[Bug tree-optimization/68140] New: ICE in vect_get_vec_def_for_operand, at tree-vect-stmts.c:1413

[anton at samba dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68140

            Bug ID: 68140
           Summary: ICE in vect_get_vec_def_for_operand, at
                    tree-vect-stmts.c:1413
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: anton at samba dot org
  Target Milestone: ---

I'm seeing an ICE on powerpc64le with a checkout from last night:

# cat testcase.c

int a, b, d, e, f;
static int c;

static void fn1(void)
{
        int b = 3;
        for (; b >= 0; b--) {
                e ^= f;
                d = 0;
                for (; d <= 3; d++) {
                        e |= f;
                        for (; c;)
                                for (;;) ;
                }
        }
}

int main(void)
{
        if (a)
                fn1();

        return 0;
}

# gcc -O3 testcase.c -Wall
testcase.c: In function ‘main’:
testcase.c:18:5: internal compiler error: in vect_get_vec_def_for_operand, at
tree-vect-stmts.c:1413
 int main(void)
     ^
0x10aed307 vect_get_vec_def_for_operand(tree_node*, gimple*)
        ../../gcc/gcc/tree-vect-stmts.c:1413
0x10aedab7 vect_get_vec_defs(tree_node*, tree_node*, gimple*, vec<tree_node*,
va_heap, vl_ptr>*, vec<tree_node*, va_heap, vl_ptr>*, _slp_tree*, int)
        ../../gcc/gcc/tree-vect-stmts.c:1574
0x10af441b vectorizable_operation
        ../../gcc/gcc/tree-vect-stmts.c:4894
0x10b0420f vect_transform_stmt(gimple*, gimple_stmt_iterator*, bool*,
_slp_tree*, _slp_instance*)
        ../../gcc/gcc/tree-vect-stmts.c:7693
0x10b0bedf vect_transform_loop(_loop_vec_info*)
        ../../gcc/gcc/tree-vect-loop.c:6452
0x10b2c70b vectorize_loops()
        ../../gcc/gcc/tree-vectorizer.c:512
0x10a0c6fb execute
        ../../gcc/gcc/tree-ssa-loop.c:278