PPC: Fix keyed element access wrt string wrappers

src/ppc/macro-assembler-ppc.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <assert.h>  // For assert
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_PPC
@@ skipping 4519 matching lines @@
   UNREACHABLE();
   return no_reg;
 }
 
 
 void MacroAssembler::JumpIfDictionaryInPrototypeChain(Register object,
                                                       Register scratch0,
                                                       Register scratch1,
                                                       Label* found) {
   DCHECK(!scratch1.is(scratch0));
-  Factory* factory = isolate()->factory();
   Register current = scratch0;
-  Label loop_again;
+  Label loop_again, end;
 
   // scratch contained elements pointer.
   mr(current, object);
+  LoadP(current, FieldMemOperand(current, HeapObject::kMapOffset));
+  LoadP(current, FieldMemOperand(current, Map::kPrototypeOffset));
+  CompareRoot(current, Heap::kNullValueRootIndex);
+  beq(&end);
 
   // Loop based on the map going up the prototype chain.
   bind(&loop_again);
   LoadP(current, FieldMemOperand(current, HeapObject::kMapOffset));
+
+  STATIC_ASSERT(JS_PROXY_TYPE < JS_OBJECT_TYPE);
+  STATIC_ASSERT(JS_VALUE_TYPE < JS_OBJECT_TYPE);
+  lbz(scratch1, FieldMemOperand(current, Map::kInstanceTypeOffset));
+  cmpi(scratch1, Operand(JS_OBJECT_TYPE));
+  blt(found);
+
   lbz(scratch1, FieldMemOperand(current, Map::kBitField2Offset));
   DecodeField<Map::ElementsKindBits>(scratch1);
   cmpi(scratch1, Operand(DICTIONARY_ELEMENTS));
   beq(found);
   LoadP(current, FieldMemOperand(current, Map::kPrototypeOffset));
-  Cmpi(current, Operand(factory->null_value()), r0);
+  CompareRoot(current, Heap::kNullValueRootIndex);
   bne(&loop_again);
+
+  bind(&end);
 }
 
 
 #ifdef DEBUG
 bool AreAliased(Register reg1, Register reg2, Register reg3, Register reg4,
                 Register reg5, Register reg6, Register reg7, Register reg8) {
   int n_of_valid_regs = reg1.is_valid() + reg2.is_valid() + reg3.is_valid() +
                         reg4.is_valid() + reg5.is_valid() + reg6.is_valid() +
                         reg7.is_valid() + reg8.is_valid();
 
@@ skipping 75 matching lines @@
   }
   if (mag.shift > 0) srawi(result, result, mag.shift);
   ExtractBit(r0, dividend, 31);
   add(result, result, r0);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC