[Bug tree-optimization/104595] unvectorized loop due to bool condition loaded from memory

["linkw at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104595

--- Comment #8 from Kewen Lin <linkw at gcc dot gnu.org> ---
I had one local hack and just found it can survive on x86 bootstrapping and
regression testing. I guess maybe it's good to post here. Just ignore this if
it looks like noise. :) The point is to do the conversion for the loaded bool
value from memory, normally it should be like a nop, but for this test case, it
can help us to generate the expected char comparison.

diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index 2baf974627e..d4b8920203b 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -3911,6 +3911,11 @@ check_bool_pattern (tree var, vec_info *vinfo,
hash_set<gimple *> &stmts)
        return false;
       break;

+    case ARRAY_REF:
+      if (TYPE_PRECISION (TREE_TYPE (var)) != 1)
+       return false;
+      break;
+
     default:
       if (TREE_CODE_CLASS (rhs_code) == tcc_comparison)
        {
@@ -4005,6 +4010,19 @@ adjust_bool_pattern (vec_info *vinfo, tree var, tree
out_type,
                               SSA_NAME, irhs1);
       break;

+    case ARRAY_REF:
+      {
+       itype = TREE_TYPE (var);
+       gcc_assert (TYPE_PRECISION (itype) == 1);
+       machine_mode mode = TYPE_MODE (itype);
+       tree scalar_type = build_nonstandard_integer_type (
+         GET_MODE_BITSIZE (mode).to_constant (), TYPE_UNSIGNED (itype));
+       pattern_stmt
+         = gimple_build_assign (vect_recog_temp_ssa_var (scalar_type, NULL),
+                                CONVERT_EXPR, var);
+      }
+      break;
+
     case BIT_NOT_EXPR:
       irhs1 = *defs.get (rhs1);
       itype = TREE_TYPE (irhs1);