flex, getReservedTmpReg());
Sandboxer(this).add_sp(AddAmount);
}
}
if (!PreservedGPRs.empty())
_pop(PreservedGPRs);
if (!PreservedSRegs.empty())
_pop(PreservedSRegs);
if (!getFlags().getUseSandboxing())
return;
// Change the original ret instruction into a sandboxed return sequence.
//
// bundle_lock
// bic lr, #0xc000000f
// bx lr
// bundle_unlock
//
// This isn't just aligning to the getBundleAlignLog2Bytes(). It needs to
// restrict to the lower 1GB as well.
Variable *LR = getPhysicalRegister(RegARM32::Reg_lr);
Variable *RetValue = nullptr;
if (RI->getSrcSize())
RetValue = llvm::cast<Variable>(RI->getSrc(0));
Sandboxer(this).ret(LR, RetValue);
RI->setDeleted();
}
bool TargetARM32::isLegalMemOffset(Type Ty, int32_t Offset) const {
constexpr bool ZeroExt = false;
return OperandARM32Mem::canHoldOffset(Ty, ZeroExt, Offset);
}
Variable *TargetARM32::PostLoweringLegalizer::newBaseRegister(
Variable *Base, int32_t Offset, RegNumT ScratchRegNum) {
// Legalize will likely need a movw/movt combination, but if the top bits are
// all 0 from negating the offset and subtracting, we could use that instead.
const bool ShouldSub = Offset != 0 && (-Offset & 0xFFFF0000) == 0;
Variable *ScratchReg = Target->makeReg(IceType_i32, ScratchRegNum);
if (ShouldSub) {
Operand *OffsetVal =
Target->legalize(Target->Ctx->getConstantInt32(-Offset),
Legal_Reg | Legal_Flex, ScratchRegNum);
Target->_sub(ScratchReg, Base, OffsetVal);
} else {
Operand *OffsetVal =
Target->legalize(Target->Ctx->getConstantInt32(Offset),
Legal_Reg | Legal_Flex, ScratchRegNum);
Target->_add(ScratchReg, Base, OffsetVal);
}
if (ScratchRegNum == Target->getReservedTmpReg()) {
const bool BaseIsStackOrFramePtr =
Base->getRegNum() == Target->getFrameOrStackReg();
// There is currently no code path that would trigger this assertion, so we
// leave this assertion here in case it is ever violated. This is not a
// fatal error (thus the use of assert() and not llvm::report_fatal_error)
// as the program compiled by subzero will still work correctly.
assert(BaseIsStackOrFramePtr);
// Side-effect: updates TempBase to reflect the new Temporary.
if (BaseIsStackOrFramePtr) {
TempBaseReg = ScratchReg;
TempBaseOffset = Offset;
} else {
TempBaseReg = nullptr;
TempBaseOffset = 0;
}
}
return ScratchReg;
}
OperandARM32Mem *TargetARM32::PostLoweringLegalizer::createMemOperand(
Type Ty, Variable *Base, int32_t Offset, bool AllowOffsets) {
assert(!Base->isRematerializable());
if (Offset == 0 || (AllowOffsets && Target->isLegalMemOffset(Ty, Offset))) {
return OperandARM32Mem::create(
Target->Func, Ty, Base,
llvm::cast<ConstantInteger32>(Target->Ctx->getConstantInt32(Offset)),
OperandARM32Mem::Offset);
}
if (!AllowOffsets || TempBaseReg == nullptr) {
newBaseRegister(Base, Offset, Target->getReservedTmpReg());
}
int32_t OffsetDiff = Offset - TempBaseOffset;
assert(AllowOffsets || OffsetDiff == 0);
if (!Target->isLegalMemOffset(Ty, OffsetDiff)) {
newBaseRegister(Base, Offset, Target->getReservedTmpReg());
OffsetDiff = 0;
}
assert(!TempBaseReg->isRematerializable());
return OperandARM32Mem::create(
Target->Func, Ty, TempBaseReg,
llvm::cast<ConstantInteger32>(Target->Ctx->getConstantInt32(OffsetDiff)),
OperandARM32Mem::Offset);
}
void TargetARM32::PostLoweringLegalizer::resetTempBaseIfClobberedBy(
const Inst *Instr) {
bool ClobbersTempBase = false;
if (TempBaseReg != nullptr) {
Variable *Dest = Instr->getDest();
if (llvm::isa<InstARM32Call>(Instr)) {
// The following assertion is an invariant, so we remove it from the if
// test. If the invariant is ever broken/invalidated/changed, remember
// to add it back to the if condition.
assert(TempBaseReg->getRegNum() == Target->getReservedTmpReg());
// The linker may need to clobber IP if the call is too far from PC. Thus,
// we assume IP will be overwritten.
ClobbersTempBase = true;
} else if (Dest != nullptr &&
Dest->getRegNum() == TempBaseReg->getRegNum()) {
// Register redefinition.
ClobbersTempBase = true;
}
}
if (ClobbersTempBase) {
TempBaseReg = nullptr;
TempBaseOffset = 0;
}
}
void TargetARM32::PostLoweringLegalizer::legalizeMov(InstARM32Mov *MovInstr) {
Variable *Dest = MovInstr->getDest();
assert(Dest != nullptr);
Type DestTy = Dest->getType();
assert(DestTy != IceType_i64);
Operand *Src = MovInstr->getSrc(0);
Type SrcTy = Src->getType();
(void)SrcTy;
assert(SrcTy != IceType_i64);
if (MovInstr->isMultiDest() || MovInstr->isMultiSource())
return;
bool Legalized = false;
if (!Dest->hasReg()) {
auto *SrcR = llvm::cast<Variable>(Src);
assert(SrcR->hasReg());
assert(!SrcR->isRematerializable());
const int32_t Offset = Dest->getStackOffset();
// This is a _mov(Mem(), Variable), i.e., a store.
TargetARM32::Sandboxer(Target)
.str(SrcR, createMemOperand(DestTy, StackOrFrameReg, Offset),
MovInstr->getPredicate());
// _str() does not have a Dest, so we add a fake-def(Dest).
Target->Context.insert<InstFakeDef>(Dest);
Legalized = true;
} else if (auto *Var = llvm::dyn_cast<Variable>(Src)) {
if (Var->isRematerializable()) {
// This is equivalent to an x86 _lea(RematOffset(%esp/%ebp), Variable).
// ExtraOffset is only needed for frame-pointer based frames as we have
// to account for spill storage.
const int32_t ExtraOffset = (Var->getRegNum() == Target->getFrameReg())
? Target->getFrameFixedAllocaOffset()
: 0;
const int32_t Offset = Var->getStackOffset() + ExtraOffset;
Variable *Base = Target->getPhysicalRegister(Var->getRegNum());
Variable *T = newBaseRegister(Base, Offset, Dest->getRegNum());
Target->_mov(Dest, T);
Legalized = true;
} else {
if (!Var->hasReg()) {
// This is a _mov(Variable, Mem()), i.e., a load.
const int32_t Offset = Var->getStackOffset();
TargetARM32::Sandboxer(Target)
.ldr(Dest, createMemOperand(DestTy, StackOrFrameReg, Offset),
MovInstr->getPredicate());
Legalized = true;
}
}
}
if (Legalized) {
if (MovInstr->isDestRedefined()) {
Target->_set_dest_redefined();
}
MovInstr->setDeleted();
}
}
// ARM32 address modes:
// ld/st i[8|16|32]: [reg], [reg +/- imm12], [pc +/- imm12],
// [reg +/- reg << shamt5]
// ld/st f[32|64] : [reg], [reg +/- imm8] , [pc +/- imm8]
// ld/st vectors : [reg]
//
// For now, we don't handle address modes with Relocatables.
namespace {
// MemTraits contains per-type valid address mode information.
#define X(tag, elementty, int_width, fp_width, uvec_width, svec_width, sbits, \
ubits, rraddr, shaddr) \
static_assert(!(shaddr) || rraddr, "Check ICETYPEARM32_TABLE::" #tag);
ICETYPEARM32_TABLE
#undef X
static const struct {
int32_t ValidImmMask;
bool CanHaveImm;
bool CanHaveIndex;
bool CanHaveShiftedIndex;
} MemTraits[] = {
#define X(tag, elementty, int_width, fp_width, uvec_width, svec_width, sbits, \
ubits, rraddr, shaddr) \
{ (1 << ubits) - 1, (ubits) > 0, rraddr, shaddr, } \
,
ICETYPEARM32_TABLE
#undef X
};
static constexpr SizeT MemTraitsSize = llvm::array_lengthof(MemTraits);
} // end of anonymous namespace
OperandARM32Mem *
TargetARM32::PostLoweringLegalizer::legalizeMemOperand(OperandARM32Mem *Mem,
bool AllowOffsets) {
assert(!Mem->isRegReg() || !Mem->getIndex()->isRematerializable());
assert(
Mem->isRegReg() ||
Target->isLegalMemOffset(Mem->getType(), Mem->getOffset()->getValue()));
bool Legalized = false;
Variable *Base = Mem->getBase();
int32_t Offset = Mem->isRegReg() ? 0 : Mem->getOffset()->getValue();
if (Base->isRematerializable()) {
const int32_t ExtraOffset = (Base->getRegNum() == Target->getFrameReg())
? Target->getFrameFixedAllocaOffset()
: 0;
Offset += Base->getStackOffset() + ExtraOffset;
Base = Target->getPhysicalRegister(Base->getRegNum());
assert(!Base->isRematerializable());
Legalized = true;
}
if (!Legalized && !Target->NeedSandboxing) {
return nullptr;
}
if (!Mem->isRegReg()) {
return createMemOperand(Mem->getType(), Base, Offset, AllowOffsets);
}
if (Target->NeedSandboxing) {
llvm::report_fatal_error("Reg-Reg address mode is not allowed.");
}
assert(MemTraits[Mem->getType()].CanHaveIndex);
if (Offset != 0) {
if (TempBaseReg == nullptr) {
Base = newBaseRegister(Base, Offset, Target->getReservedTmpReg());
} else {
uint32_t Imm8, Rotate;
const int32_t OffsetDiff = Offset - TempBaseOffset;
if (OffsetDiff == 0) {
Base = TempBaseReg;
} else if (OperandARM32FlexImm::canHoldImm(OffsetDiff, &Rotate, &Imm8)) {
auto *OffsetDiffF = OperandARM32FlexImm::create(
Target->Func, IceType_i32, Imm8, Rotate);
Target->_add(TempBaseReg, TempBaseReg, OffsetDiffF);
TempBaseOffset += OffsetDiff;
Base = TempBaseReg;
} else if (OperandARM32FlexImm::canHoldImm(-OffsetDiff, &Rotate, &Imm8)) {
auto *OffsetDiffF = OperandARM32FlexImm::create(
Target->Func, IceType_i32, Imm8, Rotate);
Target->_sub(TempBaseReg, TempBaseReg, OffsetDiffF);
TempBaseOffset += OffsetDiff;
Base = TempBaseReg;
} else {
Base = newBaseRegister(Base, Offset, Target->getReservedTmpReg());
}
}
}
return OperandARM32Mem::create(Target->Func, Mem->getType(), Base,
Mem->getIndex(), Mem->getShiftOp(),
Mem->getShiftAmt(), Mem->getAddrMode());
}
void TargetARM32::postLowerLegalization() {
// If a stack variable's frame offset doesn't fit, convert from:
// ldr X, OFF[SP]
// to:
// movw/movt TMP, OFF_PART
// add TMP, TMP, SP
// ldr X, OFF_MORE[TMP]
//
// This is safe because we have reserved TMP, and add for ARM does not
// clobber the flags register.
Func->dump("Before postLowerLegalization");
assert(hasComputedFrame());
// Do a fairly naive greedy clustering for now. Pick the first stack slot
// that's out of bounds and make a new base reg using the architecture's temp
// register. If that works for the next slot, then great. Otherwise, create a
// new base register, clobbering the previous base register. Never share a
// base reg across different basic blocks. This isn't ideal if local and
// multi-block variables are far apart and their references are interspersed.
// It may help to be more coordinated about assign stack slot numbers and may
// help to assign smaller offsets to higher-weight variables so that they
// don't depend on this legalization.
for (CfgNode *Node : Func->getNodes()) {
Context.init(Node);
// One legalizer per basic block, otherwise we would share the Temporary
// Base Register between basic blocks.
PostLoweringLegalizer Legalizer(this);
while (!Context.atEnd()) {
PostIncrLoweringContext PostIncrement(Context);
Inst *CurInstr = iteratorToInst(Context.getCur());
// Check if the previous TempBaseReg is clobbered, and reset if needed.
Legalizer.resetTempBaseIfClobberedBy(CurInstr);
if (auto *MovInstr = llvm::dyn_cast<InstARM32Mov>(CurInstr)) {
Legalizer.legalizeMov(MovInstr);
} else if (auto *LdrInstr = llvm::dyn_cast<InstARM32Ldr>(CurInstr)) {
if (OperandARM32Mem *LegalMem = Legalizer.legalizeMemOperand(
llvm::cast<OperandARM32Mem>(LdrInstr->getSrc(0)))) {
Sandboxer(this)
.ldr(CurInstr->getDest(), LegalMem, LdrInstr->getPredicate());
CurInstr->setDeleted();
}
} else if (auto *LdrexInstr = llvm::dyn_cast<InstARM32Ldrex>(CurInstr)) {
constexpr bool DisallowOffsetsBecauseLdrex = false;
if (OperandARM32Mem *LegalMem = Legalizer.legalizeMemOperand(
llvm::cast<OperandARM32Mem>(LdrexInstr->getSrc(0)),
DisallowOffsetsBecauseLdrex)) {
Sandboxer(this)
.ldrex(CurInstr->getDest(), LegalMem, LdrexInstr->getPredicate());
CurInstr->setDeleted();
}
} else if (auto *StrInstr = llvm::dyn_cast<InstARM32Str>(CurInstr)) {
if (OperandARM32Mem *LegalMem = Legalizer.legalizeMemOperand(
llvm::cast<OperandARM32Mem>(StrInstr->getSrc(1)))) {
Sandboxer(this).str(llvm::cast<Variable>(CurInstr->getSrc(0)),
LegalMem, StrInstr->getPredicate());
CurInstr->setDeleted();
}
} else if (auto *StrexInstr = llvm::dyn_cast<InstARM32Strex>(CurInstr)) {
constexpr bool DisallowOffsetsBecauseStrex = false;
if (OperandARM32Mem *LegalMem = Legalizer.legalizeMemOperand(
llvm::cast<OperandARM32Mem>(StrexInstr->getSrc(1)),
DisallowOffsetsBecauseStrex)) {
Sandboxer(this).strex(CurInstr->getDest(),
llvm::cast<Variable>(CurInstr->getSrc(0)),
LegalMem, StrexInstr->getPredicate());
CurInstr->setDeleted();
}
}
// Sanity-check: the Legalizer will either have no Temp, or it will be
// bound to IP.
Legalizer.assertNoTempOrAssignedToIP();
}
}
}
Operand *TargetARM32::loOperand(Operand *Operand) {
assert(Operand->getType() == IceType_i64);
if (Operand->getType() != IceType_i64)
return Operand;
if (auto *Var64On32 = llvm::dyn_cast<Variable64On32>(Operand))
return Var64On32->getLo();
if (auto *Const = llvm::dyn_cast<ConstantInteger64>(Operand))
return Ctx->getConstantInt32(static_cast<uint32_t>(Const->getValue()));
if (auto *Mem = llvm::dyn_cast<OperandARM32Mem>(Operand)) {
// Conservatively disallow memory operands with side-effects (pre/post
// increment) in case of duplication.
assert(Mem->getAddrMode() == OperandARM32Mem::Offset ||
Mem->getAddrMode() == OperandARM32Mem::NegOffset);
if (Mem->isRegReg()) {
Variable *IndexR = legalizeToReg(Mem->getIndex());
return OperandARM32Mem::create(Func, IceType_i32, Mem->getBase(), IndexR,
Mem->getShiftOp(), Mem->getShiftAmt(),
Mem->getAddrMode());
} else {
return OperandARM32Mem::create(Func, IceType_i32, Mem->getBase(),
Mem->getOffset(), Mem->getAddrMode());
}
}
llvm::report_fatal_error("Unsupported operand type");
return nullptr;
}
Operand *TargetARM32::hiOperand(Operand *Operand) {
assert(Operand->getType() == IceType_i64);
if (Operand->getType() != IceType_i64)
return Operand;
if (auto *Var64On32 = llvm::dyn_cast<Variable64On32>(Operand))
return Var64On32->getHi();
if (auto *Const = llvm::dyn_cast<ConstantInteger64>(Operand)) {
return Ctx->getConstantInt32(
static_cast<uint32_t>(Const->getValue() >> 32));
}
if (auto *Mem = llvm::dyn_cast<OperandARM32Mem>(Operand)) {
// Conservatively disallow memory operands with side-effects in case of
// duplication.
assert(Mem->getAddrMode() == OperandARM32Mem::Offset ||
Mem->getAddrMode() == OperandARM32Mem::NegOffset);
const Type SplitType = IceType_i32;
if (Mem->isRegReg()) {
// We have to make a temp variable T, and add 4 to either Base or Index.
// The Index may be shifted, so adding 4 can mean something else. Thus,
// prefer T := Base + 4, and use T as the new Base.
Variable *Base = Mem->getBase();
Constant *Four = Ctx->getConstantInt32(4);
Variable *NewBase = Func->makeVariable(Base->getType());
lowerArithmetic(InstArithmetic::create(Func, InstArithmetic::Add, NewBase,
Base, Four));
Variable *BaseR = legalizeToReg(NewBase);
Variable *IndexR = legalizeToReg(Mem->getIndex());
return OperandARM32Mem::create(Func, SplitType, BaseR, IndexR,
Mem->getShiftOp(), Mem->getShiftAmt(),
Mem->getAddrMode());
} else {
Variable *Base = Mem->getBase();
ConstantInteger32 *Offset = Mem->getOffset();
assert(!Utils::WouldOverflowAdd(Offset->getValue(), 4));
int32_t NextOffsetVal = Offset->getValue() + 4;
constexpr bool ZeroExt = false;
if (!OperandARM32Mem::canHoldOffset(SplitType, ZeroExt, NextOffsetVal)) {
// We have to make a temp variable and add 4 to either Base or Offset.
// If we add 4 to Offset, this will convert a non-RegReg addressing
// mode into a RegReg addressing mode. Since NaCl sandboxing disallows
// RegReg addressing modes, prefer adding to base and replacing
// instead. Thus we leave the old offset alone.
Constant *_4 = Ctx->getConstantInt32(4);
Variable *NewBase = Func->makeVariable(Base->getType());
lowerArithmetic(InstArithmetic::create(Func, InstArithmetic::Add,
NewBase, Base, _4));
Base = NewBase;
} else {
Offset =
llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(NextOffsetVal));
}
Variable *BaseR = legalizeToReg(Base);
return OperandARM32Mem::create(Func, SplitType, BaseR, Offset,
Mem->getAddrMode());
}
}
llvm::report_fatal_error("Unsupported operand type");
return nullptr;
}
SmallBitVector TargetARM32::getRegisterSet(RegSetMask Include,
RegSetMask Exclude) const {
SmallBitVector Registers(RegARM32::Reg_NUM);
for (uint32_t i = 0; i < RegARM32::Reg_NUM; ++i) {
const auto &Entry = RegARM32::RegTable[i];
if (Entry.Scratch && (Include & RegSet_CallerSave))
Registers[i] = true;
if (Entry.Preserved && (Include & RegSet_CalleeSave))
Registers[i] = true;
if (Entry.StackPtr && (Include & RegSet_StackPointer))
Registers[i] = true;
if (Entry.FramePtr && (Include & RegSet_FramePointer))
Registers[i] = true;
if (Entry.Scratch && (Exclude & RegSet_CallerSave))
Registers[i] = false;
if (Entry.Preserved && (Exclude & RegSet_CalleeSave))
Registers[i] = false;
if (Entry.StackPtr && (Exclude & RegSet_StackPointer))
Registers[i] = false;
if (Entry.FramePtr && (Exclude & RegSet_FramePointer))
Registers[i] = false;
}
return Registers;
}
void TargetARM32::lowerAlloca(const InstAlloca *Instr) {
// Conservatively require the stack to be aligned. Some stack adjustment
// operations implemented below assume that the stack is aligned before the
// alloca. All the alloca code ensures that the stack alignment is preserved
// after the alloca. The stack alignment restriction can be relaxed in some
// cases.
NeedsStackAlignment = true;
// For default align=0, set it to the real value 1, to avoid any
// bit-manipulation problems below.
const uint32_t AlignmentParam = std::max(1u, Instr->getAlignInBytes());
// LLVM enforces power of 2 alignment.
assert(llvm::isPowerOf2_32(AlignmentParam));
assert(llvm::isPowerOf2_32(ARM32_STACK_ALIGNMENT_BYTES));
const uint32_t Alignment =
std::max(AlignmentParam, ARM32_STACK_ALIGNMENT_BYTES);
const bool OverAligned = Alignment > ARM32_STACK_ALIGNMENT_BYTES;
const bool OptM1 = Func->getOptLevel() == Opt_m1;
const bool AllocaWithKnownOffset = Instr->getKnownFrameOffset();
const bool UseFramePointer =
hasFramePointer() || OverAligned || !AllocaWithKnownOffset || OptM1;
if (UseFramePointer)
setHasFramePointer();
Variable *SP = getPhysicalRegister(RegARM32::Reg_sp);
if (OverAligned) {
Sandboxer(this).align_sp(Alignment);
}
Variable *Dest = Instr->getDest();
Operand *TotalSize = Instr->getSizeInBytes();
if (const auto *ConstantTotalSize =
llvm::dyn_cast<ConstantInteger32>(TotalSize)) {
const uint32_t Value =
Utils::applyAlignment(ConstantTotalSize->getValue(), Alignment);
// Constant size alloca.
if (!UseFramePointer) {
// If we don't need a Frame Pointer, this alloca has a known offset to the
// stack pointer. We don't need adjust the stack pointer, nor assign any
// value to Dest, as Dest is rematerializable.
assert(Dest->isRematerializable());
FixedAllocaSizeBytes += Value;
Context.insert<InstFakeDef>(Dest);
return;
}
// If a frame pointer is required, then we need to store the alloca'd result
// in Dest.
Operand *SubAmountRF =
legalize(Ctx->getConstantInt32(Value), Legal_Reg | Legal_Flex);
Sandboxer(this).sub_sp(SubAmountRF);
} else {
// Non-constant sizes need to be adjusted to the next highest multiple of
// the required alignment at runtime.
TotalSize = legalize(TotalSize, Legal_Reg | Legal_Flex);
Variable *T = makeReg(IceType_i32);
_mov(T, TotalSize);
Operand *AddAmount = legalize(Ctx->getConstantInt32(Alignment - 1));
_add(T, T, AddAmount);
alignRegisterPow2(T, Alignment);
Sandboxer(this).sub_sp(T);
}
// Adds back a few bytes to SP to account for the out args area.
Variable *T = SP;
if (MaxOutArgsSizeBytes != 0) {
T = makeReg(getPointerType());
Operand *OutArgsSizeRF = legalize(
Ctx->getConstantInt32(MaxOutArgsSizeBytes), Legal_Reg | Legal_Flex);
_add(T, SP, OutArgsSizeRF);
}
_mov(Dest, T);
}
void TargetARM32::div0Check(Type Ty, Operand *SrcLo, Operand *SrcHi) {
if (isGuaranteedNonzeroInt(SrcLo) || isGuaranteedNonzeroInt(SrcHi))
return;
Variable *SrcLoReg = legalizeToReg(SrcLo);
switch (Ty) {
default:
llvm_unreachable(
("Unexpected type in div0Check: " + typeStdString(Ty)).c_str());
case IceType_i8:
case IceType_i16: {
Operand *ShAmtImm = shAmtImm(32 - getScalarIntBitWidth(Ty));
Variable *T = makeReg(IceType_i32);
_lsls(T, SrcLoReg, ShAmtImm);
Context.insert<InstFakeUse>(T);
} break;
case IceType_i32: {
_tst(SrcLoReg, SrcLoReg);
break;
}
case IceType_i64: {
Variable *T = makeReg(IceType_i32);
_orrs(T, SrcLoReg, legalize(SrcHi, Legal_Reg | Legal_Flex));
// T isn't going to be used, but we need the side-effect of setting flags
// from this operation.
