update_epilogue_loop_vinfo applies SSA renmaing to the DR_REF of a
gather or scatter, so that vect_check_gather_scatter continues to work.
However, we sometimes also rely on vect_check_gather_scatter when
using gathers and scatters to implement strided accesses.
This showed up on existing tests when testing with fixed-length
-msve-vector-bits=128.
Tested on aarch64-linux-gnu and x86_64-linux-gnu. Maybe verging
on the obvious, but: OK to install?
Richard
2020-01-10 Richard Sandiford <richard.sandif...@arm.com>
gcc/
* tree-vect-loop.c (update_epilogue_loop_vinfo): Update DR_REF
for any type of gather or scatter, including strided accesses.
Index: gcc/tree-vect-loop.c
===================================================================
--- gcc/tree-vect-loop.c 2020-01-06 12:58:08.877844402 +0000
+++ gcc/tree-vect-loop.c 2020-01-10 12:37:58.683829420 +0000
@@ -8458,7 +8458,7 @@ update_epilogue_loop_vinfo (class loop *
updated offset we set using ADVANCE. Instead we have to make sure the
reference in the data references point to the corresponding copy of
the original in the epilogue. */
- if (STMT_VINFO_GATHER_SCATTER_P (stmt_vinfo))
+ if (STMT_VINFO_MEMORY_ACCESS_TYPE (stmt_vinfo) == VMAT_GATHER_SCATTER)
{
DR_REF (dr)
= simplify_replace_tree (DR_REF (dr), NULL_TREE, NULL_TREE,
