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1 // Copyright 2013 the V8 project authors. All rights reserved. | 1 // Copyright 2013 the V8 project authors. All rights reserved. |
2 // Redistribution and use in source and binary forms, with or without | 2 // Redistribution and use in source and binary forms, with or without |
3 // modification, are permitted provided that the following conditions are | 3 // modification, are permitted provided that the following conditions are |
4 // met: | 4 // met: |
5 // | 5 // |
6 // * Redistributions of source code must retain the above copyright | 6 // * Redistributions of source code must retain the above copyright |
7 // notice, this list of conditions and the following disclaimer. | 7 // notice, this list of conditions and the following disclaimer. |
8 // * Redistributions in binary form must reproduce the above | 8 // * Redistributions in binary form must reproduce the above |
9 // copyright notice, this list of conditions and the following | 9 // copyright notice, this list of conditions and the following |
10 // disclaimer in the documentation and/or other materials provided | 10 // disclaimer in the documentation and/or other materials provided |
11 // with the distribution. | 11 // with the distribution. |
12 // * Neither the name of Google Inc. nor the names of its | 12 // * Neither the name of Google Inc. nor the names of its |
13 // contributors may be used to endorse or promote products derived | 13 // contributors may be used to endorse or promote products derived |
14 // from this software without specific prior written permission. | 14 // from this software without specific prior written permission. |
15 // | 15 // |
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | 27 |
28 // Flags: --allow-natives-syntax | 28 // Flags: --allow-natives-syntax |
29 | 29 |
30 function test() { | 30 // Presents opportunities for dead loop removal. |
31 var string = %NewString(10, true); | 31 |
32 for (var i = 0; i < 10; i++) { | 32 function loop1() { |
33 %_OneByteSeqStringSetChar(string, i, 65); | 33 while (false) ; // doesn't even loop. |
34 %_OneByteSeqStringSetChar(string, i, 66); | 34 } |
35 } | 35 |
36 for (var i = 0; i < 10; i++) { | 36 function loop2() { |
37 assertEquals("B", string[i]); | 37 var i = 0; |
| 38 while (i++ < 10) ; // nothing in the body. |
| 39 } |
| 40 |
| 41 function loop3() { |
| 42 for (var i = 0; i < 10; i++) ; // nothing in the body. |
| 43 } |
| 44 |
| 45 function loop4() { |
| 46 var a = 0; |
| 47 for (var i = 0; i < 10; i++) a++; // {a} is dead after the loop. |
| 48 } |
| 49 |
| 50 function loop5() { |
| 51 var a = new Int32Array(4), sum = 0; |
| 52 for (var i = 0; i < a.length; i++) { |
| 53 // Involves only reads on typed arrays, and {i} doesn't overflow. |
| 54 sum += a[i]; |
38 } | 55 } |
39 } | 56 } |
40 | 57 |
41 test(); | 58 function loop6() { |
42 test(); | 59 var a = new Array(4), sum = 0; |
43 %OptimizeFunctionOnNextCall(test); | 60 for (var i = 0; i < a.length; i++) { |
44 test(); | 61 // Involves only in-bounds read on the array {a}. |
| 62 // Have to prove that {a} doesn't have getters...? |
| 63 sum += a[i]; |
| 64 } |
| 65 } |
| 66 |
| 67 function loop7() { |
| 68 for (var i = 0; i < 10; i++) { |
| 69 new Object(); // Have to prove the allocation doesn't escape. |
| 70 } |
| 71 } |
| 72 |
| 73 function loop8() { |
| 74 for (var i = 0; i < 10; i++) { |
| 75 var x = {}; // Have to prove the allocation doesn't escape. |
| 76 } |
| 77 } |
| 78 |
| 79 var loops = [loop1, loop2, loop3, loop4, loop5, loop6, loop7, loop8]; |
| 80 |
| 81 for (var i = 0; i < loops.length; i++) { |
| 82 var f = loops[i]; |
| 83 f(); |
| 84 f(); |
| 85 %OptimizeFunctionOnNextCall(f); |
| 86 f(); |
| 87 } |
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