https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=239266 reports how

clang unfortunately poisons user namespace by default (without any

special options), so we need to avoid using vec_step as a variable.

Index: gcc/tree-vect-loop.c

===================================================================

--- gcc/tree-vect-loop.c	(revision 273856)

+++ gcc/tree-vect-loop.c	(working copy)

@@ -55,6 +55,8 @@ along with GCC; see the file COPYING3.  If not see

 #include "vec-perm-indices.h"

 #include "tree-eh.h"

+#define vec_step vec_step_

+

 /* Loop Vectorization Pass.

    This pass tries to vectorize loops.