Make X64 double-to-int32 conversion use the 64-bit version of cvttsd2si.

src/x64/codegen-x64.h

 // 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 693 matching lines @@
                       GenericBinaryFlags flags,
                       TypeInfo operands_type = TypeInfo::Unknown())
       : op_(op),
         mode_(mode),
         flags_(flags),
         args_in_registers_(false),
         args_reversed_(false),
         static_operands_type_(operands_type),
         runtime_operands_type_(BinaryOpIC::DEFAULT),
         name_(NULL) {
-    use_sse3_ = CpuFeatures::IsSupported(SSE3);
     ASSERT(OpBits::is_valid(Token::NUM_TOKENS));
   }
 
   GenericBinaryOpStub(int key, BinaryOpIC::TypeInfo type_info)
       : op_(OpBits::decode(key)),
         mode_(ModeBits::decode(key)),
         flags_(FlagBits::decode(key)),
         args_in_registers_(ArgsInRegistersBits::decode(key)),
         args_reversed_(ArgsReversedBits::decode(key)),
-        use_sse3_(SSE3Bits::decode(key)),
         static_operands_type_(TypeInfo::ExpandedRepresentation(
             StaticTypeInfoBits::decode(key))),
         runtime_operands_type_(type_info),
         name_(NULL) {
   }
 
   // Generate code to call the stub with the supplied arguments. This will add
   // code at the call site to prepare arguments either in registers or on the
   // stack together with the actual call.
   void GenerateCall(MacroAssembler* masm, Register left, Register right);
   void GenerateCall(MacroAssembler* masm, Register left, Smi* right);
   void GenerateCall(MacroAssembler* masm, Smi* left, Register right);
 
   Result GenerateCall(MacroAssembler* masm,
                       VirtualFrame* frame,
                       Result* left,
                       Result* right);
 
  private:
   Token::Value op_;
   OverwriteMode mode_;
   GenericBinaryFlags flags_;
   bool args_in_registers_;  // Arguments passed in registers not on the stack.
   bool args_reversed_;  // Left and right argument are swapped.
-  bool use_sse3_;
 
   // Number type information of operands, determined by code generator.
   TypeInfo static_operands_type_;
 
   // Operand type information determined at runtime.
   BinaryOpIC::TypeInfo runtime_operands_type_;
 
   char* name_;
 
   const char* GetName();
 
 #ifdef DEBUG
   void Print() {
     PrintF("GenericBinaryOpStub %d (op %s), "
            "(mode %d, flags %d, registers %d, reversed %d, only_numbers %s)\n",
            MinorKey(),
            Token::String(op_),
            static_cast<int>(mode_),
            static_cast<int>(flags_),
            static_cast<int>(args_in_registers_),
            static_cast<int>(args_reversed_),
            static_operands_type_.ToString());
   }
 #endif
 
   // Minor key encoding in 18 bits TTNNNFRASOOOOOOOMM.
   class ModeBits: public BitField<OverwriteMode, 0, 2> {};
   class OpBits: public BitField<Token::Value, 2, 7> {};
-  class SSE3Bits: public BitField<bool, 9, 1> {};
+  // One bit free here (removed SSE3 bit)
   class ArgsInRegistersBits: public BitField<bool, 10, 1> {};
   class ArgsReversedBits: public BitField<bool, 11, 1> {};
   class FlagBits: public BitField<GenericBinaryFlags, 12, 1> {};
   class StaticTypeInfoBits: public BitField<int, 13, 3> {};
   class RuntimeTypeInfoBits: public BitField<BinaryOpIC::TypeInfo, 16, 2> {};
 
   Major MajorKey() { return GenericBinaryOp; }
   int MinorKey() {
     // Encode the parameters in a unique 18 bit value.
     return OpBits::encode(op_)
            | ModeBits::encode(mode_)
            | FlagBits::encode(flags_)
-           | SSE3Bits::encode(use_sse3_)
            | ArgsInRegistersBits::encode(args_in_registers_)
            | ArgsReversedBits::encode(args_reversed_)
            | StaticTypeInfoBits::encode(
                static_operands_type_.ThreeBitRepresentation())
            | RuntimeTypeInfoBits::encode(runtime_operands_type_);
   }
 
   void Generate(MacroAssembler* masm);
   void GenerateSmiCode(MacroAssembler* masm, Label* slow);
   void GenerateLoadArguments(MacroAssembler* masm);
@@ skipping 244 matching lines @@
     return ObjectBits::encode(object_.code()) |
            AddressBits::encode(addr_.code()) |
            ScratchBits::encode(scratch_.code());
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_CODEGEN_X64_H_