Optimize Smi keys for KeyedLoads

src/ia32/lithium-ia32.h

 // 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 854 matching lines @@
  public:
   LBoundsCheck(LOperand* index, LOperand* length) {
     inputs_[0] = index;
     inputs_[1] = length;
   }
 
   LOperand* index() { return inputs_[0]; }
   LOperand* length() { return inputs_[1]; }
 
   DECLARE_CONCRETE_INSTRUCTION(BoundsCheck, "bounds-check")
+  DECLARE_HYDROGEN_ACCESSOR(BoundsCheck)
 };
 
 
 class LBitI: public LTemplateInstruction<1, 2, 0> {
  public:
   LBitI(LOperand* left, LOperand* right) {
     inputs_[0] = left;
     inputs_[1] = right;
   }
 
@@ skipping 385 matching lines @@
   DECLARE_CONCRETE_INSTRUCTION(LoadKeyedFastDoubleElement,
                                "load-keyed-fast-double-element")
   DECLARE_HYDROGEN_ACCESSOR(LoadKeyedFastDoubleElement)
 
   LOperand* elements() { return inputs_[0]; }
   LOperand* key() { return inputs_[1]; }
   uint32_t additional_index() const { return hydrogen()->index_offset(); }
 };
 
 
+inline static bool ExternalArrayOpRequiresTemp(
+    Representation key_representation,
+    ElementsKind elements_kind) {
+  // Operations that require the key to be divided by two to be converted into
+  // an index cannot fold the scale operation into a load and need an extra
+  // temp register to do the work.
+  return key_representation.IsTagged() &&
+      (elements_kind == EXTERNAL_BYTE_ELEMENTS ||
+       elements_kind == EXTERNAL_UNSIGNED_BYTE_ELEMENTS ||
+       elements_kind == EXTERNAL_PIXEL_ELEMENTS);
+}
+
+
 class LLoadKeyedSpecializedArrayElement: public LTemplateInstruction<1, 2, 0> {
  public:
   LLoadKeyedSpecializedArrayElement(LOperand* external_pointer, LOperand* key) {
     inputs_[0] = external_pointer;
     inputs_[1] = key;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(LoadKeyedSpecializedArrayElement,
                                "load-keyed-specialized-array-element")
   DECLARE_HYDROGEN_ACCESSOR(LoadKeyedSpecializedArrayElement)
@@ skipping 1201 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_LITHIUM_IA32_H_