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

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 1814 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 25 matching lines @@
        break;
     case Token::MUL:
       __ mulsd(left, right);
       break;
     case Token::DIV:
       __ divsd(left, right);
       // Don't delete this mov. It may improve performance on some CPUs,
       // when there is a mulsd depending on the result
       __ movaps(left, left);
       break;
-    case Token::MOD:
+    case Token::MOD: {
+      XMMRegister xmm_scratch = double_scratch0();
       __ PrepareCallCFunction(2);
-      __ movaps(xmm0, left);
+      __ movaps(xmm_scratch, left);
       ASSERT(right.is(xmm1));
       __ CallCFunction(
           ExternalReference::double_fp_operation(Token::MOD, isolate()), 2);
       __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
-      __ movaps(result, xmm0);
+      __ movaps(result, xmm_scratch);
       break;
+    }
     default:
       UNREACHABLE();
       break;
   }
 }
 
 
 void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
   ASSERT(ToRegister(instr->left()).is(rdx));
   ASSERT(ToRegister(instr->right()).is(rax));
@@ skipping 55 matching lines @@
     __ testl(reg, reg);
     EmitBranch(instr, not_zero);
   } else if (r.IsSmi()) {
     ASSERT(!info()->IsStub());
     Register reg = ToRegister(instr->value());
     __ testq(reg, reg);
     EmitBranch(instr, not_zero);
   } else if (r.IsDouble()) {
     ASSERT(!info()->IsStub());
     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());
       __ CompareRoot(reg, Heap::kTrueValueRootIndex);
       EmitBranch(instr, equal);
     } else if (type.IsSmi()) {
       ASSERT(!info()->IsStub());
       __ SmiCompare(reg, Smi::FromInt(0));
       EmitBranch(instr, not_equal);
     } else if (type.IsJSArray()) {
       ASSERT(!info()->IsStub());
       EmitBranch(instr, no_condition);
     } else if (type.IsHeapNumber()) {
       ASSERT(!info()->IsStub());
-      __ 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());
       __ cmpq(FieldOperand(reg, String::kLengthOffset), Immediate(0));
       EmitBranch(instr, not_equal);
     } else {
       ToBooleanStub::Types expected = instr->hydrogen()->expected_input_types();
       // Avoid deopts in the case where we've never executed this path before.
       if (expected.IsEmpty()) expected = ToBooleanStub::Types::Generic();
 
@@ skipping 60 matching lines @@
         // Symbol value -> true.
         __ CmpInstanceType(map, SYMBOL_TYPE);
         __ j(equal, instr->TrueLabel(chunk_));
       }
 
       if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
         // heap number -> false iff +0, -0, or NaN.
         Label not_heap_number;
         __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
         __ j(not_equal, &not_heap_number, Label::kNear);
-        __ 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));
         __ j(zero, instr->FalseLabel(chunk_));
         __ jmp(instr->TrueLabel(chunk_));
         __ bind(&not_heap_number);
       }
 
       if (!expected.IsGeneric()) {
         // We've seen something for the first time -> deopt.
         // This can only happen if we are not generic already.
         DeoptimizeIf(no_condition, instr->environment());
       }
@@ skipping 1361 matching lines @@
     }
     virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
    private:
     LMathAbs* instr_;
   };
 
   ASSERT(instr->value()->Equals(instr->result()));
   Representation r = instr->hydrogen()->value()->representation();
 
   if (r.IsDouble()) {
-    XMMRegister scratch = xmm0;
+    XMMRegister scratch = double_scratch0();
     XMMRegister input_reg = ToDoubleRegister(instr->value());
     __ xorps(scratch, scratch);
     __ subsd(scratch, input_reg);
     __ andpd(input_reg, scratch);
   } else if (r.IsInteger32()) {
     EmitIntegerMathAbs(instr);
   } else if (r.IsSmi()) {
     EmitSmiMathAbs(instr);
   } else {  // Tagged case.
     DeferredMathAbsTaggedHeapNumber* deferred =
         new(zone()) DeferredMathAbsTaggedHeapNumber(this, instr);
     Register input_reg = ToRegister(instr->value());
     // Smi check.
     __ JumpIfNotSmi(input_reg, deferred->entry());
     EmitSmiMathAbs(instr);
     __ bind(deferred->exit());
   }
 }
 
