Revert "Revert "ART: Ignore try blocks with no throwing instructions""
The original CL broke libcore tests because monitor-exit instructions
did not have any side-effects and got removed by DCE once not labelled
throwing any more.
This reverts commit efe374d7c25c1d48945a9198d96469de99e0c1bd.
Change-Id: I624c0f91676d9baaada6f33be9d7091f68d57535
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index e4a7aa6..59255d1 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -4131,13 +4131,19 @@
};
HMonitorOperation(HInstruction* object, OperationKind kind, uint32_t dex_pc)
- : HTemplateInstruction(SideEffects::None()), kind_(kind), dex_pc_(dex_pc) {
+ : HTemplateInstruction(SideEffects::ChangesSomething()), kind_(kind), dex_pc_(dex_pc) {
SetRawInputAt(0, object);
}
// Instruction may throw a Java exception, so we need an environment.
- bool NeedsEnvironment() const OVERRIDE { return true; }
- bool CanThrow() const OVERRIDE { return true; }
+ bool NeedsEnvironment() const OVERRIDE { return CanThrow(); }
+
+ bool CanThrow() const OVERRIDE {
+ // Verifier guarantees that monitor-exit cannot throw.
+ // This is important because it allows the HGraphBuilder to remove
+ // a dead throw-catch loop generated for `synchronized` blocks/methods.
+ return IsEnter();
+ }
uint32_t GetDexPc() const OVERRIDE { return dex_pc_; }