Nicolas Geoffray | 827eedb | 2015-01-26 15:18:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include "side_effects_analysis.h" |
| 18 | |
| 19 | namespace art { |
| 20 | |
| 21 | void SideEffectsAnalysis::Run() { |
Nicolas Geoffray | 276d9da | 2015-02-02 18:24:11 +0000 | [diff] [blame] | 22 | // Inlining might have created more blocks, so we need to increase the size |
| 23 | // if needed. |
| 24 | block_effects_.SetSize(graph_->GetBlocks().Size()); |
| 25 | loop_effects_.SetSize(graph_->GetBlocks().Size()); |
| 26 | |
Nicolas Geoffray | 827eedb | 2015-01-26 15:18:36 +0000 | [diff] [blame] | 27 | if (kIsDebugBuild) { |
| 28 | for (HReversePostOrderIterator it(*graph_); !it.Done(); it.Advance()) { |
| 29 | HBasicBlock* block = it.Current(); |
| 30 | SideEffects effects = GetBlockEffects(block); |
| 31 | DCHECK(!effects.HasSideEffects() && !effects.HasDependencies()); |
| 32 | if (block->IsLoopHeader()) { |
| 33 | effects = GetLoopEffects(block); |
| 34 | DCHECK(!effects.HasSideEffects() && !effects.HasDependencies()); |
| 35 | } |
| 36 | } |
| 37 | } |
| 38 | |
| 39 | // Do a post order visit to ensure we visit a loop header after its loop body. |
| 40 | for (HPostOrderIterator it(*graph_); !it.Done(); it.Advance()) { |
| 41 | HBasicBlock* block = it.Current(); |
| 42 | |
| 43 | SideEffects effects = SideEffects::None(); |
| 44 | // Update `effects` with the side effects of all instructions in this block. |
| 45 | for (HInstructionIterator inst_it(block->GetInstructions()); !inst_it.Done(); |
| 46 | inst_it.Advance()) { |
| 47 | HInstruction* instruction = inst_it.Current(); |
| 48 | effects = effects.Union(instruction->GetSideEffects()); |
| 49 | if (effects.HasAllSideEffects()) { |
| 50 | break; |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | block_effects_.Put(block->GetBlockId(), effects); |
| 55 | |
| 56 | if (block->IsLoopHeader()) { |
| 57 | // The side effects of the loop header are part of the loop. |
| 58 | UpdateLoopEffects(block->GetLoopInformation(), effects); |
| 59 | HBasicBlock* pre_header = block->GetLoopInformation()->GetPreHeader(); |
| 60 | if (pre_header->IsInLoop()) { |
| 61 | // Update the side effects of the outer loop with the side effects of the inner loop. |
| 62 | // Note that this works because we know all the blocks of the inner loop are visited |
| 63 | // before the loop header of the outer loop. |
| 64 | UpdateLoopEffects(pre_header->GetLoopInformation(), GetLoopEffects(block)); |
| 65 | } |
| 66 | } else if (block->IsInLoop()) { |
| 67 | // Update the side effects of the loop with the side effects of this block. |
| 68 | UpdateLoopEffects(block->GetLoopInformation(), effects); |
| 69 | } |
| 70 | } |
| 71 | has_run_ = true; |
| 72 | } |
| 73 | |
| 74 | SideEffects SideEffectsAnalysis::GetLoopEffects(HBasicBlock* block) const { |
| 75 | DCHECK(block->IsLoopHeader()); |
| 76 | return loop_effects_.Get(block->GetBlockId()); |
| 77 | } |
| 78 | |
| 79 | SideEffects SideEffectsAnalysis::GetBlockEffects(HBasicBlock* block) const { |
| 80 | return block_effects_.Get(block->GetBlockId()); |
| 81 | } |
| 82 | |
| 83 | void SideEffectsAnalysis::UpdateLoopEffects(HLoopInformation* info, SideEffects effects) { |
| 84 | int id = info->GetHeader()->GetBlockId(); |
| 85 | loop_effects_.Put(id, loop_effects_.Get(id).Union(effects)); |
| 86 | } |
| 87 | |
| 88 | } // namespace art |