Context.insert<InstFakeUse>(T);
}
}
auto *Label = InstARM32Label::create(Func, this);
_br(Label, CondARM32::NE);
_trap();
Context.insert(Label);
}
void TargetARM32::lowerIDivRem(Variable *Dest, Variable *T, Variable *Src0R,
Operand *Src1, ExtInstr ExtFunc,
DivInstr DivFunc, bool IsRemainder) {
div0Check(Dest->getType(), Src1, nullptr);
Variable *Src1R = legalizeToReg(Src1);
Variable *T0R = Src0R;
Variable *T1R = Src1R;
if (Dest->getType() != IceType_i32) {
T0R = makeReg(IceType_i32);
(this->*ExtFunc)(T0R, Src0R, CondARM32::AL);
T1R = makeReg(IceType_i32);
(this->*ExtFunc)(T1R, Src1R, CondARM32::AL);
}
if (hasCPUFeature(TargetARM32Features::HWDivArm)) {
(this->*DivFunc)(T, T0R, T1R, CondARM32::AL);
if (IsRemainder) {
Variable *T2 = makeReg(IceType_i32);
_mls(T2, T, T1R, T0R);
T = T2;
}
_mov(Dest, T);
} else {
llvm::report_fatal_error("div should have already been turned into a call");
}
}
TargetARM32::SafeBoolChain
TargetARM32::lowerInt1Arithmetic(const InstArithmetic *Instr) {
Variable *Dest = Instr->getDest();
assert(Dest->getType() == IceType_i1);
// So folding didn't work for Instr. Not a problem: We just need to
// materialize the Sources, and perform the operation. We create regular
// Variables (and not infinite-weight ones) because this call might recurse a
// lot, and we might end up with tons of infinite weight temporaries.
assert(Instr->getSrcSize() == 2);
Variable *Src0 = Func->makeVariable(IceType_i1);
SafeBoolChain Src0Safe = lowerInt1(Src0, Instr->getSrc(0));
Operand *Src1 = Instr->getSrc(1);
SafeBoolChain Src1Safe = SBC_Yes;
if (!llvm::isa<Constant>(Src1)) {
Variable *Src1V = Func->makeVariable(IceType_i1);
Src1Safe = lowerInt1(Src1V, Src1);
Src1 = Src1V;
}
Variable *T = makeReg(IceType_i1);
Src0 = legalizeToReg(Src0);
Operand *Src1RF = legalize(Src1, Legal_Reg | Legal_Flex);
switch (Instr->getOp()) {
default:
// If this Unreachable is ever executed, add the offending operation to
// the list of valid consumers.
llvm::report_fatal_error("Unhandled i1 Op");
case InstArithmetic::And:
_and(T, Src0, Src1RF);
break;
case InstArithmetic::Or:
_orr(T, Src0, Src1RF);
break;
case InstArithmetic::Xor:
_eor(T, Src0, Src1RF);
break;
}
_mov(Dest, T);
return Src0Safe == SBC_Yes && Src1Safe == SBC_Yes ? SBC_Yes : SBC_No;
}
namespace {
// NumericOperands is used during arithmetic/icmp lowering for constant folding.
// It holds the two sources operands, and maintains some state as to whether one
// of them is a constant. If one of the operands is a constant, then it will be
// be stored as the operation's second source, with a bit indicating whether the
// operands were swapped.
//
// The class is split into a base class with operand type-independent methods,
// and a derived, templated class, for each type of operand we want to fold
// constants for:
//
// NumericOperandsBase --> NumericOperands<ConstantFloat>
// --> NumericOperands<ConstantDouble>
// --> NumericOperands<ConstantInt32>
//
// NumericOperands<ConstantInt32> also exposes helper methods for emitting
// inverted/negated immediates.
class NumericOperandsBase {
NumericOperandsBase() = delete;
NumericOperandsBase(const NumericOperandsBase &) = delete;
NumericOperandsBase &operator=(const NumericOperandsBase &) = delete;
public:
NumericOperandsBase(Operand *S0, Operand *S1)
: Src0(NonConstOperand(S0, S1)), Src1(ConstOperand(S0, S1)),
Swapped(Src0 == S1 && S0 != S1) {
assert(Src0 != nullptr);
assert(Src1 != nullptr);
assert(Src0 != Src1 || S0 == S1);
}
bool hasConstOperand() const {
return llvm::isa<Constant>(Src1) && !llvm::isa<ConstantRelocatable>(Src1);
}
bool swappedOperands() const { return Swapped; }
Variable *src0R(TargetARM32 *Target) const {
return legalizeToReg(Target, Src0);
}
Variable *unswappedSrc0R(TargetARM32 *Target) const {
return legalizeToReg(Target, Swapped ? Src1 : Src0);
}
Operand *src1RF(TargetARM32 *Target) const {
return legalizeToRegOrFlex(Target, Src1);
}
Variable *unswappedSrc1R(TargetARM32 *Target) const {
return legalizeToReg(Target, Swapped ? Src0 : Src1);
}
protected:
Operand *const Src0;
Operand *const Src1;
const bool Swapped;
static Variable *legalizeToReg(TargetARM32 *Target, Operand *Src) {
return Target->legalizeToReg(Src);
}
static Operand *legalizeToRegOrFlex(TargetARM32 *Target, Operand *Src) {
return Target->legalize(Src,
TargetARM32::Legal_Reg | TargetARM32::Legal_Flex);
}
private:
static Operand *NonConstOperand(Operand *S0, Operand *S1) {
if (!llvm::isa<Constant>(S0))
return S0;
if (!llvm::isa<Constant>(S1))
return S1;
if (llvm::isa<ConstantRelocatable>(S1) &&
!llvm::isa<ConstantRelocatable>(S0))
return S1;
return S0;
}
static Operand *ConstOperand(Operand *S0, Operand *S1) {
if (!llvm::isa<Constant>(S0))
return S1;
if (!llvm::isa<Constant>(S1))
return S0;
if (llvm::isa<ConstantRelocatable>(S1) &&
!llvm::isa<ConstantRelocatable>(S0))
return S0;
return S1;
}
};
template <typename C> class NumericOperands : public NumericOperandsBase {
NumericOperands() = delete;
NumericOperands(const NumericOperands &) = delete;
NumericOperands &operator=(const NumericOperands &) = delete;
public:
NumericOperands(Operand *S0, Operand *S1) : NumericOperandsBase(S0, S1) {
assert(!hasConstOperand() || llvm::isa<C>(this->Src1));
}
typename C::PrimType getConstantValue() const {
return llvm::cast<C>(Src1)->getValue();
}
};
using FloatOperands = NumericOperands<ConstantFloat>;
using DoubleOperands = NumericOperands<ConstantDouble>;
class Int32Operands : public NumericOperands<ConstantInteger32> {
Int32Operands() = delete;
Int32Operands(const Int32Operands &) = delete;
Int32Operands &operator=(const Int32Operands &) = delete;
public:
Int32Operands(Operand *S0, Operand *S1) : NumericOperands(S0, S1) {}
Operand *unswappedSrc1RShAmtImm(TargetARM32 *Target) const {
if (!swappedOperands() && hasConstOperand()) {
return Target->shAmtImm(getConstantValue() & 0x1F);
}
return legalizeToReg(Target, Swapped ? Src0 : Src1);
}
bool immediateIsFlexEncodable() const {
uint32_t Rotate, Imm8;
return OperandARM32FlexImm::canHoldImm(getConstantValue(), &Rotate, &Imm8);
}
bool negatedImmediateIsFlexEncodable() const {
uint32_t Rotate, Imm8;
return OperandARM32FlexImm::canHoldImm(
-static_cast<int32_t>(getConstantValue()), &Rotate, &Imm8);
}
Operand *negatedSrc1F(TargetARM32 *Target) const {
return legalizeToRegOrFlex(Target,
Target->getCtx()->getConstantInt32(
-static_cast<int32_t>(getConstantValue())));
}
bool invertedImmediateIsFlexEncodable() const {
uint32_t Rotate, Imm8;
return OperandARM32FlexImm::canHoldImm(
~static_cast<uint32_t>(getConstantValue()), &Rotate, &Imm8);
}
Operand *invertedSrc1F(TargetARM32 *Target) const {
return legalizeToRegOrFlex(Target,
Target->getCtx()->getConstantInt32(
~static_cast<uint32_t>(getConstantValue())));
}
};
} // end of anonymous namespace
void TargetARM32::preambleDivRem(const InstCall *Instr) {
Operand *Src1 = Instr->getArg(1);
switch (Src1->getType()) {
default:
llvm::report_fatal_error("Invalid type for idiv.");
case IceType_i64: {
if (auto *C = llvm::dyn_cast<ConstantInteger64>(Src1)) {
if (C->getValue() == 0) {
_trap();
return;
}
}
div0Check(IceType_i64, loOperand(Src1), hiOperand(Src1));
return;
}
case IceType_i32: {
// Src0 and Src1 have already been appropriately extended to an i32, so we
// don't check for i8 and i16.
if (auto *C = llvm::dyn_cast<ConstantInteger32>(Src1)) {
if (C->getValue() == 0) {
_trap();
return;
}
}
div0Check(IceType_i32, Src1, nullptr);
return;
}
}
}
void TargetARM32::lowerInt64Arithmetic(InstArithmetic::OpKind Op,
Variable *Dest, Operand *Src0,
Operand *Src1) {
Int32Operands SrcsLo(loOperand(Src0), loOperand(Src1));
Int32Operands SrcsHi(hiOperand(Src0), hiOperand(Src1));
assert(SrcsLo.swappedOperands() == SrcsHi.swappedOperands());
assert(SrcsLo.hasConstOperand() == SrcsHi.hasConstOperand());
auto *DestLo = llvm::cast<Variable>(loOperand(Dest));
auto *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Variable *T_Lo = makeReg(DestLo->getType());
Variable *T_Hi = makeReg(DestHi->getType());
switch (Op) {
case InstArithmetic::_num:
llvm::report_fatal_error("Unknown arithmetic operator");
return;
case InstArithmetic::Add: {
Variable *Src0LoR = SrcsLo.src0R(this);
Operand *Src1LoRF = SrcsLo.src1RF(this);
Variable *Src0HiR = SrcsHi.src0R(this);
Operand *Src1HiRF = SrcsHi.src1RF(this);
_adds(T_Lo, Src0LoR, Src1LoRF);
_mov(DestLo, T_Lo);
_adc(T_Hi, Src0HiR, Src1HiRF);
_mov(DestHi, T_Hi);
return;
}
case InstArithmetic::And: {
Variable *Src0LoR = SrcsLo.src0R(this);
Operand *Src1LoRF = SrcsLo.src1RF(this);
Variable *Src0HiR = SrcsHi.src0R(this);
Operand *Src1HiRF = SrcsHi.src1RF(this);
_and(T_Lo, Src0LoR, Src1LoRF);
_mov(DestLo, T_Lo);
_and(T_Hi, Src0HiR, Src1HiRF);
_mov(DestHi, T_Hi);
return;
}
case InstArithmetic::Or: {
Variable *Src0LoR = SrcsLo.src0R(this);
Operand *Src1LoRF = SrcsLo.src1RF(this);
Variable *Src0HiR = SrcsHi.src0R(this);
Operand *Src1HiRF = SrcsHi.src1RF(this);
_orr(T_Lo, Src0LoR, Src1LoRF);
_mov(DestLo, T_Lo);
_orr(T_Hi, Src0HiR, Src1HiRF);
_mov(DestHi, T_Hi);
return;
}
case InstArithmetic::Xor: {
Variable *Src0LoR = SrcsLo.src0R(this);
Operand *Src1LoRF = SrcsLo.src1RF(this);
Variable *Src0HiR = SrcsHi.src0R(this);
Operand *Src1HiRF = SrcsHi.src1RF(this);
_eor(T_Lo, Src0LoR, Src1LoRF);
_mov(DestLo, T_Lo);
_eor(T_Hi, Src0HiR, Src1HiRF);
_mov(DestHi, T_Hi);
return;
}
case InstArithmetic::Sub: {
Variable *Src0LoR = SrcsLo.src0R(this);
Operand *Src1LoRF = SrcsLo.src1RF(this);
Variable *Src0HiR = SrcsHi.src0R(this);
Operand *Src1HiRF = SrcsHi.src1RF(this);
if (SrcsLo.swappedOperands()) {
_rsbs(T_Lo, Src0LoR, Src1LoRF);
_mov(DestLo, T_Lo);
_rsc(T_Hi, Src0HiR, Src1HiRF);
_mov(DestHi, T_Hi);
} else {
_subs(T_Lo, Src0LoR, Src1LoRF);
_mov(DestLo, T_Lo);
_sbc(T_Hi, Src0HiR, Src1HiRF);
_mov(DestHi, T_Hi);
}
return;
}
case InstArithmetic::Mul: {
// GCC 4.8 does:
// a=b*c ==>
// t_acc =(mul) (b.lo * c.hi)
// t_acc =(mla) (c.lo * b.hi) + t_acc
// t.hi,t.lo =(umull) b.lo * c.lo
// t.hi += t_acc
// a.lo = t.lo
// a.hi = t.hi
//
// LLVM does:
// t.hi,t.lo =(umull) b.lo * c.lo
// t.hi =(mla) (b.lo * c.hi) + t.hi
// t.hi =(mla) (b.hi * c.lo) + t.hi
// a.lo = t.lo
// a.hi = t.hi
//
// LLVM's lowering has fewer instructions, but more register pressure:
// t.lo is live from beginning to end, while GCC delays the two-dest
// instruction till the end, and kills c.hi immediately.
Variable *T_Acc = makeReg(IceType_i32);
Variable *T_Acc1 = makeReg(IceType_i32);
Variable *T_Hi1 = makeReg(IceType_i32);
Variable *Src0RLo = SrcsLo.unswappedSrc0R(this);
Variable *Src0RHi = SrcsHi.unswappedSrc0R(this);
Variable *Src1RLo = SrcsLo.unswappedSrc1R(this);
Variable *Src1RHi = SrcsHi.unswappedSrc1R(this);
_mul(T_Acc, Src0RLo, Src1RHi);
_mla(T_Acc1, Src1RLo, Src0RHi, T_Acc);
_umull(T_Lo, T_Hi1, Src0RLo, Src1RLo);
_add(T_Hi, T_Hi1, T_Acc1);
_mov(DestLo, T_Lo);
_mov(DestHi, T_Hi);
return;
}
case InstArithmetic::Shl: {
if (!SrcsLo.swappedOperands() && SrcsLo.hasConstOperand()) {
Variable *Src0RLo = SrcsLo.src0R(this);
// Truncating the ShAmt to [0, 63] because that's what ARM does anyway.
const int32_t ShAmtImm = SrcsLo.getConstantValue() & 0x3F;
if (ShAmtImm == 0) {
_mov(DestLo, Src0RLo);
_mov(DestHi, SrcsHi.src0R(this));
return;
}
if (ShAmtImm >= 32) {
if (ShAmtImm == 32) {
_mov(DestHi, Src0RLo);
} else {
Operand *ShAmtOp = shAmtImm(ShAmtImm - 32);
_lsl(T_Hi, Src0RLo, ShAmtOp);
_mov(DestHi, T_Hi);
}
Operand *_0 =
legalize(Ctx->getConstantZero(IceType_i32), Legal_Reg | Legal_Flex);
_mov(T_Lo, _0);
_mov(DestLo, T_Lo);
return;
}
Variable *Src0RHi = SrcsHi.src0R(this);
Operand *ShAmtOp = shAmtImm(ShAmtImm);
Operand *ComplShAmtOp = shAmtImm(32 - ShAmtImm);
_lsl(T_Hi, Src0RHi, ShAmtOp);
_orr(T_Hi, T_Hi,
OperandARM32FlexReg::create(Func, IceType_i32, Src0RLo,
OperandARM32::LSR, ComplShAmtOp));
_mov(DestHi, T_Hi);
_lsl(T_Lo, Src0RLo, ShAmtOp);
_mov(DestLo, T_Lo);
return;
}
// a=b<<c ==>
// pnacl-llc does:
// mov t_b.lo, b.lo
// mov t_b.hi, b.hi
// mov t_c.lo, c.lo
// rsb T0, t_c.lo, #32
// lsr T1, t_b.lo, T0
// orr t_a.hi, T1, t_b.hi, lsl t_c.lo
// sub T2, t_c.lo, #32
// cmp T2, #0
// lslge t_a.hi, t_b.lo, T2
// lsl t_a.lo, t_b.lo, t_c.lo
// mov a.lo, t_a.lo
// mov a.hi, t_a.hi
//
// GCC 4.8 does:
// sub t_c1, c.lo, #32
// lsl t_hi, b.hi, c.lo
// orr t_hi, t_hi, b.lo, lsl t_c1
// rsb t_c2, c.lo, #32
// orr t_hi, t_hi, b.lo, lsr t_c2
// lsl t_lo, b.lo, c.lo
// a.lo = t_lo
// a.hi = t_hi
//
// These are incompatible, therefore we mimic pnacl-llc.
// Can be strength-reduced for constant-shifts, but we don't do that for
// now.
// Given the sub/rsb T_C, C.lo, #32, one of the T_C will be negative. On
// ARM, shifts only take the lower 8 bits of the shift register, and
// saturate to the range 0-32, so the negative value will saturate to 32.
Operand *_32 = legalize(Ctx->getConstantInt32(32), Legal_Reg | Legal_Flex);
Operand *_0 =
legalize(Ctx->getConstantZero(IceType_i32), Legal_Reg | Legal_Flex);
Variable *T0 = makeReg(IceType_i32);
Variable *T1 = makeReg(IceType_i32);
Variable *T2 = makeReg(IceType_i32);
Variable *TA_Hi = makeReg(IceType_i32);
Variable *TA_Lo = makeReg(IceType_i32);
Variable *Src0RLo = SrcsLo.unswappedSrc0R(this);
Variable *Src0RHi = SrcsHi.unswappedSrc0R(this);
Variable *Src1RLo = SrcsLo.unswappedSrc1R(this);
_rsb(T0, Src1RLo, _32);
_lsr(T1, Src0RLo, T0);
_orr(TA_Hi, T1, OperandARM32FlexReg::create(Func, IceType_i32, Src0RHi,
OperandARM32::LSL, Src1RLo));
_sub(T2, Src1RLo, _32);
_cmp(T2, _0);
_lsl(TA_Hi, Src0RLo, T2, CondARM32::GE);
_set_dest_redefined();
_lsl(TA_Lo, Src0RLo, Src1RLo);
_mov(DestLo, TA_Lo);
_mov(DestHi, TA_Hi);
return;
}
case InstArithmetic::Lshr:
case InstArithmetic::Ashr: {
const bool ASR = Op == InstArithmetic::Ashr;
if (!SrcsLo.swappedOperands() && SrcsLo.hasConstOperand()) {
Variable *Src0RHi = SrcsHi.src0R(this);
// Truncating the ShAmt to [0, 63] because that's what ARM does anyway.
const int32_t ShAmt = SrcsLo.getConstantValue() & 0x3F;
if (ShAmt == 0) {
_mov(DestHi, Src0RHi);
_mov(DestLo, SrcsLo.src0R(this));
return;
}
if (ShAmt >= 32) {
if (ShAmt == 32) {
_mov(DestLo, Src0RHi);
} else {
Operand *ShAmtImm = shAmtImm(ShAmt - 32);
if (ASR) {
_asr(T_Lo, Src0RHi, ShAmtImm);
} else {
_lsr(T_Lo, Src0RHi, ShAmtImm);
}
_mov(DestLo, T_Lo);
}
if (ASR) {
Operand *_31 = shAmtImm(31);
_asr(T_Hi, Src0RHi, _31);
} else {
Operand *_0 = legalize(Ctx->getConstantZero(IceType_i32),
Legal_Reg | Legal_Flex);
_mov(T_Hi, _0);
}
_mov(DestHi, T_Hi);
return;
}
Variable *Src0RLo = SrcsLo.src0R(this);
Operand *ShAmtImm = shAmtImm(ShAmt);
Operand *ComplShAmtImm = shAmtImm(32 - ShAmt);
_lsr(T_Lo, Src0RLo, ShAmtImm);
_orr(T_Lo, T_Lo,
OperandARM32FlexReg::create(Func, IceType_i32, Src0RHi,
OperandARM32::LSL, ComplShAmtImm));
_mov(DestLo, T_Lo);
if (ASR) {
_asr(T_Hi, Src0RHi, ShAmtImm);
} else {
_lsr(T_Hi, Src0RHi, ShAmtImm);
}
_mov(DestHi, T_Hi);
return;
}
// a=b>>c
// pnacl-llc does:
// mov t_b.lo, b.lo
// mov t_b.hi, b.hi
// mov t_c.lo, c.lo
// lsr T0, t_b.lo, t_c.lo
// rsb T1, t_c.lo, #32
// orr t_a.lo, T0, t_b.hi, lsl T1
// sub T2, t_c.lo, #32
// cmp T2, #0
// [al]srge t_a.lo, t_b.hi, T2
// [al]sr t_a.hi, t_b.hi, t_c.lo
// mov a.lo, t_a.lo
// mov a.hi, t_a.hi
//
// GCC 4.8 does (lsr):
// rsb t_c1, c.lo, #32
// lsr t_lo, b.lo, c.lo
// orr t_lo, t_lo, b.hi, lsl t_c1
// sub t_c2, c.lo, #32
// orr t_lo, t_lo, b.hi, lsr t_c2
// lsr t_hi, b.hi, c.lo
// mov a.lo, t_lo
// mov a.hi, t_hi
//
// These are incompatible, therefore we mimic pnacl-llc.
Operand *_32 = legalize(Ctx->getConstantInt32(32), Legal_Reg | Legal_Flex);
Operand *_0 =
legalize(Ctx->getConstantZero(IceType_i32), Legal_Reg | Legal_Flex);
Variable *T0 = makeReg(IceType_i32);
Variable *T1 = makeReg(IceType_i32);
Variable *T2 = makeReg(IceType_i32);
Variable *TA_Lo = makeReg(IceType_i32);
Variable *TA_Hi = makeReg(IceType_i32);
Variable *Src0RLo = SrcsLo.unswappedSrc0R(this);
Variable *Src0RHi = SrcsHi.unswappedSrc0R(this);
Variable *Src1RLo = SrcsLo.unswappedSrc1R(this);
_lsr(T0, Src0RLo, Src1RLo);
_rsb(T1, Src1RLo, _32);
_orr(TA_Lo, T0, OperandARM32FlexReg::create(Func, IceType_i32, Src0RHi,
OperandARM32::LSL, T1));
_sub(T2, Src1RLo, _32);
_cmp(T2, _0);
if (ASR) {
_asr(TA_Lo, Src0RHi, T2, CondARM32::GE);
_set_dest_redefined();
_asr(TA_Hi, Src0RHi, Src1RLo);
} else {
_lsr(TA_Lo, Src0RHi, T2, CondARM32::GE);
_set_dest_redefined();
_lsr(TA_Hi, Src0RHi, Src1RLo);
}
_mov(DestLo, TA_Lo);
_mov(DestHi, TA_Hi);
return;
}
case InstArithmetic::Fadd:
case InstArithmetic::Fsub:
case InstArithmetic::Fmul:
case InstArithmetic::Fdiv:
case InstArithmetic::Frem:
llvm::report_fatal_error("FP instruction with i64 type");
return;
case InstArithmetic::Udiv:
case InstArithmetic::Sdiv:
case InstArithmetic::Urem:
case InstArithmetic::Srem:
llvm::report_fatal_error("Call-helper-involved instruction for i64 type "
"should have already been handled before");
return;
}
}
namespace {
// StrengthReduction is a namespace with the strength reduction machinery. The
// entry point is the StrengthReduction::tryToOptimize method. It returns true
// if the optimization can be performed, and false otherwise.
//
// If the optimization can be performed, tryToOptimize sets its NumOperations
// parameter to the number of shifts that are needed to perform the
// multiplication; and it sets the Operations parameter with <ShAmt, AddOrSub>
// tuples that describe how to materialize the multiplication.
//
// The algorithm finds contiguous 1s in the Multiplication source, and uses one
// or two shifts to materialize it. A sequence of 1s, e.g.,
//
// M N
// ...00000000000011111...111110000000...
//
// is materializable with (1 << (M + 1)) - (1 << N):
//
// ...00000000000100000...000000000000... [1 << (M + 1)]
// ...00000000000000000...000010000000... (-) [1 << N]
// --------------------------------------
// ...00000000000011111...111110000000...
//
// And a single bit set, which is just a left shift.
namespace StrengthReduction {
enum AggregationOperation {
AO_Invalid,
AO_Add,
AO_Sub,
};
// AggregateElement is a glorified <ShAmt, AddOrSub> tuple.
class AggregationElement {
AggregationElement(const AggregationElement &) = delete;
public:
AggregationElement() = default;
AggregationElement &operator=(const AggregationElement &) = default;
AggregationElement(AggregationOperation Op, uint32_t ShAmt)
: Op(Op), ShAmt(ShAmt) {}
Operand *createShiftedOperand(Cfg *Func, Variable *OpR) const {
assert(OpR->mustHaveReg());
if (ShAmt == 0) {
return OpR;
}
return OperandARM32FlexReg::create(
Func, IceType_i32, OpR, OperandARM32::LSL,
OperandARM32ShAmtImm::create(
Func, llvm::cast<ConstantInteger32>(
Func->getContext()->getConstantInt32(ShAmt))));
}
bool aggregateWithAdd() const {
switch (Op) {
case AO_Invalid:
llvm::report_fatal_error("Invalid Strength Reduction Operations.");
case AO_Add:
return true;
case AO_Sub:
return false;
}
llvm_unreachable("(silence g++ warning)");
}
uint32_t shAmt() const { return ShAmt; }
private:
AggregationOperation Op = AO_Invalid;
uint32_t ShAmt;
};
// [RangeStart, RangeEnd] is a range of 1s in Src.
template <std::size_t N>
bool addOperations(uint32_t RangeStart, uint32_t RangeEnd, SizeT *NumOperations,
std::array<AggregationElement, N> *Operations) {
assert(*NumOperations < N);
if (RangeStart == RangeEnd) {
// Single bit set:
// Src : 0...00010...
// RangeStart : ^
// RangeEnd : ^
// NegSrc : 0...00001...
(*Operations)[*NumOperations] = AggregationElement(AO_Add, RangeStart);
++(*NumOperations);
return true;
}
// Sequence of 1s: (two operations required.)
// Src : 0...00011...110...
