Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1 | // Copyright 2013 the V8 project authors. All rights reserved. |
Steve Block | 1e0659c | 2011-05-24 12:43:12 +0100 | [diff] [blame] | 2 | // Redistribution and use in source and binary forms, with or without |
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Ben Murdoch | 3fb3ca8 | 2011-12-02 17:19:32 +0000 | [diff] [blame] | 28 | // Flags: --allow-natives-syntax |
Steve Block | 1e0659c | 2011-05-24 12:43:12 +0100 | [diff] [blame] | 29 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 30 | // This is a boiled-down example happening in the Epic Citadel demo: |
| 31 | // After deopting, the multiplication for unary minus stayed in Smi |
| 32 | // mode instead of going to double mode, leading to deopt loops. |
Ben Murdoch | 3fb3ca8 | 2011-12-02 17:19:32 +0000 | [diff] [blame] | 33 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 34 | function unaryMinusTest(x) { |
| 35 | var g = (1 << x) | 0; |
| 36 | // Optimized code will contain a LMulI with -1 as right operand. |
| 37 | return (g & -g) - 1 | 0; |
Steve Block | 1e0659c | 2011-05-24 12:43:12 +0100 | [diff] [blame] | 38 | } |
Ben Murdoch | e0cee9b | 2011-05-25 10:26:03 +0100 | [diff] [blame] | 39 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 40 | unaryMinusTest(3); |
| 41 | unaryMinusTest(3); |
| 42 | %OptimizeFunctionOnNextCall(unaryMinusTest); |
| 43 | unaryMinusTest(3); |
| 44 | assertOptimized(unaryMinusTest); |
| 45 | |
| 46 | // Deopt on kMinInt |
| 47 | unaryMinusTest(31); |
| 48 | // The following is normally true, but not with --stress-opt. :-/ |
| 49 | // assertUnoptimized(unaryMinusTest); |
| 50 | |
| 51 | // We should have learned something from the deopt. |
| 52 | unaryMinusTest(31); |
| 53 | %OptimizeFunctionOnNextCall(unaryMinusTest); |
| 54 | unaryMinusTest(31); |
| 55 | assertOptimized(unaryMinusTest); |