Update DecodeFieldToSmi to support x32 port.

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 "assembler.h"
 #include "frames.h"
 #include "globals.h"
@@ skipping 1004 matching lines @@
     static const int shift = Field::kShift;
     static const int mask = Field::kMask >> Field::kShift;
     if (shift != 0) {
       shrp(reg, Immediate(shift));
     }
     andp(reg, Immediate(mask));
   }
 
   template<typename Field>
   void DecodeFieldToSmi(Register reg) {
-    andp(reg, Immediate(Field::kMask));
-    shlp(reg, Immediate(kSmiShift - Field::kShift));
+    if (SmiValuesAre32Bits()) {
+      andp(reg, Immediate(Field::kMask));
+      shlp(reg, Immediate(kSmiShift - Field::kShift));
+    } else {
+      static const int shift = Field::kShift;
+      static const int mask = (Field::kMask >> Field::kShift) << kSmiTagSize;

[haitao.feng, 2014/06/09 05:43:06]

Clang reports an error when using kSmiShift:

    .././src/x64/macro-assembler-x64.h:1061:63: error: shift count >= width of
type [-Werror,-Wshift-count-overflow]
        static const int mask = (Field::kMask >> Field::kShift) << kSmiShift;

Windows reports a similar error. So I changed the kSmiShift to kSmiTagSize.

+      ASSERT(SmiValuesAre31Bits());
+      ASSERT(kSmiShift == kSmiTagSize);
+      ASSERT((mask & 0x80000000u) == 0);
+      if (shift < kSmiShift) {
+        shlp(reg, Immediate(kSmiShift - shift));
+      } else if (shift > kSmiShift) {
+        sarp(reg, Immediate(shift - kSmiShift));
+      }
+      andp(reg, Immediate(mask));
+    }
   }
 
   // Abort execution if argument is not a number, enabled via --debug-code.
   void AssertNumber(Register object);
 
   // Abort execution if argument is a smi, enabled via --debug-code.
   void AssertNotSmi(Register object);
 
   // Abort execution if argument is not a smi, enabled via --debug-code.
   void AssertSmi(Register object);
@@ skipping 560 matching lines @@
     masm->popfq();                                                           \
   }                                                                          \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_