[Bug c/65961] New: ice in vect_is_simple_use_1 with -O3

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65961

            Bug ID: 65961
           Summary: ice in vect_is_simple_use_1 with -O3
           Product: gcc
           Version: 6.0
            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 35435
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35435&action=edit
C source code

The attached code, when compiled by gcc trunk dated 20150429
and with flag -O3, says this:

qshs.c: In function ‘shs1’:
qshs.c:136:1: internal compiler error: in vect_is_simple_use_1, at
tree-vect-stmts.c:7867
0xdca504 vect_is_simple_use_1(tree_node*, gimple_statement_base*,
_loop_vec_info*, _bb_vec_info*, gimple_statement_base**, tree_node**,
vect_def_type*, tree_node**)
    ../../src/trunk/gcc/tree-vect-stmts.c:7867
0xdd3d5a vectorizable_operation
    ../../src/trunk/gcc/tree-vect-stmts.c:4676
0xddc731 vect_analyze_stmt(gimple_statement_base*, bool*, _slp_tree*)
    ../../src/trunk/gcc/tree-vect-stmts.c:7196
0xdf1319 vect_slp_analyze_node_operations
    ../../src/trunk/gcc/tree-vect-slp.c:2094

tree-vect-stmts.c:7867 is

    gcc_assert (*vectype != NULL_TREE);