[gcc r14-4406] Fix SIMD call SLP discovery

[gcc r14-4406] Fix SIMD call SLP discovery

[Richard Biener]

https://gcc.gnu.org/g:6dc44436301143a286e3b45de0673af012299eba

commit r14-4406-g6dc44436301143a286e3b45de0673af012299eba
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Oct 5 10:26:34 2023 +0200

    Fix SIMD call SLP discovery
    
    When we do SLP discovery of SIMD calls we run into the issue that
    when the call is neither builtin nor internal function we have
    cfn == CFN_LAST but internal_fn_p of that returns true.  Since
    IFN_LAST isn't vectorizable we fail spuriously.
    
    Fixed by checking for cfn != CFN_LAST && internal_fn_p (cfn)
    instead.
    
            * tree-vect-slp.cc (vect_build_slp_tree_1): Do not
            ask for internal_fn_p (CFN_LAST).

Diff:
---
 gcc/tree-vect-slp.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index a3e54ebf62a..fa098f9ff4e 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -1084,7 +1084,8 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char *swap,
 	      ldst_p = true;
 	      rhs_code = CFN_MASK_STORE;
 	    }
-	  else if ((internal_fn_p (cfn)
+	  else if ((cfn != CFN_LAST
+		    && internal_fn_p (cfn)
 		    && !vectorizable_internal_fn_p (as_internal_fn (cfn)))
 		   || gimple_call_tail_p (call_stmt)
 		   || gimple_call_noreturn_p (call_stmt)