[llvm-commits] [LLVM, PR11652 PATCH]: Fixed Bug 11652 - assertion failures when Type.cpp is compiled with -Os

[Stepan Dyatkovskiy]

ping.
-Stepan.

30.12.2011, 23:41, "Stepan Dyatkovskiy" <stpworld at narod.ru>:
> The problem is in Type.h. The fields in Type class are declared in next
> order:
>    TypeID   ID : 8;
>    unsigned SubclassData : 24;
>    unsigned NumContainedTys;
>
> Attempt to set new SubclassData value rewrites lowest byte in
> NumContainedTys when -Os is set. GCC bug? Anyway setting SubclassData
> with two workaround strings fixes the problem:
>
>   void setSubclassData(unsigned val) {
>      unsigned tmp = NumContainedTys;  // Workaround for GCC -Os
>      SubclassData = val;
>      NumContainedTys = tmp;  // Workaround for GCC -Os
>      // Ensure we don't have any accidental truncation.
>      assert(SubclassData == val && "Subclass data too large for field");
>    }
>
> Probably there is another ways to protect NumContainedTys from overwritting?
>
> Please find the patch in attachment for review.
>
> -Stepan.
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits