danno@chromium.org | 169691d | 2013-07-15 08:01:13 +0000 | [diff] [blame] | 1 | // Copyright 2013 the V8 project authors. All rights reserved. |
| 2 | // Redistribution and use in source and binary forms, with or without |
| 3 | // modification, are permitted provided that the following conditions are |
| 4 | // met: |
| 5 | // |
| 6 | // * Redistributions of source code must retain the above copyright |
| 7 | // notice, this list of conditions and the following disclaimer. |
| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
| 11 | // with the distribution. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 14 | // from this software without specific prior written permission. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 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. |
| 27 | |
| 28 | #include "hydrogen-dehoist.h" |
| 29 | |
| 30 | namespace v8 { |
| 31 | namespace internal { |
| 32 | |
| 33 | static void DehoistArrayIndex(ArrayInstructionInterface* array_operation) { |
| 34 | HValue* index = array_operation->GetKey()->ActualValue(); |
| 35 | if (!index->representation().IsSmiOrInteger32()) return; |
| 36 | if (!index->IsAdd() && !index->IsSub()) return; |
| 37 | |
| 38 | HConstant* constant; |
| 39 | HValue* subexpression; |
| 40 | HBinaryOperation* binary_operation = HBinaryOperation::cast(index); |
danno@chromium.org | c16e828 | 2013-08-12 16:17:40 +0000 | [diff] [blame] | 41 | if (binary_operation->left()->IsConstant() && index->IsAdd()) { |
danno@chromium.org | 169691d | 2013-07-15 08:01:13 +0000 | [diff] [blame] | 42 | subexpression = binary_operation->right(); |
| 43 | constant = HConstant::cast(binary_operation->left()); |
| 44 | } else if (binary_operation->right()->IsConstant()) { |
| 45 | subexpression = binary_operation->left(); |
| 46 | constant = HConstant::cast(binary_operation->right()); |
| 47 | } else { |
| 48 | return; |
| 49 | } |
| 50 | |
| 51 | if (!constant->HasInteger32Value()) return; |
| 52 | int32_t sign = binary_operation->IsSub() ? -1 : 1; |
| 53 | int32_t value = constant->Integer32Value() * sign; |
| 54 | // We limit offset values to 30 bits because we want to avoid the risk of |
| 55 | // overflows when the offset is added to the object header size. |
| 56 | if (value >= 1 << 30 || value < 0) return; |
| 57 | array_operation->SetKey(subexpression); |
| 58 | if (binary_operation->HasNoUses()) { |
| 59 | binary_operation->DeleteAndReplaceWith(NULL); |
| 60 | } |
| 61 | array_operation->SetIndexOffset(static_cast<uint32_t>(value)); |
| 62 | array_operation->SetDehoisted(true); |
| 63 | } |
| 64 | |
| 65 | |
| 66 | void HDehoistIndexComputationsPhase::Run() { |
| 67 | const ZoneList<HBasicBlock*>* blocks(graph()->blocks()); |
| 68 | for (int i = 0; i < blocks->length(); ++i) { |
| 69 | for (HInstructionIterator it(blocks->at(i)); !it.Done(); it.Advance()) { |
| 70 | HInstruction* instr = it.Current(); |
| 71 | if (instr->IsLoadKeyed()) { |
| 72 | DehoistArrayIndex(HLoadKeyed::cast(instr)); |
| 73 | } else if (instr->IsStoreKeyed()) { |
| 74 | DehoistArrayIndex(HStoreKeyed::cast(instr)); |
| 75 | } |
| 76 | } |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | } } // namespace v8::internal |