Re: [PATCH v2 4/6] [powerpc] libc_feholdsetround_noex_ppc_ctx: optimize FPSCR write

[Paul E Murphy <murphyp at linux dot ibm dot com>]

On 9/19/19 1:46 PM, Paul A. Clarke wrote:
> From: "Paul A. Clarke" <pc@us.ibm.com>
>
> libc_feholdsetround_noex_ppc_ctx currently does, basically:
The listing reads awkwardly for me. I suggest a little cleanup. There is 
no need to post a new patch against my suggestion.

> 1. Read FPSCR, save to context.
> 2. Create new FPSCR value: clear enables and set new rounding mode.
> 3. Write new value to FPSCR.
>
> Since other bits just pass through, there is no need to write them.
>
> Instead, write just the changed values (enables and rounding mode),
> which can be a bit more efficient.
>
> 2019-09-19  Paul A. Clarke  <pc@us.ibm.com>
>
> 	* sysdeps/powerpc/fpu/fenv_private.h
> 	(libc_feholdsetround_noex_ppc_ctx): Call fesetenv_mode instead
> 	of fesetenv_register.
> ---
> v2: No change.
>
>   sysdeps/powerpc/fpu/fenv_private.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/sysdeps/powerpc/fpu/fenv_private.h b/sysdeps/powerpc/fpu/fenv_private.h
> index 9496026..ade0bfa 100644
> --- a/sysdeps/powerpc/fpu/fenv_private.h
> +++ b/sysdeps/powerpc/fpu/fenv_private.h
> @@ -142,7 +142,7 @@ libc_feholdsetround_noex_ppc_ctx (struct rm_ctx *ctx, int r)
>     if (__glibc_unlikely (new.l != old.l))
>       {
>         __TEST_AND_ENTER_NON_STOP (old.l, 0ULL);
> -      fesetenv_register (new.fenv);
> +      fesetenv_mode (new.fenv);
>         ctx->updated_status = true;
>       }
>     else

OK, with suggested cleanup to commit message.

Reviewed-By: Paul E Murphy <murphyp@linux.ibm.com>