| // Copyright 2015 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. |
| |
| // Flags: --allow-natives-syntax |
| |
| function boom(a1, a2) { |
| // Do something with a2 that needs a map check (for DOUBLE_ELEMENTS). |
| var s = a2[0]; |
| // Emit a load that transitions a1 to FAST_ELEMENTS. |
| var t = a1[0]; |
| // Emit a store to a2 that assumes DOUBLE_ELEMENTS. |
| // The map check is considered redundant and will be eliminated. |
| a2[0] = 0.3; |
| } |
| |
| // Prepare type feedback for the "t = a1[0]" load: fast elements. |
| var fast_elem = new Array(1); |
| fast_elem[0] = "tagged"; |
| boom(fast_elem, [1]); |
| |
| // Prepare type feedback for the "a2[0] = 0.3" store: double elements. |
| var double_elem = new Array(1); |
| double_elem[0] = 0.1; |
| boom(double_elem, double_elem); |
| |
| // Reset |double_elem| and go have a party. |
| double_elem = new Array(10); |
| double_elem[0] = 0.1; |
| |
| %OptimizeFunctionOnNextCall(boom); |
| boom(double_elem, double_elem); |
| |
| assertEquals(0.3, double_elem[0]); |
| assertEquals(undefined, double_elem[1]); |
