Fix an error in a keyed lookup stub - HeapNumbers treated as strings.

src/ia32/ic-ia32.cc

 // Copyright 2006-2008 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 25 matching lines @@
 namespace internal {
 
 // ----------------------------------------------------------------------------
 // Static IC stub generators.
 //
 
 #define __ ACCESS_MASM(masm)
 
 
 // Helper function used to load a property from a dictionary backing storage.
+// This function may return false negatives, so miss_label
+// must always call a backup property load that is complete.
+// This function is safe to call if the receiver has fast properties,
+// or if name is not a symbol, and will jump to the miss_label in that case.
 static void GenerateDictionaryLoad(MacroAssembler* masm, Label* miss_label,
                                    Register r0, Register r1, Register r2,
                                    Register name) {
   // Register use:
   //
   // r0   - used to hold the property dictionary.
   //
   // r1   - initially the receiver
   //      - used for the index into the property dictionary
   //      - holds the result on exit.
   //
   // r2   - used to hold the capacity of the property dictionary.
   //
-  // name - holds the name of the property and is unchanges.
+  // name - holds the name of the property and is unchanged.
 
   Label done;
 
   // Check for the absence of an interceptor.
   // Load the map into r0.
   __ mov(r0, FieldOperand(r1, JSObject::kMapOffset));
   // Test the has_named_interceptor bit in the map.
   __ test(FieldOperand(r0, Map::kInstanceAttributesOffset),
           Immediate(1 << (Map::kHasNamedInterceptor + (3 * 8))));
 
@@ skipping 197 matching lines @@
   __ cmp(FieldOperand(ecx, HeapObject::kMapOffset),
          Immediate(Factory::hash_table_map()));
   __ j(equal, &slow, not_taken);
   // Check that the key (index) is within bounds.
   __ cmp(eax, FieldOperand(ecx, FixedArray::kLengthOffset));
   __ j(below, &fast, taken);
   // Slow case: Load name and receiver from stack and jump to runtime.
   __ bind(&slow);
   __ IncrementCounter(&Counters::keyed_load_generic_slow, 1);
   KeyedLoadIC::Generate(masm, ExternalReference(Runtime::kKeyedGetProperty));
-  // Check if the key is a symbol that is not an array index.
+
   __ bind(&check_string);
+  // The key is not a smi.
+  // Is it a string?
+  __ CmpObjectType(eax, FIRST_NONSTRING_TYPE, edx);
+  __ j(above_equal, &slow);
+  // Is the string an array index, with cached numeric value?
   __ mov(ebx, FieldOperand(eax, String::kLengthOffset));
   __ test(ebx, Immediate(String::kIsArrayIndexMask));
   __ j(not_zero, &index_string, not_taken);
-  __ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
-  __ movzx_b(ebx, FieldOperand(ebx, Map::kInstanceTypeOffset));
+
+  // If the string is a symbol, do a quick inline probe of the receiver's
+  // dictionary, if it exists.
+  __ movzx_b(ebx, FieldOperand(exd, Map::kInstanceTypeOffset));
   __ test(ebx, Immediate(kIsSymbolMask));
   __ j(zero, &slow, not_taken);
   // Probe the dictionary leaving result in ecx.
   GenerateDictionaryLoad(masm, &slow, ebx, ecx, edx, eax);
   GenerateCheckNonObjectOrLoaded(masm, &slow, ecx, edx);
   __ mov(eax, Operand(ecx));
   __ IncrementCounter(&Counters::keyed_load_generic_symbol, 1);
   __ ret(0);
   // Array index string: If short enough use cache in length/hash field (ebx).
   // We assert that there are enough bits in an int32_t after the hash shift
@@ skipping 685 matching lines @@
 
   // Do tail-call to runtime routine.
   __ TailCallRuntime(
       ExternalReference(IC_Utility(kSharedStoreIC_ExtendStorage)), 3);
 }
 
 #undef __
 
 
 } }  // namespace v8::internal