[gcc r16-6796] Fix x86 testsuite fallout from VF == 1 epilogue vectorization change

[Richard Biener]

https://gcc.gnu.org/g:eb41f97db7dcce499468645d9cdd72b1552bb05a

commit r16-6796-geb41f97db7dcce499468645d9cdd72b1552bb05a
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Jan 15 08:55:34 2026 +0100

    Fix x86 testsuite fallout from VF == 1 epilogue vectorization change
    
    The following fixes reported fallout with -march=cascadelake.
    
            * gcc.dg/vect/fast-math-slp-38.c: Avoid epilogue vectorization.

Diff:
---
 gcc/testsuite/gcc.dg/vect/fast-math-slp-38.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.dg/vect/fast-math-slp-38.c b/gcc/testsuite/gcc.dg/vect/fast-math-slp-38.c
index 65ad9a783718..e7b37edea071 100644
--- a/gcc/testsuite/gcc.dg/vect/fast-math-slp-38.c
+++ b/gcc/testsuite/gcc.dg/vect/fast-math-slp-38.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-additional-options "-ffast-math" } */
+/* { dg-additional-options "-ffast-math --param vect-epilogues-nomask=0" } */
 /* { dg-require-effective-target vect_double } */
 
 double self[1024];