[lno][PATCH] Start using dd info in av

[Devang Patel <dpatel at apple dot com>]

This patch updates tree vectorizer to use ddg info. This expands
scope of what can be vectorized.

--
Devang


2004-02-20  Devang Patel <dpatel@apple.com>

        * tree-vectorizer.c (vect_analyze_data_ref_dependence): Use
        ddg_direction_between_stmts ().

testsuite:
        * testsuite/gcc.dg/tree-ssa-vect/tree-ssa-vect-3.c: New test.


Index: tree-vectorizer.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Attic/tree-vectorizer.c,v
retrieving revision 1.1.2.16
diff -Idpatel.pbxuser -c -3 -p -r1.1.2.16 tree-vectorizer.c
*** tree-vectorizer.c   18 Feb 2004 19:32:21 -0000      1.1.2.16
--- tree-vectorizer.c   20 Feb 2004 19:58:33 -0000
*************** vect_analyze_data_ref_dependence (struct
*** 2006,2011 ****
--- 2006,2018 ----

    if (!array_base_name_differ_p (dra, drb))
      {
+       enum data_dependence_direction ddd =
+       ddg_direction_between_stmts (DR_STMT (dra), DR_STMT (drb),
+                                     loop_num (loop_of_stmt (DR_STMT 
(dra))));
+
+       if (ddd == dir_independent)
+       return true;
+
        if (tree_dump_file && (tree_dump_flags & TDF_DETAILS))
        fprintf (tree_dump_file,
                "vect_analyze_data_ref_dependence: same base\n");
Index: testsuite/gcc.dg/tree-ssa-vect/tree-ssa-vect-3.c
===================================================================
RCS file: testsuite/gcc.dg/tree-ssa-vect/tree-ssa-vect-3.c
diff -N testsuite/gcc.dg/tree-ssa-vect/tree-ssa-vect-3.c
*** /dev/null   1 Jan 1970 00:00:00 -0000
--- testsuite/gcc.dg/tree-ssa-vect/tree-ssa-vect-3.c    20 Feb 2004 
19:58:33 -0000
***************
*** 0 ****
--- 1,24 ----
+ /* { dg-do compile { target powerpc*-*-* i?86-*-* } } */
+ /* { dg-options "-O2 -ftree-vectorize -fdump-tree-vect-stats 
-maltivec" { target powerpc*-*-* } } */
+ /* { dg-options "-O2 -ftree-vectorize -fdump-tree-vect-stats -msse" { 
target i?86-*-* } } */
+
+ #define N 16
+
+ void fbar (float *);
+
+ foo (int n)
+ {
+   float a[N*2+1];
+   float b[N];
+   float c[N];
+   int i;
+
+   /* Use of data dependence graph is required.  */
+   for (i = 0; i < N; i++){
+     a[i] = b[i];
+     a[i+N] = c[i];
+   }
+   fbar (a);
+ }
+
+ /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect"} } 
*/