Make HCompareNumericAndBranch safe for snapshots on ia32.

src/ia32/lithium-codegen-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 2538 matching lines @@
 
   if (left->IsConstantOperand() && right->IsConstantOperand()) {
     // We can statically evaluate the comparison.
     double left_val = ToDouble(LConstantOperand::cast(left));
     double right_val = ToDouble(LConstantOperand::cast(right));
     int next_block = EvalComparison(instr->op(), left_val, right_val) ?
         instr->TrueDestination(chunk_) : instr->FalseDestination(chunk_);
     EmitGoto(next_block);
   } else {
     if (instr->is_double()) {
-      CpuFeatureScope scope(masm(), SSE2);
+      if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
+        CpuFeatureScope scope(masm(), SSE2);
+        __ ucomisd(ToDoubleRegister(left), ToDoubleRegister(right));
+      } else {
+        X87Fxch(ToX87Register(right));
+        X87Fxch(ToX87Register(left), 1);
+        __ fld(0);
+        __ fld(2);
+        __ FCmp();
+      }
       // Don't base result on EFLAGS when a NaN is involved. Instead
       // jump to the false block.
-      __ ucomisd(ToDoubleRegister(left), ToDoubleRegister(right));
       __ j(parity_even, instr->FalseLabel(chunk_));
     } else {
       if (right->IsConstantOperand()) {
         __ cmp(ToOperand(left),
                ToImmediate(right, instr->hydrogen()->representation()));
       } else if (left->IsConstantOperand()) {
         __ cmp(ToOperand(right),
                ToImmediate(left, instr->hydrogen()->representation()));
         // We transposed the operands. Reverse the condition.
         cc = ReverseCondition(cc);
@@ skipping 3786 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32