From e161a2a60c0325793f04be42a0f05228955ecfdd Mon Sep 17 00:00:00 2001 From: Roland Levillain Date: Fri, 3 Oct 2014 12:45:18 +0100 Subject: Do not remove NullChecks & BoundsChecks in HDeadCodeElimination. Removing a NullCheck or a BoundsCheck instruction may change the behavior of a program. Change-Id: Ib2c9beff0cc98c382210e7cc88b1fa9af3c61887 --- compiler/optimizing/dead_code_elimination.cc | 5 ++++- compiler/optimizing/nodes.h | 5 +++++ 2 files changed, 9 insertions(+), 1 deletion(-) (limited to 'compiler/optimizing') diff --git a/compiler/optimizing/dead_code_elimination.cc b/compiler/optimizing/dead_code_elimination.cc index fe2adc77d0..5655544427 100644 --- a/compiler/optimizing/dead_code_elimination.cc +++ b/compiler/optimizing/dead_code_elimination.cc @@ -35,7 +35,10 @@ void DeadCodeElimination::Run() { for (i.Advance(); !i.Done(); i.Advance()) { HInstruction* inst = i.Current(); DCHECK(!inst->IsControlFlow()); - if (!inst->HasSideEffects() && !inst->HasUses() && !inst->IsSuspendCheck()) { + if (!inst->HasSideEffects() + && !inst->CanThrow() + && !inst->IsSuspendCheck() + && !inst->HasUses()) { block->RemoveInstruction(inst); } } diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h index 677a4f8591..c6eb806904 100644 --- a/compiler/optimizing/nodes.h +++ b/compiler/optimizing/nodes.h @@ -650,6 +650,7 @@ class HInstruction : public ArenaObject { virtual bool NeedsEnvironment() const { return false; } virtual bool IsControlFlow() const { return false; } + virtual bool CanThrow() const { return false; } bool HasSideEffects() const { return side_effects_.HasSideEffects(); } void AddUseAt(HInstruction* user, size_t index) { @@ -1642,6 +1643,8 @@ class HNullCheck : public HExpression<1> { virtual bool NeedsEnvironment() const { return true; } + virtual bool CanThrow() const { return true; } + uint32_t GetDexPc() const { return dex_pc_; } DECLARE_INSTRUCTION(NullCheck); @@ -1802,6 +1805,8 @@ class HBoundsCheck : public HExpression<2> { virtual bool NeedsEnvironment() const { return true; } + virtual bool CanThrow() const { return true; } + uint32_t GetDexPc() const { return dex_pc_; } DECLARE_INSTRUCTION(BoundsCheck); -- cgit v1.2.3-59-g8ed1b