Re: [PATCH], PowerPC target_clones minor support

[Segher Boessenkool <segher at kernel dot crashing dot org>]

On Wed, Jun 28, 2017 at 02:28:23PM -0400, Michael Meissner wrote:
> Some minor changes to the PowerPC target_clones support:
> 
> 1) I added a warning if target_clones was used and the compiler whas configured
> with an older glibc where __builtin_cpu_supports always returns 0;
> 
> 2) I reworked how the ifunc resolver function is generated, and always made it
> a static function;
> 
> 3) I added an executable target_clones test, and I made both clone tests
> dependent on GCC being configured with a new glibc.

> 	* config/rs6000/rs6000.c
> 	(rs6000_get_function_versions_dispatcher): Add warning if the
> 	compiler is not configured to use at least GLIBC version 2.23.

Please say what is really tested for here (namely,
TARGET_LIBC_PROVIDES_HWCAP_IN_TCB).

>    /* Append the filename to the resolver function if the versions are
>       not externally visible.  This is because the resolver function has
>       to be externally visible for the loader to find it.  So, appending
>       the filename will prevent conflicts with a resolver function from
>       another module which is based on the same version name.  */
> -  char *resolver_name = make_unique_name (default_decl, "resolver", is_uniq);
> +  tree decl_name = clone_function_name (default_decl, "resolver");
> +  const char *resolver_name = IDENTIFIER_POINTER (decl_name);

I think the comment needs some updating now?

> --- gcc/testsuite/gcc.target/powerpc/clone2.c	(.../svn+ssh://meissner@gcc.gnu.org/svn/gcc/trunk/gcc/testsuite/gcc.target/powerpc)	(revision 0)
> +++ gcc/testsuite/gcc.target/powerpc/clone2.c	(.../gcc/testsuite/gcc.target/powerpc)	(revision 249738)
> @@ -0,0 +1,31 @@
> +/* { dg-do run { target { powerpc*-*-linux* } } } */
> +/* { dg-options "-mvsx -O2" } */
> +/* { dg-require-effective-target powerpc_p9vector_ok } */
> +/* { dg-require-effective-target ppc_cpu_supports_hw } */

What a funny name (it reads as "the CPU supports the hardware").  Yes
I'm easily amused ;-)

The patch is okay for trunk modulo with those things looked at.  Sorry
for the slow review.


Segher