// RangeStart : ^
// RangeEnd : ^
// NegSrc : 0...00000...001...
if (*NumOperations + 1 >= N) {
return false;
}
(*Operations)[*NumOperations] = AggregationElement(AO_Add, RangeStart + 1);
++(*NumOperations);
(*Operations)[*NumOperations] = AggregationElement(AO_Sub, RangeEnd);
++(*NumOperations);
return true;
}
// tryToOptmize scans Src looking for sequences of 1s (including the unitary bit
// 1 surrounded by zeroes.
template <std::size_t N>
bool tryToOptimize(uint32_t Src, SizeT *NumOperations,
std::array<AggregationElement, N> *Operations) {
constexpr uint32_t SrcSizeBits = sizeof(Src) * CHAR_BIT;
uint32_t NegSrc = ~Src;
*NumOperations = 0;
while (Src != 0 && *NumOperations < N) {
// Each step of the algorithm:
// * finds L, the last bit set in Src;
// * clears all the upper bits in NegSrc up to bit L;
// * finds nL, the last bit set in NegSrc;
// * clears all the upper bits in Src up to bit nL;
//
// if L == nL + 1, then a unitary 1 was found in Src. Otherwise, a sequence
// of 1s starting at L, and ending at nL + 1, was found.
const uint32_t SrcLastBitSet = llvm::findLastSet(Src);
const uint32_t NegSrcClearMask =
(SrcLastBitSet == 0) ? 0
: (0xFFFFFFFFu) >> (SrcSizeBits - SrcLastBitSet);
NegSrc &= NegSrcClearMask;
if (NegSrc == 0) {
if (addOperations(SrcLastBitSet, 0, NumOperations, Operations)) {
return true;
}
return false;
}
const uint32_t NegSrcLastBitSet = llvm::findLastSet(NegSrc);
assert(NegSrcLastBitSet < SrcLastBitSet);
const uint32_t SrcClearMask =
(NegSrcLastBitSet == 0) ? 0 : (0xFFFFFFFFu) >>
(SrcSizeBits - NegSrcLastBitSet);
Src &= SrcClearMask;
if (!addOperations(SrcLastBitSet, NegSrcLastBitSet + 1, NumOperations,
Operations)) {
return false;
}
}
return Src == 0;
}
} // end of namespace StrengthReduction
} // end of anonymous namespace
void TargetARM32::lowerArithmetic(const InstArithmetic *Instr) {
Variable *Dest = Instr->getDest();
if (Dest->isRematerializable()) {
Context.insert<InstFakeDef>(Dest);
return;
}
Type DestTy = Dest->getType();
if (DestTy == IceType_i1) {
lowerInt1Arithmetic(Instr);
return;
}
Operand *Src0 = legalizeUndef(Instr->getSrc(0));
Operand *Src1 = legalizeUndef(Instr->getSrc(1));
if (DestTy == IceType_i64) {
lowerInt64Arithmetic(Instr->getOp(), Instr->getDest(), Src0, Src1);
return;
}
if (isVectorType(DestTy)) {
switch (Instr->getOp()) {
default:
UnimplementedLoweringError(this, Instr);
return;
// Explicitly whitelist vector instructions we have implemented/enabled.
case InstArithmetic::Add:
case InstArithmetic::And:
case InstArithmetic::Ashr:
case InstArithmetic::Fadd:
case InstArithmetic::Fmul:
case InstArithmetic::Fsub:
case InstArithmetic::Lshr:
case InstArithmetic::Mul:
case InstArithmetic::Or:
case InstArithmetic::Shl:
case InstArithmetic::Sub:
case InstArithmetic::Xor:
break;
}
}
Variable *T = makeReg(DestTy);
// * Handle div/rem separately. They require a non-legalized Src1 to inspect
// whether or not Src1 is a non-zero constant. Once legalized it is more
// difficult to determine (constant may be moved to a register).
// * Handle floating point arithmetic separately: they require Src1 to be
// legalized to a register.
switch (Instr->getOp()) {
default:
break;
case InstArithmetic::Udiv: {
constexpr bool NotRemainder = false;
Variable *Src0R = legalizeToReg(Src0);
lowerIDivRem(Dest, T, Src0R, Src1, &TargetARM32::_uxt, &TargetARM32::_udiv,
NotRemainder);
return;
}
case InstArithmetic::Sdiv: {
constexpr bool NotRemainder = false;
Variable *Src0R = legalizeToReg(Src0);
lowerIDivRem(Dest, T, Src0R, Src1, &TargetARM32::_sxt, &TargetARM32::_sdiv,
NotRemainder);
return;
}
case InstArithmetic::Urem: {
constexpr bool IsRemainder = true;
Variable *Src0R = legalizeToReg(Src0);
lowerIDivRem(Dest, T, Src0R, Src1, &TargetARM32::_uxt, &TargetARM32::_udiv,
IsRemainder);
return;
}
case InstArithmetic::Srem: {
constexpr bool IsRemainder = true;
Variable *Src0R = legalizeToReg(Src0);
lowerIDivRem(Dest, T, Src0R, Src1, &TargetARM32::_sxt, &TargetARM32::_sdiv,
IsRemainder);
return;
}
case InstArithmetic::Frem: {
if (!isScalarFloatingType(DestTy)) {
llvm::report_fatal_error("Unexpected type when lowering frem.");
}
llvm::report_fatal_error("Frem should have already been lowered.");
}
case InstArithmetic::Fadd: {
Variable *Src0R = legalizeToReg(Src0);
if (const Inst *Src1Producer = Computations.getProducerOf(Src1)) {
Variable *Src1R = legalizeToReg(Src1Producer->getSrc(0));
Variable *Src2R = legalizeToReg(Src1Producer->getSrc(1));
_vmla(Src0R, Src1R, Src2R);
_mov(Dest, Src0R);
return;
}
Variable *Src1R = legalizeToReg(Src1);
_vadd(T, Src0R, Src1R);
_mov(Dest, T);
return;
}
case InstArithmetic::Fsub: {
Variable *Src0R = legalizeToReg(Src0);
if (const Inst *Src1Producer = Computations.getProducerOf(Src1)) {
Variable *Src1R = legalizeToReg(Src1Producer->getSrc(0));
Variable *Src2R = legalizeToReg(Src1Producer->getSrc(1));
_vmls(Src0R, Src1R, Src2R);
_mov(Dest, Src0R);
return;
}
Variable *Src1R = legalizeToReg(Src1);
_vsub(T, Src0R, Src1R);
_mov(Dest, T);
return;
}
case InstArithmetic::Fmul: {
Variable *Src0R = legalizeToReg(Src0);
Variable *Src1R = legalizeToReg(Src1);
_vmul(T, Src0R, Src1R);
_mov(Dest, T);
return;
}
case InstArithmetic::Fdiv: {
Variable *Src0R = legalizeToReg(Src0);
Variable *Src1R = legalizeToReg(Src1);
_vdiv(T, Src0R, Src1R);
_mov(Dest, T);
return;
}
}
// Handle everything else here.
Int32Operands Srcs(Src0, Src1);
switch (Instr->getOp()) {
case InstArithmetic::_num:
llvm::report_fatal_error("Unknown arithmetic operator");
return;
case InstArithmetic::Add: {
if (const Inst *Src1Producer = Computations.getProducerOf(Src1)) {
assert(!isVectorType(DestTy));
Variable *Src0R = legalizeToReg(Src0);
Variable *Src1R = legalizeToReg(Src1Producer->getSrc(0));
Variable *Src2R = legalizeToReg(Src1Producer->getSrc(1));
_mla(T, Src1R, Src2R, Src0R);
_mov(Dest, T);
return;
}
if (Srcs.hasConstOperand()) {
if (!Srcs.immediateIsFlexEncodable() &&
Srcs.negatedImmediateIsFlexEncodable()) {
assert(!isVectorType(DestTy));
Variable *Src0R = Srcs.src0R(this);
Operand *Src1F = Srcs.negatedSrc1F(this);
if (!Srcs.swappedOperands()) {
_sub(T, Src0R, Src1F);
} else {
_rsb(T, Src0R, Src1F);
}
_mov(Dest, T);
return;
}
}
Variable *Src0R = Srcs.src0R(this);
if (isVectorType(DestTy)) {
Variable *Src1R = legalizeToReg(Src1);
_vadd(T, Src0R, Src1R);
} else {
Operand *Src1RF = Srcs.src1RF(this);
_add(T, Src0R, Src1RF);
}
_mov(Dest, T);
return;
}
case InstArithmetic::And: {
if (Srcs.hasConstOperand()) {
if (!Srcs.immediateIsFlexEncodable() &&
Srcs.invertedImmediateIsFlexEncodable()) {
Variable *Src0R = Srcs.src0R(this);
Operand *Src1F = Srcs.invertedSrc1F(this);
_bic(T, Src0R, Src1F);
_mov(Dest, T);
return;
}
}
assert(isIntegerType(DestTy));
Variable *Src0R = Srcs.src0R(this);
if (isVectorType(DestTy)) {
Variable *Src1R = legalizeToReg(Src1);
_vand(T, Src0R, Src1R);
} else {
Operand *Src1RF = Srcs.src1RF(this);
_and(T, Src0R, Src1RF);
}
_mov(Dest, T);
return;
}
case InstArithmetic::Or: {
Variable *Src0R = Srcs.src0R(this);
assert(isIntegerType(DestTy));
if (isVectorType(DestTy)) {
Variable *Src1R = legalizeToReg(Src1);
_vorr(T, Src0R, Src1R);
} else {
Operand *Src1RF = Srcs.src1RF(this);
_orr(T, Src0R, Src1RF);
}
_mov(Dest, T);
return;
}
case InstArithmetic::Xor: {
Variable *Src0R = Srcs.src0R(this);
assert(isIntegerType(DestTy));
if (isVectorType(DestTy)) {
Variable *Src1R = legalizeToReg(Src1);
_veor(T, Src0R, Src1R);
} else {
Operand *Src1RF = Srcs.src1RF(this);
_eor(T, Src0R, Src1RF);
}
_mov(Dest, T);
return;
}
case InstArithmetic::Sub: {
if (const Inst *Src1Producer = Computations.getProducerOf(Src1)) {
assert(!isVectorType(DestTy));
Variable *Src0R = legalizeToReg(Src0);
Variable *Src1R = legalizeToReg(Src1Producer->getSrc(0));
Variable *Src2R = legalizeToReg(Src1Producer->getSrc(1));
_mls(T, Src1R, Src2R, Src0R);
_mov(Dest, T);
return;
}
if (Srcs.hasConstOperand()) {
assert(!isVectorType(DestTy));
if (Srcs.immediateIsFlexEncodable()) {
Variable *Src0R = Srcs.src0R(this);
Operand *Src1RF = Srcs.src1RF(this);
if (Srcs.swappedOperands()) {
_rsb(T, Src0R, Src1RF);
} else {
_sub(T, Src0R, Src1RF);
}
_mov(Dest, T);
return;
}
if (!Srcs.swappedOperands() && Srcs.negatedImmediateIsFlexEncodable()) {
Variable *Src0R = Srcs.src0R(this);
Operand *Src1F = Srcs.negatedSrc1F(this);
_add(T, Src0R, Src1F);
_mov(Dest, T);
return;
}
}
Variable *Src0R = Srcs.unswappedSrc0R(this);
Variable *Src1R = Srcs.unswappedSrc1R(this);
if (isVectorType(DestTy)) {
_vsub(T, Src0R, Src1R);
} else {
_sub(T, Src0R, Src1R);
}
_mov(Dest, T);
return;
}
case InstArithmetic::Mul: {
const bool OptM1 = Func->getOptLevel() == Opt_m1;
if (!OptM1 && Srcs.hasConstOperand()) {
constexpr std::size_t MaxShifts = 4;
std::array<StrengthReduction::AggregationElement, MaxShifts> Shifts;
SizeT NumOperations;
int32_t Const = Srcs.getConstantValue();
const bool Invert = Const < 0;
const bool MultiplyByZero = Const == 0;
Operand *_0 =
legalize(Ctx->getConstantZero(DestTy), Legal_Reg | Legal_Flex);
if (MultiplyByZero) {
_mov(T, _0);
_mov(Dest, T);
return;
}
if (Invert) {
Const = -Const;
}
if (StrengthReduction::tryToOptimize(Const, &NumOperations, &Shifts)) {
assert(NumOperations >= 1);
Variable *Src0R = Srcs.src0R(this);
int32_t Start;
int32_t End;
if (NumOperations == 1 || Shifts[NumOperations - 1].shAmt() != 0) {
// Multiplication by a power of 2 (NumOperations == 1); or
// Multiplication by a even number not a power of 2.
Start = 1;
End = NumOperations;
assert(Shifts[0].aggregateWithAdd());
_lsl(T, Src0R, shAmtImm(Shifts[0].shAmt()));
} else {
// Multiplication by an odd number. Put the free barrel shifter to a
// good use.
Start = 0;
End = NumOperations - 2;
const StrengthReduction::AggregationElement &Last =
Shifts[NumOperations - 1];
const StrengthReduction::AggregationElement &SecondToLast =
Shifts[NumOperations - 2];
if (!Last.aggregateWithAdd()) {
assert(SecondToLast.aggregateWithAdd());
_rsb(T, Src0R, SecondToLast.createShiftedOperand(Func, Src0R));
} else if (!SecondToLast.aggregateWithAdd()) {
assert(Last.aggregateWithAdd());
_sub(T, Src0R, SecondToLast.createShiftedOperand(Func, Src0R));
} else {
_add(T, Src0R, SecondToLast.createShiftedOperand(Func, Src0R));
}
}
// Odd numbers : S E I I
// +---+---+---+---+---+---+ ... +---+---+---+---+
// Shifts = | | | | | | | ... | | | | |
// +---+---+---+---+---+---+ ... +---+---+---+---+
// Even numbers: I S E
//
// S: Start; E: End; I: Init
for (int32_t I = Start; I < End; ++I) {
const StrengthReduction::AggregationElement &Current = Shifts[I];
Operand *SrcF = Current.createShiftedOperand(Func, Src0R);
if (Current.aggregateWithAdd()) {
_add(T, T, SrcF);
} else {
_sub(T, T, SrcF);
}
}
if (Invert) {
// T = 0 - T.
_rsb(T, T, _0);
}
_mov(Dest, T);
return;
}
}
Variable *Src0R = Srcs.unswappedSrc0R(this);
Variable *Src1R = Srcs.unswappedSrc1R(this);
if (isVectorType(DestTy)) {
_vmul(T, Src0R, Src1R);
} else {
_mul(T, Src0R, Src1R);
}
_mov(Dest, T);
return;
}
case InstArithmetic::Shl: {
Variable *Src0R = Srcs.unswappedSrc0R(this);
if (!isVectorType(T->getType())) {
Operand *Src1R = Srcs.unswappedSrc1RShAmtImm(this);
_lsl(T, Src0R, Src1R);
} else {
auto *Src1R = Srcs.unswappedSrc1R(this);
_vshl(T, Src0R, Src1R)->setSignType(InstARM32::FS_Unsigned);
}
_mov(Dest, T);
return;
}
case InstArithmetic::Lshr: {
Variable *Src0R = Srcs.unswappedSrc0R(this);
if (!isVectorType(T->getType())) {
Operand *Src1R = Srcs.unswappedSrc1RShAmtImm(this);
if (DestTy != IceType_i32) {
_uxt(Src0R, Src0R);
}
_lsr(T, Src0R, Src1R);
} else {
auto *Src1R = Srcs.unswappedSrc1R(this);
auto *Src1RNeg = makeReg(Src1R->getType());
_vneg(Src1RNeg, Src1R);
_vshl(T, Src0R, Src1RNeg)->setSignType(InstARM32::FS_Unsigned);
}
_mov(Dest, T);
return;
}
case InstArithmetic::Ashr: {
Variable *Src0R = Srcs.unswappedSrc0R(this);
if (!isVectorType(T->getType())) {
if (DestTy != IceType_i32) {
_sxt(Src0R, Src0R);
}
_asr(T, Src0R, Srcs.unswappedSrc1RShAmtImm(this));
} else {
auto *Src1R = Srcs.unswappedSrc1R(this);
auto *Src1RNeg = makeReg(Src1R->getType());
_vneg(Src1RNeg, Src1R);
_vshl(T, Src0R, Src1RNeg)->setSignType(InstARM32::FS_Signed);
}
_mov(Dest, T);
return;
}
case InstArithmetic::Udiv:
case InstArithmetic::Sdiv:
case InstArithmetic::Urem:
case InstArithmetic::Srem:
llvm::report_fatal_error(
"Integer div/rem should have been handled earlier.");
return;
case InstArithmetic::Fadd:
case InstArithmetic::Fsub:
case InstArithmetic::Fmul:
case InstArithmetic::Fdiv:
case InstArithmetic::Frem:
llvm::report_fatal_error(
"Floating point arith should have been handled earlier.");
return;
}
}
void TargetARM32::lowerAssign(const InstAssign *Instr) {
Variable *Dest = Instr->getDest();
if (Dest->isRematerializable()) {
Context.insert<InstFakeDef>(Dest);
return;
}
Operand *Src0 = Instr->getSrc(0);
assert(Dest->getType() == Src0->getType());
if (Dest->getType() == IceType_i64) {
Src0 = legalizeUndef(Src0);
Variable *T_Lo = makeReg(IceType_i32);
auto *DestLo = llvm::cast<Variable>(loOperand(Dest));
Operand *Src0Lo = legalize(loOperand(Src0), Legal_Reg | Legal_Flex);
_mov(T_Lo, Src0Lo);
_mov(DestLo, T_Lo);
Variable *T_Hi = makeReg(IceType_i32);
auto *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Operand *Src0Hi = legalize(hiOperand(Src0), Legal_Reg | Legal_Flex);
_mov(T_Hi, Src0Hi);
_mov(DestHi, T_Hi);
return;
}
Operand *NewSrc;
if (Dest->hasReg()) {
// If Dest already has a physical register, then legalize the Src operand
// into a Variable with the same register assignment. This especially
// helps allow the use of Flex operands.
NewSrc = legalize(Src0, Legal_Reg | Legal_Flex, Dest->getRegNum());
} else {
// Dest could be a stack operand. Since we could potentially need to do a
// Store (and store can only have Register operands), legalize this to a
// register.
NewSrc = legalize(Src0, Legal_Reg);
}
if (isVectorType(Dest->getType()) || isScalarFloatingType(Dest->getType())) {
NewSrc = legalize(NewSrc, Legal_Reg | Legal_Mem);
}
_mov(Dest, NewSrc);
}
TargetARM32::ShortCircuitCondAndLabel TargetARM32::lowerInt1ForBranch(
Operand *Boolean, const LowerInt1BranchTarget &TargetTrue,
const LowerInt1BranchTarget &TargetFalse, uint32_t ShortCircuitable) {
InstARM32Label *NewShortCircuitLabel = nullptr;
Operand *_1 = legalize(Ctx->getConstantInt1(1), Legal_Reg | Legal_Flex);
const Inst *Producer = Computations.getProducerOf(Boolean);
if (Producer == nullptr) {
// No producer, no problem: just do emit code to perform (Boolean & 1) and
// set the flags register. The branch should be taken if the resulting flags
// indicate a non-zero result.
_tst(legalizeToReg(Boolean), _1);
return ShortCircuitCondAndLabel(CondWhenTrue(CondARM32::NE));
}
switch (Producer->getKind()) {
default:
llvm::report_fatal_error("Unexpected producer.");
case Inst::Icmp: {
return ShortCircuitCondAndLabel(
lowerIcmpCond(llvm::cast<InstIcmp>(Producer)));
} break;
case Inst::Fcmp: {
return ShortCircuitCondAndLabel(
lowerFcmpCond(llvm::cast<InstFcmp>(Producer)));
} break;
case Inst::Cast: {
const auto *CastProducer = llvm::cast<InstCast>(Producer);
assert(CastProducer->getCastKind() == InstCast::Trunc);
Operand *Src = CastProducer->getSrc(0);
if (Src->getType() == IceType_i64)
Src = loOperand(Src);
_tst(legalizeToReg(Src), _1);
return ShortCircuitCondAndLabel(CondWhenTrue(CondARM32::NE));
} break;
case Inst::Arithmetic: {
const auto *ArithProducer = llvm::cast<InstArithmetic>(Producer);
switch (ArithProducer->getOp()) {
default:
llvm::report_fatal_error("Unhandled Arithmetic Producer.");
case InstArithmetic::And: {
if (!(ShortCircuitable & SC_And)) {
NewShortCircuitLabel = InstARM32Label::create(Func, this);
}
LowerInt1BranchTarget NewTarget =
TargetFalse.createForLabelOrDuplicate(NewShortCircuitLabel);
ShortCircuitCondAndLabel CondAndLabel = lowerInt1ForBranch(
Producer->getSrc(0), TargetTrue, NewTarget, SC_And);
const CondWhenTrue &Cond = CondAndLabel.Cond;
_br_short_circuit(NewTarget, Cond.invert());
InstARM32Label *const ShortCircuitLabel = CondAndLabel.ShortCircuitTarget;
if (ShortCircuitLabel != nullptr)
Context.insert(ShortCircuitLabel);
return ShortCircuitCondAndLabel(
lowerInt1ForBranch(Producer->getSrc(1), TargetTrue, NewTarget, SC_All)
.assertNoLabelAndReturnCond(),
NewShortCircuitLabel);
} break;
case InstArithmetic::Or: {
if (!(ShortCircuitable & SC_Or)) {
NewShortCircuitLabel = InstARM32Label::create(Func, this);
}
LowerInt1BranchTarget NewTarget =
TargetTrue.createForLabelOrDuplicate(NewShortCircuitLabel);
ShortCircuitCondAndLabel CondAndLabel = lowerInt1ForBranch(
Producer->getSrc(0), NewTarget, TargetFalse, SC_Or);
const CondWhenTrue &Cond = CondAndLabel.Cond;
_br_short_circuit(NewTarget, Cond);
InstARM32Label *const ShortCircuitLabel = CondAndLabel.ShortCircuitTarget;
if (ShortCircuitLabel != nullptr)
Context.insert(ShortCircuitLabel);
return ShortCircuitCondAndLabel(lowerInt1ForBranch(Producer->getSrc(1),
NewTarget, TargetFalse,
SC_All)
.assertNoLabelAndReturnCond(),
NewShortCircuitLabel);
} break;
}
}
}
}
void TargetARM32::lowerBr(const InstBr *Instr) {
if (Instr->isUnconditional()) {
_br(Instr->getTargetUnconditional());
return;
}
CfgNode *TargetTrue = Instr->getTargetTrue();
CfgNode *TargetFalse = Instr->getTargetFalse();
ShortCircuitCondAndLabel CondAndLabel = lowerInt1ForBranch(
Instr->getCondition(), LowerInt1BranchTarget(TargetTrue),
LowerInt1BranchTarget(TargetFalse), SC_All);
assert(CondAndLabel.ShortCircuitTarget == nullptr);
const CondWhenTrue &Cond = CondAndLabel.Cond;
if (Cond.WhenTrue1 != CondARM32::kNone) {
assert(Cond.WhenTrue0 != CondARM32::AL);
_br(TargetTrue, Cond.WhenTrue1);
}
switch (Cond.WhenTrue0) {
default:
_br(TargetTrue, TargetFalse, Cond.WhenTrue0);
break;
case CondARM32::kNone:
_br(TargetFalse);
break;
case CondARM32::AL:
_br(TargetTrue);
break;
}
}
void TargetARM32::lowerCall(const InstCall *Instr) {
Operand *CallTarget = Instr->getCallTarget();
if (Instr->isTargetHelperCall()) {
auto TargetHelperPreamble = ARM32HelpersPreamble.find(CallTarget);
if (TargetHelperPreamble != ARM32HelpersPreamble.end()) {
(this->*TargetHelperPreamble->second)(Instr);
}
}
MaybeLeafFunc = false;
NeedsStackAlignment = true;
// Assign arguments to registers and stack. Also reserve stack.
TargetARM32::CallingConv CC;
// Pair of Arg Operand -> GPR number assignments.
llvm::SmallVector<std::pair<Operand *, RegNumT>, NumGPRArgs> GPRArgs;
llvm::SmallVector<std::pair<Operand *, RegNumT>, NumFP32Args> FPArgs;
// Pair of Arg Operand -> stack offset.
llvm::SmallVector<std::pair<Operand *, int32_t>, 8> StackArgs;
size_t ParameterAreaSizeBytes = 0;
// Classify each argument operand according to the location where the
// argument is passed.
for (SizeT i = 0, NumArgs = Instr->getNumArgs(); i < NumArgs; ++i) {
Operand *Arg = legalizeUndef(Instr->getArg(i));
const Type Ty = Arg->getType();
bool InReg = false;
RegNumT Reg;
if (isScalarIntegerType(Ty)) {
InReg = CC.argInGPR(Ty, &Reg);
} else {
InReg = CC.argInVFP(Ty, &Reg);
}
if (!InReg) {
ParameterAreaSizeBytes =
applyStackAlignmentTy(ParameterAreaSizeBytes, Ty);
StackArgs.push_back(std::make_pair(Arg, ParameterAreaSizeBytes));
ParameterAreaSizeBytes += typeWidthInBytesOnStack(Ty);
continue;
}
if (Ty == IceType_i64) {
Operand *Lo = loOperand(Arg);
Operand *Hi = hiOperand(Arg);
GPRArgs.push_back(std::make_pair(
Lo, RegNumT::fixme(RegARM32::getI64PairFirstGPRNum(Reg))));
GPRArgs.push_back(std::make_pair(
Hi, RegNumT::fixme(RegARM32::getI64PairSecondGPRNum(Reg))));
} else if (isScalarIntegerType(Ty)) {
GPRArgs.push_back(std::make_pair(Arg, Reg));
} else {
FPArgs.push_back(std::make_pair(Arg, Reg));
}
}
// Adjust the parameter area so that the stack is aligned. It is assumed that
// the stack is already aligned at the start of the calling sequence.
