diff options
| -rw-r--r-- | compiler/optimizing/constant_folding.cc | 20 | ||||
| -rw-r--r-- | test/442-checker-constant-folding/src/Main.java | 17 |
2 files changed, 37 insertions, 0 deletions
diff --git a/compiler/optimizing/constant_folding.cc b/compiler/optimizing/constant_folding.cc index 09e7cabfa4..2031707759 100644 --- a/compiler/optimizing/constant_folding.cc +++ b/compiler/optimizing/constant_folding.cc @@ -217,6 +217,7 @@ void InstructionWithAbsorbingInputSimplifier::VisitBelowOrEqual(HBelowOrEqual* i } void InstructionWithAbsorbingInputSimplifier::VisitAnd(HAnd* instruction) { + DataType::Type type = instruction->GetType(); HConstant* input_cst = instruction->GetConstantRight(); if ((input_cst != nullptr) && input_cst->IsZeroBitPattern()) { // Replace code looking like @@ -226,6 +227,25 @@ void InstructionWithAbsorbingInputSimplifier::VisitAnd(HAnd* instruction) { instruction->ReplaceWith(input_cst); instruction->GetBlock()->RemoveInstruction(instruction); } + + HInstruction* left = instruction->GetLeft(); + HInstruction* right = instruction->GetRight(); + + if (left->IsNot() ^ right->IsNot()) { + // Replace code looking like + // NOT notsrc, src + // AND dst, notsrc, src + // with + // CONSTANT 0 + HInstruction* hnot = (left->IsNot() ? left : right); + HInstruction* hother = (left->IsNot() ? right : left); + HInstruction* src = hnot->AsNot()->GetInput(); + + if (src == hother) { + instruction->ReplaceWith(GetGraph()->GetConstant(type, 0)); + instruction->GetBlock()->RemoveInstruction(instruction); + } + } } void InstructionWithAbsorbingInputSimplifier::VisitCompare(HCompare* instruction) { diff --git a/test/442-checker-constant-folding/src/Main.java b/test/442-checker-constant-folding/src/Main.java index 3d9294304d..45157abf1a 100644 --- a/test/442-checker-constant-folding/src/Main.java +++ b/test/442-checker-constant-folding/src/Main.java @@ -864,6 +864,23 @@ public class Main { return lhs & rhs; } + /// CHECK-START: int Main.AndSelfNegated(int) constant_folding (before) + /// CHECK-DAG: <<Arg:i\d+>> ParameterValue + /// CHECK-DAG: <<Not:i\d+>> Not [<<Arg>>] + /// CHECK-DAG: <<And:i\d+>> And [<<Not>>,<<Arg>>] + /// CHECK-DAG: Return [<<And>>] + + /// CHECK-START: int Main.AndSelfNegated(int) constant_folding (after) + /// CHECK-DAG: <<Const0:i\d+>> IntConstant 0 + /// CHECK-DAG: Return [<<Const0>>] + + /// CHECK-START: int Main.AndSelfNegated(int) constant_folding (after) + /// CHECK-NOT: And + + public static int AndSelfNegated(int arg) { + return arg & ~arg; + } + /** * Exercise constant folding on logical or. |