RE: [PATCH]middle-end: check explicitly for external or constants when checking for loop invariant [PR116817]

[Tamar Christina]

> > > Can you explain how you get to see constant/external defs with
> astmt_vec_info?  That's somehow a violation of some inherentinvariant in the
> vectorizer.
> >
> > I'm not sure I actually get any. It could be the condition is never hit
> > with a stmt_vec_info. I had assumed however since the condition is part
> > of a gimple_cond and if one of the arguments of the gimple_cond is loop
> > bound, that the condition would be analyzed too.
> >
> > So if you're saying you never get a stmt_vec_info for invariants at this
> > point (I assume you could see you see them in the corresponding slp
> > tree) then maybe checking for the stmt_vec_info is enough.
> >
> > However, when I was looking around for how to check for externals I
> > noticed other patterns also check for externals and constants. So I
> > assumed that you could indeed get them.
> 
> You usually check that after doing vect_is_simple_use on the SSA name
> or constant which internally makes all stmts with a stmt_vec_info
> one of the internal def kinds.
> 
> So I guess you could do vect_is_simple_use on 'var' as well and check
> the 'dt' it will populate
> 

Ah I see, I did see it being called in some other patterns but wasn't sure what 
it
was providing.

Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.

Ok for master?

Thanks,
Tamar

gcc/ChangeLog:

        PR tree-optimization/116817
        * tree-vect-patterns.cc (vect_recog_bool_pattern): Check for const or
        externals.

gcc/testsuite/ChangeLog:

        PR tree-optimization/116817
        * g++.dg/vect/pr116817.cc: New test.

-- inline copy of patch --

diff --git a/gcc/testsuite/g++.dg/vect/pr116817.cc 
b/gcc/testsuite/g++.dg/vect/pr116817.cc
new file mode 100644
index 
0000000000000000000000000000000000000000..7e28982fb138c2cccc4f956aedb03fa454d9d858
--- /dev/null
+++ b/gcc/testsuite/g++.dg/vect/pr116817.cc
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-O3" } */
+
+int main_ulData0;
+unsigned *main_pSrcBuffer;
+int main(void) {
+  int iSrc = 0;
+  bool bData0;
+  for (; iSrc < 4; iSrc++) {
+    if (bData0)
+      main_pSrcBuffer[iSrc] = main_ulData0;
+    else
+      main_pSrcBuffer[iSrc] = 0;
+    bData0 = !bData0;
+  }
+}
diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index 
e7e877dd2adb55262822f1660f8d92b42d44e6d0..b174ff1e705cec8e7bb414c760eb170ca98222cb
 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -6062,12 +6062,15 @@ vect_recog_bool_pattern (vec_info *vinfo,
       if (get_vectype_for_scalar_type (vinfo, type) == NULL_TREE)
        return NULL;
 
+      enum vect_def_type dt;
       if (check_bool_pattern (var, vinfo, bool_stmts))
        var = adjust_bool_stmts (vinfo, bool_stmts, type, stmt_vinfo);
       else if (integer_type_for_mask (var, vinfo))
        return NULL;
       else if (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE
-              && !vect_get_internal_def (vinfo, var))
+              && vect_is_simple_use (var, vinfo, &dt)
+              && (dt == vect_external_def
+                  || dt == vect_constant_def))
        {
          /* If the condition is already a boolean then manually convert it to a
             mask of the given integer type but don't set a vectype.  */

rb18806 (1).patch
Description: rb18806 (1).patch