[Bug libgcc/86213] -fsplit-stack runtime may clobber SSE input param reg

[ian at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86213

--- Comment #2 from ian at gcc dot gnu.org <ian at gcc dot gnu.org> ---
Author: ian
Date: Wed Jun 20 21:57:44 2018
New Revision: 261826

URL: https://gcc.gnu.org/viewcvs?rev=261826&root=gcc&view=rev
Log:
libgcc/:
        PR libgcc/86213
        * generic-morestack.c (allocate_segment): Move calls to getenv and
        getpagesize to __morestack_load_mmap.
        (__morestack_load_mmap) Initialize static_pagesize and
        use_guard_page here so as to avoid clobbering SSE regs during a
        __morestack call.
gcc/testsuite/:
        * gcc.dg/split-8.c: New.

Added:
    branches/gcc-8-branch/gcc/testsuite/gcc.dg/split-8.c
Modified:
    branches/gcc-8-branch/gcc/testsuite/ChangeLog
    branches/gcc-8-branch/libgcc/ChangeLog
    branches/gcc-8-branch/libgcc/generic-morestack.c