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

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index 5ceca4970098dc92cf7e761e452e3e39882e618e..9ee5bfbe97e33242a876c2188d4c6152a82ed18b 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1902,12 +1902,6 @@ LInstruction* LChunkBuilder::DoCheckSmi(HCheckSmi* instr) {
 }
 
 
-LInstruction* LChunkBuilder::DoCheckSmiOrInt32(HCheckSmiOrInt32* instr) {
-  LOperand* value = UseRegisterAtStart(instr->value());
-  return AssignEnvironment(new(zone()) LCheckSmi(value));
-}
-
-
 LInstruction* LChunkBuilder::DoCheckFunction(HCheckFunction* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
   return AssignEnvironment(new(zone()) LCheckFunction(value));
@@ -1953,7 +1947,7 @@ LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
     return DefineAsRegister(new(zone()) LConstantI);
   } else if (r.IsDouble()) {
     return DefineAsRegister(new(zone()) LConstantD);
-  } else if (r.IsTagged() || r.IsSmi()) {
+  } else if (r.IsSmiOrTagged()) {
     return DefineAsRegister(new(zone()) LConstantT);
   } else {
     UNREACHABLE();
@@ -2065,7 +2059,7 @@ 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();
   LOperand* key = UseRegisterOrConstantAtStart(instr->key());
   LLoadKeyed* result = NULL;