[Bug c/92205] New: ice in vect_get_vec_def_for_stmt_copy, at tree-vect-stmts.c:1688

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92205

            Bug ID: 92205
           Summary: ice in vect_get_vec_def_for_stmt_copy, at
                    tree-vect-stmts.c:1688
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

Created attachment 47098
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47098&action=edit
C source code

For the attached C code, with recent gcc trunk and compiler flag -O3,
does this:

during GIMPLE pass: vect
In file included from lib/timingsafe_bcmp.c:1:
include/string.h: In function ‘timingsafe_bcmp’:
include/string.h:104:5: internal compiler error: in
vect_get_vec_def_for_stmt_copy, at tree-vect-stmts.c:1688
0x70eda5 vect_get_vec_def_for_stmt_copy(vec_info*, tree_node*)
        ../../trunk/gcc/tree-vect-stmts.c:1688
0x70eda5 vect_get_vec_def_for_stmt_copy(vec_info*, tree_node*)
        ../../trunk/gcc/tree-vect-stmts.c:1680
0x70eda5 vectorizable_conversion
        ../../trunk/gcc/tree-vect-stmts.c:5153
0x10ee32b vect_transform_stmt(_stmt_vec_info*, gimple_stmt_iterator*,
_slp_tree*, _slp_instance*)
        ../../trunk/gcc/tree-vect-stmts.c:10832

The bug seems to start sometime between revision 277300 and 277350.

I'll have a go at reducing the code.