Use xorps to break the cvtsi2sd unnecessary dependence due to its partially written

src/x64/code-stubs-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 991 matching lines @@
   Register heap_number_map = r8;
   Register scratch1 = r9;
   Register scratch2 = r10;
   // HeapNumbers containing 32bit integer values are also allowed.
   __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
   __ cmpq(FieldOperand(input, HeapObject::kMapOffset), heap_number_map);
   __ j(not_equal, fail);
   __ movsd(xmm0, FieldOperand(input, HeapNumber::kValueOffset));
   // Convert, convert back, and compare the two doubles' bits.
   __ cvttsd2siq(scratch2, xmm0);
-  __ cvtlsi2sd(xmm1, scratch2);
+  __ Cvtlsi2sd(xmm1, scratch2);
   __ movq(scratch1, xmm0);
   __ movq(scratch2, xmm1);
   __ cmpq(scratch1, scratch2);
   __ j(not_equal, fail);
   __ bind(&ok);
 }
 
 
 void BinaryOpStub::GenerateNumberStub(MacroAssembler* masm) {
   Label gc_required, not_number;
@@ skipping 115 matching lines @@
     Label input_not_smi, loaded;
 
     // Test that rax is a number.
     StackArgumentsAccessor args(rsp, 1, ARGUMENTS_DONT_CONTAIN_RECEIVER);
     __ movq(rax, args.GetArgumentOperand(0));
     __ JumpIfNotSmi(rax, &input_not_smi, Label::kNear);
     // Input is a smi. Untag and load it onto the FPU stack.
     // Then load the bits of the double into rbx.
     __ SmiToInteger32(rax, rax);
     __ subq(rsp, Immediate(kDoubleSize));
-    __ cvtlsi2sd(xmm1, rax);
+    __ Cvtlsi2sd(xmm1, rax);
     __ movsd(Operand(rsp, 0), xmm1);
     __ movq(rbx, xmm1);
     __ movq(rdx, xmm1);
     __ fld_d(Operand(rsp, 0));
     __ addq(rsp, Immediate(kDoubleSize));
     __ jmp(&loaded, Label::kNear);
 
     __ bind(&input_not_smi);
     // Check if input is a HeapNumber.
     __ LoadRoot(rbx, Heap::kHeapNumberMapRootIndex);
@@ skipping 311 matching lines @@
   // Get the untagged integer version of the rax heap number in rcx.
   __ TruncateHeapNumberToI(rcx, rax);
 
   __ bind(&done);
   __ movl(rax, r8);
 }
 
 
 void FloatingPointHelper::LoadSSE2SmiOperands(MacroAssembler* masm) {
   __ SmiToInteger32(kScratchRegister, rdx);
-  __ cvtlsi2sd(xmm0, kScratchRegister);
+  __ Cvtlsi2sd(xmm0, kScratchRegister);
   __ SmiToInteger32(kScratchRegister, rax);
-  __ cvtlsi2sd(xmm1, kScratchRegister);
+  __ Cvtlsi2sd(xmm1, kScratchRegister);
 }
 
 
 void FloatingPointHelper::LoadSSE2UnknownOperands(MacroAssembler* masm,
                                                   Label* not_numbers) {
   Label load_smi_rdx, load_nonsmi_rax, load_smi_rax, load_float_rax, done;
   // Load operand in rdx into xmm0, or branch to not_numbers.
   __ LoadRoot(rcx, Heap::kHeapNumberMapRootIndex);
   __ JumpIfSmi(rdx, &load_smi_rdx);
   __ cmpq(FieldOperand(rdx, HeapObject::kMapOffset), rcx);
   __ j(not_equal, not_numbers);  // Argument in rdx is not a number.
   __ movsd(xmm0, FieldOperand(rdx, HeapNumber::kValueOffset));
   // Load operand in rax into xmm1, or branch to not_numbers.
   __ JumpIfSmi(rax, &load_smi_rax);
 