ParameterAreaSizeBytes = applyStackAlignment(ParameterAreaSizeBytes);
if (ParameterAreaSizeBytes > MaxOutArgsSizeBytes) {
llvm::report_fatal_error("MaxOutArgsSizeBytes is not really a max.");
}
// Copy arguments that are passed on the stack to the appropriate stack
// locations.
Variable *SP = getPhysicalRegister(RegARM32::Reg_sp);
for (auto &StackArg : StackArgs) {
ConstantInteger32 *Loc =
llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(StackArg.second));
Type Ty = StackArg.first->getType();
OperandARM32Mem *Addr;
constexpr bool SignExt = false;
if (OperandARM32Mem::canHoldOffset(Ty, SignExt, StackArg.second)) {
Addr = OperandARM32Mem::create(Func, Ty, SP, Loc);
} else {
Variable *NewBase = Func->makeVariable(SP->getType());
lowerArithmetic(
InstArithmetic::create(Func, InstArithmetic::Add, NewBase, SP, Loc));
Addr = formMemoryOperand(NewBase, Ty);
}
lowerStore(InstStore::create(Func, StackArg.first, Addr));
}
// Generate the call instruction. Assign its result to a temporary with high
// register allocation weight.
Variable *Dest = Instr->getDest();
// ReturnReg doubles as ReturnRegLo as necessary.
Variable *ReturnReg = nullptr;
Variable *ReturnRegHi = nullptr;
if (Dest) {
switch (Dest->getType()) {
case IceType_NUM:
llvm::report_fatal_error("Invalid Call dest type");
break;
case IceType_void:
break;
case IceType_i1:
assert(Computations.getProducerOf(Dest) == nullptr);
// Fall-through intended.
case IceType_i8:
case IceType_i16:
case IceType_i32:
ReturnReg = makeReg(Dest->getType(), RegARM32::Reg_r0);
break;
case IceType_i64:
ReturnReg = makeReg(IceType_i32, RegARM32::Reg_r0);
ReturnRegHi = makeReg(IceType_i32, RegARM32::Reg_r1);
break;
case IceType_f32:
ReturnReg = makeReg(Dest->getType(), RegARM32::Reg_s0);
break;
case IceType_f64:
ReturnReg = makeReg(Dest->getType(), RegARM32::Reg_d0);
break;
case IceType_v4i1:
case IceType_v8i1:
case IceType_v16i1:
case IceType_v16i8:
case IceType_v8i16:
case IceType_v4i32:
case IceType_v4f32:
ReturnReg = makeReg(Dest->getType(), RegARM32::Reg_q0);
break;
}
}
// Allow ConstantRelocatable to be left alone as a direct call, but force
// other constants like ConstantInteger32 to be in a register and make it an
// indirect call.
if (!llvm::isa<ConstantRelocatable>(CallTarget)) {
CallTarget = legalize(CallTarget, Legal_Reg);
}
// Copy arguments to be passed in registers to the appropriate registers.
CfgVector<Variable *> RegArgs;
for (auto &FPArg : FPArgs) {
RegArgs.emplace_back(legalizeToReg(FPArg.first, FPArg.second));
}
for (auto &GPRArg : GPRArgs) {
RegArgs.emplace_back(legalizeToReg(GPRArg.first, GPRArg.second));
}
// Generate a FakeUse of register arguments so that they do not get dead code
// eliminated as a result of the FakeKill of scratch registers after the call.
// These fake-uses need to be placed here to avoid argument registers from
// being used during the legalizeToReg() calls above.
for (auto *RegArg : RegArgs) {
Context.insert<InstFakeUse>(RegArg);
}
InstARM32Call *NewCall =
Sandboxer(this, InstBundleLock::Opt_AlignToEnd).bl(ReturnReg, CallTarget);
if (ReturnRegHi)
Context.insert<InstFakeDef>(ReturnRegHi);
// Insert a register-kill pseudo instruction.
Context.insert<InstFakeKill>(NewCall);
// Generate a FakeUse to keep the call live if necessary.
if (Instr->hasSideEffects() && ReturnReg) {
Context.insert<InstFakeUse>(ReturnReg);
}
if (Dest != nullptr) {
// Assign the result of the call to Dest.
if (ReturnReg != nullptr) {
if (ReturnRegHi) {
auto *Dest64On32 = llvm::cast<Variable64On32>(Dest);
Variable *DestLo = Dest64On32->getLo();
Variable *DestHi = Dest64On32->getHi();
_mov(DestLo, ReturnReg);
_mov(DestHi, ReturnRegHi);
} else {
if (isFloatingType(Dest->getType()) || isVectorType(Dest->getType())) {
_mov(Dest, ReturnReg);
} else {
assert(isIntegerType(Dest->getType()) &&
typeWidthInBytes(Dest->getType()) <= 4);
_mov(Dest, ReturnReg);
}
}
}
}
if (Instr->isTargetHelperCall()) {
auto TargetHelpersPostamble = ARM32HelpersPostamble.find(CallTarget);
if (TargetHelpersPostamble != ARM32HelpersPostamble.end()) {
(this->*TargetHelpersPostamble->second)(Instr);
}
}
}
namespace {
void configureBitcastTemporary(Variable64On32 *Var) {
Var->setMustNotHaveReg();
Var->getHi()->setMustHaveReg();
Var->getLo()->setMustHaveReg();
}
} // end of anonymous namespace
void TargetARM32::lowerCast(const InstCast *Instr) {
InstCast::OpKind CastKind = Instr->getCastKind();
Variable *Dest = Instr->getDest();
const Type DestTy = Dest->getType();
Operand *Src0 = legalizeUndef(Instr->getSrc(0));
switch (CastKind) {
default:
Func->setError("Cast type not supported");
return;
case InstCast::Sext: {
if (isVectorType(DestTy)) {
Variable *T0 = makeReg(DestTy);
Variable *T1 = makeReg(DestTy);
ConstantInteger32 *ShAmt = nullptr;
switch (DestTy) {
default:
llvm::report_fatal_error("Unexpected type in vector sext.");
case IceType_v16i8:
ShAmt = llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(7));
break;
case IceType_v8i16:
ShAmt = llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(15));
break;
case IceType_v4i32:
ShAmt = llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(31));
break;
}
auto *Src0R = legalizeToReg(Src0);
_vshl(T0, Src0R, ShAmt);
_vshr(T1, T0, ShAmt)->setSignType(InstARM32::FS_Signed);
_mov(Dest, T1);
} else if (DestTy == IceType_i64) {
// t1=sxtb src; t2= mov t1 asr #31; dst.lo=t1; dst.hi=t2
Constant *ShiftAmt = Ctx->getConstantInt32(31);
auto *DestLo = llvm::cast<Variable>(loOperand(Dest));
auto *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Variable *T_Lo = makeReg(DestLo->getType());
if (Src0->getType() == IceType_i32) {
Operand *Src0RF = legalize(Src0, Legal_Reg | Legal_Flex);
_mov(T_Lo, Src0RF);
} else if (Src0->getType() != IceType_i1) {
Variable *Src0R = legalizeToReg(Src0);
_sxt(T_Lo, Src0R);
} else {
Operand *_0 = Ctx->getConstantZero(IceType_i32);
Operand *_m1 = Ctx->getConstantInt32(-1);
lowerInt1ForSelect(T_Lo, Src0, _m1, _0);
}
_mov(DestLo, T_Lo);
Variable *T_Hi = makeReg(DestHi->getType());
if (Src0->getType() != IceType_i1) {
_mov(T_Hi, OperandARM32FlexReg::create(Func, IceType_i32, T_Lo,
OperandARM32::ASR, ShiftAmt));
} else {
// For i1, the asr instruction is already done above.
_mov(T_Hi, T_Lo);
}
_mov(DestHi, T_Hi);
} else if (Src0->getType() != IceType_i1) {
// t1 = sxt src; dst = t1
Variable *Src0R = legalizeToReg(Src0);
Variable *T = makeReg(DestTy);
_sxt(T, Src0R);
_mov(Dest, T);
} else {
Constant *_0 = Ctx->getConstantZero(IceType_i32);
Operand *_m1 = Ctx->getConstantInt(DestTy, -1);
Variable *T = makeReg(DestTy);
lowerInt1ForSelect(T, Src0, _m1, _0);
_mov(Dest, T);
}
break;
}
case InstCast::Zext: {
if (isVectorType(DestTy)) {
auto *Mask = makeReg(DestTy);
auto *_1 = Ctx->getConstantInt32(1);
auto *T = makeReg(DestTy);
auto *Src0R = legalizeToReg(Src0);
_mov(Mask, _1);
_vand(T, Src0R, Mask);
_mov(Dest, T);
} else if (DestTy == IceType_i64) {
// t1=uxtb src; dst.lo=t1; dst.hi=0
Operand *_0 =
legalize(Ctx->getConstantZero(IceType_i32), Legal_Reg | Legal_Flex);
auto *DestLo = llvm::cast<Variable>(loOperand(Dest));
auto *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Variable *T_Lo = makeReg(DestLo->getType());
switch (Src0->getType()) {
default: {
assert(Src0->getType() != IceType_i64);
_uxt(T_Lo, legalizeToReg(Src0));
} break;
case IceType_i32: {
_mov(T_Lo, legalize(Src0, Legal_Reg | Legal_Flex));
} break;
case IceType_i1: {
SafeBoolChain Safe = lowerInt1(T_Lo, Src0);
if (Safe == SBC_No) {
Operand *_1 =
legalize(Ctx->getConstantInt1(1), Legal_Reg | Legal_Flex);
_and(T_Lo, T_Lo, _1);
}
} break;
}
_mov(DestLo, T_Lo);
Variable *T_Hi = makeReg(DestLo->getType());
_mov(T_Hi, _0);
_mov(DestHi, T_Hi);
} else if (Src0->getType() == IceType_i1) {
Variable *T = makeReg(DestTy);
SafeBoolChain Safe = lowerInt1(T, Src0);
if (Safe == SBC_No) {
Operand *_1 = legalize(Ctx->getConstantInt1(1), Legal_Reg | Legal_Flex);
_and(T, T, _1);
}
_mov(Dest, T);
} else {
// t1 = uxt src; dst = t1
Variable *Src0R = legalizeToReg(Src0);
Variable *T = makeReg(DestTy);
_uxt(T, Src0R);
_mov(Dest, T);
}
break;
}
case InstCast::Trunc: {
if (isVectorType(DestTy)) {
auto *T = makeReg(DestTy);
auto *Src0R = legalizeToReg(Src0);
_mov(T, Src0R);
_mov(Dest, T);
} else {
if (Src0->getType() == IceType_i64)
Src0 = loOperand(Src0);
Operand *Src0RF = legalize(Src0, Legal_Reg | Legal_Flex);
// t1 = trunc Src0RF; Dest = t1
Variable *T = makeReg(DestTy);
_mov(T, Src0RF);
if (DestTy == IceType_i1)
_and(T, T, Ctx->getConstantInt1(1));
_mov(Dest, T);
}
break;
}
case InstCast::Fptrunc:
case InstCast::Fpext: {
// fptrunc: dest.f32 = fptrunc src0.fp64
// fpext: dest.f64 = fptrunc src0.fp32
const bool IsTrunc = CastKind == InstCast::Fptrunc;
assert(!isVectorType(DestTy));
assert(DestTy == (IsTrunc ? IceType_f32 : IceType_f64));
assert(Src0->getType() == (IsTrunc ? IceType_f64 : IceType_f32));
Variable *Src0R = legalizeToReg(Src0);
Variable *T = makeReg(DestTy);
_vcvt(T, Src0R, IsTrunc ? InstARM32Vcvt::D2s : InstARM32Vcvt::S2d);
_mov(Dest, T);
break;
}
case InstCast::Fptosi:
case InstCast::Fptoui: {
const bool DestIsSigned = CastKind == InstCast::Fptosi;
Variable *Src0R = legalizeToReg(Src0);
if (isVectorType(DestTy)) {
assert(typeElementType(Src0->getType()) == IceType_f32);
auto *T = makeReg(DestTy);
_vcvt(T, Src0R,
DestIsSigned ? InstARM32Vcvt::Vs2si : InstARM32Vcvt::Vs2ui);
_mov(Dest, T);
break;
}
const bool Src0IsF32 = isFloat32Asserting32Or64(Src0->getType());
if (llvm::isa<Variable64On32>(Dest)) {
llvm::report_fatal_error("fp-to-i64 should have been pre-lowered.");
}
// fptosi:
// t1.fp = vcvt src0.fp
// t2.i32 = vmov t1.fp
// dest.int = conv t2.i32 @ Truncates the result if needed.
// fptoui:
// t1.fp = vcvt src0.fp
// t2.u32 = vmov t1.fp
// dest.uint = conv t2.u32 @ Truncates the result if needed.
Variable *T_fp = makeReg(IceType_f32);
const InstARM32Vcvt::VcvtVariant Conversion =
Src0IsF32 ? (DestIsSigned ? InstARM32Vcvt::S2si : InstARM32Vcvt::S2ui)
: (DestIsSigned ? InstARM32Vcvt::D2si : InstARM32Vcvt::D2ui);
_vcvt(T_fp, Src0R, Conversion);
Variable *T = makeReg(IceType_i32);
_mov(T, T_fp);
if (DestTy != IceType_i32) {
Variable *T_1 = makeReg(DestTy);
lowerCast(InstCast::create(Func, InstCast::Trunc, T_1, T));
T = T_1;
}
_mov(Dest, T);
break;
}
case InstCast::Sitofp:
case InstCast::Uitofp: {
const bool SourceIsSigned = CastKind == InstCast::Sitofp;
if (isVectorType(DestTy)) {
assert(typeElementType(DestTy) == IceType_f32);
auto *T = makeReg(DestTy);
Variable *Src0R = legalizeToReg(Src0);
_vcvt(T, Src0R,
SourceIsSigned ? InstARM32Vcvt::Vsi2s : InstARM32Vcvt::Vui2s);
_mov(Dest, T);
break;
}
const bool DestIsF32 = isFloat32Asserting32Or64(DestTy);
if (Src0->getType() == IceType_i64) {
llvm::report_fatal_error("i64-to-fp should have been pre-lowered.");
}
// sitofp:
// t1.i32 = sext src.int @ sign-extends src0 if needed.
// t2.fp32 = vmov t1.i32
// t3.fp = vcvt.{fp}.s32 @ fp is either f32 or f64
// uitofp:
// t1.i32 = zext src.int @ zero-extends src0 if needed.
// t2.fp32 = vmov t1.i32
// t3.fp = vcvt.{fp}.s32 @ fp is either f32 or f64
if (Src0->getType() != IceType_i32) {
Variable *Src0R_32 = makeReg(IceType_i32);
lowerCast(InstCast::create(Func, SourceIsSigned ? InstCast::Sext
: InstCast::Zext,
Src0R_32, Src0));
Src0 = Src0R_32;
}
Variable *Src0R = legalizeToReg(Src0);
Variable *Src0R_f32 = makeReg(IceType_f32);
_mov(Src0R_f32, Src0R);
Src0R = Src0R_f32;
Variable *T = makeReg(DestTy);
const InstARM32Vcvt::VcvtVariant Conversion =
DestIsF32
? (SourceIsSigned ? InstARM32Vcvt::Si2s : InstARM32Vcvt::Ui2s)
: (SourceIsSigned ? InstARM32Vcvt::Si2d : InstARM32Vcvt::Ui2d);
_vcvt(T, Src0R, Conversion);
_mov(Dest, T);
break;
}
case InstCast::Bitcast: {
Operand *Src0 = Instr->getSrc(0);
if (DestTy == Src0->getType()) {
auto *Assign = InstAssign::create(Func, Dest, Src0);
lowerAssign(Assign);
return;
}
switch (DestTy) {
case IceType_NUM:
case IceType_void:
llvm::report_fatal_error("Unexpected bitcast.");
case IceType_i1:
UnimplementedLoweringError(this, Instr);
break;
case IceType_i8:
assert(Src0->getType() == IceType_v8i1);
llvm::report_fatal_error(
"i8 to v8i1 conversion should have been prelowered.");
break;
case IceType_i16:
assert(Src0->getType() == IceType_v16i1);
llvm::report_fatal_error(
"i16 to v16i1 conversion should have been prelowered.");
break;
case IceType_i32:
case IceType_f32: {
Variable *Src0R = legalizeToReg(Src0);
Variable *T = makeReg(DestTy);
_mov(T, Src0R);
lowerAssign(InstAssign::create(Func, Dest, T));
break;
}
case IceType_i64: {
// t0, t1 <- src0
// dest[31..0] = t0
// dest[63..32] = t1
assert(Src0->getType() == IceType_f64);
auto *T = llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
T->initHiLo(Func);
configureBitcastTemporary(T);
Variable *Src0R = legalizeToReg(Src0);
_mov(T, Src0R);
Context.insert<InstFakeUse>(T->getHi());
Context.insert<InstFakeUse>(T->getLo());
lowerAssign(InstAssign::create(Func, Dest, T));
break;
}
case IceType_f64: {
// T0 <- lo(src)
// T1 <- hi(src)
// vmov T2, T0, T1
// Dest <- T2
assert(Src0->getType() == IceType_i64);
Variable *T = makeReg(DestTy);
auto *Src64 = llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
Src64->initHiLo(Func);
configureBitcastTemporary(Src64);
lowerAssign(InstAssign::create(Func, Src64, Src0));
_mov(T, Src64);
lowerAssign(InstAssign::create(Func, Dest, T));
break;
}
case IceType_v8i1:
assert(Src0->getType() == IceType_i8);
llvm::report_fatal_error(
"v8i1 to i8 conversion should have been prelowered.");
break;
case IceType_v16i1:
assert(Src0->getType() == IceType_i16);
llvm::report_fatal_error(
"v16i1 to i16 conversion should have been prelowered.");
break;
case IceType_v4i1:
case IceType_v8i16:
case IceType_v16i8:
case IceType_v4f32:
case IceType_v4i32: {
assert(typeWidthInBytes(DestTy) == typeWidthInBytes(Src0->getType()));
assert(isVectorType(DestTy) == isVectorType(Src0->getType()));
Variable *T = makeReg(DestTy);
_mov(T, Src0);
_mov(Dest, T);
break;
}
}
break;
}
}
}
void TargetARM32::lowerExtractElement(const InstExtractElement *Instr) {
Variable *Dest = Instr->getDest();
Type DestTy = Dest->getType();
Variable *Src0 = legalizeToReg(Instr->getSrc(0));
Operand *Src1 = Instr->getSrc(1);
if (const auto *Imm = llvm::dyn_cast<ConstantInteger32>(Src1)) {
const uint32_t Index = Imm->getValue();
Variable *T = makeReg(DestTy);
Variable *TSrc0 = makeReg(Src0->getType());
if (isFloatingType(DestTy)) {
// We need to make sure the source is in a suitable register.
TSrc0->setRegClass(RegARM32::RCARM32_QtoS);
}
_mov(TSrc0, Src0);
_extractelement(T, TSrc0, Index);
_mov(Dest, T);
return;
}
assert(false && "extractelement requires a constant index");
}
namespace {
// Validates FCMPARM32_TABLE's declaration w.r.t. InstFcmp::FCondition ordering
// (and naming).
enum {
#define X(val, CC0, CC1, CC0_V, CC1_V, INV_V, NEG_V) _fcmp_ll_##val,
FCMPARM32_TABLE
#undef X
_fcmp_ll_NUM
};
enum {
#define X(tag, str) _fcmp_hl_##tag = InstFcmp::tag,
ICEINSTFCMP_TABLE
#undef X
_fcmp_hl_NUM
};
static_assert((uint32_t)_fcmp_hl_NUM == (uint32_t)_fcmp_ll_NUM,
"Inconsistency between high-level and low-level fcmp tags.");
#define X(tag, str) \
static_assert( \
(uint32_t)_fcmp_hl_##tag == (uint32_t)_fcmp_ll_##tag, \
"Inconsistency between high-level and low-level fcmp tag " #tag);
ICEINSTFCMP_TABLE
#undef X
struct {
CondARM32::Cond CC0;
CondARM32::Cond CC1;
} TableFcmp[] = {
#define X(val, CC0, CC1, CC0_V, CC1_V, INV_V, NEG_V) \
{ CondARM32::CC0, CondARM32::CC1 } \
,
FCMPARM32_TABLE
#undef X
};
bool isFloatingPointZero(const Operand *Src) {
if (const auto *F32 = llvm::dyn_cast<const ConstantFloat>(Src)) {
return Utils::isPositiveZero(F32->getValue());
}
if (const auto *F64 = llvm::dyn_cast<const ConstantDouble>(Src)) {
return Utils::isPositiveZero(F64->getValue());
}
return false;
}
} // end of anonymous namespace
TargetARM32::CondWhenTrue TargetARM32::lowerFcmpCond(const InstFcmp *Instr) {
InstFcmp::FCond Condition = Instr->getCondition();
switch (Condition) {
case InstFcmp::False:
return CondWhenTrue(CondARM32::kNone);
case InstFcmp::True:
return CondWhenTrue(CondARM32::AL);
break;
default: {
Variable *Src0R = legalizeToReg(Instr->getSrc(0));
Operand *Src1 = Instr->getSrc(1);
if (isFloatingPointZero(Src1)) {
_vcmp(Src0R, OperandARM32FlexFpZero::create(Func, Src0R->getType()));
} else {
_vcmp(Src0R, legalizeToReg(Src1));
}
_vmrs();
assert(Condition < llvm::array_lengthof(TableFcmp));
return CondWhenTrue(TableFcmp[Condition].CC0, TableFcmp[Condition].CC1);
}
}
}
void TargetARM32::lowerFcmp(const InstFcmp *Instr) {
Variable *Dest = Instr->getDest();
const Type DestTy = Dest->getType();
if (isVectorType(DestTy)) {
if (Instr->getCondition() == InstFcmp::False) {
constexpr Type SafeTypeForMovingConstant = IceType_v4i32;
auto *T = makeReg(SafeTypeForMovingConstant);
_mov(T, llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(0)));
_mov(Dest, T);
return;
}
if (Instr->getCondition() == InstFcmp::True) {
constexpr Type SafeTypeForMovingConstant = IceType_v4i32;
auto *T = makeReg(SafeTypeForMovingConstant);
_mov(T, llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(1)));
_mov(Dest, T);
return;
}
Variable *T0;
Variable *T1;
bool Negate = false;
auto *Src0 = legalizeToReg(Instr->getSrc(0));
auto *Src1 = legalizeToReg(Instr->getSrc(1));
switch (Instr->getCondition()) {
default:
llvm::report_fatal_error("Unhandled fp comparison.");
#define _Vcnone(Tptr, S0, S1) \
do { \
*(Tptr) = nullptr; \
} while (0)
#define _Vceq(Tptr, S0, S1) \
do { \
*(Tptr) = makeReg(DestTy); \
_vceq(*(Tptr), S0, S1); \
} while (0)
#define _Vcge(Tptr, S0, S1) \
do { \
*(Tptr) = makeReg(DestTy); \
_vcge(*(Tptr), S0, S1)->setSignType(InstARM32::FS_Signed); \
} while (0)
#define _Vcgt(Tptr, S0, S1) \
do { \
*(Tptr) = makeReg(DestTy); \
_vcgt(*(Tptr), S0, S1)->setSignType(InstARM32::FS_Signed); \
} while (0)
#define X(val, CC0, CC1, CC0_V, CC1_V, INV_V, NEG_V) \
case InstFcmp::val: { \
_Vc##CC0_V(&T0, (INV_V) ? Src1 : Src0, (INV_V) ? Src0 : Src1); \
_Vc##CC1_V(&T1, (INV_V) ? Src0 : Src1, (INV_V) ? Src1 : Src0); \
Negate = NEG_V; \
} break;
FCMPARM32_TABLE
#undef X
#undef _Vcgt
#undef _Vcge
#undef _Vceq
#undef _Vcnone
}
assert(T0 != nullptr);
Variable *T = T0;
if (T1 != nullptr) {
T = makeReg(DestTy);
_vorr(T, T0, T1);
}
if (Negate) {
auto *TNeg = makeReg(DestTy);
_vmvn(TNeg, T);
T = TNeg;
}
_mov(Dest, T);
return;
}
Variable *T = makeReg(IceType_i1);
Operand *_1 = legalize(Ctx->getConstantInt32(1), Legal_Reg | Legal_Flex);
Operand *_0 =
legalize(Ctx->getConstantZero(IceType_i32), Legal_Reg | Legal_Flex);
CondWhenTrue Cond = lowerFcmpCond(Instr);
bool RedefineT = false;
if (Cond.WhenTrue0 != CondARM32::AL) {
_mov(T, _0);
RedefineT = true;
}
if (Cond.WhenTrue0 == CondARM32::kNone) {
_mov(Dest, T);
return;
}
if (RedefineT) {
_mov_redefined(T, _1, Cond.WhenTrue0);
} else {
_mov(T, _1, Cond.WhenTrue0);
}
if (Cond.WhenTrue1 != CondARM32::kNone) {
_mov_redefined(T, _1, Cond.WhenTrue1);
}
_mov(Dest, T);
}
TargetARM32::CondWhenTrue
TargetARM32::lowerInt64IcmpCond(InstIcmp::ICond Condition, Operand *Src0,
Operand *Src1) {
assert(Condition < llvm::array_lengthof(TableIcmp64));
Int32Operands SrcsLo(loOperand(Src0), loOperand(Src1));
Int32Operands SrcsHi(hiOperand(Src0), hiOperand(Src1));
assert(SrcsLo.hasConstOperand() == SrcsHi.hasConstOperand());
assert(SrcsLo.swappedOperands() == SrcsHi.swappedOperands());
if (SrcsLo.hasConstOperand()) {
const uint32_t ValueLo = SrcsLo.getConstantValue();
const uint32_t ValueHi = SrcsHi.getConstantValue();
const uint64_t Value = (static_cast<uint64_t>(ValueHi) << 32) | ValueLo;
if ((Condition == InstIcmp::Eq || Condition == InstIcmp::Ne) &&
Value == 0) {
Variable *T = makeReg(IceType_i32);
Variable *Src0LoR = SrcsLo.src0R(this);
Variable *Src0HiR = SrcsHi.src0R(this);
_orrs(T, Src0LoR, Src0HiR);
Context.insert<InstFakeUse>(T);
return CondWhenTrue(TableIcmp64[Condition].C1);
}
Variable *Src0RLo = SrcsLo.src0R(this);
Variable *Src0RHi = SrcsHi.src0R(this);
Operand *Src1RFLo = SrcsLo.src1RF(this);
Operand *Src1RFHi = ValueLo == ValueHi ? Src1RFLo : SrcsHi.src1RF(this);
const bool UseRsb =
TableIcmp64[Condition].Swapped != SrcsLo.swappedOperands();
if (UseRsb) {
if (TableIcmp64[Condition].IsSigned) {
Variable *T = makeReg(IceType_i32);
_rsbs(T, Src0RLo, Src1RFLo);
Context.insert<InstFakeUse>(T);
T = makeReg(IceType_i32);
_rscs(T, Src0RHi, Src1RFHi);
// We need to add a FakeUse here because liveness gets mad at us (Def
// without Use.) Note that flag-setting instructions are considered to
// have side effects and, therefore, are not DCE'ed.
