[X87] [crankshaft] Fix Math.max(-0, 0) bug.

src/crankshaft/x87/lithium-codegen-x87.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X87
 
 #include "src/crankshaft/x87/lithium-codegen-x87.h"
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 1951 matching lines @@
       __ fld(1);
       __ sub(esp, Immediate(2 * kPointerSize));
       __ fstp_s(MemOperand(esp, 0));
       __ fstp_s(MemOperand(esp, kPointerSize));
       __ pop(scratch_reg);
       __ or_(MemOperand(esp, 0), scratch_reg);
       X87Mov(left_reg, MemOperand(esp, 0), kX87FloatOperand);
       __ pop(scratch_reg);  // restore esp
     } else {
       // Since we operate on +0 and/or -0, addsd and andsd have the same effect.
-      X87Fxch(left_reg);
-      __ fadd(1);
+      // Should put the result in stX0
+      __ fadd_i(1);
     }
     __ jmp(&return_left, Label::kNear);
 
     __ bind(&check_nan_left);
     __ fld(0);
     __ fld(0);
     __ FCmp();                                      // NaN check.
     __ j(parity_even, &return_left, Label::kNear);  // left == NaN.
 
     __ bind(&return_right);
-    X87Fxch(left_reg);
     X87Mov(left_reg, right_reg);
 
     __ bind(&return_left);
   }
 }
 
 
 void LCodeGen::DoArithmeticD(LArithmeticD* instr) {
   X87Register left = ToX87Register(instr->left());
   X87Register right = ToX87Register(instr->right());
@@ skipping 3778 matching lines @@
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X87