X64 tweaks.

src/x64/code-stubs-x64.cc

 // Copyright 2011 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 248 matching lines @@
   __ movq(rdx, FieldOperand(rax, String::kLengthOffset));
   __ SmiTest(rdx);
   __ j(zero, &false_result);
   __ jmp(&true_result);
 
   __ bind(&not_string);
   __ CompareRoot(rdx, Heap::kHeapNumberMapRootIndex);
   __ j(not_equal, &true_result);
   // HeapNumber => false iff +0, -0, or NaN.
   // These three cases set the zero flag when compared to zero using ucomisd.
-  __ xorpd(xmm0, xmm0);
+  __ xorps(xmm0, xmm0);
   __ ucomisd(xmm0, FieldOperand(rax, HeapNumber::kValueOffset));
   __ j(zero, &false_result);
   // Fall through to |true_result|.
 
   // Return 1/0 for true/false in rax.
   __ bind(&true_result);
   __ Set(rax, 1);
   __ ret(1 * kPointerSize);
   __ bind(&false_result);
   __ Set(rax, 0);
@@ skipping 1315 matching lines @@
   __ movq(rdx, rax);
 
   // Get absolute value of exponent.
   NearLabel no_neg;
   __ cmpl(rax, Immediate(0));
   __ j(greater_equal, &no_neg);
   __ negl(rax);
   __ bind(&no_neg);
 
   // Load xmm1 with 1.
-  __ movsd(xmm1, xmm3);
+  __ movaps(xmm1, xmm3);
   NearLabel while_true;
   NearLabel no_multiply;
 
   __ bind(&while_true);
   __ shrl(rax, Immediate(1));
   __ j(not_carry, &no_multiply);
   __ mulsd(xmm1, xmm0);
   __ bind(&no_multiply);
   __ mulsd(xmm0, xmm0);
   __ j(not_zero, &while_true);
 
   // Base has the original value of the exponent - if the exponent  is
   // negative return 1/result.
   __ testl(rdx, rdx);
   __ j(positive, &allocate_return);
   // Special case if xmm1 has reached infinity.
   __ divsd(xmm3, xmm1);
-  __ movsd(xmm1, xmm3);
-  __ xorpd(xmm0, xmm0);
+  __ movaps(xmm1, xmm3);
+  __ xorps(xmm0, xmm0);
   __ ucomisd(xmm0, xmm1);
   __ j(equal, &call_runtime);
 
   __ jmp(&allocate_return);
 
   // Exponent (or both) is a heapnumber - no matter what we should now work
   // on doubles.
   __ bind(&exponent_nonsmi);
   __ CompareRoot(FieldOperand(rax, HeapObject::kMapOffset),
                  Heap::kHeapNumberMapRootIndex);
@@ skipping 27 matching lines @@
   // Test for -0.5.
   // Load xmm2 with -0.5.
   __ movq(rcx, V8_UINT64_C(0xBFE0000000000000), RelocInfo::NONE);
   __ movq(xmm2, rcx);
   // xmm2 now has -0.5.
   __ ucomisd(xmm2, xmm1);
   __ j(not_equal, &not_minus_half);
 
   // Calculates reciprocal of square root.
   // sqrtsd returns -0 when input is -0.  ECMA spec requires +0.
-  __ xorpd(xmm1, xmm1);
+  __ xorps(xmm1, xmm1);
   __ addsd(xmm1, xmm0);
   __ sqrtsd(xmm1, xmm1);
   __ divsd(xmm3, xmm1);
-  __ movsd(xmm1, xmm3);
+  __ movaps(xmm1, xmm3);
   __ jmp(&allocate_return);
 
   // Test for 0.5.
   __ bind(&not_minus_half);
   // Load xmm2 with 0.5.
   // Since xmm3 is 1 and xmm2 is -0.5 this is simply xmm2 + xmm3.
   __ addsd(xmm2, xmm3);
   // xmm2 now has 0.5.
   __ ucomisd(xmm2, xmm1);
   __ j(not_equal, &call_runtime);
   // Calculates square root.
   // sqrtsd returns -0 when input is -0.  ECMA spec requires +0.
-  __ xorpd(xmm1, xmm1);
-  __ addsd(xmm1, xmm0);
+  __ xorps(xmm1, xmm1);
+  __ addsd(xmm1, xmm0);  // Convert -0 to 0.
   __ sqrtsd(xmm1, xmm1);
 
   __ bind(&allocate_return);
   __ AllocateHeapNumber(rcx, rax, &call_runtime);
   __ movsd(FieldOperand(rcx, HeapNumber::kValueOffset), xmm1);
   __ movq(rax, rcx);
   __ ret(2 * kPointerSize);
 
   __ bind(&call_runtime);
   __ TailCallRuntime(Runtime::kMath_pow_cfunction, 2, 1);
@@ skipping 2843 matching lines @@
   // Do a tail call to the rewritten stub.
   __ jmp(rdi);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64