   __ bind(&load_nonsmi_rax);
   __ cmpq(FieldOperand(rax, HeapObject::kMapOffset), rcx);
   __ j(not_equal, not_numbers);
   __ movsd(xmm1, FieldOperand(rax, HeapNumber::kValueOffset));
   __ jmp(&done);
 
   __ bind(&load_smi_rdx);
   __ SmiToInteger32(kScratchRegister, rdx);
-  __ cvtlsi2sd(xmm0, kScratchRegister);
+  __ Cvtlsi2sd(xmm0, kScratchRegister);
   __ JumpIfNotSmi(rax, &load_nonsmi_rax);
 
   __ bind(&load_smi_rax);
   __ SmiToInteger32(kScratchRegister, rax);
-  __ cvtlsi2sd(xmm1, kScratchRegister);
+  __ Cvtlsi2sd(xmm1, kScratchRegister);
   __ bind(&done);
 }
 
 
 void FloatingPointHelper::NumbersToSmis(MacroAssembler* masm,
                                         Register first,
                                         Register second,
                                         Register scratch1,
                                         Register scratch2,
                                         Register scratch3,
@@ skipping 12 matching lines @@
   __ j(not_equal,
        (convert_undefined == CONVERT_UNDEFINED_TO_ZERO)
            ? &maybe_undefined_first
            : on_not_smis);
   // Convert HeapNumber to smi if possible.
   __ movsd(xmm0, FieldOperand(first, HeapNumber::kValueOffset));
   __ movq(scratch2, xmm0);
   __ cvttsd2siq(smi_result, xmm0);
   // Check if conversion was successful by converting back and
   // comparing to the original double's bits.
-  __ cvtlsi2sd(xmm1, smi_result);
+  __ Cvtlsi2sd(xmm1, smi_result);
   __ movq(kScratchRegister, xmm1);
   __ cmpq(scratch2, kScratchRegister);
   __ j(not_equal, on_not_smis);
   __ Integer32ToSmi(first, smi_result);
 
   __ bind(&first_done);
   __ JumpIfSmi(second, (on_success != NULL) ? on_success : &done);
   __ bind(&first_smi);
   __ AssertNotSmi(second);
   __ cmpq(FieldOperand(second, HeapObject::kMapOffset), heap_number_map);
   __ j(not_equal,
        (convert_undefined == CONVERT_UNDEFINED_TO_ZERO)
            ? &maybe_undefined_second
            : on_not_smis);
   // Convert second to smi, if possible.
   __ movsd(xmm0, FieldOperand(second, HeapNumber::kValueOffset));
   __ movq(scratch2, xmm0);
   __ cvttsd2siq(smi_result, xmm0);
-  __ cvtlsi2sd(xmm1, smi_result);
+  __ Cvtlsi2sd(xmm1, smi_result);
   __ movq(kScratchRegister, xmm1);
   __ cmpq(scratch2, kScratchRegister);
   __ j(not_equal, on_not_smis);
   __ Integer32ToSmi(second, smi_result);
   if (on_success != NULL) {
     __ jmp(on_success);
   } else {
     __ jmp(&done);
   }
 
@@ skipping 22 matching lines @@
   const Register scratch = rcx;
   const XMMRegister double_result = xmm3;
   const XMMRegister double_base = xmm2;
   const XMMRegister double_exponent = xmm1;
   const XMMRegister double_scratch = xmm4;
 
   Label call_runtime, done, exponent_not_smi, int_exponent;
 
   // Save 1 in double_result - we need this several times later on.
   __ movq(scratch, Immediate(1));
-  __ cvtlsi2sd(double_result, scratch);
+  __ Cvtlsi2sd(double_result, scratch);
 
   if (exponent_type_ == ON_STACK) {
     Label base_is_smi, unpack_exponent;
     // The exponent and base are supplied as arguments on the stack.
     // This can only happen if the stub is called from non-optimized code.
     // Load input parameters from stack.
     StackArgumentsAccessor args(rsp, 2, ARGUMENTS_DONT_CONTAIN_RECEIVER);
     __ movq(base, args.GetArgumentOperand(0));
     __ movq(exponent, args.GetArgumentOperand(1));
     __ JumpIfSmi(base, &base_is_smi, Label::kNear);
     __ CompareRoot(FieldOperand(base, HeapObject::kMapOffset),
                    Heap::kHeapNumberMapRootIndex);
     __ j(not_equal, &call_runtime);
 
     __ movsd(double_base, FieldOperand(base, HeapNumber::kValueOffset));
     __ jmp(&unpack_exponent, Label::kNear);
 
     __ bind(&base_is_smi);
     __ SmiToInteger32(base, base);
-    __ cvtlsi2sd(double_base, base);
+    __ Cvtlsi2sd(double_base, base);
     __ bind(&unpack_exponent);
 
     __ JumpIfNotSmi(exponent, &exponent_not_smi, Label::kNear);
     __ SmiToInteger32(exponent, exponent);
     __ jmp(&int_exponent);
 
     __ bind(&exponent_not_smi);
     __ CompareRoot(FieldOperand(exponent, HeapObject::kMapOffset),
                    Heap::kHeapNumberMapRootIndex);
     __ j(not_equal, &call_runtime);
@@ skipping 168 matching lines @@
   __ divsd(double_scratch2, double_result);
   __ movsd(double_result, double_scratch2);
   // Test whether result is zero.  Bail out to check for subnormal result.
   // Due to subnormals, x^-y == (1/x)^y does not hold in all cases.
   __ xorps(double_scratch2, double_scratch2);
   __ ucomisd(double_scratch2, double_result);
   // double_exponent aliased as double_scratch2 has already been overwritten
   // and may not have contained the exponent value in the first place when the
   // input was a smi.  We reset it with exponent value before bailing out.
   __ j(not_equal, &done);
-  __ cvtlsi2sd(double_exponent, exponent);
+  __ Cvtlsi2sd(double_exponent, exponent);
 
   // Returning or bailing out.
   Counters* counters = masm->isolate()->counters();
   if (exponent_type_ == ON_STACK) {
     // The arguments are still on the stack.
     __ bind(&call_runtime);
     __ TailCallRuntime(Runtime::kMath_pow_cfunction, 2, 1);
 
     // The stub is called from non-optimized code, which expects the result
     // as heap number in rax.
@@ skipping 3557 matching lines @@
 
   // Load left and right operand.
   Label done, left, left_smi, right_smi;
   __ JumpIfSmi(rax, &right_smi, Label::kNear);
   __ CompareMap(rax, masm->isolate()->factory()->heap_number_map(), NULL);
   __ j(not_equal, &maybe_undefined1, Label::kNear);
   __ movsd(xmm1, FieldOperand(rax, HeapNumber::kValueOffset));
   __ jmp(&left, Label::kNear);
   __ bind(&right_smi);
   __ SmiToInteger32(rcx, rax);  // Can't clobber rax yet.
-  __ cvtlsi2sd(xmm1, rcx);
+  __ Cvtlsi2sd(xmm1, rcx);
 
   __ bind(&left);
   __ JumpIfSmi(rdx, &left_smi, Label::kNear);
   __ CompareMap(rdx, masm->isolate()->factory()->heap_number_map(), NULL);
   __ j(not_equal, &maybe_undefined2, Label::kNear);
   __ movsd(xmm0, FieldOperand(rdx, HeapNumber::kValueOffset));
   __ jmp(&done);
   __ bind(&left_smi);
   __ SmiToInteger32(rcx, rdx);  // Can't clobber rdx yet.
-  __ cvtlsi2sd(xmm0, rcx);
+  __ Cvtlsi2sd(xmm0, rcx);
 
   __ bind(&done);
   // Compare operands
   __ ucomisd(xmm0, xmm1);
 
   // Don't base result on EFLAGS when a NaN is involved.
   __ j(parity_even, &unordered, Label::kNear);
 
   // Return a result of -1, 0, or 1, based on EFLAGS.
   // Performing mov, because xor would destroy the flag register.
@@ skipping 1205 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64