[builtins] Make Math.max and Math.min fast by default.

src/x64/macro-assembler-x64.h

 // 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.
 
 #ifndef V8_X64_MACRO_ASSEMBLER_X64_H_
 #define V8_X64_MACRO_ASSEMBLER_X64_H_
 
 #include "src/assembler.h"
 #include "src/bailout-reason.h"
 #include "src/base/flags.h"
@@ skipping 409 matching lines @@
 
   // Convert smi to 32-bit integer. I.e., not sign extended into
   // high 32 bits of destination.
   void SmiToInteger32(Register dst, Register src);
   void SmiToInteger32(Register dst, const Operand& src);
 
   // Convert smi to 64-bit integer (sign extended if necessary).
   void SmiToInteger64(Register dst, Register src);
   void SmiToInteger64(Register dst, const Operand& src);
 
+  // Convert smi to double.
+  void SmiToDouble(XMMRegister dst, Register src) {
+    SmiToInteger32(kScratchRegister, src);
+    Cvtlsi2sd(dst, kScratchRegister);
+  }
+
   // Multiply a positive smi's integer value by a power of two.
   // Provides result as 64-bit integer value.
   void PositiveSmiTimesPowerOfTwoToInteger64(Register dst,
                                              Register src,
                                              int power);
 
   // Divide a positive smi's integer value by a power of two.
   // Provides result as 32-bit integer value.
   void PositiveSmiDivPowerOfTwoToInteger32(Register dst,
                                            Register src,
@@ skipping 1299 matching lines @@
   }                                                                          \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_