[Bug rtl-optimization/60664] comparison of constant SPR_POINTER with unsigned_flag is always false

["manu at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60664

Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|diagnostic                  |
          Component|c++                         |rtl-optimization
            Summary|bool / out of range int     |comparison of constant
                   |comparison warning failure  |SPR_POINTER with
                   |                            |unsigned_flag is always
                   |                            |false

--- Comment #8 from Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> ---
(In reply to David Binderman from comment #7)
> 
> #define SUBREG_CHECK_PROMOTED_SIGN(RTX, SIGN)   \
> ((SIGN) == SRP_POINTER ? SUBREG_PROMOTED_GET (RTX) == SRP_POINTER   \
>  : (SIGN) == SRP_SIGNED ? SUBREG_PROMOTED_SIGNED_P (RTX)        \
>  : SUBREG_PROMOTED_UNSIGNED_P (RTX))
> 
> Leaving aside the side issue of ? : being right associative,
> so some () would help clarify, I notice that 
> 
> const int SRP_POINTER = -1;
> const int SRP_SIGNED = 0;
> const int SRP_UNSIGNED = 1;
> const int SRP_SIGNED_AND_UNSIGNED = 2;
> 
> so it looks as if this bitfield 
> 
>       unsigned unsigned_flag : 1;
> 
> is being compared to SRP_POINTER. One possible fix might be to change 
> the value of SRP_POINTER to 3 and see if the problem goes away.
> 
> Clang certainly seems to be finding a problem, AFAIK.


It seems to me that independently of the value of SRP_POINTER, the result will
be always false. Thus, I don't see the bug. In any case, someone else would
need to decide whether this is actually a bug or not. RTL is not my expertise.