Make the use of xmm0 as double scratch register explicit in ia32 and x64.

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1978 matching lines @@
         } else {
           __ xorps(res, res);
           __ Set(temp, Immediate(upper));
           __ pinsrd(res, Operand(temp), 1);
         }
       } else {
         __ Set(temp, Immediate(upper));
         __ movd(res, Operand(temp));
         __ psllq(res, 32);
         if (lower != 0) {
+          XMMRegister xmm_scratch = double_scratch0();
           __ Set(temp, Immediate(lower));
-          __ movd(xmm0, Operand(temp));
-          __ por(res, xmm0);
+          __ movd(xmm_scratch, Operand(temp));
+          __ por(res, xmm_scratch);
         }
       }
     }
   }
 }
 
 
 void LCodeGen::DoConstantE(LConstantE* instr) {
   __ lea(ToRegister(instr->result()), Operand::StaticVariable(instr->value()));
 }
@@ skipping 188 matching lines @@
     Condition condition = (operation == HMathMinMax::kMathMin) ? below : above;
     XMMRegister left_reg = ToDoubleRegister(left);
     XMMRegister right_reg = ToDoubleRegister(right);
     __ ucomisd(left_reg, right_reg);
     __ j(parity_even, &check_nan_left, Label::kNear);  // At least one NaN.
     __ j(equal, &check_zero, Label::kNear);  // left == right.
     __ j(condition, &return_left, Label::kNear);
     __ jmp(&return_right, Label::kNear);
 
     __ bind(&check_zero);
-    XMMRegister xmm_scratch = xmm0;
+    XMMRegister xmm_scratch = double_scratch0();
     __ xorps(xmm_scratch, xmm_scratch);
     __ ucomisd(left_reg, xmm_scratch);
     __ j(not_equal, &return_left, Label::kNear);  // left == right != 0.
     // At this point, both left and right are either 0 or -0.
     if (operation == HMathMinMax::kMathMin) {
       __ orpd(left_reg, right_reg);
     } else {
       // Since we operate on +0 and/or -0, addsd and andsd have the same effect.
       __ addsd(left_reg, right_reg);
     }
@@ skipping 149 matching lines @@
 void LCodeGen::DoBranch(LBranch* instr) {
   Representation r = instr->hydrogen()->value()->representation();
   if (r.IsSmiOrInteger32()) {
     Register reg = ToRegister(instr->value());
     __ test(reg, Operand(reg));
     EmitBranch(instr, not_zero);
   } else if (r.IsDouble()) {
     ASSERT(!info()->IsStub());
     CpuFeatureScope scope(masm(), SSE2);
     XMMRegister reg = ToDoubleRegister(instr->value());
-    __ xorps(xmm0, xmm0);
-    __ ucomisd(reg, xmm0);
+    XMMRegister xmm_scratch = double_scratch0();
+    __ xorps(xmm_scratch, xmm_scratch);
+    __ ucomisd(reg, xmm_scratch);
     EmitBranch(instr, not_equal);
   } else {
     ASSERT(r.IsTagged());
     Register reg = ToRegister(instr->value());
     HType type = instr->hydrogen()->value()->type();
     if (type.IsBoolean()) {
       ASSERT(!info()->IsStub());
       __ cmp(reg, factory()->true_value());
       EmitBranch(instr, equal);
     } else if (type.IsSmi()) {
       ASSERT(!info()->IsStub());
       __ test(reg, Operand(reg));
       EmitBranch(instr, not_equal);
     } else if (type.IsJSArray()) {
       ASSERT(!info()->IsStub());
       EmitBranch(instr, no_condition);
     } else if (type.IsHeapNumber()) {
       ASSERT(!info()->IsStub());
       CpuFeatureScope scope(masm(), SSE2);
-      __ xorps(xmm0, xmm0);
-      __ ucomisd(xmm0, FieldOperand(reg, HeapNumber::kValueOffset));
+      XMMRegister xmm_scratch = double_scratch0();
+      __ xorps(xmm_scratch, xmm_scratch);
+      __ ucomisd(xmm_scratch, FieldOperand(reg, HeapNumber::kValueOffset));
       EmitBranch(instr, not_equal);
     } else if (type.IsString()) {
       ASSERT(!info()->IsStub());
       __ cmp(FieldOperand(reg, String::kLengthOffset), Immediate(0));
       EmitBranch(instr, not_equal);
     } else {
       ToBooleanStub::Types expected = instr->hydrogen()->expected_input_types();
       if (expected.IsEmpty()) expected = ToBooleanStub::Types::Generic();
 
