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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 #include "hydrogen-escape-analysis.h" | 28 #include "hydrogen-sce.h" |
| 29 #include "v8.h" |
29 | 30 |
30 namespace v8 { | 31 namespace v8 { |
31 namespace internal { | 32 namespace internal { |
32 | 33 |
| 34 void HStackCheckEliminationPhase::Run() { |
| 35 // For each loop block walk the dominator tree from the backwards branch to |
| 36 // the loop header. If a call instruction is encountered the backwards branch |
| 37 // is dominated by a call and the stack check in the backwards branch can be |
| 38 // removed. |
| 39 for (int i = 0; i < graph()->blocks()->length(); i++) { |
| 40 HBasicBlock* block = graph()->blocks()->at(i); |
| 41 if (block->IsLoopHeader()) { |
| 42 HBasicBlock* back_edge = block->loop_information()->GetLastBackEdge(); |
| 43 HBasicBlock* dominator = back_edge; |
| 44 while (true) { |
| 45 for (HInstructionIterator it(dominator); !it.Done(); it.Advance()) { |
| 46 if (it.Current()->IsCall()) { |
| 47 block->loop_information()->stack_check()->Eliminate(); |
| 48 break; |
| 49 } |
| 50 } |
33 | 51 |
34 void HEscapeAnalysisPhase::CollectIfNoEscapingUses(HInstruction* instr) { | 52 // Done when the loop header is processed. |
35 for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) { | 53 if (dominator == block) break; |
36 HValue* use = it.value(); | |
37 if (use->HasEscapingOperandAt(it.index())) { | |
38 if (FLAG_trace_escape_analysis) { | |
39 PrintF("#%d (%s) escapes through #%d (%s) @%d\n", instr->id(), | |
40 instr->Mnemonic(), use->id(), use->Mnemonic(), it.index()); | |
41 } | |
42 return; | |
43 } | |
44 } | |
45 if (FLAG_trace_escape_analysis) { | |
46 PrintF("#%d (%s) is being captured\n", instr->id(), instr->Mnemonic()); | |
47 } | |
48 captured_.Add(instr, zone()); | |
49 } | |
50 | 54 |
51 | 55 // Move up the dominator tree. |
52 void HEscapeAnalysisPhase::CollectCapturedValues() { | 56 dominator = dominator->dominator(); |
53 int block_count = graph()->blocks()->length(); | |
54 for (int i = 0; i < block_count; ++i) { | |
55 HBasicBlock* block = graph()->blocks()->at(i); | |
56 for (HInstructionIterator it(block); !it.Done(); it.Advance()) { | |
57 HInstruction* instr = it.Current(); | |
58 if (instr->IsAllocate() || instr->IsAllocateObject()) { | |
59 CollectIfNoEscapingUses(instr); | |
60 } | 57 } |
61 } | 58 } |
62 } | 59 } |
63 } | 60 } |
64 | 61 |
65 | |
66 } } // namespace v8::internal | 62 } } // namespace v8::internal |
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