Porting r9392 to arm (smi-only arrays).

src/arm/full-codegen-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 1486 matching lines @@
       continue;
     }
 
     if (!result_saved) {
       __ push(r0);
       result_saved = true;
     }
     VisitForAccumulatorValue(subexpr);
 
     // Store the subexpression value in the array's elements.
-    __ ldr(r1, MemOperand(sp));  // Copy of array literal.
-    __ ldr(r1, FieldMemOperand(r1, JSObject::kElementsOffset));
+    __ ldr(r6, MemOperand(sp));  // Copy of array literal.
+    __ ldr(r1, FieldMemOperand(r6, JSObject::kElementsOffset));
     int offset = FixedArray::kHeaderSize + (i * kPointerSize);
     __ str(result_register(), FieldMemOperand(r1, offset));
 
+    Label no_map_change;
+    __ JumpIfSmi(result_register(), &no_map_change);
     // Update the write barrier for the array store with r0 as the scratch
     // register.
     __ RecordWriteField(
-        r1, offset, result_register(), r2, kLRHasBeenSaved, kDontSaveFPRegs);
+        r1, offset, result_register(), r2, kLRHasBeenSaved, kDontSaveFPRegs,
+        EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+    if (FLAG_smi_only_arrays) {
+      __ ldr(r3, FieldMemOperand(r1, HeapObject::kMapOffset));
+      __ CheckFastSmiOnlyElements(r3, r2, &no_map_change);
+      __ push(r6);

[Rico, 2011/09/22 17:06:07]

maybe a comment here:
__ push(r6);  // Copy of array literal

+      __ CallRuntime(Runtime::kNonSmiElementStored, 1);
+    }
+    __ bind(&no_map_change);
 
     PrepareForBailoutForId(expr->GetIdForElement(i), NO_REGISTERS);
   }
 
   if (result_saved) {
     context()->PlugTOS();
   } else {
     context()->Plug(r0);
   }
 }
@@ skipping 2730 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM