Fix improved LoadICs for dictionaries with callbacks.

src/ia32/stub-cache-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 1042 matching lines @@
 
 
 void StubCompiler::GenerateDictionaryLoadCallback(Register receiver,
                                                   Register name_reg,
                                                   Register scratch1,
                                                   Register scratch2,
                                                   Register scratch3,
                                                   Handle<AccessorInfo> callback,
                                                   Handle<String> name,
                                                   Label* miss) {
+  ASSERT(!receiver.is(scratch2));
+  ASSERT(!receiver.is(scratch3));
   Register dictionary = scratch1;
+  bool must_preserve_dictionary_reg = receiver.is(dictionary);
+
+  // Load the properties dictionary.
+  if (must_preserve_dictionary_reg) {
+    __ push(dictionary);
+  }
   __ mov(dictionary, FieldOperand(receiver, JSObject::kPropertiesOffset));
 
   // Probe the dictionary.
-  Label probe_done;
+  Label probe_done, pop_and_miss;
   StringDictionaryLookupStub::GeneratePositiveLookup(masm(),
-                                                     miss,
+                                                     &pop_and_miss,
                                                      &probe_done,
                                                      dictionary,
                                                      name_reg,
                                                      scratch2,
                                                      scratch3);
+  __ bind(&pop_and_miss);
+  if (must_preserve_dictionary_reg) {
+    __ pop(dictionary);
+  }
+  __ jmp(miss);
   __ bind(&probe_done);
 
   // If probing finds an entry in the dictionary, scratch2 contains the
   // index into the dictionary. Check that the value is the callback.
   Register index = scratch2;
   const int kElementsStartOffset =
       StringDictionary::kHeaderSize +
       StringDictionary::kElementsStartIndex * kPointerSize;
   const int kValueOffset = kElementsStartOffset + kPointerSize;
   __ mov(scratch3,
          Operand(dictionary, index, times_4, kValueOffset - kHeapObjectTag));
+  if (must_preserve_dictionary_reg) {
+    __ pop(dictionary);
+  }
   __ cmp(scratch3, callback);
   __ j(not_equal, miss);
 }
 
 
 void StubCompiler::GenerateLoadCallback(Handle<JSObject> object,
                                         Handle<JSObject> holder,
                                         Register receiver,
                                         Register name_reg,
                                         Register scratch1,
                                         Register scratch2,
                                         Register scratch3,
                                         Handle<AccessorInfo> callback,
                                         Handle<String> name,
                                         Label* miss) {
   // Check that the receiver isn't a smi.
   __ JumpIfSmi(receiver, miss);
 
   // Check that the maps haven't changed.
   Register reg = CheckPrototypes(object, receiver, holder, scratch1,
                                  scratch2, scratch3, name, miss);
 
   if (!holder->HasFastProperties() && !holder->IsJSGlobalObject()) {
     GenerateDictionaryLoadCallback(
-        receiver, name_reg, scratch1, scratch2, scratch3, callback, name, miss);
+        reg, name_reg, scratch1, scratch2, scratch3, callback, name, miss);
   }
 
   // Insert additional parameters into the stack frame above return address.
   ASSERT(!scratch3.is(reg));
   __ pop(scratch3);  // Get return address to place it below.
 
   __ push(receiver);  // receiver
   __ mov(scratch2, esp);
   ASSERT(!scratch2.is(reg));
   __ push(reg);  // holder
@@ skipping 3166 matching lines @@
     __ jmp(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32