[Bug go/66870] split stack issues on ppc64le and ppc64

["amodra at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66870

--- Comment #22 from Alan Modra <amodra at gcc dot gnu.org> ---
Author: amodra
Date: Thu Aug 13 05:25:02 2015
New Revision: 226848

URL: https://gcc.gnu.org/viewcvs?rev=226848&root=gcc&view=rev
Log:
More split-stack fixes

Backport rev 226443
2015-07-31  Alan Modra  <amodra@gmail.com>

        PR target/66870
        * config/rs6000/rs6000.c (machine_function): Add split_stack_argp_used.
        (rs6000_emit_prologue): Set it.
        (rs6000_set_up_by_prologue): Specify r12 when split_stack_argp_used.

Backport rev 223878
2015-05-30  Alan Modra  <amodra@gmail.com>

        * config/rs6000/rs6000.c (split_stack_arg_pointer_used_p): Scan
        correct block for use of r12.
        (rs6000_expand_split_stack_prologue): Error on r29 asm global reg.

Backport rev 223427
2015-05-20  Alan Modra  <amodra@gmail.com>

        * config/rs6000/rs6000.c (rs6000_emit_allocate_stack): Return
        stack adjusting insn.  Formatting.
        (rs6000_emit_prologue): Track stack adjusting insn, and use of
        r12.  If possible, emit first -fsplit-stack arg pointer insn
        before stack adjust.  Don't use r12 to save cr if split-stack.

Backport rev 223425
2015-05-20  Alan Modra  <amodra@gmail.com>

        * config/rs6000/rs6000.c (struct rs6000_stack): Correct comments.
        (direct_return): Test vrsave_size rather than vrsave_mask.
        (rs6000_emit_prologue): Likewise.  Remove redundant altivec tests.
        (rs6000_emit_epilogue): Likewise.

Revert bogus rs6000_function_ok_for_sibcall change that caused failure
of glibc build.

Revert rs6000_can_eliminate cosmetic change


Modified:
    branches/ibm/gcc-5-branch/gcc/config/rs6000/rs6000.c