re PR middle-end/31699 (-march=opteron -ftree-vectorize generates wrong code)

        PR tree-optimization/31699
        * tree-vect-analyze.c (vect_update_misalignment_for_peel): Remove wrong
        code.
        (vect_enhance_data_refs_alignment): Compute peel amount using
        TYPE_VECTOR_SUBPARTS instead of vf.
        * tree-vect-transform.c (vect_gen_niters_for_prolog_loop): Likewise.

From-SVN: r124375

1 files changed, 14 insertions, 9 deletions

diff --git a/gcc/tree-vect-transform.c b/gcc/tree-vect-transform.c
index 161e82d..4775e2c 100644
--- a/gcc/tree-vect-transform.c
+++ b/gcc/tree-vect-transform.c
@@ -4786,13 +4786,17 @@ vect_do_peeling_for_loop_bound (loop_vec_info loop_vinfo, tree *ratio)
    prolog_niters = min ( LOOP_NITERS , 
                         (VF/group_size - addr_mis/elem_size)&(VF/group_size-1) )
 	 where group_size is the size of the interleaved group.
-*/
+
+   The above formulas assume that VF == number of elements in the vector. This
+   may not hold when there are multiple-types in the loop.
+   In this case, for some data-references in the loop the VF does not represent
+   the number of elements that fit in the vector.  Therefore, instead of VF we
+   use TYPE_VECTOR_SUBPARTS.  */
 
 static tree 
 vect_gen_niters_for_prolog_loop (loop_vec_info loop_vinfo, tree loop_niters)
 {
   struct data_reference *dr = LOOP_VINFO_UNALIGNED_DR (loop_vinfo);
-  int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
   tree var, stmt;
   tree iters, iters_name;
@@ -4805,6 +4809,7 @@ vect_gen_niters_for_prolog_loop (loop_vec_info loop_vinfo, tree loop_niters)
   tree niters_type = TREE_TYPE (loop_niters);
   int group_size = 1;
   int element_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr))));
+  int nelements = TYPE_VECTOR_SUBPARTS (vectype);
 
   if (DR_GROUP_FIRST_DR (stmt_info))
     {
@@ -4825,7 +4830,7 @@ vect_gen_niters_for_prolog_loop (loop_vec_info loop_vinfo, tree loop_niters)
       if (vect_print_dump_info (REPORT_DETAILS))
         fprintf (vect_dump, "known alignment = %d.", byte_misalign);
       iters = build_int_cst (niters_type, 
-			     (vf - elem_misalign)&(vf/group_size-1));
+			     (nelements - elem_misalign)&(nelements/group_size-1));
     }
   else
     {
@@ -4837,9 +4842,9 @@ vect_gen_niters_for_prolog_loop (loop_vec_info loop_vinfo, tree loop_niters)
       tree type = lang_hooks.types.type_for_size (tree_low_cst (size, 1), 1);
       tree vectype_size_minus_1 = build_int_cst (type, vectype_align - 1);
       tree elem_size_log =
-        build_int_cst (type, exact_log2 (vectype_align/vf));
-      tree vf_minus_1 = build_int_cst (type, vf - 1);
-      tree vf_tree = build_int_cst (type, vf);
+        build_int_cst (type, exact_log2 (vectype_align/nelements));
+      tree nelements_minus_1 = build_int_cst (type, nelements - 1);
+      tree nelements_tree = build_int_cst (type, nelements);
       tree byte_misalign;
       tree elem_misalign;
 
@@ -4854,9 +4859,9 @@ vect_gen_niters_for_prolog_loop (loop_vec_info loop_vinfo, tree loop_niters)
       elem_misalign =
         fold_build2 (RSHIFT_EXPR, type, byte_misalign, elem_size_log);
 
-      /* Create:  (niters_type) (VF - elem_misalign)&(VF - 1)  */
-      iters = fold_build2 (MINUS_EXPR, type, vf_tree, elem_misalign);
-      iters = fold_build2 (BIT_AND_EXPR, type, iters, vf_minus_1);
+      /* Create:  (niters_type) (nelements - elem_misalign)&(nelements - 1)  */
+      iters = fold_build2 (MINUS_EXPR, type, nelements_tree, elem_misalign);
+      iters = fold_build2 (BIT_AND_EXPR, type, iters, nelements_minus_1);
       iters = fold_convert (niters_type, iters);
     }