Optimizing/ARM: Fix CmpConstant().

CMN updates flags based on addition of its operands.
Do not confuse the "N" suffix with bitwise inversion
performed by MVN.

Also add more special cases analogous to AddConstant()
and use CmpConstant() more in code generator.

Change-Id: I0d4571770a3f0fdf162e97d4bde56814098e7246

1 files changed, 6 insertions, 17 deletions

diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 9fda83840c..680b200c69 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -1358,17 +1358,6 @@ void LocationsBuilderARM::VisitExit(HExit* exit) {
 void InstructionCodeGeneratorARM::VisitExit(HExit* exit ATTRIBUTE_UNUSED) {
 }
 
-void InstructionCodeGeneratorARM::GenerateCompareWithImmediate(Register left, int32_t right) {
-  ShifterOperand operand;
-  if (GetAssembler()->ShifterOperandCanHold(R0, left, CMP, right, &operand)) {
-    __ cmp(left, operand);
-  } else {
-    Register temp = IP;
-    __ LoadImmediate(temp, right);
-    __ cmp(left, ShifterOperand(temp));
-  }
-}
-
 void InstructionCodeGeneratorARM::GenerateFPJumps(HCondition* cond,
                                                   Label* true_label,
                                                   Label* false_label) {
@@ -1434,7 +1423,7 @@ void InstructionCodeGeneratorARM::GenerateLongComparesAndJumps(HCondition* cond,
     int32_t val_low = Low32Bits(value);
     int32_t val_high = High32Bits(value);
 
-    GenerateCompareWithImmediate(left_high, val_high);
+    __ CmpConstant(left_high, val_high);
     if (if_cond == kCondNE) {
       __ b(true_label, ARMCondition(true_high_cond));
     } else if (if_cond == kCondEQ) {
@@ -1444,7 +1433,7 @@ void InstructionCodeGeneratorARM::GenerateLongComparesAndJumps(HCondition* cond,
       __ b(false_label, ARMCondition(false_high_cond));
     }
     // Must be equal high, so compare the lows.
-    GenerateCompareWithImmediate(left_low, val_low);
+    __ CmpConstant(left_low, val_low);
   } else {
     Register right_high = right.AsRegisterPairHigh<Register>();
     Register right_low = right.AsRegisterPairLow<Register>();
@@ -1568,7 +1557,7 @@ void InstructionCodeGeneratorARM::GenerateTestAndBranch(HInstruction* instructio
       __ cmp(left, ShifterOperand(right.AsRegister<Register>()));
     } else {
       DCHECK(right.IsConstant());
-      GenerateCompareWithImmediate(left, CodeGenerator::GetInt32ValueOf(right.GetConstant()));
+      __ CmpConstant(left, CodeGenerator::GetInt32ValueOf(right.GetConstant()));
     }
     if (true_target == nullptr) {
       __ b(false_target, ARMCondition(condition->GetOppositeCondition()));
@@ -1667,8 +1656,8 @@ void InstructionCodeGeneratorARM::VisitCondition(HCondition* cond) {
         __ cmp(left.AsRegister<Register>(), ShifterOperand(right.AsRegister<Register>()));
       } else {
         DCHECK(right.IsConstant());
-        GenerateCompareWithImmediate(left.AsRegister<Register>(),
-                                     CodeGenerator::GetInt32ValueOf(right.GetConstant()));
+        __ CmpConstant(left.AsRegister<Register>(),
+                       CodeGenerator::GetInt32ValueOf(right.GetConstant()));
       }
       __ it(ARMCondition(cond->GetCondition()), kItElse);
       __ mov(locations->Out().AsRegister<Register>(), ShifterOperand(1),
@@ -6288,7 +6277,7 @@ void InstructionCodeGeneratorARM::VisitPackedSwitch(HPackedSwitch* switch_instr)
     }
     if (num_entries - last_index == 2) {
       // The last missing case_value.
-      GenerateCompareWithImmediate(temp_reg, 1);
+      __ CmpConstant(temp_reg, 1);
       __ b(codegen_->GetLabelOf(successors[last_index + 1]), EQ);
     }