src/x64/codegen-x64.cc

// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#if V8_TARGET_ARCH_X64

#include "src/codegen.h"
#include "src/macro-assembler.h"
#include "src/x64/assembler-x64-inl.h"

namespace v8 {
namespace internal {

#define __ masm.

UnaryMathFunction CreateSqrtFunction() {
  DCHECK(!FLAG_jitless);
  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
  size_t allocated = 0;
  byte* buffer = AllocatePage(page_allocator,
                              page_allocator->GetRandomMmapAddr(), &allocated);
  if (buffer == nullptr) return nullptr;

  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));

  // xmm0: raw double input.
  // Move double input into registers.
  __ Sqrtsd(xmm0, xmm0);
  __ Ret();

  CodeDesc desc;
  masm.GetCode(nullptr, &desc);
  DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));

  Assembler::FlushICache(buffer, allocated);
  CHECK(SetPermissions(page_allocator, buffer, allocated,
                       PageAllocator::kReadExecute));
  return FUNCTION_CAST<UnaryMathFunction>(buffer);
}

#undef __

}  // namespace internal
}  // namespace v8

#endif  // V8_TARGET_ARCH_X64