upload android base code part3

android/art/compiler/optimizing/side_effects_analysis.cc

@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "side_effects_analysis.h"
+
+namespace art {
+
+void SideEffectsAnalysis::Run() {
+  // Inlining might have created more blocks, so we need to increase the size
+  // if needed.
+  block_effects_.resize(graph_->GetBlocks().size());
+  loop_effects_.resize(graph_->GetBlocks().size());
+
+  // In DEBUG mode, ensure side effects are properly initialized to empty.
+  if (kIsDebugBuild) {
+    for (HBasicBlock* block : graph_->GetReversePostOrder()) {
+      SideEffects effects = GetBlockEffects(block);
+      DCHECK(effects.DoesNothing());
+      if (block->IsLoopHeader()) {
+        effects = GetLoopEffects(block);
+        DCHECK(effects.DoesNothing());
+      }
+    }
+  }
+
+  // Do a post order visit to ensure we visit a loop header after its loop body.
+  for (HBasicBlock* block : graph_->GetPostOrder()) {
+    SideEffects effects = SideEffects::None();
+    // Update `effects` with the side effects of all instructions in this block.
+    for (HInstructionIterator inst_it(block->GetInstructions()); !inst_it.Done();
+         inst_it.Advance()) {
+      HInstruction* instruction = inst_it.Current();
+      effects = effects.Union(instruction->GetSideEffects());
+      // If all side effects are represented, scanning further will not add any
+      // more information to side-effects of this block.
+      if (effects.DoesAll()) {
+        break;
+      }
+    }
+
+    block_effects_[block->GetBlockId()] = effects;
+
+    if (block->IsLoopHeader()) {
+      // The side effects of the loop header are part of the loop.
+      UpdateLoopEffects(block->GetLoopInformation(), effects);
+      HBasicBlock* pre_header = block->GetLoopInformation()->GetPreHeader();
+      if (pre_header->IsInLoop()) {
+        // Update the side effects of the outer loop with the side effects of the inner loop.
+        // Note that this works because we know all the blocks of the inner loop are visited
+        // before the loop header of the outer loop.
+        UpdateLoopEffects(pre_header->GetLoopInformation(), GetLoopEffects(block));
+      }
+    } else if (block->IsInLoop()) {
+      // Update the side effects of the loop with the side effects of this block.
+      UpdateLoopEffects(block->GetLoopInformation(), effects);
+    }
+  }
+  has_run_ = true;
+}
+
+SideEffects SideEffectsAnalysis::GetLoopEffects(HBasicBlock* block) const {
+  DCHECK(block->IsLoopHeader());
+  return loop_effects_[block->GetBlockId()];
+}
+
+SideEffects SideEffectsAnalysis::GetBlockEffects(HBasicBlock* block) const {
+  return block_effects_[block->GetBlockId()];
+}
+
+void SideEffectsAnalysis::UpdateLoopEffects(HLoopInformation* info, SideEffects effects) {
+  uint32_t id = info->GetHeader()->GetBlockId();
+  loop_effects_[id] = loop_effects_[id].Union(effects);
+}
+
+}  // namespace art