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| author | Alexandre Rames <alexandre.rames@arm.com> | 2015-02-17 15:08:20 +0000 |
|---|---|---|
| committer | Alexandre Rames <alexandre.rames@arm.com> | 2015-02-17 15:08:20 +0000 |
| commit | 9341546f1e5177a0328c67c5899ee81d19bd5d88 (patch) | |
| tree | 80ffb6a99abae69d9a6b1b4ef17ee6d4f68c02d6 | |
| parent | 6e27f82193a8f54cd8ecdc8fb2c4c1adadafbaf4 (diff) | |
| download | art-9341546f1e5177a0328c67c5899ee81d19bd5d88.tar.gz art-9341546f1e5177a0328c67c5899ee81d19bd5d88.tar.bz2 art-9341546f1e5177a0328c67c5899ee81d19bd5d88.zip | |
Opt compiler: ARM64: Optimise floating-point comparison with 0.0.
Change-Id: I297ed92445f20fae2ebf301e90e97772072da364
| -rw-r--r-- | compiler/optimizing/code_generator_arm64.cc | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc index ec716a414e..32721e0efc 100644 --- a/compiler/optimizing/code_generator_arm64.cc +++ b/compiler/optimizing/code_generator_arm64.cc @@ -1388,7 +1388,13 @@ void LocationsBuilderARM64::VisitCompare(HCompare* compare) { case Primitive::kPrimFloat: case Primitive::kPrimDouble: { locations->SetInAt(0, Location::RequiresFpuRegister()); - locations->SetInAt(1, Location::RequiresFpuRegister()); + HInstruction* right = compare->InputAt(1); + if ((right->IsFloatConstant() && (right->AsFloatConstant()->GetValue() == 0.0f)) || + (right->IsDoubleConstant() && (right->AsDoubleConstant()->GetValue() == 0.0))) { + locations->SetInAt(1, Location::ConstantLocation(right->AsConstant())); + } else { + locations->SetInAt(1, Location::RequiresFpuRegister()); + } locations->SetOut(Location::RequiresRegister()); break; } @@ -1418,9 +1424,17 @@ void InstructionCodeGeneratorARM64::VisitCompare(HCompare* compare) { case Primitive::kPrimDouble: { Register result = OutputRegister(compare); FPRegister left = InputFPRegisterAt(compare, 0); - FPRegister right = InputFPRegisterAt(compare, 1); - - __ Fcmp(left, right); + if (compare->GetLocations()->InAt(1).IsConstant()) { + if (kIsDebugBuild) { + HInstruction* right = compare->GetLocations()->InAt(1).GetConstant(); + DCHECK((right->IsFloatConstant() && (right->AsFloatConstant()->GetValue() == 0.0f)) || + (right->IsDoubleConstant() && (right->AsDoubleConstant()->GetValue() == 0.0))); + } + // 0.0 is the only immediate that can be encoded directly in a FCMP instruction. + __ Fcmp(left, 0.0); + } else { + __ Fcmp(left, InputFPRegisterAt(compare, 1)); + } if (compare->IsGtBias()) { __ Cset(result, ne); } else { |