Replace tagged keys for fast access by smi, and use smi in boundscheck.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index ef6c22315331a74bdf40d17c0557d3542d24e106..a112662a9aa8f49abd75c6aa661717b86b8bfb5e 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -2069,12 +2069,6 @@ LInstruction* LChunkBuilder::DoCheckSmi(HCheckSmi* instr) {
 }
 
 
-LInstruction* LChunkBuilder::DoCheckSmiOrInt32(HCheckSmiOrInt32* instr) {
-  LOperand* value = UseAtStart(instr->value());
-  return AssignEnvironment(new(zone()) LCheckSmi(value));
-}
-
-
 LInstruction* LChunkBuilder::DoCheckFunction(HCheckFunction* instr) {
   // If the target is in new space, we'll emit a global cell compare and so
   // want the value in a register.  If the target gets promoted before we
@@ -2145,7 +2139,7 @@ LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
     } else {
       return DefineX87TOS(new(zone()) LConstantD(NULL));
     }
-  } else if (r.IsTagged()) {
+  } else if (r.IsSmiOrTagged()) {
     return DefineAsRegister(new(zone()) LConstantT);
   } else {
     UNREACHABLE();
@@ -2262,7 +2256,7 @@ LInstruction* LChunkBuilder::DoLoadExternalArrayPointer(
 
 LInstruction* LChunkBuilder::DoLoadKeyed(HLoadKeyed* instr) {
   ASSERT(instr->key()->representation().IsInteger32() ||
-         instr->key()->representation().IsTagged());
+         instr->key()->representation().IsSmi());
   ElementsKind elements_kind = instr->elements_kind();
   bool clobbers_key = ExternalArrayOpRequiresTemp(
       instr->key()->representation(), elements_kind);
@@ -2331,7 +2325,7 @@ LInstruction* LChunkBuilder::DoStoreKeyed(HStoreKeyed* instr) {
   if (!instr->is_external()) {
     ASSERT(instr->elements()->representation().IsTagged());
     ASSERT(instr->key()->representation().IsInteger32() ||
-           instr->key()->representation().IsTagged());
+           instr->key()->representation().IsSmi());
 
     if (instr->value()->representation().IsDouble()) {
       LOperand* object = UseRegisterAtStart(instr->elements());