Context.insert<InstFakeUse>(T);
} else {
Variable *T = makeReg(IceType_i32);
_rsbs(T, Src0RHi, Src1RFHi);
Context.insert<InstFakeUse>(T);
T = makeReg(IceType_i32);
_rsbs(T, Src0RLo, Src1RFLo, CondARM32::EQ);
Context.insert<InstFakeUse>(T);
}
} else {
if (TableIcmp64[Condition].IsSigned) {
_cmp(Src0RLo, Src1RFLo);
Variable *T = makeReg(IceType_i32);
_sbcs(T, Src0RHi, Src1RFHi);
Context.insert<InstFakeUse>(T);
} else {
_cmp(Src0RHi, Src1RFHi);
_cmp(Src0RLo, Src1RFLo, CondARM32::EQ);
}
}
return CondWhenTrue(TableIcmp64[Condition].C1);
}
Variable *Src0RLo, *Src0RHi;
Operand *Src1RFLo, *Src1RFHi;
if (TableIcmp64[Condition].Swapped) {
Src0RLo = legalizeToReg(loOperand(Src1));
Src0RHi = legalizeToReg(hiOperand(Src1));
Src1RFLo = legalizeToReg(loOperand(Src0));
Src1RFHi = legalizeToReg(hiOperand(Src0));
} else {
Src0RLo = legalizeToReg(loOperand(Src0));
Src0RHi = legalizeToReg(hiOperand(Src0));
Src1RFLo = legalizeToReg(loOperand(Src1));
Src1RFHi = legalizeToReg(hiOperand(Src1));
}
// a=icmp cond, b, c ==>
// GCC does:
// cmp b.hi, c.hi or cmp b.lo, c.lo
// cmp.eq b.lo, c.lo sbcs t1, b.hi, c.hi
// mov.<C1> t, #1 mov.<C1> t, #1
// mov.<C2> t, #0 mov.<C2> t, #0
// mov a, t mov a, t
// where the "cmp.eq b.lo, c.lo" is used for unsigned and "sbcs t1, hi, hi"
// is used for signed compares. In some cases, b and c need to be swapped as
// well.
//
// LLVM does:
// for EQ and NE:
// eor t1, b.hi, c.hi
// eor t2, b.lo, c.hi
// orrs t, t1, t2
// mov.<C> t, #1
// mov a, t
//
// that's nice in that it's just as short but has fewer dependencies for
// better ILP at the cost of more registers.
//
// Otherwise for signed/unsigned <, <=, etc. LLVM uses a sequence with two
// unconditional mov #0, two cmps, two conditional mov #1, and one
// conditional reg mov. That has few dependencies for good ILP, but is a
// longer sequence.
//
// So, we are going with the GCC version since it's usually better (except
// perhaps for eq/ne). We could revisit special-casing eq/ne later.
if (TableIcmp64[Condition].IsSigned) {
Variable *ScratchReg = makeReg(IceType_i32);
_cmp(Src0RLo, Src1RFLo);
_sbcs(ScratchReg, Src0RHi, Src1RFHi);
// ScratchReg isn't going to be used, but we need the side-effect of
// setting flags from this operation.
Context.insert<InstFakeUse>(ScratchReg);
} else {
_cmp(Src0RHi, Src1RFHi);
_cmp(Src0RLo, Src1RFLo, CondARM32::EQ);
}
return CondWhenTrue(TableIcmp64[Condition].C1);
}
TargetARM32::CondWhenTrue
TargetARM32::lowerInt32IcmpCond(InstIcmp::ICond Condition, Operand *Src0,
Operand *Src1) {
Int32Operands Srcs(Src0, Src1);
if (!Srcs.hasConstOperand()) {
Variable *Src0R = Srcs.src0R(this);
Operand *Src1RF = Srcs.src1RF(this);
_cmp(Src0R, Src1RF);
return CondWhenTrue(getIcmp32Mapping(Condition));
}
Variable *Src0R = Srcs.src0R(this);
const int32_t Value = Srcs.getConstantValue();
if ((Condition == InstIcmp::Eq || Condition == InstIcmp::Ne) && Value == 0) {
_tst(Src0R, Src0R);
return CondWhenTrue(getIcmp32Mapping(Condition));
}
if (!Srcs.swappedOperands() && !Srcs.immediateIsFlexEncodable() &&
Srcs.negatedImmediateIsFlexEncodable()) {
Operand *Src1F = Srcs.negatedSrc1F(this);
_cmn(Src0R, Src1F);
return CondWhenTrue(getIcmp32Mapping(Condition));
}
Operand *Src1RF = Srcs.src1RF(this);
if (!Srcs.swappedOperands()) {
_cmp(Src0R, Src1RF);
} else {
Variable *T = makeReg(IceType_i32);
_rsbs(T, Src0R, Src1RF);
Context.insert<InstFakeUse>(T);
}
return CondWhenTrue(getIcmp32Mapping(Condition));
}
TargetARM32::CondWhenTrue
TargetARM32::lowerInt8AndInt16IcmpCond(InstIcmp::ICond Condition, Operand *Src0,
Operand *Src1) {
Int32Operands Srcs(Src0, Src1);
const int32_t ShAmt = 32 - getScalarIntBitWidth(Src0->getType());
assert(ShAmt >= 0);
if (!Srcs.hasConstOperand()) {
Variable *Src0R = makeReg(IceType_i32);
Operand *ShAmtImm = shAmtImm(ShAmt);
_lsl(Src0R, legalizeToReg(Src0), ShAmtImm);
Variable *Src1R = legalizeToReg(Src1);
auto *Src1F = OperandARM32FlexReg::create(Func, IceType_i32, Src1R,
OperandARM32::LSL, ShAmtImm);
_cmp(Src0R, Src1F);
return CondWhenTrue(getIcmp32Mapping(Condition));
}
const int32_t Value = Srcs.getConstantValue();
if ((Condition == InstIcmp::Eq || Condition == InstIcmp::Ne) && Value == 0) {
Operand *ShAmtImm = shAmtImm(ShAmt);
Variable *T = makeReg(IceType_i32);
_lsls(T, Srcs.src0R(this), ShAmtImm);
Context.insert<InstFakeUse>(T);
return CondWhenTrue(getIcmp32Mapping(Condition));
}
Variable *ConstR = makeReg(IceType_i32);
_mov(ConstR,
legalize(Ctx->getConstantInt32(Value << ShAmt), Legal_Reg | Legal_Flex));
Operand *NonConstF = OperandARM32FlexReg::create(
Func, IceType_i32, Srcs.src0R(this), OperandARM32::LSL,
Ctx->getConstantInt32(ShAmt));
if (Srcs.swappedOperands()) {
_cmp(ConstR, NonConstF);
} else {
Variable *T = makeReg(IceType_i32);
_rsbs(T, ConstR, NonConstF);
Context.insert<InstFakeUse>(T);
}
return CondWhenTrue(getIcmp32Mapping(Condition));
}
TargetARM32::CondWhenTrue TargetARM32::lowerIcmpCond(const InstIcmp *Instr) {
return lowerIcmpCond(Instr->getCondition(), Instr->getSrc(0),
Instr->getSrc(1));
}
TargetARM32::CondWhenTrue TargetARM32::lowerIcmpCond(InstIcmp::ICond Condition,
Operand *Src0,
Operand *Src1) {
Src0 = legalizeUndef(Src0);
Src1 = legalizeUndef(Src1);
// a=icmp cond b, c ==>
// GCC does:
// <u/s>xtb tb, b
// <u/s>xtb tc, c
// cmp tb, tc
// mov.C1 t, #0
// mov.C2 t, #1
// mov a, t
// where the unsigned/sign extension is not needed for 32-bit. They also have
// special cases for EQ and NE. E.g., for NE:
// <extend to tb, tc>
// subs t, tb, tc
// movne t, #1
// mov a, t
//
// LLVM does:
// lsl tb, b, #<N>
// mov t, #0
// cmp tb, c, lsl #<N>
// mov.<C> t, #1
// mov a, t
//
// the left shift is by 0, 16, or 24, which allows the comparison to focus on
// the digits that actually matter (for 16-bit or 8-bit signed/unsigned). For
// the unsigned case, for some reason it does similar to GCC and does a uxtb
// first. It's not clear to me why that special-casing is needed.
//
// We'll go with the LLVM way for now, since it's shorter and has just as few
// dependencies.
switch (Src0->getType()) {
default:
llvm::report_fatal_error("Unhandled type in lowerIcmpCond");
case IceType_i1:
case IceType_i8:
case IceType_i16:
return lowerInt8AndInt16IcmpCond(Condition, Src0, Src1);
case IceType_i32:
return lowerInt32IcmpCond(Condition, Src0, Src1);
case IceType_i64:
return lowerInt64IcmpCond(Condition, Src0, Src1);
}
}
void TargetARM32::lowerIcmp(const InstIcmp *Instr) {
Variable *Dest = Instr->getDest();
const Type DestTy = Dest->getType();
if (isVectorType(DestTy)) {
auto *T = makeReg(DestTy);
auto *Src0 = legalizeToReg(Instr->getSrc(0));
auto *Src1 = legalizeToReg(Instr->getSrc(1));
const Type SrcTy = Src0->getType();
bool NeedsShl = false;
Type NewTypeAfterShl;
SizeT ShAmt;
switch (SrcTy) {
default:
break;
case IceType_v16i1:
NeedsShl = true;
NewTypeAfterShl = IceType_v16i8;
ShAmt = 7;
break;
case IceType_v8i1:
NeedsShl = true;
NewTypeAfterShl = IceType_v8i16;
ShAmt = 15;
break;
case IceType_v4i1:
NeedsShl = true;
NewTypeAfterShl = IceType_v4i32;
ShAmt = 31;
break;
}
if (NeedsShl) {
auto *Imm = llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(ShAmt));
auto *Src0T = makeReg(NewTypeAfterShl);
auto *Src0Shl = makeReg(NewTypeAfterShl);
_mov(Src0T, Src0);
_vshl(Src0Shl, Src0T, Imm);
Src0 = Src0Shl;
auto *Src1T = makeReg(NewTypeAfterShl);
auto *Src1Shl = makeReg(NewTypeAfterShl);
_mov(Src1T, Src1);
_vshl(Src1Shl, Src1T, Imm);
Src1 = Src1Shl;
}
switch (Instr->getCondition()) {
default:
llvm::report_fatal_error("Unhandled integer comparison.");
#define _Vceq(T, S0, S1, Signed) _vceq(T, S0, S1)
#define _Vcge(T, S0, S1, Signed) \
_vcge(T, S0, S1) \
->setSignType(Signed ? InstARM32::FS_Signed : InstARM32::FS_Unsigned)
#define _Vcgt(T, S0, S1, Signed) \
_vcgt(T, S0, S1) \
->setSignType(Signed ? InstARM32::FS_Signed : InstARM32::FS_Unsigned)
#define X(val, is_signed, swapped64, C_32, C1_64, C2_64, C_V, INV_V, NEG_V) \
case InstIcmp::val: { \
_Vc##C_V(T, (INV_V) ? Src1 : Src0, (INV_V) ? Src0 : Src1, is_signed); \
if (NEG_V) { \
auto *TInv = makeReg(DestTy); \
_vmvn(TInv, T); \
T = TInv; \
} \
} break;
ICMPARM32_TABLE
#undef X
#undef _Vcgt
#undef _Vcge
#undef _Vceq
}
_mov(Dest, T);
return;
}
Operand *_0 =
legalize(Ctx->getConstantZero(IceType_i32), Legal_Reg | Legal_Flex);
Operand *_1 = legalize(Ctx->getConstantInt32(1), Legal_Reg | Legal_Flex);
Variable *T = makeReg(IceType_i1);
_mov(T, _0);
CondWhenTrue Cond = lowerIcmpCond(Instr);
_mov_redefined(T, _1, Cond.WhenTrue0);
_mov(Dest, T);
assert(Cond.WhenTrue1 == CondARM32::kNone);
return;
}
void TargetARM32::lowerInsertElement(const InstInsertElement *Instr) {
Variable *Dest = Instr->getDest();
Type DestTy = Dest->getType();
Variable *Src0 = legalizeToReg(Instr->getSrc(0));
Variable *Src1 = legalizeToReg(Instr->getSrc(1));
Operand *Src2 = Instr->getSrc(2);
if (const auto *Imm = llvm::dyn_cast<ConstantInteger32>(Src2)) {
const uint32_t Index = Imm->getValue();
Variable *T = makeReg(DestTy);
if (isFloatingType(DestTy)) {
T->setRegClass(RegARM32::RCARM32_QtoS);
}
_mov(T, Src0);
_insertelement(T, Src1, Index);
_set_dest_redefined();
_mov(Dest, T);
return;
}
assert(false && "insertelement requires a constant index");
}
namespace {
inline uint64_t getConstantMemoryOrder(Operand *Opnd) {
if (auto *Integer = llvm::dyn_cast<ConstantInteger32>(Opnd))
return Integer->getValue();
return Intrinsics::MemoryOrderInvalid;
}
} // end of anonymous namespace
void TargetARM32::lowerLoadLinkedStoreExclusive(
Type Ty, Operand *Addr, std::function<Variable *(Variable *)> Operation,
CondARM32::Cond Cond) {
auto *Retry = Context.insert<InstARM32Label>(this);
{ // scoping for loop highlighting.
Variable *Success = makeReg(IceType_i32);
Variable *Tmp = (Ty == IceType_i64) ? makeI64RegPair() : makeReg(Ty);
auto *_0 = Ctx->getConstantZero(IceType_i32);
Context.insert<InstFakeDef>(Tmp);
Context.insert<InstFakeUse>(Tmp);
Variable *AddrR = legalizeToReg(Addr);
_ldrex(Tmp, formMemoryOperand(AddrR, Ty))->setDestRedefined();
auto *StoreValue = Operation(Tmp);
assert(StoreValue->mustHaveReg());
// strex requires Dest to be a register other than Value or Addr. This
// restriction is cleanly represented by adding an "early" definition of
// Dest (or a latter use of all the sources.)
Context.insert<InstFakeDef>(Success);
if (Cond != CondARM32::AL) {
_mov_redefined(Success, legalize(_0, Legal_Reg | Legal_Flex),
InstARM32::getOppositeCondition(Cond));
}
_strex(Success, StoreValue, formMemoryOperand(AddrR, Ty), Cond)
->setDestRedefined();
_cmp(Success, _0);
}
_br(Retry, CondARM32::NE);
}
namespace {
InstArithmetic *createArithInst(Cfg *Func, uint32_t Operation, Variable *Dest,
Variable *Src0, Operand *Src1) {
InstArithmetic::OpKind Oper;
switch (Operation) {
default:
llvm::report_fatal_error("Unknown AtomicRMW operation");
case Intrinsics::AtomicExchange:
llvm::report_fatal_error("Can't handle Atomic xchg operation");
case Intrinsics::AtomicAdd:
Oper = InstArithmetic::Add;
break;
case Intrinsics::AtomicAnd:
Oper = InstArithmetic::And;
break;
case Intrinsics::AtomicSub:
Oper = InstArithmetic::Sub;
break;
case Intrinsics::AtomicOr:
Oper = InstArithmetic::Or;
break;
case Intrinsics::AtomicXor:
Oper = InstArithmetic::Xor;
break;
}
return InstArithmetic::create(Func, Oper, Dest, Src0, Src1);
}
} // end of anonymous namespace
void TargetARM32::lowerAtomicRMW(Variable *Dest, uint32_t Operation,
Operand *Addr, Operand *Val) {
// retry:
// ldrex tmp, [addr]
// mov contents, tmp
// op result, contents, Val
// strex success, result, [addr]
// cmp success, 0
// jne retry
// fake-use(addr, operand) @ prevents undesirable clobbering.
// mov dest, contents
auto DestTy = Dest->getType();
if (DestTy == IceType_i64) {
lowerInt64AtomicRMW(Dest, Operation, Addr, Val);
return;
}
Operand *ValRF = nullptr;
if (llvm::isa<ConstantInteger32>(Val)) {
ValRF = Val;
} else {
ValRF = legalizeToReg(Val);
}
auto *ContentsR = makeReg(DestTy);
auto *ResultR = makeReg(DestTy);
_dmb();
lowerLoadLinkedStoreExclusive(
DestTy, Addr,
[this, Operation, ResultR, ContentsR, ValRF](Variable *Tmp) {
lowerAssign(InstAssign::create(Func, ContentsR, Tmp));
if (Operation == Intrinsics::AtomicExchange) {
lowerAssign(InstAssign::create(Func, ResultR, ValRF));
} else {
lowerArithmetic(
createArithInst(Func, Operation, ResultR, ContentsR, ValRF));
}
return ResultR;
});
_dmb();
if (auto *ValR = llvm::dyn_cast<Variable>(ValRF)) {
Context.insert<InstFakeUse>(ValR);
}
// Can't dce ContentsR.
Context.insert<InstFakeUse>(ContentsR);
lowerAssign(InstAssign::create(Func, Dest, ContentsR));
}
void TargetARM32::lowerInt64AtomicRMW(Variable *Dest, uint32_t Operation,
Operand *Addr, Operand *Val) {
assert(Dest->getType() == IceType_i64);
auto *ResultR = makeI64RegPair();
Context.insert<InstFakeDef>(ResultR);
Operand *ValRF = nullptr;
if (llvm::dyn_cast<ConstantInteger64>(Val)) {
ValRF = Val;
} else {
auto *ValR64 = llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
ValR64->initHiLo(Func);
ValR64->setMustNotHaveReg();
ValR64->getLo()->setMustHaveReg();
ValR64->getHi()->setMustHaveReg();
lowerAssign(InstAssign::create(Func, ValR64, Val));
ValRF = ValR64;
}
auto *ContentsR = llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
ContentsR->initHiLo(Func);
ContentsR->setMustNotHaveReg();
ContentsR->getLo()->setMustHaveReg();
ContentsR->getHi()->setMustHaveReg();
_dmb();
lowerLoadLinkedStoreExclusive(
IceType_i64, Addr,
[this, Operation, ResultR, ContentsR, ValRF](Variable *Tmp) {
lowerAssign(InstAssign::create(Func, ContentsR, Tmp));
Context.insert<InstFakeUse>(Tmp);
if (Operation == Intrinsics::AtomicExchange) {
lowerAssign(InstAssign::create(Func, ResultR, ValRF));
} else {
lowerArithmetic(
createArithInst(Func, Operation, ResultR, ContentsR, ValRF));
}
Context.insert<InstFakeUse>(ResultR->getHi());
Context.insert<InstFakeDef>(ResultR, ResultR->getLo())
->setDestRedefined();
return ResultR;
});
_dmb();
if (auto *ValR64 = llvm::dyn_cast<Variable64On32>(ValRF)) {
Context.insert<InstFakeUse>(ValR64->getLo());
Context.insert<InstFakeUse>(ValR64->getHi());
}
lowerAssign(InstAssign::create(Func, Dest, ContentsR));
}
void TargetARM32::postambleCtpop64(const InstCall *Instr) {
Operand *Arg0 = Instr->getArg(0);
if (isInt32Asserting32Or64(Arg0->getType())) {
return;
}
// The popcount helpers always return 32-bit values, while the intrinsic's
// signature matches some 64-bit platform's native instructions and expect to
// fill a 64-bit reg. Thus, clear the upper bits of the dest just in case the
// user doesn't do that in the IR or doesn't toss the bits via truncate.
auto *DestHi = llvm::cast<Variable>(hiOperand(Instr->getDest()));
Variable *T = makeReg(IceType_i32);
Operand *_0 =
legalize(Ctx->getConstantZero(IceType_i32), Legal_Reg | Legal_Flex);
_mov(T, _0);
_mov(DestHi, T);
}
void TargetARM32::lowerIntrinsicCall(const InstIntrinsicCall *Instr) {
Variable *Dest = Instr->getDest();
Type DestTy = (Dest != nullptr) ? Dest->getType() : IceType_void;
Intrinsics::IntrinsicID ID = Instr->getIntrinsicInfo().ID;
switch (ID) {
case Intrinsics::AtomicFence:
case Intrinsics::AtomicFenceAll:
assert(Dest == nullptr);
_dmb();
return;
case Intrinsics::AtomicIsLockFree: {
Operand *ByteSize = Instr->getArg(0);
auto *CI = llvm::dyn_cast<ConstantInteger32>(ByteSize);
if (CI == nullptr) {
// The PNaCl ABI requires the byte size to be a compile-time constant.
Func->setError("AtomicIsLockFree byte size should be compile-time const");
return;
}
static constexpr int32_t NotLockFree = 0;
static constexpr int32_t LockFree = 1;
int32_t Result = NotLockFree;
switch (CI->getValue()) {
case 1:
case 2:
case 4:
case 8:
Result = LockFree;
break;
}
_mov(Dest, legalizeToReg(Ctx->getConstantInt32(Result)));
return;
}
case Intrinsics::AtomicLoad: {
assert(isScalarIntegerType(DestTy));
// We require the memory address to be naturally aligned. Given that is the
// case, then normal loads are atomic.
if (!Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Instr->getArg(1)))) {
Func->setError("Unexpected memory ordering for AtomicLoad");
return;
}
Variable *T;
if (DestTy == IceType_i64) {
// ldrex is the only arm instruction that is guaranteed to load a 64-bit
// integer atomically. Everything else works with a regular ldr.
T = makeI64RegPair();
_ldrex(T, formMemoryOperand(Instr->getArg(0), IceType_i64));
} else {
T = makeReg(DestTy);
_ldr(T, formMemoryOperand(Instr->getArg(0), DestTy));
}
_dmb();
lowerAssign(InstAssign::create(Func, Dest, T));
// Adding a fake-use T to ensure the atomic load is not removed if Dest is
// unused.
Context.insert<InstFakeUse>(T);
return;
}
case Intrinsics::AtomicStore: {
// We require the memory address to be naturally aligned. Given that is the
// case, then normal loads are atomic.
if (!Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Instr->getArg(2)))) {
Func->setError("Unexpected memory ordering for AtomicStore");
return;
}
auto *Value = Instr->getArg(0);
if (Value->getType() == IceType_i64) {
auto *ValueR = makeI64RegPair();
Context.insert<InstFakeDef>(ValueR);
lowerAssign(InstAssign::create(Func, ValueR, Value));
_dmb();
lowerLoadLinkedStoreExclusive(
IceType_i64, Instr->getArg(1), [this, ValueR](Variable *Tmp) {
// The following fake-use prevents the ldrex instruction from being
// dead code eliminated.
Context.insert<InstFakeUse>(llvm::cast<Variable>(loOperand(Tmp)));
Context.insert<InstFakeUse>(llvm::cast<Variable>(hiOperand(Tmp)));
Context.insert<InstFakeUse>(Tmp);
return ValueR;
});
Context.insert<InstFakeUse>(ValueR);
_dmb();
return;
}
auto *ValueR = legalizeToReg(Instr->getArg(0));
const auto ValueTy = ValueR->getType();
assert(isScalarIntegerType(ValueTy));
auto *Addr = legalizeToReg(Instr->getArg(1));
// non-64-bit stores are atomically as long as the address is aligned. This
// is PNaCl, so addresses are aligned.
