MIPS: Use TempDoubleRegister.

Port r21517 (53d6507)

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/305563002

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21537 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-mips.cc

@@ -633,6 +633,19 @@ LUnallocated* LChunkBuilder::TempRegister() {
 }
 
 
+LUnallocated* LChunkBuilder::TempDoubleRegister() {
+  LUnallocated* operand =
+      new(zone()) LUnallocated(LUnallocated::MUST_HAVE_DOUBLE_REGISTER);
+  int vreg = allocator_->GetVirtualRegister();
+  if (!allocator_->AllocationOk()) {
+    Abort(kOutOfVirtualRegistersWhileTryingToAllocateTempRegister);
+    vreg = 0;
+  }
+  operand->set_virtual_register(vreg);
+  return operand;
+}
+
+
 LOperand* LChunkBuilder::FixedTemp(Register reg) {
   LUnallocated* operand = ToUnallocated(reg);
   ASSERT(operand->HasFixedPolicy());
@@ -1134,7 +1147,7 @@ LInstruction* LChunkBuilder::DoMathExp(HUnaryMathOperation* instr) {
   LOperand* input = UseRegister(instr->value());
   LOperand* temp1 = TempRegister();
   LOperand* temp2 = TempRegister();
-  LOperand* double_temp = FixedTemp(f6);  // Chosen by fair dice roll.
+  LOperand* double_temp = TempDoubleRegister();
   LMathExp* result = new(zone()) LMathExp(input, double_temp, temp1, temp2);
   return DefineAsRegister(result);
 }
@@ -1143,7 +1156,7 @@ LInstruction* LChunkBuilder::DoMathExp(HUnaryMathOperation* instr) {
 LInstruction* LChunkBuilder::DoMathPowHalf(HUnaryMathOperation* instr) {
   // Input cannot be the same as the result, see LCodeGen::DoMathPowHalf.
   LOperand* input = UseFixedDouble(instr->value(), f8);
-  LOperand* temp = FixedTemp(f6);
+  LOperand* temp = TempDoubleRegister();
   LMathPowHalf* result = new(zone()) LMathPowHalf(input, temp);
   return DefineFixedDouble(result, f4);
 }
@@ -1180,7 +1193,7 @@ LInstruction* LChunkBuilder::DoMathSqrt(HUnaryMathOperation* instr) {
 
 LInstruction* LChunkBuilder::DoMathRound(HUnaryMathOperation* instr) {
   LOperand* input = UseRegister(instr->value());
-  LOperand* temp = FixedTemp(f6);
+  LOperand* temp = TempDoubleRegister();
   LMathRound* result = new(zone()) LMathRound(input, temp);
   return AssignEnvironment(DefineAsRegister(result));
 }
@@ -1842,7 +1855,7 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
       } else {
         LOperand* value = UseRegister(val);
         LOperand* temp1 = TempRegister();
-        LOperand* temp2 = FixedTemp(f22);
+        LOperand* temp2 = TempDoubleRegister();
         LInstruction* result =
             DefineSameAsFirst(new(zone()) LTaggedToI(value, temp1, temp2));
         if (!val->representation().IsSmi()) result = AssignEnvironment(result);
@@ -1954,14 +1967,14 @@ LInstruction* LChunkBuilder::DoClampToUint8(HClampToUint8* instr) {
   LOperand* reg = UseRegister(value);
   if (input_rep.IsDouble()) {
     // Revisit this decision, here and 8 lines below.
-    return DefineAsRegister(new(zone()) LClampDToUint8(reg, FixedTemp(f22)));
+    return DefineAsRegister(new(zone()) LClampDToUint8(reg,
+        TempDoubleRegister()));
   } else if (input_rep.IsInteger32()) {
     return DefineAsRegister(new(zone()) LClampIToUint8(reg));
   } else {
     ASSERT(input_rep.IsSmiOrTagged());
-    // Register allocator doesn't (yet) support allocation of double
-    // temps. Reserve f22 explicitly.
-    LClampTToUint8* result = new(zone()) LClampTToUint8(reg, FixedTemp(f22));
+    LClampTToUint8* result =
+        new(zone()) LClampTToUint8(reg, TempDoubleRegister());
     return AssignEnvironment(DefineAsRegister(result));
   }
 }

src/mips/lithium-mips.h

@@ -2764,6 +2764,7 @@ class LChunkBuilder V8_FINAL : public LChunkBuilderBase {
 
   // Temporary operand that must be in a register.
   MUST_USE_RESULT LUnallocated* TempRegister();
+  MUST_USE_RESULT LUnallocated* TempDoubleRegister();
   MUST_USE_RESULT LOperand* FixedTemp(Register reg);
   MUST_USE_RESULT LOperand* FixedTemp(DoubleRegister reg);