Richard how would I check for a full masked main vector loop?
On 2/22/23 03:20, Richard Biener wrote:
On Wed, Feb 22, 2023 at 12:03 AM Michael Collison <colli...@rivosinc.com> wrote:
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?
I wonder how you arrive at prologue peeling with a non-constant VF?
In any case it would probably be better to use constant_lower_bound (vf)
here? Also it looks wrong to apply this limit in case we are using
a fully masked main vector loop. But as said, the specific case of
non-constant VF and prologue peeling probably wasn't supposed to happen,
instead the prologue usually is applied via an offset to a fully masked loop?
Richard?
Thanks,
Richard.
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