_dmb();
_str(ValueR, formMemoryOperand(Addr, ValueTy));
_dmb();
return;
}
case Intrinsics::AtomicCmpxchg: {
// retry:
// ldrex tmp, [addr]
// cmp tmp, expected
// mov expected, tmp
// strexeq success, new, [addr]
// cmpeq success, #0
// bne retry
// mov dest, expected
assert(isScalarIntegerType(DestTy));
// We require the memory address to be naturally aligned. Given that is the
// case, then normal loads are atomic.
if (!Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Instr->getArg(3)),
getConstantMemoryOrder(Instr->getArg(4)))) {
Func->setError("Unexpected memory ordering for AtomicCmpxchg");
return;
}
if (DestTy == IceType_i64) {
Variable *LoadedValue = nullptr;
auto *New = makeI64RegPair();
Context.insert<InstFakeDef>(New);
lowerAssign(InstAssign::create(Func, New, Instr->getArg(2)));
auto *Expected = makeI64RegPair();
Context.insert<InstFakeDef>(Expected);
lowerAssign(InstAssign::create(Func, Expected, Instr->getArg(1)));
_dmb();
lowerLoadLinkedStoreExclusive(
DestTy, Instr->getArg(0),
[this, Expected, New, Instr, DestTy, &LoadedValue](Variable *Tmp) {
auto *ExpectedLoR = llvm::cast<Variable>(loOperand(Expected));
auto *ExpectedHiR = llvm::cast<Variable>(hiOperand(Expected));
auto *TmpLoR = llvm::cast<Variable>(loOperand(Tmp));
auto *TmpHiR = llvm::cast<Variable>(hiOperand(Tmp));
_cmp(TmpLoR, ExpectedLoR);
_cmp(TmpHiR, ExpectedHiR, CondARM32::EQ);
LoadedValue = Tmp;
return New;
},
CondARM32::EQ);
_dmb();
Context.insert<InstFakeUse>(LoadedValue);
lowerAssign(InstAssign::create(Func, Dest, LoadedValue));
// The fake-use Expected prevents the assignments to Expected (above)
// from being removed if Dest is not used.
Context.insert<InstFakeUse>(Expected);
// New needs to be alive here, or its live range will end in the
// strex instruction.
Context.insert<InstFakeUse>(New);
return;
}
auto *New = legalizeToReg(Instr->getArg(2));
auto *Expected = legalizeToReg(Instr->getArg(1));
Variable *LoadedValue = nullptr;
_dmb();
lowerLoadLinkedStoreExclusive(
DestTy, Instr->getArg(0),
[this, Expected, New, Instr, DestTy, &LoadedValue](Variable *Tmp) {
lowerIcmpCond(InstIcmp::Eq, Tmp, Expected);
LoadedValue = Tmp;
return New;
},
CondARM32::EQ);
_dmb();
lowerAssign(InstAssign::create(Func, Dest, LoadedValue));
Context.insert<InstFakeUse>(Expected);
Context.insert<InstFakeUse>(New);
return;
}
case Intrinsics::AtomicRMW: {
if (!Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Instr->getArg(3)))) {
Func->setError("Unexpected memory ordering for AtomicRMW");
return;
}
lowerAtomicRMW(
Dest, static_cast<uint32_t>(
llvm::cast<ConstantInteger32>(Instr->getArg(0))->getValue()),
Instr->getArg(1), Instr->getArg(2));
return;
}
case Intrinsics::Bswap: {
Operand *Val = Instr->getArg(0);
Type Ty = Val->getType();
if (Ty == IceType_i64) {
Val = legalizeUndef(Val);
Variable *Val_Lo = legalizeToReg(loOperand(Val));
Variable *Val_Hi = legalizeToReg(hiOperand(Val));
Variable *T_Lo = makeReg(IceType_i32);
Variable *T_Hi = makeReg(IceType_i32);
auto *DestLo = llvm::cast<Variable>(loOperand(Dest));
auto *DestHi = llvm::cast<Variable>(hiOperand(Dest));
_rev(T_Lo, Val_Lo);
_rev(T_Hi, Val_Hi);
_mov(DestLo, T_Hi);
_mov(DestHi, T_Lo);
} else {
assert(Ty == IceType_i32 || Ty == IceType_i16);
Variable *ValR = legalizeToReg(Val);
Variable *T = makeReg(Ty);
_rev(T, ValR);
if (Val->getType() == IceType_i16) {
Operand *_16 = shAmtImm(16);
_lsr(T, T, _16);
}
_mov(Dest, T);
}
return;
}
case Intrinsics::Ctpop: {
llvm::report_fatal_error("Ctpop should have been prelowered.");
}
case Intrinsics::Ctlz: {
// The "is zero undef" parameter is ignored and we always return a
// well-defined value.
Operand *Val = Instr->getArg(0);
Variable *ValLoR;
Variable *ValHiR = nullptr;
if (Val->getType() == IceType_i64) {
Val = legalizeUndef(Val);
ValLoR = legalizeToReg(loOperand(Val));
ValHiR = legalizeToReg(hiOperand(Val));
} else {
ValLoR = legalizeToReg(Val);
}
lowerCLZ(Dest, ValLoR, ValHiR);
return;
}
case Intrinsics::Cttz: {
// Essentially like Clz, but reverse the bits first.
Operand *Val = Instr->getArg(0);
Variable *ValLoR;
Variable *ValHiR = nullptr;
if (Val->getType() == IceType_i64) {
Val = legalizeUndef(Val);
ValLoR = legalizeToReg(loOperand(Val));
ValHiR = legalizeToReg(hiOperand(Val));
Variable *TLo = makeReg(IceType_i32);
Variable *THi = makeReg(IceType_i32);
_rbit(TLo, ValLoR);
_rbit(THi, ValHiR);
ValLoR = THi;
ValHiR = TLo;
} else {
ValLoR = legalizeToReg(Val);
Variable *T = makeReg(IceType_i32);
_rbit(T, ValLoR);
ValLoR = T;
}
lowerCLZ(Dest, ValLoR, ValHiR);
return;
}
case Intrinsics::Fabs: {
Type DestTy = Dest->getType();
Variable *T = makeReg(DestTy);
_vabs(T, legalizeToReg(Instr->getArg(0)));
_mov(Dest, T);
return;
}
case Intrinsics::Longjmp: {
llvm::report_fatal_error("longjmp should have been prelowered.");
}
case Intrinsics::Memcpy: {
llvm::report_fatal_error("memcpy should have been prelowered.");
}
case Intrinsics::Memmove: {
llvm::report_fatal_error("memmove should have been prelowered.");
}
case Intrinsics::Memset: {
llvm::report_fatal_error("memmove should have been prelowered.");
}
case Intrinsics::NaClReadTP: {
if (SandboxingType != ST_NaCl) {
llvm::report_fatal_error("nacl-read-tp should have been prelowered.");
}
Variable *TP = legalizeToReg(OperandARM32Mem::create(
Func, getPointerType(), getPhysicalRegister(RegARM32::Reg_r9),
llvm::cast<ConstantInteger32>(Ctx->getConstantZero(IceType_i32))));
_mov(Dest, TP);
return;
}
case Intrinsics::Setjmp: {
llvm::report_fatal_error("setjmp should have been prelowered.");
}
case Intrinsics::Sqrt: {
Variable *Src = legalizeToReg(Instr->getArg(0));
Variable *T = makeReg(Dest->getType());
_vsqrt(T, Src);
_mov(Dest, T);
return;
}
case Intrinsics::Stacksave: {
Variable *SP = getPhysicalRegister(RegARM32::Reg_sp);
_mov(Dest, SP);
return;
}
case Intrinsics::Stackrestore: {
Variable *Val = legalizeToReg(Instr->getArg(0));
Sandboxer(this).reset_sp(Val);
return;
}
case Intrinsics::Trap:
_trap();
return;
case Intrinsics::LoadSubVector: {
UnimplementedLoweringError(this, Instr);
return;
}
case Intrinsics::StoreSubVector: {
UnimplementedLoweringError(this, Instr);
return;
}
default: // UnknownIntrinsic
Func->setError("Unexpected intrinsic");
return;
}
return;
}
void TargetARM32::lowerCLZ(Variable *Dest, Variable *ValLoR, Variable *ValHiR) {
Type Ty = Dest->getType();
assert(Ty == IceType_i32 || Ty == IceType_i64);
Variable *T = makeReg(IceType_i32);
_clz(T, ValLoR);
if (Ty == IceType_i64) {
auto *DestLo = llvm::cast<Variable>(loOperand(Dest));
auto *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Operand *Zero =
legalize(Ctx->getConstantZero(IceType_i32), Legal_Reg | Legal_Flex);
Operand *ThirtyTwo =
legalize(Ctx->getConstantInt32(32), Legal_Reg | Legal_Flex);
_cmp(ValHiR, Zero);
Variable *T2 = makeReg(IceType_i32);
_add(T2, T, ThirtyTwo);
_clz(T2, ValHiR, CondARM32::NE);
// T2 is actually a source as well when the predicate is not AL (since it
// may leave T2 alone). We use _set_dest_redefined to prolong the liveness
// of T2 as if it was used as a source.
_set_dest_redefined();
_mov(DestLo, T2);
Variable *T3 = makeReg(Zero->getType());
_mov(T3, Zero);
_mov(DestHi, T3);
return;
}
_mov(Dest, T);
return;
}
void TargetARM32::lowerLoad(const InstLoad *Load) {
// A Load instruction can be treated the same as an Assign instruction, after
// the source operand is transformed into an OperandARM32Mem operand.
Type Ty = Load->getDest()->getType();
Operand *Src0 = formMemoryOperand(Load->getSourceAddress(), Ty);
Variable *DestLoad = Load->getDest();
// TODO(jvoung): handled folding opportunities. Sign and zero extension can
// be folded into a load.
auto *Assign = InstAssign::create(Func, DestLoad, Src0);
lowerAssign(Assign);
}
namespace {
void dumpAddressOpt(const Cfg *Func, const Variable *Base, int32_t Offset,
const Variable *OffsetReg, int16_t OffsetRegShAmt,
const Inst *Reason) {
if (!BuildDefs::dump())
return;
if (!Func->isVerbose(IceV_AddrOpt))
return;
OstreamLocker _(Func->getContext());
Ostream &Str = Func->getContext()->getStrDump();
Str << "Instruction: ";
Reason->dumpDecorated(Func);
Str << " results in Base=";
if (Base)
Base->dump(Func);
else
Str << "<null>";
Str << ", OffsetReg=";
if (OffsetReg)
OffsetReg->dump(Func);
else
Str << "<null>";
Str << ", Shift=" << OffsetRegShAmt << ", Offset=" << Offset << "\n";
}
bool matchAssign(const VariablesMetadata *VMetadata, Variable **Var,
int32_t *Offset, const Inst **Reason) {
// Var originates from Var=SrcVar ==> set Var:=SrcVar
if (*Var == nullptr)
return false;
const Inst *VarAssign = VMetadata->getSingleDefinition(*Var);
if (!VarAssign)
return false;
assert(!VMetadata->isMultiDef(*Var));
if (!llvm::isa<InstAssign>(VarAssign))
return false;
Operand *SrcOp = VarAssign->getSrc(0);
bool Optimized = false;
if (auto *SrcVar = llvm::dyn_cast<Variable>(SrcOp)) {
if (!VMetadata->isMultiDef(SrcVar) ||
// TODO: ensure SrcVar stays single-BB
false) {
Optimized = true;
*Var = SrcVar;
} else if (auto *Const = llvm::dyn_cast<ConstantInteger32>(SrcOp)) {
int32_t MoreOffset = Const->getValue();
int32_t NewOffset = MoreOffset + *Offset;
if (Utils::WouldOverflowAdd(*Offset, MoreOffset))
return false;
*Var = nullptr;
*Offset += NewOffset;
Optimized = true;
}
}
if (Optimized) {
*Reason = VarAssign;
}
return Optimized;
}
bool isAddOrSub(const Inst *Instr, InstArithmetic::OpKind *Kind) {
if (const auto *Arith = llvm::dyn_cast<InstArithmetic>(Instr)) {
switch (Arith->getOp()) {
default:
return false;
case InstArithmetic::Add:
case InstArithmetic::Sub:
*Kind = Arith->getOp();
return true;
}
}
return false;
}
bool matchCombinedBaseIndex(const VariablesMetadata *VMetadata, Variable **Base,
Variable **OffsetReg, int32_t OffsetRegShamt,
const Inst **Reason) {
// OffsetReg==nullptr && Base is Base=Var1+Var2 ==>
// set Base=Var1, OffsetReg=Var2, Shift=0
if (*Base == nullptr)
return false;
if (*OffsetReg != nullptr)
return false;
(void)OffsetRegShamt;
assert(OffsetRegShamt == 0);
const Inst *BaseInst = VMetadata->getSingleDefinition(*Base);
if (BaseInst == nullptr)
return false;
assert(!VMetadata->isMultiDef(*Base));
if (BaseInst->getSrcSize() < 2)
return false;
auto *Var1 = llvm::dyn_cast<Variable>(BaseInst->getSrc(0));
if (!Var1)
return false;
if (VMetadata->isMultiDef(Var1))
return false;
auto *Var2 = llvm::dyn_cast<Variable>(BaseInst->getSrc(1));
if (!Var2)
return false;
if (VMetadata->isMultiDef(Var2))
return false;
InstArithmetic::OpKind _;
if (!isAddOrSub(BaseInst, &_) ||
// TODO: ensure Var1 and Var2 stay single-BB
false)
return false;
*Base = Var1;
*OffsetReg = Var2;
// OffsetRegShamt is already 0.
*Reason = BaseInst;
return true;
}
bool matchShiftedOffsetReg(const VariablesMetadata *VMetadata,
Variable **OffsetReg, OperandARM32::ShiftKind *Kind,
int32_t *OffsetRegShamt, const Inst **Reason) {
// OffsetReg is OffsetReg=Var*Const && log2(Const)+Shift<=32 ==>
// OffsetReg=Var, Shift+=log2(Const)
// OffsetReg is OffsetReg=Var<<Const && Const+Shift<=32 ==>
// OffsetReg=Var, Shift+=Const
// OffsetReg is OffsetReg=Var>>Const && Const-Shift>=-32 ==>
// OffsetReg=Var, Shift-=Const
OperandARM32::ShiftKind NewShiftKind = OperandARM32::kNoShift;
if (*OffsetReg == nullptr)
return false;
auto *IndexInst = VMetadata->getSingleDefinition(*OffsetReg);
if (IndexInst == nullptr)
return false;
assert(!VMetadata->isMultiDef(*OffsetReg));
if (IndexInst->getSrcSize() < 2)
return false;
auto *ArithInst = llvm::dyn_cast<InstArithmetic>(IndexInst);
if (ArithInst == nullptr)
return false;
auto *Var = llvm::dyn_cast<Variable>(ArithInst->getSrc(0));
if (Var == nullptr)
return false;
auto *Const = llvm::dyn_cast<ConstantInteger32>(ArithInst->getSrc(1));
if (Const == nullptr) {
assert(!llvm::isa<ConstantInteger32>(ArithInst->getSrc(0)));
return false;
}
if (VMetadata->isMultiDef(Var) || Const->getType() != IceType_i32)
return false;
uint32_t NewShamt = -1;
switch (ArithInst->getOp()) {
default:
return false;
case InstArithmetic::Shl: {
NewShiftKind = OperandARM32::LSL;
NewShamt = Const->getValue();
if (NewShamt > 31)
return false;
} break;
case InstArithmetic::Lshr: {
NewShiftKind = OperandARM32::LSR;
NewShamt = Const->getValue();
if (NewShamt > 31)
return false;
} break;
case InstArithmetic::Ashr: {
NewShiftKind = OperandARM32::ASR;
NewShamt = Const->getValue();
if (NewShamt > 31)
return false;
} break;
case InstArithmetic::Udiv:
case InstArithmetic::Mul: {
const uint32_t UnsignedConst = Const->getValue();
NewShamt = llvm::findFirstSet(UnsignedConst);
if (NewShamt != llvm::findLastSet(UnsignedConst)) {
// First bit set is not the same as the last bit set, so Const is not
// a power of 2.
return false;
}
NewShiftKind = ArithInst->getOp() == InstArithmetic::Udiv
? OperandARM32::LSR
: OperandARM32::LSL;
} break;
}
// Allowed "transitions":
// kNoShift -> * iff NewShamt < 31
// LSL -> LSL iff NewShamt + OffsetRegShamt < 31
// LSR -> LSR iff NewShamt + OffsetRegShamt < 31
// ASR -> ASR iff NewShamt + OffsetRegShamt < 31
if (*Kind != OperandARM32::kNoShift && *Kind != NewShiftKind) {
return false;
}
const int32_t NewOffsetRegShamt = *OffsetRegShamt + NewShamt;
if (NewOffsetRegShamt > 31)
return false;
*OffsetReg = Var;
*OffsetRegShamt = NewOffsetRegShamt;
*Kind = NewShiftKind;
*Reason = IndexInst;
return true;
}
bool matchOffsetBase(const VariablesMetadata *VMetadata, Variable **Base,
int32_t *Offset, const Inst **Reason) {
// Base is Base=Var+Const || Base is Base=Const+Var ==>
// set Base=Var, Offset+=Const
// Base is Base=Var-Const ==>
// set Base=Var, Offset-=Const
if (*Base == nullptr)
return false;
const Inst *BaseInst = VMetadata->getSingleDefinition(*Base);
if (BaseInst == nullptr) {
return false;
}
assert(!VMetadata->isMultiDef(*Base));
auto *ArithInst = llvm::dyn_cast<const InstArithmetic>(BaseInst);
if (ArithInst == nullptr)
return false;
InstArithmetic::OpKind Kind;
if (!isAddOrSub(ArithInst, &Kind))
return false;
bool IsAdd = Kind == InstArithmetic::Add;
Operand *Src0 = ArithInst->getSrc(0);
Operand *Src1 = ArithInst->getSrc(1);
auto *Var0 = llvm::dyn_cast<Variable>(Src0);
auto *Var1 = llvm::dyn_cast<Variable>(Src1);
auto *Const0 = llvm::dyn_cast<ConstantInteger32>(Src0);
auto *Const1 = llvm::dyn_cast<ConstantInteger32>(Src1);
Variable *NewBase = nullptr;
int32_t NewOffset = *Offset;
if (Var0 == nullptr && Const0 == nullptr) {
assert(llvm::isa<ConstantRelocatable>(Src0));
return false;
}
if (Var1 == nullptr && Const1 == nullptr) {
assert(llvm::isa<ConstantRelocatable>(Src1));
return false;
}
if (Var0 && Var1)
// TODO(jpp): merge base/index splitting into here.
return false;
if (!IsAdd && Var1)
return false;
if (Var0)
NewBase = Var0;
else if (Var1)
NewBase = Var1;
// Compute the updated constant offset.
if (Const0) {
int32_t MoreOffset = IsAdd ? Const0->getValue() : -Const0->getValue();
if (Utils::WouldOverflowAdd(NewOffset, MoreOffset))
return false;
NewOffset += MoreOffset;
}
if (Const1) {
int32_t MoreOffset = IsAdd ? Const1->getValue() : -Const1->getValue();
if (Utils::WouldOverflowAdd(NewOffset, MoreOffset))
return false;
NewOffset += MoreOffset;
}
// Update the computed address parameters once we are sure optimization
// is valid.
*Base = NewBase;
*Offset = NewOffset;
*Reason = BaseInst;
return true;
}
} // end of anonymous namespace
OperandARM32Mem *TargetARM32::formAddressingMode(Type Ty, Cfg *Func,
const Inst *LdSt,
Operand *Base) {
assert(Base != nullptr);
int32_t OffsetImm = 0;
Variable *OffsetReg = nullptr;
int32_t OffsetRegShamt = 0;
OperandARM32::ShiftKind ShiftKind = OperandARM32::kNoShift;
Func->resetCurrentNode();
if (Func->isVerbose(IceV_AddrOpt)) {
OstreamLocker _(Func->getContext());
Ostream &Str = Func->getContext()->getStrDump();
Str << "\nAddress mode formation:\t";
LdSt->dumpDecorated(Func);
}
if (isVectorType(Ty))
// vector loads and stores do not allow offsets, and only support the
// "[reg]" addressing mode (the other supported modes are write back.)
return nullptr;
auto *BaseVar = llvm::dyn_cast<Variable>(Base);
if (BaseVar == nullptr)
return nullptr;
(void)MemTraitsSize;
assert(Ty < MemTraitsSize);
auto *TypeTraits = &MemTraits[Ty];
const bool CanHaveIndex = !NeedSandboxing && TypeTraits->CanHaveIndex;
const bool CanHaveShiftedIndex =
!NeedSandboxing && TypeTraits->CanHaveShiftedIndex;
const bool CanHaveImm = TypeTraits->CanHaveImm;
const int32_t ValidImmMask = TypeTraits->ValidImmMask;
(void)ValidImmMask;
assert(!CanHaveImm || ValidImmMask >= 0);
const VariablesMetadata *VMetadata = Func->getVMetadata();
const Inst *Reason = nullptr;
do {
if (Reason != nullptr) {
dumpAddressOpt(Func, BaseVar, OffsetImm, OffsetReg, OffsetRegShamt,
Reason);
Reason = nullptr;
}
if (matchAssign(VMetadata, &BaseVar, &OffsetImm, &Reason)) {
continue;
}
if (CanHaveIndex &&
matchAssign(VMetadata, &OffsetReg, &OffsetImm, &Reason)) {
continue;
}
if (CanHaveIndex && matchCombinedBaseIndex(VMetadata, &BaseVar, &OffsetReg,
OffsetRegShamt, &Reason)) {
continue;
}
if (CanHaveShiftedIndex) {
if (matchShiftedOffsetReg(VMetadata, &OffsetReg, &ShiftKind,
&OffsetRegShamt, &Reason)) {
continue;
}
if ((OffsetRegShamt == 0) &&
matchShiftedOffsetReg(VMetadata, &BaseVar, &ShiftKind,
&OffsetRegShamt, &Reason)) {
std::swap(BaseVar, OffsetReg);
continue;
}
}
if (matchOffsetBase(VMetadata, &BaseVar, &OffsetImm, &Reason)) {
continue;
}
} while (Reason);
if (BaseVar == nullptr) {
// [OffsetReg{, LSL Shamt}{, #OffsetImm}] is not legal in ARM, so we have to
// legalize the addressing mode to [BaseReg, OffsetReg{, LSL Shamt}].
// Instead of a zeroed BaseReg, we initialize it with OffsetImm:
//
// [OffsetReg{, LSL Shamt}{, #OffsetImm}] ->
// mov BaseReg, #OffsetImm
// use of [BaseReg, OffsetReg{, LSL Shamt}]
//
const Type PointerType = getPointerType();
BaseVar = makeReg(PointerType);
Context.insert<InstAssign>(BaseVar, Ctx->getConstantInt32(OffsetImm));
OffsetImm = 0;
} else if (OffsetImm != 0) {
// ARM Ldr/Str instructions have limited range immediates. The formation
// loop above materialized an Immediate carelessly, so we ensure the
// generated offset is sane.
const int32_t PositiveOffset = OffsetImm > 0 ? OffsetImm : -OffsetImm;
const InstArithmetic::OpKind Op =
OffsetImm > 0 ? InstArithmetic::Add : InstArithmetic::Sub;
if (!CanHaveImm || !isLegalMemOffset(Ty, OffsetImm) ||
OffsetReg != nullptr) {
if (OffsetReg == nullptr) {
// We formed a [Base, #const] addressing mode which is not encodable in
// ARM. There is little point in forming an address mode now if we don't
// have an offset. Effectively, we would end up with something like
//
// [Base, #const] -> add T, Base, #const
// use of [T]
//
// Which is exactly what we already have. So we just bite the bullet
// here and don't form any address mode.
return nullptr;
}
// We formed [Base, Offset {, LSL Amnt}, #const]. Oops. Legalize it to
//
// [Base, Offset, {LSL amount}, #const] ->
// add T, Base, #const
// use of [T, Offset {, LSL amount}]
const Type PointerType = getPointerType();
Variable *T = makeReg(PointerType);
Context.insert<InstArithmetic>(Op, T, BaseVar,
Ctx->getConstantInt32(PositiveOffset));
BaseVar = T;
OffsetImm = 0;
}
}
assert(BaseVar != nullptr);
assert(OffsetImm == 0 || OffsetReg == nullptr);
assert(OffsetReg == nullptr || CanHaveIndex);
assert(OffsetImm < 0 ? (ValidImmMask & -OffsetImm) == -OffsetImm
: (ValidImmMask & OffsetImm) == OffsetImm);
if (OffsetReg != nullptr) {
Variable *OffsetR = makeReg(getPointerType());
Context.insert<InstAssign>(OffsetR, OffsetReg);
return OperandARM32Mem::create(Func, Ty, BaseVar, OffsetR, ShiftKind,
OffsetRegShamt);
}
return OperandARM32Mem::create(
Func, Ty, BaseVar,
llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(OffsetImm)));
}
void TargetARM32::doAddressOptLoad() {
Inst *Instr = iteratorToInst(Context.getCur());
assert(llvm::isa<InstLoad>(Instr));
Variable *Dest = Instr->getDest();
Operand *Addr = Instr->getSrc(0);
if (OperandARM32Mem *Mem =
formAddressingMode(Dest->getType(), Func, Instr, Addr)) {
Instr->setDeleted();
Context.insert<InstLoad>(Dest, Mem);
}
}
void TargetARM32::randomlyInsertNop(float Probability,
RandomNumberGenerator &RNG) {
RandomNumberGeneratorWrapper RNGW(RNG);
if (RNGW.getTrueWithProbability(Probability)) {
_nop();
}
}
void TargetARM32::lowerPhi(const InstPhi * /*Instr*/) {
Func->setError("Phi found in regular instruction list");
}
void TargetARM32::lowerRet(const InstRet *Instr) {
Variable *Reg = nullptr;
if (Instr->hasRetValue()) {
Operand *Src0 = Instr->getRetValue();
Type Ty = Src0->getType();
if (Ty == IceType_i64) {
Src0 = legalizeUndef(Src0);
Variable *R0 = legalizeToReg(loOperand(Src0), RegARM32::Reg_r0);
Variable *R1 = legalizeToReg(hiOperand(Src0), RegARM32::Reg_r1);
Reg = R0;
Context.insert<InstFakeUse>(R1);
} else if (Ty == IceType_f32) {
Variable *S0 = legalizeToReg(Src0, RegARM32::Reg_s0);
Reg = S0;
} else if (Ty == IceType_f64) {
Variable *D0 = legalizeToReg(Src0, RegARM32::Reg_d0);
Reg = D0;
} else if (isVectorType(Src0->getType())) {
Variable *Q0 = legalizeToReg(Src0, RegARM32::Reg_q0);
Reg = Q0;
} else {
Operand *Src0F = legalize(Src0, Legal_Reg | Legal_Flex);
Reg = makeReg(Src0F->getType(), RegARM32::Reg_r0);
_mov(Reg, Src0F, CondARM32::AL);
}
}
// Add a ret instruction even if sandboxing is enabled, because addEpilog
// explicitly looks for a ret instruction as a marker for where to insert the
// frame removal instructions. addEpilog is responsible for restoring the
// "lr" register as needed prior to this ret instruction.
