Changed GeneratePow ensure xmm1 is loaded with y before making the test for N...

src/ia32/codegen-ia32.cc

 // Copyright 2010 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 5350 matching lines @@
       __ divsd(xmm3, xmm1);
       __ movsd(xmm1, xmm3);
       __ jmp(&allocate_and_return);
 
       // y (or both) is a double - no matter what we should now work
       // on doubles.
       __ bind(&y_nonsmi);
       __ cmp(FieldOperand(y.reg(), HeapObject::kMapOffset),
              Factory::heap_number_map());
       __ j(not_equal, &go_runtime);
+      // Y must be a double.
+      __ movdbl(xmm1, FieldOperand(y.reg(), HeapNumber::kValueOffset));
       // Test if y is nan.
       __ ucomisd(xmm1, xmm1);
       __ j(parity_even, &go_runtime);
 
-      // Y must be a double.
-      __ movdbl(xmm1, FieldOperand(y.reg(), HeapNumber::kValueOffset));
-
       Label x_not_smi;
       Label handle_special_cases;
       __ test(x.reg(), Immediate(kSmiTagMask));
       __ j(not_zero, &x_not_smi);
       __ SmiUntag(x.reg());
       __ cvtsi2sd(xmm0, Operand(x.reg()));
       __ jmp(&handle_special_cases);
       __ bind(&x_not_smi);
       __ cmp(FieldOperand(x.reg(), HeapObject::kMapOffset),
              Factory::heap_number_map());
@@ skipping 5843 matching lines @@
 
   // Call the runtime; it returns -1 (less), 0 (equal), or 1 (greater)
   // tagged as a small integer.
   __ bind(&runtime);
   __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
 }
 
 #undef __
 
 } }  // namespace v8::internal