       if (expected.Contains(ToBooleanStub::UNDEFINED)) {
@@ skipping 64 matching lines @@
       }
 
       if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
         // heap number -> false iff +0, -0, or NaN.
         Label not_heap_number;
         __ cmp(FieldOperand(reg, HeapObject::kMapOffset),
                factory()->heap_number_map());
         __ j(not_equal, &not_heap_number, Label::kNear);
         if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
           CpuFeatureScope scope(masm(), SSE2);
-          __ xorps(xmm0, xmm0);
-          __ ucomisd(xmm0, FieldOperand(reg, HeapNumber::kValueOffset));
+          XMMRegister xmm_scratch = double_scratch0();
+          __ xorps(xmm_scratch, xmm_scratch);
+          __ ucomisd(xmm_scratch, FieldOperand(reg, HeapNumber::kValueOffset));
         } else {
           __ fldz();
           __ fld_d(FieldOperand(reg, HeapNumber::kValueOffset));
           __ FCmp();
         }
         __ j(zero, instr->FalseLabel(chunk_));
         __ jmp(instr->TrueLabel(chunk_));
         __ bind(&not_heap_number);
       }
 
@@ skipping 1419 matching lines @@
     virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
    private:
     LMathAbs* instr_;
   };
 
   ASSERT(instr->value()->Equals(instr->result()));
   Representation r = instr->hydrogen()->value()->representation();
 
   CpuFeatureScope scope(masm(), SSE2);
   if (r.IsDouble()) {
-    XMMRegister  scratch = xmm0;
+    XMMRegister scratch = double_scratch0();
     XMMRegister input_reg = ToDoubleRegister(instr->value());
     __ xorps(scratch, scratch);
     __ subsd(scratch, input_reg);
     __ pand(input_reg, scratch);
   } else if (r.IsSmiOrInteger32()) {
     EmitIntegerMathAbs(instr);
   } else {  // Tagged case.
     DeferredMathAbsTaggedHeapNumber* deferred =
         new(zone()) DeferredMathAbsTaggedHeapNumber(this, instr, x87_stack_);
     Register input_reg = ToRegister(instr->value());
     // Smi check.
     __ JumpIfNotSmi(input_reg, deferred->entry());
     EmitIntegerMathAbs(instr);
     __ bind(deferred->exit());
   }
 }
 
 
 void LCodeGen::DoMathFloor(LMathFloor* instr) {
   CpuFeatureScope scope(masm(), SSE2);
-  XMMRegister xmm_scratch = xmm0;
+  XMMRegister xmm_scratch = double_scratch0();
   Register output_reg = ToRegister(instr->result());
   XMMRegister input_reg = ToDoubleRegister(instr->value());
 
   if (CpuFeatures::IsSupported(SSE4_1)) {
     CpuFeatureScope scope(masm(), SSE4_1);
     if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
       // Deoptimize on negative zero.
       Label non_zero;
       __ xorps(xmm_scratch, xmm_scratch);  // Zero the register.
       __ ucomisd(input_reg, xmm_scratch);
@@ skipping 47 matching lines @@
 
     __ bind(&done);
   }
 }
 
 
 void LCodeGen::DoMathRound(LMathRound* instr) {
   CpuFeatureScope scope(masm(), SSE2);
   Register output_reg = ToRegister(instr->result());
   XMMRegister input_reg = ToDoubleRegister(instr->value());
-  XMMRegister xmm_scratch = xmm0;
+  XMMRegister xmm_scratch = double_scratch0();
   XMMRegister input_temp = ToDoubleRegister(instr->temp());
   ExternalReference one_half = ExternalReference::address_of_one_half();
   ExternalReference minus_one_half =
       ExternalReference::address_of_minus_one_half();
 
   Label done, round_to_zero, below_one_half, do_not_compensate;
   __ movdbl(xmm_scratch, Operand::StaticVariable(one_half));
   __ ucomisd(xmm_scratch, input_reg);
   __ j(above, &below_one_half);
 
@@ skipping 46 matching lines @@
 void LCodeGen::DoMathSqrt(LMathSqrt* instr) {
   CpuFeatureScope scope(masm(), SSE2);
   XMMRegister input_reg = ToDoubleRegister(instr->value());
   ASSERT(ToDoubleRegister(instr->result()).is(input_reg));
   __ sqrtsd(input_reg, input_reg);
 }
 
 
 void LCodeGen::DoMathPowHalf(LMathPowHalf* instr) {
   CpuFeatureScope scope(masm(), SSE2);
-  XMMRegister xmm_scratch = xmm0;
+  XMMRegister xmm_scratch = double_scratch0();
   XMMRegister input_reg = ToDoubleRegister(instr->value());
   Register scratch = ToRegister(instr->temp());
   ASSERT(ToDoubleRegister(instr->result()).is(input_reg));
 
