[PATCH, rs6000] Deprecate -mno-speculate-indirect-jumps

[Segher Boessenkool]

Hi Bill,

On Mon, Feb 05, 2018 at 12:28:34PM -0600, Bill Schmidt wrote:
> It's been determined that we won't recommend use of the recently added
> undocumented option -mno-speculate-indirect-jumps.  This patch provides
> a warning indicating that the option is deprecated.  We will leave the
> code in place for potential emergency use (not expected), and plan to
> remove it completely in GCC 9.

> +  /* Deprecate use of -mno-speculate-indirect-jumps.  */
> +  if (!rs6000_speculate_indirect_jumps)
> +    warning (0, "%qs is deprecated and not recommended in any circumstances",
> +	     "-mno-speculate-indirect-jumps");

Wow that is a stern warning :-)

> --- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-1.c	(revision 257367)
> +++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-1.c	(working copy)
> @@ -1,5 +1,6 @@
>  /* { dg-do compile } */
>  /* { dg-additional-options "-mno-speculate-indirect-jumps" } */
> +/* { dg-warning "'-mno-speculate-indirect-jumps' is deprecated" "" { target *-*-* } 0 } */

Just

/* { dg-warning "'-mno-speculate-indirect-jumps' is deprecated" } */

will do I think?

(Some tests use . instead of ' but the latter works as well).

You could just add "-w" to the options instead.

Okay for trunk with or without that changed.  Okay for 7 too.  Thanks!


Segher