Porting r9392 to arm (smi-only arrays).

src/arm/ic-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 1342 matching lines @@
 
   // Check the key against the length in the array.
   __ ldr(ip, FieldMemOperand(receiver, JSArray::kLengthOffset));
   __ cmp(key, Operand(ip));
   __ b(hs, &extra);
   // Fall through to fast case.
 
   __ bind(&fast);
   Register scratch_value = r4;
   Register address = r5;
+  if (FLAG_smi_only_arrays) {
+    Label not_smi_only;
+    // Make sure the elements are smi-only.
+    __ ldr(scratch_value, FieldMemOperand(receiver, HeapObject::kMapOffset));
+    __ CheckFastSmiOnlyElements(scratch_value, scratch_value, &not_smi_only);
+    // Non-smis need to call into the runtime if the array is smi only.
+    __ JumpIfNotSmi(value, &slow);
+    __ add(address, elements,
+           Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+    __ add(address, address, Operand(key, LSL, kPointerSizeLog2 - kSmiTagSize));
+    __ str(value, MemOperand(address));
+    __ Ret();
+    __ bind(&not_smi_only);
+  }
   // Fast case, store the value to the elements backing store.
   __ add(address, elements, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
   __ add(address, address, Operand(key, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ str(value, MemOperand(address));
   // Skip write barrier if the written value is a smi.
   __ tst(value, Operand(kSmiTagMask));
   __ Ret(eq);
 
   // Update write barrier for the elements array address.
   __ mov(scratch_value, value);  // Preserve the value which is returned.
@@ skipping 258 matching lines @@
     Register reg = Assembler::GetRn(instr_at_patch);
     patcher.masm()->tst(reg, Operand(kSmiTagMask));
     patcher.EmitCondition(eq);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM