ART: Implement HBooleanNot instruction

Optimizations simplifying operations on boolean values (boolean
simplifier, instruction simplifier) can benefit from having a special
HInstruction for negating booleans in order to perform more transforms
and produce faster machine code.

This patch implements HBooleanNot as 'x xor 1', assuming that booleans
are 1-bit integers and allowing for a single-instruction negation on
all supported platforms.

Change-Id: I33a2649c1821255b18a86ca68ed16416063c739f

1 files changed, 15 insertions, 0 deletions

diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 332c99ae64..72b07cd9e8 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -2657,6 +2657,21 @@ void InstructionCodeGeneratorARM::VisitNot(HNot* not_) {
   }
 }
 
+void LocationsBuilderARM::VisitBooleanNot(HBooleanNot* bool_not) {
+  LocationSummary* locations =
+      new (GetGraph()->GetArena()) LocationSummary(bool_not, LocationSummary::kNoCall);
+  locations->SetInAt(0, Location::RequiresRegister());
+  locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
+}
+
+void InstructionCodeGeneratorARM::VisitBooleanNot(HBooleanNot* bool_not) {
+  DCHECK_EQ(bool_not->InputAt(0)->GetType(), Primitive::kPrimBoolean);
+  LocationSummary* locations = bool_not->GetLocations();
+  Location out = locations->Out();
+  Location in = locations->InAt(0);
+  __ eor(out.AsRegister<Register>(), in.AsRegister<Register>(), ShifterOperand(1));
+}
+
 void LocationsBuilderARM::VisitCompare(HCompare* compare) {
   LocationSummary* locations =
       new (GetGraph()->GetArena()) LocationSummary(compare, LocationSummary::kNoCall);