Basic support for tracking smi-only arrays on ia32.

src/ia32/full-codegen-ia32.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 1469 matching lines @@
     }
 
     if (!result_saved) {
       __ push(eax);
       result_saved = true;
       increment_stack_height();
     }
     VisitForAccumulatorValue(subexpr);
 
     // Store the subexpression value in the array's elements.
     __ mov(ebx, Operand(esp, 0));  // Copy of array literal.

[Yang, 2011/09/21 14:47:50]

Why not load this into edi instead of ebx and remove the same load into edi a
few lines later.

[danno, 2011/09/22 11:23:15]

This was actually another bug. Fixed.
On 2011/09/21 14:47:50, Yang wrote:

     __ mov(ebx, FieldOperand(ebx, JSObject::kElementsOffset));
     int offset = FixedArray::kHeaderSize + (i * kPointerSize);
     __ mov(FieldOperand(ebx, offset), result_register());
 
+    Label no_map_change;
+    __ JumpIfSmi(result_register(), &no_map_change);
     // Update the write barrier for the array store.
-    __ RecordWriteField(ebx, offset, result_register(), ecx, kDontSaveFPRegs);
+    __ RecordWriteField(ebx, offset, result_register(), ecx,
+                        kDontSaveFPRegs,
+                        EMIT_REMEMBERED_SET,
+                        OMIT_SMI_CHECK);
+    if (FLAG_smi_only_arrays) {
+      __ mov(edi, Operand(esp, 0));
+      __ CheckFastSmiOnlyElements(edi, &no_map_change, Label::kNear);
+      __ push(Operand(esp, 0));
+      __ CallRuntime(Runtime::kNonSmiElementStored, 1);
+    }
+    __ bind(&no_map_change);
 
     PrepareForBailoutForId(expr->GetIdForElement(i), NO_REGISTERS);
   }
 
   if (result_saved) {
     context()->PlugTOS();
   } else {
     context()->Plug(eax);
   }
 }
@@ skipping 2796 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32