Add MathPowStub to x64 platform, and fix error in stub on ia32 platform.

src/ia32/code-stubs-ia32.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 3381 matching lines @@
   __ cvtsi2sd(xmm3, Operand(ecx));
 
   Label exponent_nonsmi;
   Label base_nonsmi;
   // If the exponent is a heap number go to that specific case.
   __ test(eax, Immediate(kSmiTagMask));
   __ j(not_zero, &exponent_nonsmi);
   __ test(edx, Immediate(kSmiTagMask));
   __ j(not_zero, &base_nonsmi);
 
-  // Optimized version when both exponent and base is a smi.
+  // Optimized version when both exponent and base are smis.
   Label powi;
   __ SmiUntag(edx);
   __ cvtsi2sd(xmm0, Operand(edx));
   __ jmp(&powi);
   // exponent is smi and base is a heapnumber.
   __ bind(&base_nonsmi);
   __ cmp(FieldOperand(edx, HeapObject::kMapOffset),
          Factory::heap_number_map());
   __ j(not_equal, &call_runtime);
 
@@ skipping 18 matching lines @@
   // Load xmm1 with 1.
   __ movsd(xmm1, xmm3);
   NearLabel while_true;
   NearLabel no_multiply;
 
   __ bind(&while_true);
   __ shr(eax, 1);
   __ j(not_carry, &no_multiply);
   __ mulsd(xmm1, xmm0);
   __ bind(&no_multiply);
-  __ test(eax, Operand(eax));
   __ mulsd(xmm0, xmm0);
   __ j(not_zero, &while_true);
 
   // base has the original value of the exponent - if the exponent  is
   // negative return 1/result.
   __ test(edx, Operand(edx));
   __ j(positive, &allocate_return);
   // Special case if xmm1 has reached infinity.
   __ mov(ecx, Immediate(0x7FB00000));
   __ movd(xmm0, Operand(ecx));
@@ skipping 66 matching lines @@
   // Calculates square root.
   // sqrtsd returns -0 when input is -0.  ECMA spec requires +0.
   __ xorpd(xmm1, xmm1);
   __ addsd(xmm1, xmm0);
   __ sqrtsd(xmm1, xmm1);
 
   __ bind(&allocate_return);
   __ AllocateHeapNumber(ecx, eax, edx, &call_runtime);
   __ movdbl(FieldOperand(ecx, HeapNumber::kValueOffset), xmm1);
   __ mov(eax, ecx);
-  __ ret(2);
+  __ ret(2 * kPointerSize);
 
   __ bind(&call_runtime);
   __ TailCallRuntime(Runtime::kMath_pow_cfunction, 2, 1);
 }
 
 
 void ArgumentsAccessStub::GenerateReadElement(MacroAssembler* masm) {
   // The key is in edx and the parameter count is in eax.
 
   // The displacement is used for skipping the frame pointer on the
@@ skipping 3077 matching lines @@
   __ mov_b(Operand(external_pointer, untagged_key, times_1, 0), untagged_value);
   __ ret(0);  // Return value in eax.
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32