X64: Many small tweaks and more usages of "load smi as int32".

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index b7a6aaf9ef4d24d752b97594b2fc27047b08be38..33e1f8de0cf55ff4be0e966fd4a15215ac82250b 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -573,6 +573,11 @@ void MacroAssembler::SmiToInteger32(Register dst, Register src) {
 }
 
 
+void MacroAssembler::SmiToInteger32(Register dst, const Operand& src) {
+  movl(dst, Operand(src, kIntSize));

[William Hesse, 2010/05/27 08:36:03]

Is kIntSize really better than "4" here?  If anything ever changes, there is no
reason to think kIntSize will remain the correct value.

+}
+
+
 void MacroAssembler::SmiToInteger64(Register dst, Register src) {
   ASSERT_EQ(0, kSmiTag);
   if (!dst.is(src)) {