[gcc/devel/ranger] Fix gather/scatter check when updating a vector epilogue loop

[Aldy Hernandez]

https://gcc.gnu.org/g:ac190fcea1bebf87a2c8c3963548a0e5272c42ec

commit ac190fcea1bebf87a2c8c3963548a0e5272c42ec
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Fri Jan 10 14:56:20 2020 +0000

    Fix gather/scatter check when updating a vector epilogue loop
    
    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.
    
    2020-01-10  Richard Sandiford  <richard.sandiford@arm.com>
    
    gcc/
            * tree-vect-loop.c (update_epilogue_loop_vinfo): Update DR_REF
            for any type of gather or scatter, including strided accesses.
    
    From-SVN: r280111

Diff:
---
 gcc/ChangeLog        | 5 +++++
 gcc/tree-vect-loop.c | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f8298abebd7..28564f723e1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2020-01-10  Richard Sandiford  <richard.sandiford@arm.com>
+
+	* tree-vect-loop.c (update_epilogue_loop_vinfo): Update DR_REF
+	for any type of gather or scatter, including strided accesses.
+
 2020-01-10  Andre Vieira  <andre.simoesdiasvieira@arm.com>
 
 	* tree-vectorizer.h (get_dr_vinfo_offset): Add missing function
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 596eafc2d3f..1fa3ba6d932 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -8451,7 +8451,7 @@ update_epilogue_loop_vinfo (class loop *epilogue, tree advance)
 	 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,