[PATCH][V4] rs6000: Remove unnecessary option manipulation.

[Martin Liška]

@Segher: PING

On 11/12/21 17:12, Martin Liska wrote:
> Do not set flag_rename_registers, it's already enabled with EnabledBy(funroll-loops)
> in the common.opt file. Use EnabledBy for unroll_only_small_loops which
> is a canonical approach how can be make option dependencies.
> 
> gcc/ChangeLog:
> 
> 	* config/rs6000/rs6000.c (rs6000_override_options_after_change):
> 	Do not set flag_rename_registers and unroll_only_small_loops.
> 	* config/rs6000/rs6000.opt: Use EnabledBy for unroll_only_small_loops.
> ---
>   gcc/config/rs6000/rs6000.c   | 7 +------
>   gcc/config/rs6000/rs6000.opt | 2 +-
>   2 files changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> index e4843eb0f1c..5550113a94c 100644
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -3466,13 +3466,8 @@ rs6000_override_options_after_change (void)
>     /* Explicit -funroll-loops turns -munroll-only-small-loops off, and
>        turns -frename-registers on.  */
>     if ((OPTION_SET_P (flag_unroll_loops) && flag_unroll_loops)
> -       || (OPTION_SET_P (flag_unroll_all_loops)
> -	   && flag_unroll_all_loops))
> +       || (OPTION_SET_P (flag_unroll_all_loops) && flag_unroll_all_loops))
>       {
> -      if (!OPTION_SET_P (unroll_only_small_loops))
> -	unroll_only_small_loops = 0;
> -      if (!OPTION_SET_P (flag_rename_registers))
> -	flag_rename_registers = 1;
>         if (!OPTION_SET_P (flag_cunroll_grow_size))
>   	flag_cunroll_grow_size = 1;
>       }
> diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
> index 9d7878f144a..faeb7423ca7 100644
> --- a/gcc/config/rs6000/rs6000.opt
> +++ b/gcc/config/rs6000/rs6000.opt
> @@ -546,7 +546,7 @@ Target Undocumented Var(rs6000_optimize_swaps) Init(1) Save
>   Analyze and remove doubleword swaps from VSX computations.
>   
>   munroll-only-small-loops
> -Target Undocumented Var(unroll_only_small_loops) Init(0) Save
> +Target Undocumented Var(unroll_only_small_loops) Init(0) Save EnabledBy(funroll-loops)
>   ; Use conservative small loop unrolling.
>   
>   mpower9-misc
>