[Bug tree-optimization/67816] [6 Regression] ICE in duplicate_thread_path, 186.crafty fails to build

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67816

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Reduction result looks the same.  Maybe critical is that the compiler is built
with release checking (though that would be pretty serious - code gen depending
on CHECKING)

> /gcc/spec/sb-czerny-head-64/x86_64/install-201510042000/bin/gcc -O3 iterate.i -v -S
Using built-in specs.
COLLECT_GCC=/gcc/spec/sb-czerny-head-64/x86_64/install-201510042000/bin/gcc
Target: x86_64-pc-linux-gnu
Configured with: /gcc/spec/sb-czerny-head-64/gcc/configure --disable-bootstrap
--prefix=/gcc/spec/sb-czerny-head-64/x86_64/install-201510042000
--enable-languages=c,c++,fortran --enable-threads=posix --disable-nls
--enable-__cxa_atexit --enable-clocale=gnu --enable-checking=release
--disable-libstdcxx-pch --disable-libsanitizer --disable-libcilkrts
Thread model: posix
gcc version 6.0.0 20151004 (experimental) [trunk revision 228461] (GCC) 
COLLECT_GCC_OPTIONS='-O3' '-v' '-S' '-mtune=generic' '-march=x86-64'

/home/gcc/spec/sb-czerny-head-64/x86_64/install-201510042000/bin/../libexec/gcc/x86_64-pc-linux-gnu/6.0.0/cc1
-fpreprocessed iterate.i -quiet -dumpbase iterate.i -mtune=generic
-march=x86-64 -auxbase iterate -O3 -version -o iterate.s
GNU C11 (GCC) version 6.0.0 20151004 (experimental) [trunk revision 228461]
(x86_64-pc-linux-gnu)
        compiled by GNU C version 4.8.3 20141208 [gcc-4_8-branch revision
218481], GMP version 5.1.2, MPFR version 3.1.2, MPC version 1.0
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C11 (GCC) version 6.0.0 20151004 (experimental) [trunk revision 228461]
(x86_64-pc-linux-gnu)
        compiled by GNU C version 4.8.3 20141208 [gcc-4_8-branch revision
218481], GMP version 5.1.2, MPFR version 3.1.2, MPC version 1.0
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: f102ae58a97e9c99e076c734516f015f
iterate.c: In function 'Iterate':
iterate.c:17:5: internal compiler error: in duplicate_thread_path, at
tree-ssa-threadupdate.c:2446
0xade9af duplicate_thread_path
        /gcc/spec/sb-czerny-head-64/gcc/gcc/tree-ssa-threadupdate.c:2445
0xade9af thread_through_all_blocks(bool)
        /gcc/spec/sb-czerny-head-64/gcc/gcc/tree-ssa-threadupdate.c:2632
0xa3c628 execute
        /gcc/spec/sb-czerny-head-64/gcc/gcc/tree-ssa-dom.c:622
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.