[ia32/x64] Smaller instruction to check NaN

src/ia32/code-stubs-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 827 matching lines @@
 
   if (exponent_type_ != INTEGER) {
     Label fast_power, try_arithmetic_simplification;
     __ DoubleToI(exponent, double_exponent, double_scratch,
                  TREAT_MINUS_ZERO_AS_ZERO, &try_arithmetic_simplification);
     __ jmp(&int_exponent);
 
     __ bind(&try_arithmetic_simplification);
     // Skip to runtime if possibly NaN (indicated by the indefinite integer).
     __ cvttsd2si(exponent, Operand(double_exponent));
-    __ cmp(exponent, Immediate(0x80000000u));
-    __ j(equal, &call_runtime);
+    __ cmp(exponent, Immediate(0x1));
+    __ j(overflow, &call_runtime);
 
     if (exponent_type_ == ON_STACK) {
       // Detect square root case.  Crankshaft detects constant +/-0.5 at
       // compile time and uses DoMathPowHalf instead.  We then skip this check
       // for non-constant cases of +/-0.5 as these hardly occur.
       Label continue_sqrt, continue_rsqrt, not_plus_half;
       // Test for 0.5.
       // Load double_scratch with 0.5.
       __ mov(scratch, Immediate(0x3F000000u));
       __ movd(double_scratch, scratch);
@@ skipping 4591 matching lines @@
                               Operand(ebp, 7 * kPointerSize),
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32