[PATCH] vect: Check that vector factor is a compile-time constant

[Michael Collison <collison@rivosinc.com>]

While working on autovectorizing for the RISCV port I encountered an 
issue where vect_do_peeling assumes that the vectorization factor is a 
compile-time constant. The vectorization is not a compile-time constant 
on RISCV.

Tested on RISCV and x86_64-linux-gnu. Okay?

Michael

gcc/

     * tree-vect-loop-manip.cc (vect_do_peeling): Verify
     that vectorization factor is a compile-time constant.

---
  gcc/tree-vect-loop-manip.cc | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
index 6aa3d2ed0bf..1ad1961c788 100644
--- a/gcc/tree-vect-loop-manip.cc
+++ b/gcc/tree-vect-loop-manip.cc
@@ -2930,7 +2930,7 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree 
niters, tree nitersm1,
        niters = vect_build_loop_niters (loop_vinfo, &new_var_p);
        /* It's guaranteed that vector loop bound before vectorization is at
       least VF, so set range information for newly generated var. */
-      if (new_var_p)
+      if (new_var_p && vf.is_constant ())
      {
        value_range vr (type,
                wi::to_wide (build_int_cst (type, vf)),
-- 
2.34.1