Handle holes in smi-untag from LoadKeyed requiring hole handling.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 4588 matching lines @@
   __ Integer32ToSmi(input, input);
 }
 
 
 void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
   ASSERT(instr->value()->Equals(instr->result()));
   Register input = ToRegister(instr->value());
   if (instr->needs_check()) {
     Condition is_smi = __ CheckSmi(input);
     DeoptimizeIf(NegateCondition(is_smi), instr->environment());
+  } else if (instr->hydrogen()->value()->IsLoadKeyed()) {
+    HLoadKeyed* load = HLoadKeyed::cast(instr->hydrogen()->value());
+    if (load->UsesMustHandleHole()) {
+      Label done;
+      Condition cc = masm()->CheckSmi(input);
+      __ j(cc, &done);
+      __ xor_(input, input);
+      __ bind(&done);
+    } else {
+      __ AssertSmi(input);
+    }
   } else {
     __ AssertSmi(input);
   }
   __ SmiToInteger32(input, input);
 }
 
 
 void LCodeGen::EmitNumberUntagD(Register input_reg,
                                 XMMRegister result_reg,
                                 bool deoptimize_on_undefined,
@@ skipping 986 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64