diff options
| -rw-r--r-- | compiler/optimizing/ssa_phi_elimination.cc | 21 | ||||
| -rw-r--r-- | test/510-checker-try-catch/smali/SsaBuilder.smali | 36 |
2 files changed, 44 insertions, 13 deletions
diff --git a/compiler/optimizing/ssa_phi_elimination.cc b/compiler/optimizing/ssa_phi_elimination.cc index 917341a1e7..a9f04cd201 100644 --- a/compiler/optimizing/ssa_phi_elimination.cc +++ b/compiler/optimizing/ssa_phi_elimination.cc @@ -98,7 +98,8 @@ void SsaDeadPhiElimination::EliminateDeadPhis() { } void SsaRedundantPhiElimination::Run() { - // Add all phis in the worklist. + // Add all phis in the worklist. Order does not matter for correctness, and + // neither will necessarily converge faster. for (HReversePostOrderIterator it(*graph_); !it.Done(); it.Advance()) { HBasicBlock* block = it.Current(); for (HInstructionIterator inst_it(block->GetPhis()); !inst_it.Done(); inst_it.Advance()) { @@ -148,18 +149,16 @@ void SsaRedundantPhiElimination::Run() { continue; } - if (phi->IsInLoop()) { - // Because we're updating the users of this phi, we may have new - // phis candidate for elimination if this phi is in a loop. Add phis that - // used this phi to the worklist. - for (HUseIterator<HInstruction*> it(phi->GetUses()); !it.Done(); it.Advance()) { - HUseListNode<HInstruction*>* current = it.Current(); - HInstruction* user = current->GetUser(); - if (user->IsPhi()) { - worklist_.Add(user->AsPhi()); - } + // Because we're updating the users of this phi, we may have new candidates + // for elimination. Add phis that use this phi to the worklist. + for (HUseIterator<HInstruction*> it(phi->GetUses()); !it.Done(); it.Advance()) { + HUseListNode<HInstruction*>* current = it.Current(); + HInstruction* user = current->GetUser(); + if (user->IsPhi()) { + worklist_.Add(user->AsPhi()); } } + phi->ReplaceWith(candidate); phi->GetBlock()->RemovePhi(phi); } diff --git a/test/510-checker-try-catch/smali/SsaBuilder.smali b/test/510-checker-try-catch/smali/SsaBuilder.smali index 2ddcbced9c..710e849c45 100644 --- a/test/510-checker-try-catch/smali/SsaBuilder.smali +++ b/test/510-checker-try-catch/smali/SsaBuilder.smali @@ -124,7 +124,7 @@ # Tests that phi elimination does not remove catch phis where the value does # not dominate the phi. -## CHECK-START: int SsaBuilder.testPhiElimination(int, int) ssa_builder (after) +## CHECK-START: int SsaBuilder.testPhiElimination_Domination(int, int) ssa_builder (after) ## CHECK-DAG: <<P0:i\d+>> ParameterValue ## CHECK-DAG: <<P1:i\d+>> ParameterValue ## CHECK-DAG: <<Cst5:i\d+>> IntConstant 5 @@ -140,7 +140,7 @@ ## CHECK-DAG: <<Phi2:i\d+>> Phi [<<Cst5>>,<<Add2>>] reg:0 is_catch_phi:false ## CHECK-DAG: Return [<<Phi2>>] -.method public static testPhiElimination(II)I +.method public static testPhiElimination_Domination(II)I .registers 4 :try_start @@ -163,6 +163,38 @@ goto :return .end method +# Tests that phi elimination loops until no more phis can be removed. + +## CHECK-START: int SsaBuilder.testPhiElimination_Dependencies(int, int, int) ssa_builder (after) +## CHECK-NOT: Phi + +.method public static testPhiElimination_Dependencies(III)I + .registers 4 + + # This constant reaches Return via the normal control-flow path and both + # exceptional paths. Since v0 is never changed, there should be no phis. + const v0, 5 + + :try_start + div-int/2addr p0, p1 + div-int/2addr p0, p2 + :try_end + .catch Ljava/lang/ArithmeticException; {:try_start .. :try_end} :catch_arith + .catchall {:try_start .. :try_end} :catch_all + + :return + # Phi [v0, CatchPhi1, CatchPhi2] + return v0 + + :catch_arith + # CatchPhi1 [v0, v0] + goto :return + + :catch_all + # CatchPhi2 [v0, v0] + goto :return +.end method + # Tests that dead catch blocks are removed. ## CHECK-START: int SsaBuilder.testDeadCatchBlock(int, int, int) ssa_builder (before) |