_ret(getPhysicalRegister(RegARM32::Reg_lr), Reg);
// Add a fake use of sp to make sure sp stays alive for the entire function.
// Otherwise post-call sp adjustments get dead-code eliminated.
// TODO: Are there more places where the fake use should be inserted? E.g.
// "void f(int n){while(1) g(n);}" may not have a ret instruction.
Variable *SP = getPhysicalRegister(RegARM32::Reg_sp);
Context.insert<InstFakeUse>(SP);
}
void TargetARM32::lowerShuffleVector(const InstShuffleVector *Instr) {
auto *Dest = Instr->getDest();
const Type DestTy = Dest->getType();
auto *T = makeReg(DestTy);
switch (DestTy) {
default:
break;
// TODO(jpp): figure out how to properly lower this without scalarization.
}
// Unoptimized shuffle. Perform a series of inserts and extracts.
Context.insert<InstFakeDef>(T);
auto *Src0 = llvm::cast<Variable>(Instr->getSrc(0));
auto *Src1 = llvm::cast<Variable>(Instr->getSrc(1));
const SizeT NumElements = typeNumElements(DestTy);
const Type ElementType = typeElementType(DestTy);
for (SizeT I = 0; I < Instr->getNumIndexes(); ++I) {
auto *Index = Instr->getIndex(I);
const SizeT Elem = Index->getValue();
auto *ExtElmt = makeReg(ElementType);
if (Elem < NumElements) {
lowerExtractElement(
InstExtractElement::create(Func, ExtElmt, Src0, Index));
} else {
lowerExtractElement(InstExtractElement::create(
Func, ExtElmt, Src1,
Ctx->getConstantInt32(Index->getValue() - NumElements)));
}
auto *NewT = makeReg(DestTy);
lowerInsertElement(InstInsertElement::create(Func, NewT, T, ExtElmt,
Ctx->getConstantInt32(I)));
T = NewT;
}
_mov(Dest, T);
}
void TargetARM32::lowerSelect(const InstSelect *Instr) {
Variable *Dest = Instr->getDest();
Type DestTy = Dest->getType();
Operand *SrcT = Instr->getTrueOperand();
Operand *SrcF = Instr->getFalseOperand();
Operand *Condition = Instr->getCondition();
if (!isVectorType(DestTy)) {
lowerInt1ForSelect(Dest, Condition, legalizeUndef(SrcT),
legalizeUndef(SrcF));
return;
}
Type TType = DestTy;
switch (DestTy) {
default:
llvm::report_fatal_error("Unexpected type for vector select.");
case IceType_v4i1:
TType = IceType_v4i32;
break;
case IceType_v8i1:
TType = IceType_v8i16;
break;
case IceType_v16i1:
TType = IceType_v16i8;
break;
case IceType_v4f32:
TType = IceType_v4i32;
break;
case IceType_v4i32:
case IceType_v8i16:
case IceType_v16i8:
break;
}
auto *T = makeReg(TType);
lowerCast(InstCast::create(Func, InstCast::Sext, T, Condition));
auto *SrcTR = legalizeToReg(SrcT);
auto *SrcFR = legalizeToReg(SrcF);
_vbsl(T, SrcTR, SrcFR)->setDestRedefined();
_mov(Dest, T);
}
void TargetARM32::lowerStore(const InstStore *Instr) {
Operand *Value = Instr->getData();
Operand *Addr = Instr->getAddr();
OperandARM32Mem *NewAddr = formMemoryOperand(Addr, Value->getType());
Type Ty = NewAddr->getType();
if (Ty == IceType_i64) {
Value = legalizeUndef(Value);
Variable *ValueHi = legalizeToReg(hiOperand(Value));
Variable *ValueLo = legalizeToReg(loOperand(Value));
_str(ValueHi, llvm::cast<OperandARM32Mem>(hiOperand(NewAddr)));
_str(ValueLo, llvm::cast<OperandARM32Mem>(loOperand(NewAddr)));
} else {
Variable *ValueR = legalizeToReg(Value);
_str(ValueR, NewAddr);
}
}
void TargetARM32::doAddressOptStore() {
Inst *Instr = iteratorToInst(Context.getCur());
assert(llvm::isa<InstStore>(Instr));
Operand *Src = Instr->getSrc(0);
Operand *Addr = Instr->getSrc(1);
if (OperandARM32Mem *Mem =
formAddressingMode(Src->getType(), Func, Instr, Addr)) {
Instr->setDeleted();
Context.insert<InstStore>(Src, Mem);
}
}
void TargetARM32::lowerSwitch(const InstSwitch *Instr) {
// This implements the most naive possible lowering.
// cmp a,val[0]; jeq label[0]; cmp a,val[1]; jeq label[1]; ... jmp default
Operand *Src0 = Instr->getComparison();
SizeT NumCases = Instr->getNumCases();
if (Src0->getType() == IceType_i64) {
Src0 = legalizeUndef(Src0);
Variable *Src0Lo = legalizeToReg(loOperand(Src0));
Variable *Src0Hi = legalizeToReg(hiOperand(Src0));
for (SizeT I = 0; I < NumCases; ++I) {
Operand *ValueLo = Ctx->getConstantInt32(Instr->getValue(I));
Operand *ValueHi = Ctx->getConstantInt32(Instr->getValue(I) >> 32);
ValueLo = legalize(ValueLo, Legal_Reg | Legal_Flex);
ValueHi = legalize(ValueHi, Legal_Reg | Legal_Flex);
_cmp(Src0Lo, ValueLo);
_cmp(Src0Hi, ValueHi, CondARM32::EQ);
_br(Instr->getLabel(I), CondARM32::EQ);
}
_br(Instr->getLabelDefault());
return;
}
Variable *Src0Var = legalizeToReg(Src0);
// If Src0 is not an i32, we left shift it -- see the icmp lowering for the
// reason.
assert(Src0Var->mustHaveReg());
const size_t ShiftAmt = 32 - getScalarIntBitWidth(Src0->getType());
assert(ShiftAmt < 32);
if (ShiftAmt > 0) {
Operand *ShAmtImm = shAmtImm(ShiftAmt);
Variable *T = makeReg(IceType_i32);
_lsl(T, Src0Var, ShAmtImm);
Src0Var = T;
}
for (SizeT I = 0; I < NumCases; ++I) {
Operand *Value = Ctx->getConstantInt32(Instr->getValue(I) << ShiftAmt);
Value = legalize(Value, Legal_Reg | Legal_Flex);
_cmp(Src0Var, Value);
_br(Instr->getLabel(I), CondARM32::EQ);
}
_br(Instr->getLabelDefault());
}
void TargetARM32::lowerBreakpoint(const InstBreakpoint *Instr) {
UnimplementedLoweringError(this, Instr);
}
void TargetARM32::lowerUnreachable(const InstUnreachable * /*Instr*/) {
_trap();
}
namespace {
// Returns whether Opnd needs the GOT address. Currently, ConstantRelocatables,
// and fp constants will need access to the GOT address.
bool operandNeedsGot(const Operand *Opnd) {
if (llvm::isa<ConstantRelocatable>(Opnd)) {
return true;
}
if (llvm::isa<ConstantFloat>(Opnd)) {
uint32_t _;
return !OperandARM32FlexFpImm::canHoldImm(Opnd, &_);
}
const auto *F64 = llvm::dyn_cast<ConstantDouble>(Opnd);
if (F64 != nullptr) {
uint32_t _;
return !OperandARM32FlexFpImm::canHoldImm(Opnd, &_) &&
!isFloatingPointZero(F64);
}
return false;
}
// Returns whether Phi needs the GOT address (which it does if any of its
// operands needs the GOT address.)
bool phiNeedsGot(const InstPhi *Phi) {
if (Phi->isDeleted()) {
return false;
}
for (SizeT I = 0; I < Phi->getSrcSize(); ++I) {
if (operandNeedsGot(Phi->getSrc(I))) {
return true;
}
}
return false;
}
// Returns whether **any** phi in Node needs the GOT address.
bool anyPhiInNodeNeedsGot(CfgNode *Node) {
for (auto &Inst : Node->getPhis()) {
if (phiNeedsGot(llvm::cast<InstPhi>(&Inst))) {
return true;
}
}
return false;
}
} // end of anonymous namespace
void TargetARM32::prelowerPhis() {
CfgNode *Node = Context.getNode();
if (SandboxingType == ST_Nonsfi) {
assert(GotPtr != nullptr);
if (anyPhiInNodeNeedsGot(Node)) {
// If any phi instruction needs the GOT address, we place a
// fake-use GotPtr
// in Node to prevent the GotPtr's initialization from being dead code
// eliminated.
Node->getInsts().push_front(InstFakeUse::create(Func, GotPtr));
}
}
PhiLowering::prelowerPhis32Bit(this, Node, Func);
}
Variable *TargetARM32::makeVectorOfZeros(Type Ty, RegNumT RegNum) {
Variable *Reg = makeReg(Ty, RegNum);
Context.insert<InstFakeDef>(Reg);
assert(isVectorType(Ty));
_veor(Reg, Reg, Reg);
return Reg;
}
// Helper for legalize() to emit the right code to lower an operand to a
// register of the appropriate type.
Variable *TargetARM32::copyToReg(Operand *Src, RegNumT RegNum) {
Type Ty = Src->getType();
Variable *Reg = makeReg(Ty, RegNum);
if (auto *Mem = llvm::dyn_cast<OperandARM32Mem>(Src)) {
_ldr(Reg, Mem);
} else {
_mov(Reg, Src);
}
return Reg;
}
// TODO(jpp): remove unneeded else clauses in legalize.
Operand *TargetARM32::legalize(Operand *From, LegalMask Allowed,
RegNumT RegNum) {
Type Ty = From->getType();
// Assert that a physical register is allowed. To date, all calls to
// legalize() allow a physical register. Legal_Flex converts registers to the
// right type OperandARM32FlexReg as needed.
assert(Allowed & Legal_Reg);
// Copied ipsis literis from TargetX86Base<Machine>.
if (RegNum.hasNoValue()) {
if (Variable *Subst = getContext().availabilityGet(From)) {
// At this point we know there is a potential substitution available.
if (!Subst->isRematerializable() && Subst->mustHaveReg() &&
!Subst->hasReg()) {
// At this point we know the substitution will have a register.
if (From->getType() == Subst->getType()) {
// At this point we know the substitution's register is compatible.
return Subst;
}
}
}
}
// Go through the various types of operands: OperandARM32Mem,
// OperandARM32Flex, Constant, and Variable. Given the above assertion, if
// type of operand is not legal (e.g., OperandARM32Mem and !Legal_Mem), we
// can always copy to a register.
if (auto *Mem = llvm::dyn_cast<OperandARM32Mem>(From)) {
// Before doing anything with a Mem operand, we need to ensure that the
// Base and Index components are in physical registers.
Variable *Base = Mem->getBase();
Variable *Index = Mem->getIndex();
ConstantInteger32 *Offset = Mem->getOffset();
assert(Index == nullptr || Offset == nullptr);
Variable *RegBase = nullptr;
Variable *RegIndex = nullptr;
assert(Base);
RegBase = llvm::cast<Variable>(
legalize(Base, Legal_Reg | Legal_Rematerializable));
assert(Ty < MemTraitsSize);
if (Index) {
assert(Offset == nullptr);
assert(MemTraits[Ty].CanHaveIndex);
RegIndex = legalizeToReg(Index);
}
if (Offset && Offset->getValue() != 0) {
assert(Index == nullptr);
static constexpr bool ZeroExt = false;
assert(MemTraits[Ty].CanHaveImm);
if (!OperandARM32Mem::canHoldOffset(Ty, ZeroExt, Offset->getValue())) {
llvm::report_fatal_error("Invalid memory offset.");
}
}
// Create a new operand if there was a change.
if (Base != RegBase || Index != RegIndex) {
// There is only a reg +/- reg or reg + imm form.
// Figure out which to re-create.
if (RegIndex) {
Mem = OperandARM32Mem::create(Func, Ty, RegBase, RegIndex,
Mem->getShiftOp(), Mem->getShiftAmt(),
Mem->getAddrMode());
} else {
Mem = OperandARM32Mem::create(Func, Ty, RegBase, Offset,
Mem->getAddrMode());
}
}
if (Allowed & Legal_Mem) {
From = Mem;
} else {
Variable *Reg = makeReg(Ty, RegNum);
_ldr(Reg, Mem);
From = Reg;
}
return From;
}
if (auto *Flex = llvm::dyn_cast<OperandARM32Flex>(From)) {
if (!(Allowed & Legal_Flex)) {
if (auto *FlexReg = llvm::dyn_cast<OperandARM32FlexReg>(Flex)) {
if (FlexReg->getShiftOp() == OperandARM32::kNoShift) {
From = FlexReg->getReg();
// Fall through and let From be checked as a Variable below, where it
// may or may not need a register.
} else {
return copyToReg(Flex, RegNum);
}
} else {
return copyToReg(Flex, RegNum);
}
} else {
return From;
}
}
if (llvm::isa<Constant>(From)) {
if (llvm::isa<ConstantUndef>(From)) {
From = legalizeUndef(From, RegNum);
if (isVectorType(Ty))
return From;
}
// There should be no constants of vector type (other than undef).
assert(!isVectorType(Ty));
if (auto *C32 = llvm::dyn_cast<ConstantInteger32>(From)) {
uint32_t RotateAmt;
uint32_t Immed_8;
uint32_t Value = static_cast<uint32_t>(C32->getValue());
if (OperandARM32FlexImm::canHoldImm(Value, &RotateAmt, &Immed_8)) {
// The immediate can be encoded as a Flex immediate. We may return the
// Flex operand if the caller has Allow'ed it.
auto *OpF = OperandARM32FlexImm::create(Func, Ty, Immed_8, RotateAmt);
const bool CanBeFlex = Allowed & Legal_Flex;
if (CanBeFlex)
return OpF;
return copyToReg(OpF, RegNum);
} else if (OperandARM32FlexImm::canHoldImm(~Value, &RotateAmt,
&Immed_8)) {
// Even though the immediate can't be encoded as a Flex operand, its
// inverted bit pattern can, thus we use ARM's mvn to load the 32-bit
// constant with a single instruction.
auto *InvOpF =
OperandARM32FlexImm::create(Func, Ty, Immed_8, RotateAmt);
Variable *Reg = makeReg(Ty, RegNum);
_mvn(Reg, InvOpF);
return Reg;
} else {
// Do a movw/movt to a register.
Variable *Reg = makeReg(Ty, RegNum);
uint32_t UpperBits = (Value >> 16) & 0xFFFF;
_movw(Reg,
UpperBits != 0 ? Ctx->getConstantInt32(Value & 0xFFFF) : C32);
if (UpperBits != 0) {
_movt(Reg, Ctx->getConstantInt32(UpperBits));
}
return Reg;
}
} else if (auto *C = llvm::dyn_cast<ConstantRelocatable>(From)) {
Variable *Reg = makeReg(Ty, RegNum);
if (SandboxingType != ST_Nonsfi) {
_movw(Reg, C);
_movt(Reg, C);
} else {
auto *GotAddr = legalizeToReg(GotPtr);
GlobalString CGotoffName = createGotoffRelocation(C);
loadNamedConstantRelocatablePIC(
CGotoffName, Reg, [this, Reg](Variable *PC) {
_ldr(Reg, OperandARM32Mem::create(Func, IceType_i32, PC, Reg));
});
_add(Reg, GotAddr, Reg);
}
return Reg;
} else {
assert(isScalarFloatingType(Ty));
uint32_t ModifiedImm;
if (OperandARM32FlexFpImm::canHoldImm(From, &ModifiedImm)) {
Variable *T = makeReg(Ty, RegNum);
_mov(T,
OperandARM32FlexFpImm::create(Func, From->getType(), ModifiedImm));
return T;
}
if (Ty == IceType_f64 && isFloatingPointZero(From)) {
// Use T = T ^ T to load a 64-bit fp zero. This does not work for f32
// because ARM does not have a veor instruction with S registers.
Variable *T = makeReg(IceType_f64, RegNum);
Context.insert<InstFakeDef>(T);
_veor(T, T, T);
return T;
}
// Load floats/doubles from literal pool.
auto *CFrom = llvm::cast<Constant>(From);
assert(CFrom->getShouldBePooled());
Constant *Offset = Ctx->getConstantSym(0, CFrom->getLabelName());
Variable *BaseReg = nullptr;
if (SandboxingType == ST_Nonsfi) {
// vldr does not support the [base, index] addressing mode, so we need
// to legalize Offset to a register. Otherwise, we could simply
// vldr dest, [got, reg(Offset)]
BaseReg = legalizeToReg(Offset);
} else {
BaseReg = makeReg(getPointerType());
_movw(BaseReg, Offset);
_movt(BaseReg, Offset);
}
From = formMemoryOperand(BaseReg, Ty);
return copyToReg(From, RegNum);
}
}
if (auto *Var = llvm::dyn_cast<Variable>(From)) {
if (Var->isRematerializable()) {
if (Allowed & Legal_Rematerializable) {
return From;
}
Variable *T = makeReg(Var->getType(), RegNum);
_mov(T, Var);
return T;
}
// Check if the variable is guaranteed a physical register. This can happen
// either when the variable is pre-colored or when it is assigned infinite
// weight.
bool MustHaveRegister = (Var->hasReg() || Var->mustHaveReg());
// We need a new physical register for the operand if:
// Mem is not allowed and Var isn't guaranteed a physical
// register, or
// RegNum is required and Var->getRegNum() doesn't match.
if ((!(Allowed & Legal_Mem) && !MustHaveRegister) ||
(RegNum.hasValue() && (RegNum != Var->getRegNum()))) {
From = copyToReg(From, RegNum);
}
return From;
}
llvm::report_fatal_error("Unhandled operand kind in legalize()");
return From;
}
/// Provide a trivial wrapper to legalize() for this common usage.
Variable *TargetARM32::legalizeToReg(Operand *From, RegNumT RegNum) {
return llvm::cast<Variable>(legalize(From, Legal_Reg, RegNum));
}
/// Legalize undef values to concrete values.
Operand *TargetARM32::legalizeUndef(Operand *From, RegNumT RegNum) {
Type Ty = From->getType();
if (llvm::isa<ConstantUndef>(From)) {
// Lower undefs to zero. Another option is to lower undefs to an
// uninitialized register; however, using an uninitialized register results
// in less predictable code.
//
// If in the future the implementation is changed to lower undef values to
// uninitialized registers, a FakeDef will be needed:
// Context.insert(InstFakeDef::create(Func, Reg)); This is in order to
// ensure that the live range of Reg is not overestimated. If the constant
// being lowered is a 64 bit value, then the result should be split and the
// lo and hi components will need to go in uninitialized registers.
if (isVectorType(Ty))
return makeVectorOfZeros(Ty, RegNum);
return Ctx->getConstantZero(Ty);
}
return From;
}
OperandARM32Mem *TargetARM32::formMemoryOperand(Operand *Operand, Type Ty) {
auto *Mem = llvm::dyn_cast<OperandARM32Mem>(Operand);
// It may be the case that address mode optimization already creates an
// OperandARM32Mem, so in that case it wouldn't need another level of
// transformation.
if (Mem) {
return llvm::cast<OperandARM32Mem>(legalize(Mem));
}
// If we didn't do address mode optimization, then we only have a
// base/offset to work with. ARM always requires a base register, so
// just use that to hold the operand.
auto *Base = llvm::cast<Variable>(
legalize(Operand, Legal_Reg | Legal_Rematerializable));
return OperandARM32Mem::create(
Func, Ty, Base,
llvm::cast<ConstantInteger32>(Ctx->getConstantZero(IceType_i32)));
}
Variable64On32 *TargetARM32::makeI64RegPair() {
Variable64On32 *Reg =
llvm::cast<Variable64On32>(Func->makeVariable(IceType_i64));
Reg->setMustHaveReg();
Reg->initHiLo(Func);
Reg->getLo()->setMustNotHaveReg();
Reg->getHi()->setMustNotHaveReg();
return Reg;
}
Variable *TargetARM32::makeReg(Type Type, RegNumT RegNum) {
// There aren't any 64-bit integer registers for ARM32.
assert(Type != IceType_i64);
assert(AllowTemporaryWithNoReg || RegNum.hasValue());
Variable *Reg = Func->makeVariable(Type);
if (RegNum.hasValue())
Reg->setRegNum(RegNum);
else
Reg->setMustHaveReg();
return Reg;
}
void TargetARM32::alignRegisterPow2(Variable *Reg, uint32_t Align,
RegNumT TmpRegNum) {
assert(llvm::isPowerOf2_32(Align));
uint32_t RotateAmt;
uint32_t Immed_8;
Operand *Mask;
// Use AND or BIC to mask off the bits, depending on which immediate fits (if
// it fits at all). Assume Align is usually small, in which case BIC works
// better. Thus, this rounds down to the alignment.
if (OperandARM32FlexImm::canHoldImm(Align - 1, &RotateAmt, &Immed_8)) {
Mask = legalize(Ctx->getConstantInt32(Align - 1), Legal_Reg | Legal_Flex,
TmpRegNum);
_bic(Reg, Reg, Mask);
} else {
Mask = legalize(Ctx->getConstantInt32(-Align), Legal_Reg | Legal_Flex,
TmpRegNum);
_and(Reg, Reg, Mask);
}
}
void TargetARM32::postLower() {
if (Func->getOptLevel() == Opt_m1)
return;
markRedefinitions();
Context.availabilityUpdate();
}
void TargetARM32::makeRandomRegisterPermutation(
llvm::SmallVectorImpl<RegNumT> &Permutation,
const SmallBitVector &ExcludeRegisters, uint64_t Salt) const {
(void)Permutation;
(void)ExcludeRegisters;
(void)Salt;
UnimplementedError(getFlags());
}
void TargetARM32::emit(const ConstantInteger32 *C) const {
if (!BuildDefs::dump())
return;
Ostream &Str = Ctx->getStrEmit();
Str << "#" << C->getValue();
}
void TargetARM32::emit(const ConstantInteger64 *) const {
llvm::report_fatal_error("Not expecting to emit 64-bit integers");
}
void TargetARM32::emit(const ConstantFloat *C) const {
(void)C;
UnimplementedError(getFlags());
}
void TargetARM32::emit(const ConstantDouble *C) const {
(void)C;
UnimplementedError(getFlags());
}
void TargetARM32::emit(const ConstantUndef *) const {
llvm::report_fatal_error("undef value encountered by emitter.");
}
void TargetARM32::emit(const ConstantRelocatable *C) const {
if (!BuildDefs::dump())
return;
Ostream &Str = Ctx->getStrEmit();
Str << "#";
emitWithoutPrefix(C);
}
void TargetARM32::lowerInt1ForSelect(Variable *Dest, Operand *Boolean,
Operand *TrueValue, Operand *FalseValue) {
Operand *_1 = legalize(Ctx->getConstantInt1(1), Legal_Reg | Legal_Flex);
assert(Boolean->getType() == IceType_i1);
bool NeedsAnd1 = false;
if (TrueValue->getType() == IceType_i1) {
assert(FalseValue->getType() == IceType_i1);
Variable *TrueValueV = Func->makeVariable(IceType_i1);
SafeBoolChain Src0Safe = lowerInt1(TrueValueV, TrueValue);
TrueValue = TrueValueV;
Variable *FalseValueV = Func->makeVariable(IceType_i1);
SafeBoolChain Src1Safe = lowerInt1(FalseValueV, FalseValue);
FalseValue = FalseValueV;
NeedsAnd1 = Src0Safe == SBC_No || Src1Safe == SBC_No;
}
Variable *DestLo = (Dest->getType() == IceType_i64)
? llvm::cast<Variable>(loOperand(Dest))
: Dest;
Variable *DestHi = (Dest->getType() == IceType_i64)
? llvm::cast<Variable>(hiOperand(Dest))
: nullptr;
Operand *FalseValueLo = (FalseValue->getType() == IceType_i64)
? loOperand(FalseValue)
: FalseValue;
Operand *FalseValueHi =
(FalseValue->getType() == IceType_i64) ? hiOperand(FalseValue) : nullptr;
Operand *TrueValueLo =
(TrueValue->getType() == IceType_i64) ? loOperand(TrueValue) : TrueValue;
Operand *TrueValueHi =
(TrueValue->getType() == IceType_i64) ? hiOperand(TrueValue) : nullptr;
Variable *T_Lo = makeReg(DestLo->getType());
Variable *T_Hi = (DestHi == nullptr) ? nullptr : makeReg(DestHi->getType());
_mov(T_Lo, legalize(FalseValueLo, Legal_Reg | Legal_Flex));
if (DestHi) {
_mov(T_Hi, legalize(FalseValueHi, Legal_Reg | Legal_Flex));
}
CondWhenTrue Cond(CondARM32::kNone);
// FlagsWereSet is used to determine wether Boolean was folded or not. If not,
// add an explicit _tst instruction below.
bool FlagsWereSet = false;
if (const Inst *Producer = Computations.getProducerOf(Boolean)) {
switch (Producer->getKind()) {
default:
llvm::report_fatal_error("Unexpected producer.");
case Inst::Icmp: {
Cond = lowerIcmpCond(llvm::cast<InstIcmp>(Producer));
FlagsWereSet = true;
} break;
case Inst::Fcmp: {
Cond = lowerFcmpCond(llvm::cast<InstFcmp>(Producer));
FlagsWereSet = true;
} break;
case Inst::Cast: {
const auto *CastProducer = llvm::cast<InstCast>(Producer);
assert(CastProducer->getCastKind() == InstCast::Trunc);
Boolean = CastProducer->getSrc(0);
// No flags were set, so a _tst(Src, 1) will be emitted below. Don't
// bother legalizing Src to a Reg because it will be legalized before
// emitting the tst instruction.
