[Bug tree-optimization/69328] [6 Regression] ice in vect_get_vec_def_for_operand, at tree-vect-stmts.c:1379 with -O3

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69328

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
1378      is_simple_use = vect_is_simple_use (op, loop_vinfo, &def_stmt, &dt);
1379      gcc_assert (is_simple_use);
(gdb) p op
$2 = <ne_expr 0x7ffff69c4cf8>

ehm.

              if (masked)
                {
                  vec_cond_lhs
                    = vect_get_vec_def_for_operand (cond_expr, stmt,
                                                    comp_vectype);
                  vect_is_simple_use (cond_expr, stmt_info->vinfo,
                                      &gtemp, &dts[0]);
                }
              else
                {
                  vec_cond_lhs =
                    vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 0),
                                                  stmt, comp_vectype);
                  vect_is_simple_use (TREE_OPERAND (cond_expr, 0),
                                      loop_vinfo, &gtemp, &dts[0]);

                  vec_cond_rhs =
                    vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 1),
                                                  stmt, comp_vectype);
                  vect_is_simple_use (TREE_OPERAND (cond_expr, 1),
                                      loop_vinfo, &gtemp, &dts[1]);
                }

Probably better test ! COMPARISON_CLASS_P (cond_expr) here.  OTOH we have

  if (VECTOR_BOOLEAN_TYPE_P (comp_vectype))
    {
      vec_cmp_type = comp_vectype;
      masked = true;
    }
  else
    vec_cmp_type = build_same_sized_truth_vector_type (comp_vectype);

not sure why that's specially only for boolean vector types.  So

@@ -7544,11 +7545,9 @@ vectorizable_condition (gimple *stmt, gi
   if (!vect_is_simple_use (else_clause, stmt_info->vinfo, &def_stmt, &dt))
     return false;

+  bool masked = ! COMPARISON_CLASS_P (cond_expr);
   if (VECTOR_BOOLEAN_TYPE_P (comp_vectype))
-    {
-      vec_cmp_type = comp_vectype;
-      masked = true;
-    }
+    vec_cmp_type = comp_vectype;
   else
     vec_cmp_type = build_same_sized_truth_vector_type (comp_vectype);
   if (vec_cmp_type == NULL_TREE)

but that later ICEs then with

> ./cc1 -quiet t.c -O3
t.c: In function ‘fn1’:
t.c:2:6: internal compiler error: in vector_compare_rtx, at optabs.c:5290
 void fn1() {
      ^~~

0xca84f2 vector_compare_rtx
        /space/rguenther/src/svn/trunk3/gcc/optabs.c:5290
0xca979f expand_vec_cond_expr(tree_node*, tree_node*, tree_node*, tree_node*,
rtx_def*)
        /space/rguenther/src/svn/trunk3/gcc/optabs.c:5612

sth else is wrong here.