Re: RFA: Fix match_scratch bug in define_subst

[Richard Sandiford <richard.sandiford@arm.com>]

Joern Rennecke <joern.rennecke@embecosm.com> writes:
> Bootstrapped on x86_64-pc-linux-gnu.
>
> 2020-12-10  Joern Rennecke  <joern.rennecke@embecosm.com>
>
>     Fix bug in the define_subst handling that made match_scratch unusable for
>     multi-alternative patterns.

OK, and sorry for the slow response.

The changelog won't pass, but I'll leave you to negotiate that with the
commit hook. :-)

Thanks,
Richard

>
> diff --git a/gcc/gensupport.c b/gcc/gensupport.c
> index e1ca06dbc1e..4022c661adb 100644
> --- a/gcc/gensupport.c
> +++ b/gcc/gensupport.c
> @@ -1291,6 +1291,9 @@ alter_constraints (rtx pattern, int n_dup, constraints_handler_t alter)
>      case MATCH_OPERAND:
>        XSTR (pattern, 2) = alter (XSTR (pattern, 2), n_dup);
>        break;
> +    case MATCH_SCRATCH:
> +      XSTR (pattern, 1) = alter (XSTR (pattern, 1), n_dup);
> +      break;
>  
>      default:
>        break;