[Bug c/81492] New: internal compiler error: Segmentation fault (ia64 target with "-O1 -g" and __attribute__((optimize("O3"))))

[slyfox at inbox dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81492

            Bug ID: 81492
           Summary: internal compiler error: Segmentation fault (ia64
                    target with "-O1 -g" and
                    __attribute__((optimize("O3"))))
           Product: gcc
           Version: 6.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: slyfox at inbox dot ru
  Target Milestone: ---

Original failure was noticed on numpy-1.13.1 package and was reduced
down to tiny example using c-reduce:

$ cat loops.c 
/*
  how to crash: 
    $ LANG=C ia64-unknown-linux-gnu-gcc -O1 -g -c loops.c -o loops.o -Wall

    loops.c: In function 'a':
    loops.c:15:1: internal compiler error: Segmentation fault
    }
    ^
*/
struct b;
int d(void);
int e(const char*, int, const char *);
__attribute__((optimize("O3"))) void a(struct b c()) {
  d() ?: e("", 5, __PRETTY_FUNCTION__);
}
void* f() { return (void*)&a; }

$ LANG=C ia64-unknown-linux-gnu-gcc -O1 -g -c loops.c -o loops.o -Wall
loops.c: In function 'a':
loops.c:15:1: internal compiler error: Segmentation fault
 }
 ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://bugs.gentoo.org/> for instructions.

Some target info:

$ LANG=C ia64-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=ia64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ia64-unknown-linux-gnu/6.3.0/lto-wrapper
Target: ia64-unknown-linux-gnu
Configured with:
/tmp/portage-tmpdir/portage/cross-ia64-unknown-linux-gnu/gcc-6.3.0/work/gcc-6.3.0/configure
--host=x86_64-pc-linux-gnu --target=ia64-unknown-linux-gnu
--build=x86_64-pc-linux-gnu --prefix=/usr
--bindir=/usr/x86_64-pc-linux-gnu/ia64-unknown-linux-gnu/gcc-bin/6.3.0
--includedir=/usr/lib/gcc/ia64-unknown-linux-gnu/6.3.0/include
--datadir=/usr/share/gcc-data/ia64-unknown-linux-gnu/6.3.0
--mandir=/usr/share/gcc-data/ia64-unknown-linux-gnu/6.3.0/man
--infodir=/usr/share/gcc-data/ia64-unknown-linux-gnu/6.3.0/info
--with-gxx-include-dir=/usr/lib/gcc/ia64-unknown-linux-gnu/6.3.0/include/g++-v6
--with-python-dir=/share/gcc-data/ia64-unknown-linux-gnu/6.3.0/python
--enable-languages=c,c++ --enable-obsolete --enable-secureplt --disable-werror
--with-system-zlib --enable-nls --without-included-gettext
--enable-checking=release --with-bugurl=https://bugs.gentoo.org/
--with-pkgversion='Gentoo 6.3.0 p1.0' --disable-esp --enable-libstdcxx-time
--enable-poison-system-directories --with-sysroot=/usr/ia64-unknown-linux-gnu
--disable-bootstrap --enable-__cxa_atexit --enable-clocale=gnu
--disable-multilib --disable-altivec --disable-fixed-point --disable-libgcj
--enable-libgomp --disable-libmudflap --disable-libssp --disable-libcilkrts
--disable-libmpx --disable-vtable-verify --disable-libvtv --disable-libquadmath
--enable-lto --without-isl --disable-libsanitizer --enable-default-pie
--disable-default-ssp
Thread model: posix
gcc version 6.3.0 (Gentoo 6.3.0 p1.0)