   // Note that according to ECMA-262 15.8.2.13:
   // Math.pow(-Infinity, 0.5) == Infinity
   // Math.sqrt(-Infinity) == NaN
   Label done, sqrt;
   // Check base for -Infinity.  According to IEEE-754, single-precision
   // -Infinity has the highest 9 bits set and the lowest 23 bits cleared.
@@ skipping 98 matching lines @@
   // Random bit pattern = (state[0] << 14) + (state[1] & 0x3FFFF)
   Register random = state0;
   __ shl(random, 14);
   __ and_(state1, Immediate(0x3FFFF));
   __ add(random, state1);
 
   // Convert 32 random bits in random to 0.(32 random bits) in a double
   // by computing:
   // ( 1.(20 0s)(32 random bits) x 2^20 ) - (1.0 x 2^20)).
   XMMRegister result = ToDoubleRegister(instr->result());
-  // We use xmm0 as fixed scratch register here.
-  XMMRegister scratch4 = xmm0;
+  XMMRegister scratch4 = double_scratch0();
   __ mov(scratch3, Immediate(0x49800000));  // 1.0 x 2^20 as single.
   __ movd(scratch4, scratch3);
   __ movd(result, random);
   __ cvtss2sd(scratch4, scratch4);
   __ xorps(result, scratch4);
   __ subsd(result, scratch4);
 }
 
 
 void LCodeGen::DoMathLog(LMathLog* instr) {
   CpuFeatureScope scope(masm(), SSE2);
   ASSERT(instr->value()->Equals(instr->result()));
   XMMRegister input_reg = ToDoubleRegister(instr->value());
+  XMMRegister xmm_scratch = double_scratch0();
   Label positive, done, zero;
-  __ xorps(xmm0, xmm0);
-  __ ucomisd(input_reg, xmm0);
+  __ xorps(xmm_scratch, xmm_scratch);
+  __ ucomisd(input_reg, xmm_scratch);
   __ j(above, &positive, Label::kNear);
   __ j(equal, &zero, Label::kNear);
   ExternalReference nan =
       ExternalReference::address_of_canonical_non_hole_nan();
   __ movdbl(input_reg, Operand::StaticVariable(nan));
   __ jmp(&done, Label::kNear);
   __ bind(&zero);
   __ push(Immediate(0xFFF00000));
   __ push(Immediate(0));
   __ movdbl(input_reg, Operand(esp, 0));
   __ add(Operand(esp), Immediate(kDoubleSize));
   __ jmp(&done, Label::kNear);
   __ bind(&positive);
   __ fldln2();
   __ sub(Operand(esp), Immediate(kDoubleSize));
   __ movdbl(Operand(esp, 0), input_reg);
   __ fld_d(Operand(esp, 0));
   __ fyl2x();
   __ fstp_d(Operand(esp, 0));
   __ movdbl(input_reg, Operand(esp, 0));
   __ add(Operand(esp), Immediate(kDoubleSize));
   __ bind(&done);
 }
 
 
 void LCodeGen::DoMathExp(LMathExp* instr) {
   CpuFeatureScope scope(masm(), SSE2);
   XMMRegister input = ToDoubleRegister(instr->value());
   XMMRegister result = ToDoubleRegister(instr->result());
+  XMMRegister temp0 = double_scratch0();
   Register temp1 = ToRegister(instr->temp1());
   Register temp2 = ToRegister(instr->temp2());
 
-  MathExpGenerator::EmitMathExp(masm(), input, result, xmm0, temp1, temp2);
+  MathExpGenerator::EmitMathExp(masm(), input, result, temp0, temp1, temp2);
 }
 