 
 void LCodeGen::DoMathFloor(LMathFloor* instr) {
-  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 if minus zero.
       __ movq(output_reg, input_reg);
       __ subq(output_reg, Immediate(1));
       DeoptimizeIf(overflow, instr->environment());
@@ skipping 38 matching lines @@
     __ j(equal, &done, Label::kNear);
     __ subl(output_reg, Immediate(1));
     DeoptimizeIf(overflow, instr->environment());
 
     __ bind(&done);
   }
 }
 
 
 void LCodeGen::DoMathRound(LMathRound* instr) {
-  const XMMRegister xmm_scratch = xmm0;
+  const XMMRegister xmm_scratch = double_scratch0();
   Register output_reg = ToRegister(instr->result());
   XMMRegister input_reg = ToDoubleRegister(instr->value());
   static int64_t one_half = V8_INT64_C(0x3FE0000000000000);  // 0.5
   static int64_t minus_one_half = V8_INT64_C(0xBFE0000000000000);  // -0.5
 
   Label done, round_to_zero, below_one_half, do_not_compensate, restore;
   __ movq(kScratchRegister, one_half, RelocInfo::NONE64);
   __ movq(xmm_scratch, kScratchRegister);
   __ ucomisd(xmm_scratch, input_reg);
   __ j(above, &below_one_half);
@@ skipping 47 matching lines @@
 
 
 void LCodeGen::DoMathSqrt(LMathSqrt* instr) {
   XMMRegister input_reg = ToDoubleRegister(instr->value());
   ASSERT(ToDoubleRegister(instr->result()).is(input_reg));
   __ sqrtsd(input_reg, input_reg);
 }
 
 
 void LCodeGen::DoMathPowHalf(LMathPowHalf* instr) {
-  XMMRegister xmm_scratch = xmm0;
+  XMMRegister xmm_scratch = double_scratch0();
   XMMRegister input_reg = ToDoubleRegister(instr->value());
   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, double-precision
   // -Infinity has the highest 12 bits set and the lowest 52 bits cleared.
   __ movq(kScratchRegister, V8_INT64_C(0xFFF0000000000000), RelocInfo::NONE64);
@@ skipping 96 matching lines @@
   // Random bit pattern = (state[0] << 14) + (state[1] & 0x3FFFF)
   Register random = state0;
   __ shll(random, Immediate(14));
   __ andl(state1, Immediate(0x3FFFF));
   __ addl(random, state1);
 
   // Convert 32 random bits in rax 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();
   __ movq(scratch3, V8_INT64_C(0x4130000000000000),
           RelocInfo::NONE64);  // 1.0 x 2^20 as double
   __ movq(scratch4, scratch3);
   __ movd(result, random);
   __ xorps(result, scratch4);
   __ subsd(result, scratch4);
 }
 
 
 void LCodeGen::DoMathExp(LMathExp* instr) {
   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::DoMathLog(LMathLog* instr) {
   ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
   TranscendentalCacheStub stub(TranscendentalCache::LOG,
                                TranscendentalCacheStub::UNTAGGED);
   CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
 }
 
@@ skipping 780 matching lines @@
   Register reg = ToRegister(instr->value());
   Register tmp = reg.is(rax) ? rcx : rax;
 
   // Preserve the value of all registers.
   PushSafepointRegistersScope scope(this);
 
