Adding assertions to fast elements conversion.

src/ia32/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 360 matching lines @@
   } else {
     __ push(ebx);
     __ fild_s(Operand(esp, 0));
     __ pop(ebx);
     __ fstp_d(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize));
   }
   __ jmp(&entry);
 
   // Found hole, store hole_nan_as_double instead.
   __ bind(&convert_hole);
+
+  if (FLAG_debug_code) {
+    Label is_really_the_hole;
+    __ cmp(ebx, masm->isolate()->factory()->the_hole_value());
+    __ j(equal, &is_really_the_hole);
+    __ Abort("object found in smi-only array");
+    __ bind(&is_really_the_hole);
+  }
+
   if (CpuFeatures::IsSupported(SSE2)) {
     CpuFeatures::Scope use_sse2(SSE2);
     __ movdbl(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize),
               the_hole_nan);
   } else {
     __ fld_d(Operand::StaticVariable(canonical_the_hole_nan_reference));
     __ fstp_d(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize));
   }
 
   __ bind(&entry);
@@ skipping 125 matching lines @@
   // Restore registers.
   __ pop(eax);
   __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32