FlagsWereSet = false;
} break;
case Inst::Arithmetic: {
// This is a special case: we eagerly assumed Producer could be folded,
// but in reality, it can't. No reason to panic: we just lower it using
// the regular lowerArithmetic helper.
const auto *ArithProducer = llvm::cast<InstArithmetic>(Producer);
lowerArithmetic(ArithProducer);
Boolean = ArithProducer->getDest();
// No flags were set, so a _tst(Dest, 1) will be emitted below. Don't
// bother legalizing Dest to a Reg because it will be legalized before
// emitting the tst instruction.
FlagsWereSet = false;
} break;
}
}
if (!FlagsWereSet) {
// No flags have been set, so emit a tst Boolean, 1.
Variable *Src = legalizeToReg(Boolean);
_tst(Src, _1);
Cond = CondWhenTrue(CondARM32::NE); // i.e., CondARM32::NotZero.
}
if (Cond.WhenTrue0 == CondARM32::kNone) {
assert(Cond.WhenTrue1 == CondARM32::kNone);
} else {
_mov_redefined(T_Lo, legalize(TrueValueLo, Legal_Reg | Legal_Flex),
Cond.WhenTrue0);
if (DestHi) {
_mov_redefined(T_Hi, legalize(TrueValueHi, Legal_Reg | Legal_Flex),
Cond.WhenTrue0);
}
}
if (Cond.WhenTrue1 != CondARM32::kNone) {
_mov_redefined(T_Lo, legalize(TrueValueLo, Legal_Reg | Legal_Flex),
Cond.WhenTrue1);
if (DestHi) {
_mov_redefined(T_Hi, legalize(TrueValueHi, Legal_Reg | Legal_Flex),
Cond.WhenTrue1);
}
}
if (NeedsAnd1) {
// We lowered something that is unsafe (i.e., can't provably be zero or
// one). Truncate the result.
_and(T_Lo, T_Lo, _1);
}
_mov(DestLo, T_Lo);
if (DestHi) {
_mov(DestHi, T_Hi);
}
}
TargetARM32::SafeBoolChain TargetARM32::lowerInt1(Variable *Dest,
Operand *Boolean) {
assert(Boolean->getType() == IceType_i1);
Variable *T = makeReg(IceType_i1);
Operand *_0 =
legalize(Ctx->getConstantZero(IceType_i1), Legal_Reg | Legal_Flex);
Operand *_1 = legalize(Ctx->getConstantInt1(1), Legal_Reg | Legal_Flex);
SafeBoolChain Safe = SBC_Yes;
if (const Inst *Producer = Computations.getProducerOf(Boolean)) {
switch (Producer->getKind()) {
default:
llvm::report_fatal_error("Unexpected producer.");
case Inst::Icmp: {
_mov(T, _0);
CondWhenTrue Cond = lowerIcmpCond(llvm::cast<InstIcmp>(Producer));
assert(Cond.WhenTrue0 != CondARM32::AL);
assert(Cond.WhenTrue0 != CondARM32::kNone);
assert(Cond.WhenTrue1 == CondARM32::kNone);
_mov_redefined(T, _1, Cond.WhenTrue0);
} break;
case Inst::Fcmp: {
_mov(T, _0);
Inst *MovZero = Context.getLastInserted();
CondWhenTrue Cond = lowerFcmpCond(llvm::cast<InstFcmp>(Producer));
if (Cond.WhenTrue0 == CondARM32::AL) {
assert(Cond.WhenTrue1 == CondARM32::kNone);
MovZero->setDeleted();
_mov(T, _1);
} else if (Cond.WhenTrue0 != CondARM32::kNone) {
_mov_redefined(T, _1, Cond.WhenTrue0);
}
if (Cond.WhenTrue1 != CondARM32::kNone) {
assert(Cond.WhenTrue0 != CondARM32::kNone);
assert(Cond.WhenTrue0 != CondARM32::AL);
_mov_redefined(T, _1, Cond.WhenTrue1);
}
} break;
case Inst::Cast: {
const auto *CastProducer = llvm::cast<InstCast>(Producer);
assert(CastProducer->getCastKind() == InstCast::Trunc);
Operand *Src = CastProducer->getSrc(0);
if (Src->getType() == IceType_i64)
Src = loOperand(Src);
_mov(T, legalize(Src, Legal_Reg | Legal_Flex));
Safe = SBC_No;
} break;
case Inst::Arithmetic: {
const auto *ArithProducer = llvm::cast<InstArithmetic>(Producer);
Safe = lowerInt1Arithmetic(ArithProducer);
_mov(T, ArithProducer->getDest());
} break;
}
} else {
_mov(T, legalize(Boolean, Legal_Reg | Legal_Flex));
}
_mov(Dest, T);
return Safe;
}
namespace {
namespace BoolFolding {
bool shouldTrackProducer(const Inst &Instr) {
switch (Instr.getKind()) {
default:
return false;
case Inst::Icmp:
case Inst::Fcmp:
return true;
case Inst::Cast: {
switch (llvm::cast<InstCast>(&Instr)->getCastKind()) {
default:
return false;
case InstCast::Trunc:
return true;
}
}
case Inst::Arithmetic: {
switch (llvm::cast<InstArithmetic>(&Instr)->getOp()) {
default:
return false;
case InstArithmetic::And:
case InstArithmetic::Or:
return true;
}
}
}
}
bool isValidConsumer(const Inst &Instr) {
switch (Instr.getKind()) {
default:
return false;
case Inst::Br:
return true;
case Inst::Select:
return !isVectorType(Instr.getDest()->getType());
case Inst::Cast: {
switch (llvm::cast<InstCast>(&Instr)->getCastKind()) {
default:
return false;
case InstCast::Sext:
return !isVectorType(Instr.getDest()->getType());
case InstCast::Zext:
return !isVectorType(Instr.getDest()->getType());
}
}
case Inst::Arithmetic: {
switch (llvm::cast<InstArithmetic>(&Instr)->getOp()) {
default:
return false;
case InstArithmetic::And:
return !isVectorType(Instr.getDest()->getType());
case InstArithmetic::Or:
return !isVectorType(Instr.getDest()->getType());
}
}
}
}
} // end of namespace BoolFolding
namespace FpFolding {
bool shouldTrackProducer(const Inst &Instr) {
switch (Instr.getKind()) {
default:
return false;
case Inst::Arithmetic: {
switch (llvm::cast<InstArithmetic>(&Instr)->getOp()) {
default:
return false;
case InstArithmetic::Fmul:
return true;
}
}
}
}
bool isValidConsumer(const Inst &Instr) {
switch (Instr.getKind()) {
default:
return false;
case Inst::Arithmetic: {
switch (llvm::cast<InstArithmetic>(&Instr)->getOp()) {
default:
return false;
case InstArithmetic::Fadd:
case InstArithmetic::Fsub:
return true;
}
}
}
}
} // end of namespace FpFolding
namespace IntFolding {
bool shouldTrackProducer(const Inst &Instr) {
switch (Instr.getKind()) {
default:
return false;
case Inst::Arithmetic: {
switch (llvm::cast<InstArithmetic>(&Instr)->getOp()) {
default:
return false;
case InstArithmetic::Mul:
return true;
}
}
}
}
bool isValidConsumer(const Inst &Instr) {
switch (Instr.getKind()) {
default:
return false;
case Inst::Arithmetic: {
switch (llvm::cast<InstArithmetic>(&Instr)->getOp()) {
default:
return false;
case InstArithmetic::Add:
case InstArithmetic::Sub:
return true;
}
}
}
}
} // end of namespace FpFolding
} // end of anonymous namespace
void TargetARM32::ComputationTracker::recordProducers(CfgNode *Node) {
for (Inst &Instr : Node->getInsts()) {
// Check whether Instr is a valid producer.
Variable *Dest = Instr.getDest();
if (!Instr.isDeleted() // only consider non-deleted instructions; and
&& Dest // only instructions with an actual dest var; and
&& Dest->getType() == IceType_i1 // only bool-type dest vars; and
&& BoolFolding::shouldTrackProducer(Instr)) { // white-listed instr.
KnownComputations.emplace(Dest->getIndex(),
ComputationEntry(&Instr, IceType_i1));
}
if (!Instr.isDeleted() // only consider non-deleted instructions; and
&& Dest // only instructions with an actual dest var; and
&& isScalarFloatingType(Dest->getType()) // fp-type only dest vars; and
&& FpFolding::shouldTrackProducer(Instr)) { // white-listed instr.
KnownComputations.emplace(Dest->getIndex(),
ComputationEntry(&Instr, Dest->getType()));
}
if (!Instr.isDeleted() // only consider non-deleted instructions; and
&& Dest // only instructions with an actual dest var; and
&& Dest->getType() == IceType_i32 // i32 only dest vars; and
&& IntFolding::shouldTrackProducer(Instr)) { // white-listed instr.
KnownComputations.emplace(Dest->getIndex(),
ComputationEntry(&Instr, IceType_i32));
}
// Check each src variable against the map.
FOREACH_VAR_IN_INST(Var, Instr) {
SizeT VarNum = Var->getIndex();
auto ComputationIter = KnownComputations.find(VarNum);
if (ComputationIter == KnownComputations.end()) {
continue;
}
++ComputationIter->second.NumUses;
switch (ComputationIter->second.ComputationType) {
default:
KnownComputations.erase(VarNum);
continue;
case IceType_i1:
if (!BoolFolding::isValidConsumer(Instr)) {
KnownComputations.erase(VarNum);
continue;
}
break;
case IceType_i32:
if (IndexOfVarInInst(Var) != 1 || !IntFolding::isValidConsumer(Instr)) {
KnownComputations.erase(VarNum);
continue;
}
break;
case IceType_f32:
case IceType_f64:
if (IndexOfVarInInst(Var) != 1 || !FpFolding::isValidConsumer(Instr)) {
KnownComputations.erase(VarNum);
continue;
}
break;
}
if (Instr.isLastUse(Var)) {
ComputationIter->second.IsLiveOut = false;
}
}
}
for (auto Iter = KnownComputations.begin(), End = KnownComputations.end();
Iter != End;) {
// Disable the folding if its dest may be live beyond this block.
if (Iter->second.IsLiveOut || Iter->second.NumUses > 1) {
Iter = KnownComputations.erase(Iter);
continue;
}
// Mark as "dead" rather than outright deleting. This is so that other
// peephole style optimizations during or before lowering have access to
// this instruction in undeleted form. See for example
// tryOptimizedCmpxchgCmpBr().
Iter->second.Instr->setDead();
++Iter;
}
}
TargetARM32::Sandboxer::Sandboxer(TargetARM32 *Target,
InstBundleLock::Option BundleOption)
: Target(Target), BundleOption(BundleOption) {}
TargetARM32::Sandboxer::~Sandboxer() {}
namespace {
OperandARM32FlexImm *indirectBranchBicMask(Cfg *Func) {
constexpr uint32_t Imm8 = 0xFC; // 0xC000000F
constexpr uint32_t RotateAmt = 2;
return OperandARM32FlexImm::create(Func, IceType_i32, Imm8, RotateAmt);
}
OperandARM32FlexImm *memOpBicMask(Cfg *Func) {
constexpr uint32_t Imm8 = 0x0C; // 0xC0000000
constexpr uint32_t RotateAmt = 2;
return OperandARM32FlexImm::create(Func, IceType_i32, Imm8, RotateAmt);
}
static bool baseNeedsBic(Variable *Base) {
return Base->getRegNum() != RegARM32::Reg_r9 &&
Base->getRegNum() != RegARM32::Reg_sp;
}
} // end of anonymous namespace
void TargetARM32::Sandboxer::createAutoBundle() {
Bundler = makeUnique<AutoBundle>(Target, BundleOption);
}
void TargetARM32::Sandboxer::add_sp(Operand *AddAmount) {
Variable *SP = Target->getPhysicalRegister(RegARM32::Reg_sp);
if (!Target->NeedSandboxing) {
Target->_add(SP, SP, AddAmount);
return;
}
createAutoBundle();
Target->_add(SP, SP, AddAmount);
Target->_bic(SP, SP, memOpBicMask(Target->Func));
}
void TargetARM32::Sandboxer::align_sp(size_t Alignment) {
Variable *SP = Target->getPhysicalRegister(RegARM32::Reg_sp);
if (!Target->NeedSandboxing) {
Target->alignRegisterPow2(SP, Alignment);
return;
}
createAutoBundle();
Target->alignRegisterPow2(SP, Alignment);
Target->_bic(SP, SP, memOpBicMask(Target->Func));
}
InstARM32Call *TargetARM32::Sandboxer::bl(Variable *ReturnReg,
Operand *CallTarget) {
if (Target->NeedSandboxing) {
createAutoBundle();
if (auto *CallTargetR = llvm::dyn_cast<Variable>(CallTarget)) {
Target->_bic(CallTargetR, CallTargetR,
indirectBranchBicMask(Target->Func));
}
}
return Target->Context.insert<InstARM32Call>(ReturnReg, CallTarget);
}
void TargetARM32::Sandboxer::ldr(Variable *Dest, OperandARM32Mem *Mem,
CondARM32::Cond Pred) {
Variable *MemBase = Mem->getBase();
if (Target->NeedSandboxing && baseNeedsBic(MemBase)) {
createAutoBundle();
assert(!Mem->isRegReg());
Target->_bic(MemBase, MemBase, memOpBicMask(Target->Func), Pred);
}
Target->_ldr(Dest, Mem, Pred);
}
void TargetARM32::Sandboxer::ldrex(Variable *Dest, OperandARM32Mem *Mem,
CondARM32::Cond Pred) {
Variable *MemBase = Mem->getBase();
if (Target->NeedSandboxing && baseNeedsBic(MemBase)) {
createAutoBundle();
assert(!Mem->isRegReg());
Target->_bic(MemBase, MemBase, memOpBicMask(Target->Func), Pred);
}
Target->_ldrex(Dest, Mem, Pred);
}
void TargetARM32::Sandboxer::reset_sp(Variable *Src) {
Variable *SP = Target->getPhysicalRegister(RegARM32::Reg_sp);
if (!Target->NeedSandboxing) {
Target->_mov_redefined(SP, Src);
return;
}
createAutoBundle();
Target->_mov_redefined(SP, Src);
Target->_bic(SP, SP, memOpBicMask(Target->Func));
}
void TargetARM32::Sandboxer::ret(Variable *RetAddr, Variable *RetValue) {
if (Target->NeedSandboxing) {
createAutoBundle();
Target->_bic(RetAddr, RetAddr, indirectBranchBicMask(Target->Func));
}
Target->_ret(RetAddr, RetValue);
}
void TargetARM32::Sandboxer::str(Variable *Src, OperandARM32Mem *Mem,
CondARM32::Cond Pred) {
Variable *MemBase = Mem->getBase();
if (Target->NeedSandboxing && baseNeedsBic(MemBase)) {
createAutoBundle();
assert(!Mem->isRegReg());
Target->_bic(MemBase, MemBase, memOpBicMask(Target->Func), Pred);
}
Target->_str(Src, Mem, Pred);
}
void TargetARM32::Sandboxer::strex(Variable *Dest, Variable *Src,
OperandARM32Mem *Mem, CondARM32::Cond Pred) {
Variable *MemBase = Mem->getBase();
if (Target->NeedSandboxing && baseNeedsBic(MemBase)) {
createAutoBundle();
assert(!Mem->isRegReg());
Target->_bic(MemBase, MemBase, memOpBicMask(Target->Func), Pred);
}
Target->_strex(Dest, Src, Mem, Pred);
}
void TargetARM32::Sandboxer::sub_sp(Operand *SubAmount) {
Variable *SP = Target->getPhysicalRegister(RegARM32::Reg_sp);
if (!Target->NeedSandboxing) {
Target->_sub(SP, SP, SubAmount);
return;
}
createAutoBundle();
Target->_sub(SP, SP, SubAmount);
Target->_bic(SP, SP, memOpBicMask(Target->Func));
}
TargetDataARM32::TargetDataARM32(GlobalContext *Ctx)
: TargetDataLowering(Ctx) {}
void TargetDataARM32::lowerGlobals(const VariableDeclarationList &Vars,
const std::string &SectionSuffix) {
const bool IsPIC = getFlags().getUseNonsfi();
switch (getFlags().getOutFileType()) {
case FT_Elf: {
ELFObjectWriter *Writer = Ctx->getObjectWriter();
Writer->writeDataSection(Vars, llvm::ELF::R_ARM_ABS32, SectionSuffix,
IsPIC);
} break;
case FT_Asm:
case FT_Iasm: {
OstreamLocker _(Ctx);
for (const VariableDeclaration *Var : Vars) {
if (getFlags().matchTranslateOnly(Var->getName(), 0)) {
emitGlobal(*Var, SectionSuffix);
}
}
} break;
}
}
namespace {
template <typename T> struct ConstantPoolEmitterTraits;
static_assert(sizeof(uint64_t) == 8,
"uint64_t is supposed to be 8 bytes wide.");
// TODO(jpp): implement the following when implementing constant randomization:
// * template <> struct ConstantPoolEmitterTraits<uint8_t>
// * template <> struct ConstantPoolEmitterTraits<uint16_t>
// * template <> struct ConstantPoolEmitterTraits<uint32_t>
template <> struct ConstantPoolEmitterTraits<float> {
using ConstantType = ConstantFloat;
static constexpr Type IceType = IceType_f32;
// AsmTag and TypeName can't be constexpr because llvm::StringRef is unhappy
// about them being constexpr.
static const char AsmTag[];
static const char TypeName[];
static uint64_t bitcastToUint64(float Value) {
static_assert(sizeof(Value) == sizeof(uint32_t),
"Float should be 4 bytes.");
const uint32_t IntValue = Utils::bitCopy<uint32_t>(Value);
return static_cast<uint64_t>(IntValue);
}
};
const char ConstantPoolEmitterTraits<float>::AsmTag[] = ".long";
const char ConstantPoolEmitterTraits<float>::TypeName[] = "f32";
template <> struct ConstantPoolEmitterTraits<double> {
using ConstantType = ConstantDouble;
static constexpr Type IceType = IceType_f64;
static const char AsmTag[];
static const char TypeName[];
static uint64_t bitcastToUint64(double Value) {
static_assert(sizeof(double) == sizeof(uint64_t),
"Double should be 8 bytes.");
return Utils::bitCopy<uint64_t>(Value);
}
};
const char ConstantPoolEmitterTraits<double>::AsmTag[] = ".quad";
const char ConstantPoolEmitterTraits<double>::TypeName[] = "f64";
template <typename T>
void emitConstant(
Ostream &Str,
const typename ConstantPoolEmitterTraits<T>::ConstantType *Const) {
using Traits = ConstantPoolEmitterTraits<T>;
Str << Const->getLabelName();
Str << ":\n\t" << Traits::AsmTag << "\t0x";
T Value = Const->getValue();
Str.write_hex(Traits::bitcastToUint64(Value));
Str << "\t/* " << Traits::TypeName << " " << Value << " */\n";
}
template <typename T> void emitConstantPool(GlobalContext *Ctx) {
if (!BuildDefs::dump()) {
return;
}
using Traits = ConstantPoolEmitterTraits<T>;
static constexpr size_t MinimumAlignment = 4;
SizeT Align = std::max(MinimumAlignment, typeAlignInBytes(Traits::IceType));
assert((Align % 4) == 0 && "Constants should be aligned");
Ostream &Str = Ctx->getStrEmit();
ConstantList Pool = Ctx->getConstantPool(Traits::IceType);
Str << "\t.section\t.rodata.cst" << Align << ",\"aM\",%progbits," << Align
<< "\n"
<< "\t.align\t" << Align << "\n";
if (getFlags().getReorderPooledConstants()) {
// TODO(jpp): add constant pooling.
UnimplementedError(getFlags());
}
for (Constant *C : Pool) {
if (!C->getShouldBePooled()) {
continue;
}
emitConstant<T>(Str, llvm::dyn_cast<typename Traits::ConstantType>(C));
}
}
} // end of anonymous namespace
void TargetDataARM32::lowerConstants() {
if (getFlags().getDisableTranslation())
return;
switch (getFlags().getOutFileType()) {
case FT_Elf: {
ELFObjectWriter *Writer = Ctx->getObjectWriter();
Writer->writeConstantPool<ConstantFloat>(IceType_f32);
Writer->writeConstantPool<ConstantDouble>(IceType_f64);
} break;
case FT_Asm:
case FT_Iasm: {
OstreamLocker _(Ctx);
emitConstantPool<float>(Ctx);
emitConstantPool<double>(Ctx);
break;
}
}
}
void TargetDataARM32::lowerJumpTables() {
if (getFlags().getDisableTranslation())
return;
switch (getFlags().getOutFileType()) {
case FT_Elf:
if (!Ctx->getJumpTables().empty()) {
llvm::report_fatal_error("ARM32 does not support jump tables yet.");
}
break;
case FT_Asm:
// Already emitted from Cfg
break;
case FT_Iasm: {
// TODO(kschimpf): Fill this in when we get more information.
break;
}
}
}
TargetHeaderARM32::TargetHeaderARM32(GlobalContext *Ctx)
: TargetHeaderLowering(Ctx), CPUFeatures(getFlags()) {}
void TargetHeaderARM32::lower() {
OstreamLocker _(Ctx);
Ostream &Str = Ctx->getStrEmit();
Str << ".syntax unified\n";
// Emit build attributes in format: .eabi_attribute TAG, VALUE. See Sec. 2 of
// "Addenda to, and Errata in the ABI for the ARM architecture"
// http://infocenter.arm.com
// /help/topic/com.arm.doc.ihi0045d/IHI0045D_ABI_addenda.pdf
//
// Tag_conformance should be be emitted first in a file-scope sub-subsection
// of the first public subsection of the attributes.
Str << ".eabi_attribute 67, \"2.09\" @ Tag_conformance\n";
// Chromebooks are at least A15, but do A9 for higher compat. For some
// reason, the LLVM ARM asm parser has the .cpu directive override the mattr
// specified on the commandline. So to test hwdiv, we need to set the .cpu
// directive higher (can't just rely on --mattr=...).
if (CPUFeatures.hasFeature(TargetARM32Features::HWDivArm)) {
Str << ".cpu cortex-a15\n";
} else {
Str << ".cpu cortex-a9\n";
}
Str << ".eabi_attribute 6, 10 @ Tag_CPU_arch: ARMv7\n"
<< ".eabi_attribute 7, 65 @ Tag_CPU_arch_profile: App profile\n";
Str << ".eabi_attribute 8, 1 @ Tag_ARM_ISA_use: Yes\n"
<< ".eabi_attribute 9, 2 @ Tag_THUMB_ISA_use: Thumb-2\n";
Str << ".fpu neon\n"
<< ".eabi_attribute 17, 1 @ Tag_ABI_PCS_GOT_use: permit directly\n"
<< ".eabi_attribute 20, 1 @ Tag_ABI_FP_denormal\n"
<< ".eabi_attribute 21, 1 @ Tag_ABI_FP_exceptions\n"
<< ".eabi_attribute 23, 3 @ Tag_ABI_FP_number_model: IEEE 754\n"
<< ".eabi_attribute 34, 1 @ Tag_CPU_unaligned_access\n"
<< ".eabi_attribute 24, 1 @ Tag_ABI_align_needed: 8-byte\n"
<< ".eabi_attribute 25, 1 @ Tag_ABI_align_preserved: 8-byte\n"
<< ".eabi_attribute 28, 1 @ Tag_ABI_VFP_args\n"
<< ".eabi_attribute 36, 1 @ Tag_FP_HP_extension\n"
<< ".eabi_attribute 38, 1 @ Tag_ABI_FP_16bit_format\n"
<< ".eabi_attribute 42, 1 @ Tag_MPextension_use\n"
<< ".eabi_attribute 68, 1 @ Tag_Virtualization_use\n";
if (CPUFeatures.hasFeature(TargetARM32Features::HWDivArm)) {
Str << ".eabi_attribute 44, 2 @ Tag_DIV_use\n";
}
// Technically R9 is used for TLS with Sandboxing, and we reserve it.
// However, for compatibility with current NaCl LLVM, don't claim that.
Str << ".eabi_attribute 14, 3 @ Tag_ABI_PCS_R9_use: Not used\n";
}
SmallBitVector TargetARM32::TypeToRegisterSet[RegARM32::RCARM32_NUM];
SmallBitVector TargetARM32::TypeToRegisterSetUnfiltered[RegARM32::RCARM32_NUM];
SmallBitVector TargetARM32::RegisterAliases[RegARM32::Reg_NUM];
} // end of namespace ARM32
} // end of namespace Ice