   Label done;
   // Load value into xmm1 which will be preserved across potential call to
   // runtime (MacroAssembler::EnterExitFrameEpilogue preserves only allocatable
   // XMM registers on x64).
-  __ LoadUint32(xmm1, reg, xmm0);
+  XMMRegister xmm_scratch = double_scratch0();
+  __ LoadUint32(xmm1, reg, xmm_scratch);
 
   if (FLAG_inline_new) {
     __ AllocateHeapNumber(reg, tmp, &slow);
     __ jmp(&done, Label::kNear);
   }
 
   // Slow case: Call the runtime system to do the number allocation.
   __ bind(&slow);
 
   // Put a valid pointer value in the stack slot where the result
@@ skipping 98 matching lines @@
     // check, since all heap objects are at least two words long.
     __ movsd(result_reg, FieldOperand(input_reg, HeapNumber::kValueOffset));
 
     if (can_convert_undefined_to_nan) {
       __ j(not_equal, &convert);
     } else {
       DeoptimizeIf(not_equal, env);
     }
 
     if (deoptimize_on_minus_zero) {
-      XMMRegister xmm_scratch = xmm0;
+      XMMRegister xmm_scratch = double_scratch0();
       __ xorps(xmm_scratch, xmm_scratch);
       __ ucomisd(xmm_scratch, result_reg);
       __ j(not_equal, &done, Label::kNear);
       __ movmskpd(kScratchRegister, result_reg);
       __ testq(kScratchRegister, Immediate(1));
       DeoptimizeIf(not_zero, env);
     }
     __ jmp(&done, Label::kNear);
 
     if (can_convert_undefined_to_nan) {
@@ skipping 107 matching lines @@
   LOperand* result = instr->result();
   ASSERT(result->IsRegister());
 
   XMMRegister input_reg = ToDoubleRegister(input);
   Register result_reg = ToRegister(result);
 
   if (instr->truncating()) {
     __ TruncateDoubleToI(result_reg, input_reg);
   } else {
     Label bailout, done;
-    __ DoubleToI(result_reg, input_reg, xmm0,
+    XMMRegister xmm_scratch = double_scratch0();
+    __ DoubleToI(result_reg, input_reg, xmm_scratch,
         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());
 
   XMMRegister input_reg = ToDoubleRegister(input);
   Register result_reg = ToRegister(result);
 
   Label bailout, done;
-  __ DoubleToI(result_reg, input_reg, xmm0,
+  XMMRegister xmm_scratch = double_scratch0();
+  __ DoubleToI(result_reg, input_reg, xmm_scratch,
       instr->hydrogen()->GetMinusZeroMode(), &bailout, Label::kNear);
 
   __ jmp(&done, Label::kNear);
   __ bind(&bailout);
   DeoptimizeIf(no_condition, instr->environment());
   __ bind(&done);
 
   __ Integer32ToSmi(result_reg, result_reg);
   DeoptimizeIf(overflow, instr->environment());
 }
@@ skipping 125 matching lines @@
   } else {
     DeoptimizeIf(not_equal, instr->environment());
   }
 
   __ bind(&success);
 }
 
 
 void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
   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) {
   ASSERT(instr->unclamped()->Equals(instr->result()));
   Register input_reg = ToRegister(instr->unclamped());
   XMMRegister temp_xmm_reg = ToDoubleRegister(instr->temp_xmm());
+  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());
   __ movq(input_reg, Immediate(0));
   __ jmp(&done, Label::kNear);
 
   // Heap number
   __ bind(&heap_number);
-  __ movsd(xmm0, FieldOperand(input_reg, HeapNumber::kValueOffset));
-  __ ClampDoubleToUint8(xmm0, temp_xmm_reg, input_reg);
+  __ movsd(xmm_scratch, FieldOperand(input_reg, HeapNumber::kValueOffset));
+  __ ClampDoubleToUint8(xmm_scratch, temp_xmm_reg, input_reg);
   __ jmp(&done, Label::kNear);
 
   // smi
   __ bind(&is_smi);
   __ SmiToInteger32(input_reg, input_reg);
   __ ClampUint8(input_reg);
 
   __ bind(&done);
 }
 
@@ skipping 512 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64