Improved side effect analysis (field/array write/read).
Rationale:
Types (int, float etc.) and access type (field vs. array)
can be used to disambiguate write/read side-effects analysis.
This directly improves e.g. dead code elimination and licm.
Change-Id: I371f6909a3f42bda13190a03f04c4a867bde1d06
diff --git a/compiler/optimizing/side_effects_analysis.cc b/compiler/optimizing/side_effects_analysis.cc
index ea1ca5a..9dbf638 100644
--- a/compiler/optimizing/side_effects_analysis.cc
+++ b/compiler/optimizing/side_effects_analysis.cc
@@ -24,14 +24,15 @@
block_effects_.SetSize(graph_->GetBlocks().Size());
loop_effects_.SetSize(graph_->GetBlocks().Size());
+ // In DEBUG mode, ensure side effects are properly initialized to empty.
if (kIsDebugBuild) {
for (HReversePostOrderIterator it(*graph_); !it.Done(); it.Advance()) {
HBasicBlock* block = it.Current();
SideEffects effects = GetBlockEffects(block);
- DCHECK(!effects.HasSideEffects() && !effects.HasDependencies());
+ DCHECK(effects.DoesNothing());
if (block->IsLoopHeader()) {
effects = GetLoopEffects(block);
- DCHECK(!effects.HasSideEffects() && !effects.HasDependencies());
+ DCHECK(effects.DoesNothing());
}
}
}
@@ -46,7 +47,9 @@
inst_it.Advance()) {
HInstruction* instruction = inst_it.Current();
effects = effects.Union(instruction->GetSideEffects());
- if (effects.HasAllSideEffects()) {
+ // If every possible write/read is represented, scanning further
+ // will not add any more information to side-effects of this block.
+ if (effects.DoesAll()) {
break;
}
}