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

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index db216ddbeeac0db1c821ed3b534a580109b3d05e..160b6310d55924f4b8c7114312c4434886f865a1 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -2914,7 +2914,7 @@ void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
     key = ToRegister(instr->key());
   }
   int element_size_shift = ElementsKindToShiftSize(elements_kind);
-  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
+  int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
       ? (element_size_shift - kSmiTagSize) : element_size_shift;
   int additional_offset = instr->additional_index() << element_size_shift;
 
@@ -2988,7 +2988,7 @@ void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
   Register scratch = scratch0();
 
   int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
-  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
+  int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
       ? (element_size_shift - kSmiTagSize) : element_size_shift;
   int constant_key = 0;
   if (key_is_constant) {
@@ -3033,7 +3033,7 @@ void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
     // representation for the key to be an integer, the input gets replaced
     // during bound check elimination with the index argument to the bounds
     // check, which can be tagged, so that case must be handled here, too.
-    if (instr->hydrogen()->key()->representation().IsTagged()) {
+    if (instr->hydrogen()->key()->representation().IsSmi()) {
       __ sll(scratch, key, kPointerSizeLog2 - kSmiTagSize);
       __ addu(scratch, elements, scratch);
     } else {
@@ -4019,7 +4019,7 @@ void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
   if (instr->index()->IsConstantOperand()) {
     int constant_index =
         ToInteger32(LConstantOperand::cast(instr->index()));
-    if (instr->hydrogen()->length()->representation().IsTagged()) {
+    if (instr->hydrogen()->length()->representation().IsSmi()) {
       __ li(at, Operand(Smi::FromInt(constant_index)));
     } else {
       __ li(at, Operand(constant_index));
@@ -4052,7 +4052,7 @@ void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
     key = ToRegister(instr->key());
   }
   int element_size_shift = ElementsKindToShiftSize(elements_kind);
-  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
+  int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
       ? (element_size_shift - kSmiTagSize) : element_size_shift;
   int additional_offset = instr->additional_index() << element_size_shift;
 
@@ -4130,7 +4130,7 @@ void LCodeGen::DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr) {
     key = ToRegister(instr->key());
   }
   int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
-  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
+  int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
       ? (element_size_shift - kSmiTagSize) : element_size_shift;
   if (key_is_constant) {
     __ Addu(scratch, elements, Operand((constant_key << element_size_shift) +
@@ -4180,7 +4180,7 @@ void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
     // representation for the key to be an integer, the input gets replaced
     // during bound check elimination with the index argument to the bounds
     // check, which can be tagged, so that case must be handled here, too.
-    if (instr->hydrogen()->key()->representation().IsTagged()) {
+    if (instr->hydrogen()->key()->representation().IsSmi()) {
       __ sll(scratch, key, kPointerSizeLog2 - kSmiTagSize);
       __ addu(scratch, elements, scratch);
     } else {