[gcc(refs/users/giulianob/heads/autopar_rebase2)] vect: CSE for bump and offset in strided load/store operations.

[Giuliano Belinassi]

https://gcc.gnu.org/g:39d63338deca70909554ef20e8b02a8d0a33385c

commit 39d63338deca70909554ef20e8b02a8d0a33385c
Author: Kaipeng Zhou <zhoukaipeng3@huawei.com>
Date:   Wed Jun 17 20:19:16 2020 +0100

    vect: CSE for bump and offset in strided load/store operations.
    
    Every time "vect_get_strided_load_store_ops" is called, new bump and offset
    variables and a series of stmts are created.  And IVOPTs is not able to
    eliminate them.  The patch use "cse_and_gimplify_to_preheader" to CSE them.
    
    2020-06-17  Bin Cheng  <bin.cheng@linux.alibaba.com>
                Kaipeng Zhou  <zhoukaipeng3@huawei.com>
    
            PR tree-optimization/95199
            * tree-vect-stmts.c: Eliminate common stmts for bump and offset in
            strided load/store operations and remove redundant code.
    
    2020-06-17  Bin Cheng  <bin.cheng@linux.alibaba.com>
                Kaipeng Zhou  <zhoukaipeng3@huawei.com>
    
            PR tree-optimization/95199
            * gcc.target/aarch64/sve/pr95199.c: New test.

Diff:
---
 gcc/testsuite/gcc.target/aarch64/sve/pr95199.c | 17 +++++++++++++++++
 gcc/tree-vect-stmts.c                          | 17 +++++------------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pr95199.c b/gcc/testsuite/gcc.target/aarch64/sve/pr95199.c
new file mode 100644
index 00000000000..adcd5124a7c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/pr95199.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=armv8.2-a+sve -fdump-tree-vect" } */
+
+void
+foo (double *a, double *b, double m, int inc_x, int inc_y)
+{
+  int ix = 0, iy = 0;
+  for (int i = 0; i < 1000; ++i)
+    {
+      a[ix] += m * b[iy];
+      ix += inc_x;
+      iy += inc_y;
+    }
+  return ;
+}
+
+/* { dg-final { scan-tree-dump-times "VEC_SERIES_EXPR" 2 "vect" } } */
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 4a0a907fcb4..c9174395fca 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -2846,33 +2846,26 @@ vect_get_strided_load_store_ops (stmt_vec_info stmt_info,
 				 tree *dataref_bump, tree *vec_offset)
 {
   struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
-  class loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
-  gimple_seq stmts;
 
   tree bump = size_binop (MULT_EXPR,
 			  fold_convert (sizetype, unshare_expr (DR_STEP (dr))),
 			  size_int (TYPE_VECTOR_SUBPARTS (vectype)));
-  *dataref_bump = force_gimple_operand (bump, &stmts, true, NULL_TREE);
-  if (stmts)
-    gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
+  *dataref_bump = cse_and_gimplify_to_preheader (loop_vinfo, bump);
 
   /* The offset given in GS_INFO can have pointer type, so use the element
      type of the vector instead.  */
-  tree offset_type = TREE_TYPE (gs_info->offset);
-  offset_type = TREE_TYPE (gs_info->offset_vectype);
+  tree offset_type = TREE_TYPE (gs_info->offset_vectype);
 
   /* Calculate X = DR_STEP / SCALE and convert it to the appropriate type.  */
   tree step = size_binop (EXACT_DIV_EXPR, unshare_expr (DR_STEP (dr)),
 			  ssize_int (gs_info->scale));
   step = fold_convert (offset_type, step);
-  step = force_gimple_operand (step, &stmts, true, NULL_TREE);
 
   /* Create {0, X, X*2, X*3, ...}.  */
-  *vec_offset = gimple_build (&stmts, VEC_SERIES_EXPR, gs_info->offset_vectype,
-			      build_zero_cst (offset_type), step);
-  if (stmts)
-    gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
+  tree offset = fold_build2 (VEC_SERIES_EXPR, gs_info->offset_vectype,
+			     build_zero_cst (offset_type), step);
+  *vec_offset = cse_and_gimplify_to_preheader (loop_vinfo, offset);
 }
 
 /* Return the amount that should be added to a vector pointer to move