[Bug tree-optimization/69107] New: def does not dominate use ICE with -O2 -ftree-paralellize-loops=2

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69107

            Bug ID: 69107
           Summary: def does not dominate use ICE with -O2
                    -ftree-paralellize-loops=2
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vries at gcc dot gnu.org
  Target Milestone: ---

...
$ gcc src/gcc/testsuite/gcc.c-torture/compile/pr32399.c -O3 -S
-ftree-parallelize-loops=2
src/gcc/testsuite/gcc.c-torture/compile/pr32399.c: In function ‘f’:
src/gcc/testsuite/gcc.c-torture/compile/pr32399.c:1:6: error: definition in
block 11 does not dominate use in block 27
 void f(unsigned char *src, unsigned char *dst, int num, unsigned char *pos,
unsigned char *diffuse, int hasdiffuse, unsigned char *specular, int
hasspecular) {
      ^

for SSA_NAME: .MEM_62 in statement:
.MEM_97 = PHI <.MEM_62(27)>
PHI argument
.MEM_62
for PHI node
.MEM_97 = PHI <.MEM_62(27)>
src/gcc/testsuite/gcc.c-torture/compile/pr32399.c:1:6: internal compiler error:
verify_ssa failed
0x1176e2d verify_ssa(bool, bool)
        /home/vries/gcc_versions/devel/src/gcc/tree-ssa.c:1039
0xfd157b checking_verify_ssa
        /home/vries/gcc_versions/devel/src/gcc/tree-ssa.h:87
0xfd55e0 transform_to_exit_first_loop_alt
        /home/vries/gcc_versions/devel/src/gcc/tree-parloops.c:1755
0xfd5b37 try_transform_to_exit_first_loop_alt
        /home/vries/gcc_versions/devel/src/gcc/tree-parloops.c:1870
0xfd728f gen_parallel_loop
        /home/vries/gcc_versions/devel/src/gcc/tree-parloops.c:2304
0xfd88fc parallelize_loops
        /home/vries/gcc_versions/devel/src/gcc/tree-parloops.c:2792
0xfd8a91 execute
        /home/vries/gcc_versions/devel/src/gcc/tree-parloops.c:2846
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.
...