Optionally use 31-bits SMI value for 64-bit system

src/x64/assembler-x64.h

Index: src/x64/assembler-x64.h
diff --git a/src/x64/assembler-x64.h b/src/x64/assembler-x64.h
index 07afc129dc82c76b76a5eadb2c6bd3425eb0289e..b329a2d3000180e046c189ca99a1431025e1a996 100644
--- a/src/x64/assembler-x64.h
+++ b/src/x64/assembler-x64.h
@@ -378,6 +378,11 @@ inline Condition ReverseCondition(Condition cc) {
 class Immediate BASE_EMBEDDED {
  public:
   explicit Immediate(int32_t value) : value_(value) {}
+#if V8_USE_31_BITS_SMI_VALUE
+  explicit Immediate(Smi* value) {

[danno, 2013/07/29 13:02:23]

Don't add a Smi* constructor here. The wrapper function that allows inlining of
31-bit smis should do the work that this constructor does and call through to
the existing version.

[haitao.feng, 2013/07/30 08:56:43]

Done.

+    value_ = static_cast<int32_t>(reinterpret_cast<intptr_t>(value));
+  }
+#endif
 
  private:
   int32_t value_;
@@ -988,6 +993,12 @@ class Assembler : public AssemblerBase {
     shift(dst, imm8, 0x0);
   }
 
+#if V8_USE_31_BITS_SMI_VALUE

[danno, 2013/07/29 13:02:23]

Is there some way to not including this conditionally? I think the assembler
should have no conditionally included code, it should be as "dumb" as possible
and not know anything about Smis if possible. 

[haitao.feng, 2013/07/30 08:56:43]

Done.

+  void roll(Register dst, Immediate imm8) {
+    shift_32(dst, imm8, 0x0);
+  }
+#endif
+
   void rcr(Register dst, Immediate imm8) {
     shift(dst, imm8, 0x3);
   }
@@ -1378,6 +1389,9 @@ class Assembler : public AssemblerBase {
 
   void movmskpd(Register dst, XMMRegister src);
   void movmskps(Register dst, XMMRegister src);
+#if V8_USE_31_BITS_SMI_VALUE
+  void pcmpeqd(XMMRegister dst, XMMRegister src);

[danno, 2013/07/29 13:02:23]

Why can't this always be part of the code (no conditional include)?

[haitao.feng, 2013/07/30 08:56:43]

Done.

+#endif
 
   // The first argument is the reg field, the second argument is the r/m field.
   void emit_sse_operand(XMMRegister dst, XMMRegister src);