 
 void LCodeGen::DoMathTan(LMathTan* instr) {
   ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
   // Set the context register to a GC-safe fake value. Clobbering it is
   // OK because this instruction is marked as a call.
   __ Set(esi, Immediate(0));
   TranscendentalCacheStub stub(TranscendentalCache::TAN,
                                TranscendentalCacheStub::UNTAGGED);
@@ skipping 360 matching lines @@
   Operand operand(BuildFastArrayOperand(
       instr->elements(),
       key,
       instr->hydrogen()->key()->representation(),
       elements_kind,
       0,
       instr->additional_index()));
   if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
     if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
       CpuFeatureScope scope(masm(), SSE2);
-      __ cvtsd2ss(xmm0, ToDoubleRegister(instr->value()));
-      __ movss(operand, xmm0);
+      XMMRegister xmm_scratch = double_scratch0();
+      __ cvtsd2ss(xmm_scratch, ToDoubleRegister(instr->value()));
+      __ movss(operand, xmm_scratch);
     } else {
       __ fld(0);
       __ fstp_s(operand);
     }
   } else if (elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
     if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
       CpuFeatureScope scope(masm(), SSE2);
       __ movdbl(operand, ToDoubleRegister(instr->value()));
     } else {
       X87Mov(operand, ToX87Register(instr->value()));
@@ skipping 442 matching lines @@
   __ bind(deferred->exit());
 }
 
 
 void LCodeGen::DoDeferredNumberTagI(LInstruction* instr,
                                     LOperand* value,
                                     IntegerSignedness signedness) {
   Label slow;
   Register reg = ToRegister(value);
   Register tmp = reg.is(eax) ? ecx : eax;
+  XMMRegister xmm_scratch = double_scratch0();
 
   // Preserve the value of all registers.
   PushSafepointRegistersScope scope(this);
 
   Label done;
 
   if (signedness == SIGNED_INT32) {
     // There was overflow, so bits 30 and 31 of the original integer
     // disagree. Try to allocate a heap number in new space and store
     // the value in there. If that fails, call the runtime system.
     __ SmiUntag(reg);
     __ xor_(reg, 0x80000000);
     if (CpuFeatures::IsSupported(SSE2)) {
       CpuFeatureScope feature_scope(masm(), SSE2);
-      __ Cvtsi2sd(xmm0, Operand(reg));
+      __ Cvtsi2sd(xmm_scratch, Operand(reg));
     } else {
       __ push(reg);
       __ fild_s(Operand(esp, 0));
       __ pop(reg);
     }
   } else {
     if (CpuFeatures::IsSupported(SSE2)) {
       CpuFeatureScope feature_scope(masm(), SSE2);
-      __ LoadUint32(xmm0, reg,
+      __ LoadUint32(xmm_scratch, reg,
                     ToDoubleRegister(LNumberTagU::cast(instr)->temp()));
     } else {
       // There's no fild variant for unsigned values, so zero-extend to a 64-bit
       // int manually.
       __ push(Immediate(0));
       __ push(reg);
       __ fild_d(Operand(esp, 0));
       __ pop(reg);
       __ pop(reg);
     }
@@ skipping 15 matching lines @@
   // the environment's HContext or HInlinedContext value.
   // They only call Runtime::kAllocateHeapNumber.
   // The corresponding HChange instructions are added in a phase that does
   // not have easy access to the local context.
   __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
   __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
   RecordSafepointWithRegisters(
       instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
   if (!reg.is(eax)) __ mov(reg, eax);
 
-  // Done. Put the value in xmm0 into the value of the allocated heap
+  // Done. Put the value in xmm_scratch into the value of the allocated heap
   // number.
   __ bind(&done);
   if (CpuFeatures::IsSupported(SSE2)) {
     CpuFeatureScope feature_scope(masm(), SSE2);
-    __ movdbl(FieldOperand(reg, HeapNumber::kValueOffset), xmm0);
+    __ movdbl(FieldOperand(reg, HeapNumber::kValueOffset), xmm_scratch);
   } else {
     __ fstp_d(FieldOperand(reg, HeapNumber::kValueOffset));
   }
   __ StoreToSafepointRegisterSlot(reg, reg);
 }
 
 
 void LCodeGen::DoNumberTagD(LNumberTagD* instr) {
   class DeferredNumberTagD V8_FINAL : public LDeferredCode {
    public:
@@ skipping 169 matching lines @@
     if (can_convert_undefined_to_nan) {
       __ j(not_equal, &convert, Label::kNear);
     } else {
       DeoptimizeIf(not_equal, env);
     }
 
