[Bug tree-optimization/106322] [12/13 Regression] tree-vectorize: Wrong code at O2 level (-fno-tree-vectorize is working) since r12-2404-ga1d27560770818c5

[linkw at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106322

--- Comment #44 from Kewen Lin <linkw at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #43)
> (In reply to Richard Biener from comment #42)
> > I think this goes wrong in vectorizable_operation which does
> > 
> >   if (using_emulated_vectors_p
> >       && !vect_can_vectorize_without_simd_p (code))
> > 
> > to guard this but I'm not sure how this slips through?
> 
> Ah, it's an internal function.  I think we should simply return false
> during analysis for any vect_emulated_vector_p type in vectorizable_call.
> 
> Alternatively pattern recognition could also be made to fail but the above
> is definitely more future proof.

Thanks for the pointer!  I think you meant:

diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index c9534ef9b1e..ee10fa3e0fb 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -3388,6 +3388,14 @@ vectorizable_call (vec_info *vinfo,
       return false;
     }

+  if (vect_emulated_vector_p (vectype_in) || vect_emulated_vector_p
(vectype_out))
+  {
+      if (dump_enabled_p ())
+       dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+                        "use emulated vector type for call\n");
+      return false;
+  }
+
   /* FORNOW */
   nunits_in = TYPE_VECTOR_SUBPARTS (vectype_in);
   nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);

Will kick off some testings on x64/aarch64/ppc64{,le} and post it later.