Re: [PATCH] rs6000: Fix restored rs6000_long_double_type_size.

[Segher Boessenkool <segher@kernel.crashing.org>]

Hi!

On Wed, Jun 23, 2021 at 03:22:34PM +0200, Martin Liška wrote:
> As mentioned in the "Fallout: save/restore target options in 
> handle_optimize_attribute"
> thread, we need to support target option restore of 
> rs6000_long_double_type_size == FLOAT_PRECISION_TFmode.

I have no idea?  Could you explain please?

> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -4185,6 +4185,8 @@ rs6000_option_override_internal (bool global_init_p)
>        else
>  	rs6000_long_double_type_size = default_long_double_size;
>      }
> +  else if (rs6000_long_double_type_size == FLOAT_PRECISION_TFmode)
> +    ; /* The option can be restored a TREE_TARGET_OPTION.  */

What does that mean?  It is not grammatical, and not obvious what it
should mean.

> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pragma-optimize.c
> @@ -0,0 +1,14 @@
> +/* { dg-do compile { target { powerpc*-*-linux* } } } */

Why on Linux only?  That doesn't sound right.  Do you need some other
selector(s)?

> +/* { dg-options "-O2 -mlong-double-128 -mabi=ibmlongdouble" } */
> +
> +extern unsigned long int x;
> +extern float f (float);
> +extern __typeof (f) f_power8;
> +extern __typeof (f) f_power9;
> +extern __typeof (f) f __attribute__ ((ifunc ("f_ifunc")));
> +static __attribute__ ((optimize ("-fno-stack-protector"))) __typeof (f) *

-fno-stack-protector is default.

> +f_ifunc (void)
> +{
> +  __typeof (f) *res = x ? f_power9 : f_power8;
> +  return res;
> +}

The testcase should say what it is testing for, it is not obvious?


Segher