Fix zero hash handling on ARM.

src/arm/code-stubs-arm.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 5741 matching lines @@
 }
 
 
 void StringHelper::GenerateHashGetHash(MacroAssembler* masm,
                                        Register hash) {
   // hash += hash << 3;
   __ add(hash, hash, Operand(hash, LSL, 3));
   // hash ^= hash >> 11;
   __ eor(hash, hash, Operand(hash, LSR, 11));
   // hash += hash << 15;
-  __ add(hash, hash, Operand(hash, LSL, 15), SetCC);
+  __ add(hash, hash, Operand(hash, LSL, 15));
 
-  uint32_t kHashShiftCutOffMask = (1 << (32 - String::kHashShift)) - 1;
-  __ and_(hash, hash, Operand(kHashShiftCutOffMask));
+  __ and_(hash, hash, Operand(String::kHashBitMask), SetCC);
 
   // if (hash == 0) hash = 27;
-  __ mov(hash, Operand(27), LeaveCC, eq);
+  __ mov(hash, Operand(StringHasher::kZeroHash), LeaveCC, eq);
 }
 
 
 void SubStringStub::Generate(MacroAssembler* masm) {
   Label runtime;
 
   // Stack frame on entry.
   //  lr: return address
   //  sp[0]: to
   //  sp[4]: from
@@ skipping 1535 matching lines @@
   __ StoreNumberToDoubleElements(r0, r3, r1, r5, r6, r7, r9, r10,
                                  &slow_elements);
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM