[PATCH] i386: Disable check_consistency for GCC 5 and above [BZ #25788]

[Adhemerval Zanella]

On 06/04/2020 10:24, H.J. Lu via Libc-alpha wrote:
> check_consistency should be disabled for GCC 5 and above since there is
> no fixed PIC register in GCC 5 and above.  Check __GNUC_PREREQ (5,0)
> instead OPTIMIZE_FOR_GCC_5 since OPTIMIZE_FOR_GCC_5 is false with
> -fno-omit-frame-pointer.
> ---
>  sysdeps/unix/sysv/linux/i386/sysdep.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h
> index 5e3888060b..6671afe65e 100644
> --- a/sysdeps/unix/sysv/linux/i386/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
> @@ -580,8 +580,9 @@ struct libc_do_syscall_args
>  # define EXTRAVAR_5
>  #endif
>  
> -/* Consistency check for position-independent code.  */
> -#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5
> +/* Consistency check for position-independent code.  Disabled for GCC 5
> +   and above since there is no fixed PIC register in GCC 5 and above.  */
> +#if defined __PIC__ && !__GNUC_PREREQ (5,0)
>  # define check_consistency()						      \
>    ({ int __res;								      \
>       __asm__ __volatile__						      \
> 

I think we can just remove the check_consistency altogether, since 
we already required GCC 6.2 or later to build gcc (4dcbbc3b28a).