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

src/arm/lithium-codegen-arm.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 4887 matching lines @@
 
 
 void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
   Register input = ToRegister(instr->value());
   Register result = ToRegister(instr->result());
   if (instr->needs_check()) {
     STATIC_ASSERT(kHeapObjectTag == 1);
     // If the input is a HeapObject, SmiUntag will set the carry flag.
     __ SmiUntag(result, input, SetCC);
     DeoptimizeIf(cs, instr->environment());
+  } else if (instr->hydrogen()->value()->IsLoadKeyed()) {
+    HLoadKeyed* load = HLoadKeyed::cast(instr->hydrogen()->value());
+    if (load->UsesMustHandleHole()) {
+      __ SmiUntag(result, input, SetCC);
+      if (load->hole_mode() == ALLOW_RETURN_HOLE) {
+        Label done;
+        __ b(cc, &done);
+        __ mov(result, Operand(Smi::FromInt(0)));
+        __ bind(&done);
+      } else {
+        DeoptimizeIf(cs, instr->environment());
+      }
+    } else {
+      __ SmiUntag(result, input);
+    }
   } else {
     __ SmiUntag(result, input);
   }
 }
 
 
 void LCodeGen::EmitNumberUntagD(Register input_reg,
                                 DwVfpRegister result_reg,
                                 bool deoptimize_on_undefined,
                                 bool deoptimize_on_minus_zero,
@@ skipping 989 matching lines @@
   __ sub(scratch, result, Operand::PointerOffsetFromSmiKey(index));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal