Fix keyed lookup cache to have 2 entried per bucket instead

src/ia32/ic-ia32.cc

 // Copyright 2011 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 455 matching lines @@
                         edx,
                         eax,
                         ecx,
                         eax,
                         NULL,
                         &slow);
   Isolate* isolate = masm->isolate();
   Counters* counters = isolate->counters();
   __ IncrementCounter(counters->keyed_load_generic_smi(), 1);
   __ ret(0);
-
   __ bind(&check_number_dictionary);
   __ mov(ebx, eax);
   __ SmiUntag(ebx);
   __ mov(ecx, FieldOperand(edx, JSObject::kElementsOffset));
 
   // Check whether the elements is a number dictionary.
   // edx: receiver
   // ebx: untagged index
   // eax: key
   // ecx: elements
@@ skipping 41 matching lines @@
   __ j(equal, &probe_dictionary);
 
   // Load the map of the receiver, compute the keyed lookup cache hash
   // based on 32 bits of the map pointer and the string hash.
   __ mov(ebx, FieldOperand(edx, HeapObject::kMapOffset));
   __ mov(ecx, ebx);
   __ shr(ecx, KeyedLookupCache::kMapHashShift);
   __ mov(edi, FieldOperand(eax, String::kHashFieldOffset));
   __ shr(edi, String::kHashShift);
   __ xor_(ecx, edi);
-  __ and_(ecx, KeyedLookupCache::kCapacityMask);
+  __ and_(ecx, KeyedLookupCache::kCapacityMask & KeyedLookupCache::kHashMask);
 
   // Load the key (consisting of map and symbol) from the cache and
   // check for match.
+  Label try_second_entry, hit_on_first_entry, load_in_object_property;
   ExternalReference cache_keys =
       ExternalReference::keyed_lookup_cache_keys(masm->isolate());
   __ mov(edi, ecx);
   __ shl(edi, kPointerSizeLog2 + 1);
   __ cmp(ebx, Operand::StaticArray(edi, times_1, cache_keys));
+  __ j(not_equal, &try_second_entry);
+  __ add(edi, Immediate(kPointerSize));
+  __ cmp(eax, Operand::StaticArray(edi, times_1, cache_keys));
+  __ j(equal, &hit_on_first_entry);
+
+  __ bind(&try_second_entry);
+  __ lea(edi, Operand(ecx, 1));
+  __ shl(edi, kPointerSizeLog2 + 1);
+  __ cmp(ebx, Operand::StaticArray(edi, times_1, cache_keys));
   __ j(not_equal, &slow);
   __ add(edi, Immediate(kPointerSize));
   __ cmp(eax, Operand::StaticArray(edi, times_1, cache_keys));
   __ j(not_equal, &slow);
 
+
   // Get field offset.
   // edx     : receiver
   // ebx     : receiver's map
   // eax     : key
   // ecx     : lookup cache index
   ExternalReference cache_field_offsets =
       ExternalReference::keyed_lookup_cache_field_offsets(masm->isolate());
+
+  // Hit on second entry.
+  __ add(ecx, Immediate(1));
+  __ mov(edi,
+         Operand::StaticArray(ecx, times_pointer_size, cache_field_offsets));
+  __ movzx_b(ecx, FieldOperand(ebx, Map::kInObjectPropertiesOffset));
+  __ sub(edi, ecx);
+  __ j(above_equal, &property_array_property);
+  __ jmp(&load_in_object_property);
+
+  // Hit on first entry.
+  __ bind(&hit_on_first_entry);
   __ mov(edi,
          Operand::StaticArray(ecx, times_pointer_size, cache_field_offsets));
   __ movzx_b(ecx, FieldOperand(ebx, Map::kInObjectPropertiesOffset));
   __ sub(edi, ecx);
   __ j(above_equal, &property_array_property);
 
   // Load in-object property.
+  __ bind(&load_in_object_property);
   __ movzx_b(ecx, FieldOperand(ebx, Map::kInstanceSizeOffset));
   __ add(ecx, edi);
   __ mov(eax, FieldOperand(edx, ecx, times_pointer_size, 0));
   __ IncrementCounter(counters->keyed_load_generic_lookup_cache(), 1);
   __ ret(0);
 
   // Load property array property.
   __ bind(&property_array_property);
   __ mov(eax, FieldOperand(edx, JSObject::kPropertiesOffset));
   __ mov(eax, FieldOperand(eax, edi, times_pointer_size,
@@ skipping 1108 matching lines @@
   Condition cc = *jmp_address == Assembler::kJncShortOpcode
       ? not_zero
       : zero;
   *jmp_address = static_cast<byte>(Assembler::kJccShortPrefix | cc);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32