     // Heap number to XMM conversion.
     __ movdbl(result_reg, FieldOperand(input_reg, HeapNumber::kValueOffset));
 
     if (deoptimize_on_minus_zero) {
-      XMMRegister xmm_scratch = xmm0;
+      XMMRegister xmm_scratch = double_scratch0();
       __ xorps(xmm_scratch, xmm_scratch);
       __ ucomisd(result_reg, xmm_scratch);
       __ j(not_zero, &done, Label::kNear);
       __ movmskpd(temp_reg, result_reg);
       __ test_b(temp_reg, 1);
       DeoptimizeIf(not_zero, env);
     }
     __ jmp(&done, Label::kNear);
 
     if (can_convert_undefined_to_nan) {
@@ skipping 145 matching lines @@
     } else {
       X87Register input_reg = ToX87Register(input);
       X87Fxch(input_reg);
       __ TruncateX87TOSToI(result_reg);
     }
   } else {
     Label bailout, done;
     if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
       CpuFeatureScope scope(masm(), SSE2);
       XMMRegister input_reg = ToDoubleRegister(input);
-       __ DoubleToI(result_reg, input_reg, xmm0,
+      XMMRegister xmm_scratch = double_scratch0();
+       __ DoubleToI(result_reg, input_reg, xmm_scratch,
            instr->hydrogen()->GetMinusZeroMode(), &bailout, Label::kNear);
     } else {
       X87Register input_reg = ToX87Register(input);
       X87Fxch(input_reg);
       __ X87TOSToI(result_reg, instr->hydrogen()->GetMinusZeroMode(),
                    &bailout, Label::kNear);
     }
     __ jmp(&done, Label::kNear);
     __ bind(&bailout);
     DeoptimizeIf(no_condition, instr->environment());
     __ bind(&done);
   }
 }
 
 
 void LCodeGen::DoDoubleToSmi(LDoubleToSmi* instr) {
   LOperand* input = instr->value();
   ASSERT(input->IsDoubleRegister());
   LOperand* result = instr->result();
   ASSERT(result->IsRegister());
   Register result_reg = ToRegister(result);
 
   Label bailout, done;
   if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
     CpuFeatureScope scope(masm(), SSE2);
     XMMRegister input_reg = ToDoubleRegister(input);
-    __ DoubleToI(result_reg, input_reg, xmm0,
+    XMMRegister xmm_scratch = double_scratch0();
+    __ DoubleToI(result_reg, input_reg, xmm_scratch,
         instr->hydrogen()->GetMinusZeroMode(), &bailout, Label::kNear);
   } else {
     X87Register input_reg = ToX87Register(input);
     X87Fxch(input_reg);
     __ X87TOSToI(result_reg, instr->hydrogen()->GetMinusZeroMode(),
         &bailout, Label::kNear);
   }
   __ jmp(&done, Label::kNear);
   __ bind(&bailout);
   DeoptimizeIf(no_condition, instr->environment());
@@ skipping 143 matching lines @@
     DeoptimizeIf(not_equal, instr->environment());
   }
 
   __ bind(&success);
 }
 
 
 void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
   CpuFeatureScope scope(masm(), SSE2);
   XMMRegister value_reg = ToDoubleRegister(instr->unclamped());
+  XMMRegister xmm_scratch = double_scratch0();
   Register result_reg = ToRegister(instr->result());
-  __ ClampDoubleToUint8(value_reg, xmm0, result_reg);
+  __ ClampDoubleToUint8(value_reg, xmm_scratch, result_reg);
 }
 
 
 void LCodeGen::DoClampIToUint8(LClampIToUint8* instr) {
   ASSERT(instr->unclamped()->Equals(instr->result()));
   Register value_reg = ToRegister(instr->result());
   __ ClampUint8(value_reg);
 }
 
 
 void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
   CpuFeatureScope scope(masm(), SSE2);
 
   ASSERT(instr->unclamped()->Equals(instr->result()));
   Register input_reg = ToRegister(instr->unclamped());
+  XMMRegister xmm_scratch = double_scratch0();
   Label is_smi, done, heap_number;
 
   __ JumpIfSmi(input_reg, &is_smi);
 
   // Check for heap number
   __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
          factory()->heap_number_map());
   __ j(equal, &heap_number, Label::kNear);
 
   // Check for undefined. Undefined is converted to zero for clamping
   // conversions.
   __ cmp(input_reg, factory()->undefined_value());
   DeoptimizeIf(not_equal, instr->environment());
   __ mov(input_reg, 0);
   __ jmp(&done, Label::kNear);
 
   // Heap number
   __ bind(&heap_number);
-  __ movdbl(xmm0, FieldOperand(input_reg, HeapNumber::kValueOffset));
-  __ ClampDoubleToUint8(xmm0, xmm1, input_reg);
+  __ movdbl(xmm_scratch, FieldOperand(input_reg, HeapNumber::kValueOffset));
+  __ ClampDoubleToUint8(xmm_scratch, xmm1, input_reg);
   __ jmp(&done, Label::kNear);
 
   // smi
   __ bind(&is_smi);
   __ SmiUntag(input_reg);
   __ ClampUint8(input_reg);
   __ bind(&done);
 }
 
 
@@ skipping 628 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32