[Bug c/84477] New: internal compiler error: in compute_live_loop_exits, at tree-ssa-loop-manip.c:255

["tianjiao.sun.2010 at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84477

            Bug ID: 84477
           Summary: internal compiler error: in compute_live_loop_exits,
                    at tree-ssa-loop-manip.c:255
           Product: gcc
           Version: 5.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tianjiao.sun.2010 at gmail dot com
  Target Milestone: ---

Created attachment 43466
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43466&action=edit
example code

Hi,

Compiling the attached file with -fPIC -Wall -march=haswell -O3 -ffast-math
-shared resulted in error:
internal compiler error: in compute_live_loop_exits, at
tree-ssa-loop-manip.c:255

The code is a simplified version of our original code which is a local assembly
kernel for finite element method. I deleted as many lines as possible to
preserve the same error in compilation.

Note that swapping line 33 and 35 somehow fix the problem.

Compiling with -fno-tree-loop-vectorize also fix the problem.

This affects GCC 5.x only.

Thanks,
-TJ