MIPS64: Correct register use.

src/mips64/ic-mips64.cc

 // Copyright 2012 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 "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS64
 
@@ skipping 427 matching lines @@
 
   Label slow, notin;
   MemOperand mapped_location =
       GenerateMappedArgumentsLookup(
           masm, receiver, key, a0, a3, a4, &notin, &slow);
   __ Ret(USE_DELAY_SLOT);
   __ ld(v0, mapped_location);
   __ bind(&notin);
   // The unmapped lookup expects that the parameter map is in a2.
   MemOperand unmapped_location =
-      GenerateUnmappedArgumentsLookup(masm, a0, a0, a3, &slow);
+      GenerateUnmappedArgumentsLookup(masm, key, a0, a3, &slow);
   __ ld(a0, unmapped_location);
   __ LoadRoot(a3, Heap::kTheHoleValueRootIndex);
   __ Branch(&slow, eq, a0, Operand(a3));
   __ Ret(USE_DELAY_SLOT);
   __ mov(v0, a0);
   __ bind(&slow);
   GenerateMiss(masm);
 }
 
 
@@ skipping 801 matching lines @@
   } else {
     ASSERT(Assembler::IsBne(branch_instr));
     patcher.ChangeBranchCondition(eq);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS64