Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | // Flags: --allow-natives-syntax |
| 6 | |
| 7 | function boom(a1, a2) { |
| 8 | // Do something with a2 that needs a map check (for DOUBLE_ELEMENTS). |
| 9 | var s = a2[0]; |
| 10 | // Emit a load that transitions a1 to FAST_ELEMENTS. |
| 11 | var t = a1[0]; |
| 12 | // Emit a store to a2 that assumes DOUBLE_ELEMENTS. |
| 13 | // The map check is considered redundant and will be eliminated. |
| 14 | a2[0] = 0.3; |
| 15 | } |
| 16 | |
| 17 | // Prepare type feedback for the "t = a1[0]" load: fast elements. |
| 18 | var fast_elem = new Array(1); |
| 19 | fast_elem[0] = "tagged"; |
| 20 | boom(fast_elem, [1]); |
| 21 | |
| 22 | // Prepare type feedback for the "a2[0] = 0.3" store: double elements. |
| 23 | var double_elem = new Array(1); |
| 24 | double_elem[0] = 0.1; |
| 25 | boom(double_elem, double_elem); |
| 26 | |
| 27 | // Reset |double_elem| and go have a party. |
| 28 | double_elem = new Array(10); |
| 29 | double_elem[0] = 0.1; |
| 30 | |
| 31 | %OptimizeFunctionOnNextCall(boom); |
| 32 | boom(double_elem, double_elem); |
| 33 | |
| 34 | assertEquals(0.3, double_elem[0]); |
| 35 | assertEquals(undefined, double_elem[1]); |