[PATCH] Fix PR91522

[Uros Bizjak]

On Thu, Aug 22, 2019 at 3:35 PM Richard Biener <rguenther@suse.de> wrote:
>
>
> This fixes quadraticness in STV and makes
>
>  machine dep reorg                  :  89.07 ( 95%)   0.02 ( 18%)  89.10 (
> 95%)      54 kB (  0%)
>
> drop to zero.  Anybody remembers why it is the way it is now?
>
> Bootstrap / regtest running on x86_64-unknown-linux-gnu.
>
> OK?

Looking at the PR, comment #3 [1], I assume this patch is obsoltete
and will be updated?

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91522#c3

Uros.

> Thanks,
> Richard.
>
> 2019-08-22  Richard Biener  <rguenther@suse.de>
>
>         PR target/91522
>         * config/i386/i386-features.c (scalar_chain::add_insn): Do not
>         iterate over all defs of a reg.
>
> Index: gcc/config/i386/i386-features.c
> ===================================================================
> --- gcc/config/i386/i386-features.c     (revision 274764)
> +++ gcc/config/i386/i386-features.c     (working copy)
> @@ -419,10 +419,7 @@ scalar_chain::add_insn (bitmap candidate
>    df_ref def;
>    for (ref = DF_INSN_UID_DEFS (insn_uid); ref; ref = DF_REF_NEXT_LOC (ref))
>      if (!HARD_REGISTER_P (DF_REF_REG (ref)))
> -      for (def = DF_REG_DEF_CHAIN (DF_REF_REGNO (ref));
> -          def;
> -          def = DF_REF_NEXT_REG (def))
> -       analyze_register_chain (candidates, def);
> +      analyze_register_chain (candidates, ref);
>    for (ref = DF_INSN_UID_USES (insn_uid); ref; ref = DF_REF_NEXT_LOC (ref))
>      if (!DF_REF_REG_MEM_P (ref))
>        analyze_register_chain (candidates, ref);
>