[Bug c/87836] New: ICE in cc1 for gcc-6.5.0 with SPARC hardware

[gary_mills at fastmail dot fm]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87836

            Bug ID: 87836
           Summary: ICE in cc1 for gcc-6.5.0 with SPARC hardware
           Product: gcc
           Version: 6.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gary_mills at fastmail dot fm
  Target Milestone: ---

Here's information on the compiler:
<mills@t2000:941>$
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/build/sparcv7/./gcc/xgcc
--version
xgcc (OpenIndiana 6.5.0-OI-4) 6.5.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

<mills@t2000:944>$ -6/build/sparcv7/./gcc/xgcc -v                            <
Using built-in specs.
COLLECT_GCC=/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/build/sparcv7/./gcc/xgcc
Target: sparc-sun-solaris2.11
Configured with:
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/gcc-6.5.0/configure
CC=/usr/gcc/4.9/bin/gcc CXX=/usr/gcc/4.9/bin/g++ F77=/usr/gcc/4.9/bin/gfortran
FC=/usr/gcc/4.9/bin/gfortran CFLAGS='-g -O2' CXXFLAGS=' ' FFLAGS=' ' FCFLAGS=
LDFLAGS=-m32 PKG_CONFIG_PATH=/usr/lib/pkgconfig --prefix=/usr/gcc/6
--mandir=/usr/gcc/6/share/man --bindir=/usr/gcc/6/bin --libdir=/usr/gcc/6/lib
--sbindir=/usr/gcc/6/sbin --sbindir=/usr/gcc/6/bin --libdir=/usr/gcc/6/lib
--libexecdir=/usr/gcc/6/lib --host sparc-sun-solaris2.11 --build
sparc-sun-solaris2.11 --target sparc-sun-solaris2.11
--with-pkgversion='OpenIndiana 6.5.0-OI-4'
--with-bugurl=https://bugs.openindiana.org --enable-plugins --enable-objc-gc
--enable-initfini-array --enable-languages=c,c++,fortran,lto,objc
--without-gnu-ld --with-ld=/usr/bin/ld
--with-build-time-tools=/usr/gnu/sparc-sun-solaris2.11/bin --disable-libitm
--without-gnu-as --with-as=/usr/bin/as LDFLAGS=-R/usr/gcc/6/lib
Thread model: posix
gcc version 6.5.0 (OpenIndiana 6.5.0-OI-4) 

Here's the error I get:
<mills@t2000:946>$
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/build/sparcv7/./gcc/xgcc
-B/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/build/sparcv7/./gcc/
-S conftest.c
conftest.c: In function 'main':
conftest.c:2:1: internal compiler error: Segmentation Fault
 main ()
 ^~~~
0x631deb crash_signal
       
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/gcc-6.5.0/gcc/toplev.c:333
0x360b3c et_splay
       
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/gcc-6.5.0/gcc/et-forest.c:311
0x361833 et_set_father
       
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/gcc-6.5.0/gcc/et-forest.c:525
0x301e6b calculate_dominance_info(cdi_direction)
       
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/gcc-6.5.0/gcc/dominance.c:658
0x6701cb cleanup_tree_cfg_noloop
       
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/gcc-6.5.0/gcc/tree-cfgcleanup.c:759
0x6701cb cleanup_tree_cfg()
       
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/gcc-6.5.0/gcc/tree-cfgcleanup.c:818
0x66ab87 execute_build_cfg
       
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/gcc-6.5.0/gcc/tree-cfg.c:360
0x66ab87 execute
       
/export/home/mills/Downloads/code/oi-userland/components/developer/gcc-6/gcc-6.5.0/gcc/tree-cfg.c:389
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://bugs.openindiana.org> for instructions.

Here's the source file:
<mills@t2000:948>$ cat conftest.c
int
main ()
{

  ;
  return 0;
}

This happens on a Sun T2000 running v9os (oi_151a9).  The kernel is illumos.
I get the same error and backtrace with gcc-6.4.0 and gcc-7.3.0 .  It worked
with gcc-4.9.4 .  The error appears with the configuration for phase 2 and
also when xgcc is run separately as in this test.  It does build correctly on
x86 hardware.

Note that all of these gcc versions have some patches applied.  These patches
adapt gcc for building the illumos kernel.

I'm willing to test potential fixes on my hardware and OS or to gather
additional debugging information.