When vectorizing an early break loop with LENs (do we miss some
check here to disallow this?) we can end up deciding to insert
stmts after a GIMPLE_COND when doing SLP scheduling and trying
to be conservative with placing of stmts only dependent on
the implicit loop mask/len. The following avoids this, I guess
it's not perfect but it does the job fixing some observed
RISC-V regression.
* tree-vect-slp.cc (vect_schedule_slp_node): For mask/len
loops make sure to not advance the insertion iterator
beyond a GIMPLE_COND.
---
gcc/tree-vect-slp.cc | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index bf1f467f53f..11ec82086fc 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -9650,7 +9650,12 @@ vect_schedule_slp_node (vec_info *vinfo,
else
{
si = gsi_for_stmt (last_stmt);
- gsi_next (&si);
+ /* When we're getting gsi_after_labels from the starting
+ condition of a fully masked/len loop avoid insertion
+ after a GIMPLE_COND that can appear as the only header
+ stmt with early break vectorization. */
+ if (gimple_code (last_stmt) != GIMPLE_COND)
+ gsi_next (&si);
}
}
--
2.35.3
