[Bug tree-optimization/60903] New: [4.8/4.9/4.10 Regression] ICE: in verify_loop_structure, at cfgloop.c:1647: : edge from 13 to 14 should be marked irreducible

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60903

            Bug ID: 60903
           Summary: [4.8/4.9/4.10 Regression] ICE: in
                    verify_loop_structure, at cfgloop.c:1647: : edge from
                    13 to 14 should be marked irreducible
           Product: gcc
           Version: 4.10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz

Created attachment 32636
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32636&action=edit
reduced testcase

Compiler output:
$ gcc -Os -fno-tree-copy-prop -ftree-loop-distribute-patterns
-fno-tree-scev-cprop --param=allow-store-data-races=0 testcase.c
testcase.c: In function 'foo':
testcase.c:4:1: error: edge from 13 to 14 should be marked irreducible
 foo ()
 ^
testcase.c:4:1: error: basic block 14 should be marked irreducible
testcase.c:4:1: error: edge from 14 to 12 should be marked irreducible
testcase.c:4:1: internal compiler error: in verify_loop_structure, at
cfgloop.c:1647
0x762369 verify_loop_structure()
        /mnt/svn/gcc-trunk/gcc/cfgloop.c:1647
0xbb2c32 execute
        /mnt/svn/gcc-trunk/gcc/tree-loop-distribution.c:1821
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.

$ gcc -v
Using built-in specs.
COLLECT_GCC=/mnt/svn/gcc-trunk/binary-latest/bin/gcc
COLLECT_LTO_WRAPPER=/mnt/svn/gcc-trunk/binary-209530-lto-fortran-checking-yes-rtl-df/libexec/gcc/x86_64-unknown-linux-gnu/4.10.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /mnt/svn/gcc-trunk//configure --enable-checking=yes,rtl,df
--enable-languages=c,c++,lto,fortran
--prefix=/mnt/svn/gcc-trunk/binary-209530-lto-fortran-checking-yes-rtl-df/
--without-cloog --without-ppl
Thread model: posix
gcc version 4.10.0 20140419 (experimental) (GCC) 

Tested revisions:
r209530 - ICE
4.9 r209346 - ICE
4.8 r209342 - ICE
4.7 r209345 - OK