MIPS: Correct handling of arrays with callbacks in the prototype chain.

src/mips/macro-assembler-mips.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 5636 matching lines @@
   for (int i = 0; i < Register::NumAllocatableRegisters(); i++) {
     Register candidate = Register::FromAllocationIndex(i);
     if (regs & candidate.bit()) continue;
     return candidate;
   }
   UNREACHABLE();
   return no_reg;
 }
 
 
+void MacroAssembler::JumpIfDictionaryInPrototypeChain(
+    Register object,
+    Register scratch0,
+    Register scratch1,
+    Label* found) {
+  ASSERT(!scratch1.is(scratch0));
+  Factory* factory = isolate()->factory();
+  Register current = scratch0;
+  Label loop_again;
+
+  // Scratch contained elements pointer.
+  Move(current, object);
+
+  // Loop based on the map going up the prototype chain.
+  bind(&loop_again);
+  lw(current, FieldMemOperand(current, HeapObject::kMapOffset));
+  lb(scratch1, FieldMemOperand(current, Map::kBitField2Offset));
+  Ext(scratch1, scratch1, Map::kElementsKindShift, Map::kElementsKindBitCount);
+  Branch(found, eq, scratch1, Operand(DICTIONARY_ELEMENTS));
+  lw(current, FieldMemOperand(current, Map::kPrototypeOffset));
+  Branch(&loop_again, ne, current, Operand(factory->null_value()));
+}
+
+
 bool AreAliased(Register r1, Register r2, Register r3, Register r4) {
   if (r1.is(r2)) return true;
   if (r1.is(r3)) return true;
   if (r1.is(r4)) return true;
   if (r2.is(r3)) return true;
   if (r2.is(r4)) return true;
   if (r3.is(r4)) return true;
   return false;
 }
 
@@ skipping 47 matching lines @@
        opcode == BGTZL);
   opcode = (cond == eq) ? BEQ : BNE;
   instr = (instr & ~kOpcodeMask) | opcode;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS