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

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3346 matching lines @@
   if (key->IsConstantOperand()) {
     int constant_value = ToInteger32(LConstantOperand::cast(key));
     if (constant_value & 0xF0000000) {
       Abort("array index constant value too big");
     }
     return Operand(elements_pointer_reg,
                    ((constant_value + additional_index) << shift_size)
                        + offset);
   } else {
     // Take the tag bit into account while computing the shift size.
-    if (key_representation.IsTagged() && (shift_size >= 1)) {
+    if (key_representation.IsSmi() && (shift_size >= 1)) {
       shift_size -= kSmiTagSize;
     }
     ScaleFactor scale_factor = static_cast<ScaleFactor>(shift_size);
     return Operand(elements_pointer_reg,
                    ToRegister(key),
                    scale_factor,
                    offset + (additional_index << element_shift_size));
   }
 }
 
@@ skipping 974 matching lines @@
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
 }
 
 
 void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
   if (instr->hydrogen()->skip_check()) return;
 
   if (instr->index()->IsConstantOperand()) {
     int constant_index =
         ToInteger32(LConstantOperand::cast(instr->index()));
-    if (instr->hydrogen()->length()->representation().IsTagged()) {
+    if (instr->hydrogen()->length()->representation().IsSmi()) {
       __ cmp(ToOperand(instr->length()),
              Immediate(Smi::FromInt(constant_index)));
     } else {
       __ cmp(ToOperand(instr->length()), Immediate(constant_index));
     }
     DeoptimizeIf(below_equal, instr->environment());
   } else {
     __ cmp(ToRegister(instr->index()), ToOperand(instr->length()));
     DeoptimizeIf(above_equal, instr->environment());
   }
@@ skipping 2221 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32