tree-scalar-evolution.c: Document instantiate_scev.

2008-05-09  Jan Sjodin  <jan.sjodin@amd.com>
	    Sebastian Pop  <sebastian.pop@amd.com>

	* tree-scalar-evolution.c: Document instantiate_scev.
	(instantiate_parameters_1): Renamed instantiate_scev_1.
	Don't use the same loop for instantiation_loop and evolution_loop.
	(instantiate_scev): New.
	(instantiate_parameters): Moved...
	(resolve_mixers): Update call to instantiate_scev_1 to pass the
	same loop twice.  Maintains the semantics for this function.
	* tree-scalar-evolution.h (instantiate_scev): Declare.
	(instantiate_parameters): ...here.  Now static inline.
	* tree-data-ref.c (dr_analyze_indices): Call instantiate_scev
	instead of resolve_mixers.


Co-Authored-By: Sebastian Pop <sebastian.pop@amd.com>

From-SVN: r135116

gcc/ChangeLog

+2008-05-09  Jan Sjodin  <jan.sjodin@amd.com>
+	    Sebastian Pop  <sebastian.pop@amd.com>
+
+	* tree-scalar-evolution.c: Document instantiate_scev.
+	(instantiate_parameters_1): Renamed instantiate_scev_1.
+	Don't use the same loop for instantiation_loop and evolution_loop.
+	(instantiate_scev): New.
+	(instantiate_parameters): Moved...
+	(resolve_mixers): Update call to instantiate_scev_1 to pass the
+	same loop twice.  Maintains the semantics for this function.
+	* tree-scalar-evolution.h (instantiate_scev): Declare.
+	(instantiate_parameters): ...here.  Now static inline.
+	* tree-data-ref.c (dr_analyze_indices): Call instantiate_scev
+	instead of resolve_mixers.
+
 2008-05-09  Maxim Kuvyrkov  <maxim@codesourcery.com>
 
 	* rtl-factoring.c (collect_pattern_seqs): Fix typo.

gcc/testsuite/ChangeLog

+2008-01-08  Jan Sjodin  <jan.sjodin@amd.com>
+	    Sebastian Pop  <sebastian.pop@amd.com>
+
+	* gcc.dg/tree-ssa/data-dep-1.c: New.
+
 2008-05-08  Richard Guenther  <rguenther@suse.de>
 
 	* gcc.dg/tree-ssa/20040911-1.c: Adjust.

gcc/testsuite/gcc.dg/tree-ssa/data-dep-1.c

+/* { dg-do compile } */ 
+/* { dg-options "-O2 -ftree-loop-linear -fdump-tree-ltrans-all" } */
+
+int foo (int n, int m)
+{
+  int a[10000][10000];
+  int i, j, k;
+
+  for(k = 0; k < 1234; k++)
+    for(j = 0; j < 5; j++)
+      for(i = 0; i < 67; i++)
+	{
+	  a[j+i-(-m+n+3)][i-k+4] = a[k+j][i];
+	}
+
+  return a[0][0];
+}
+
+
+/* For the data dependence analysis of the outermost loop, the
+   evolution of "k+j" should be instantiated in the outermost loop "k"
+   and the evolution should be taken in the innermost loop "i".  The
+   pattern below ensures that the evolution is not computed in the
+   outermost "k" loop: the 4 comes from the instantiation of the
+   number of iterations of loop "j".  */
+
+/* { dg-final { scan-tree-dump-times "4, \\+, 1" 0 "ltrans" } } */ 
+/* { dg-final { cleanup-tree-dump "ltrans" } } */

gcc/tree-data-ref.c

@@ -741,7 +741,7 @@ dr_analyze_indices (struct data_reference *dr, struct loop *nest)
 	{
 	  op = TREE_OPERAND (aref, 1);
 	  access_fn = analyze_scalar_evolution (loop, op);
-	  access_fn = resolve_mixers (nest, access_fn);
+	  access_fn = instantiate_scev (nest, loop, access_fn);
 	  VEC_safe_push (tree, heap, access_fns, access_fn);
 
 	  TREE_OPERAND (aref, 1) = build_int_cst (TREE_TYPE (op), 0);

gcc/tree-scalar-evolution.h

@@ -30,7 +30,7 @@ extern void scev_reset (void);
 extern void scev_reset_except_niters (void);
 extern void scev_finalize (void);
 extern tree analyze_scalar_evolution (struct loop *, tree);
-extern tree instantiate_parameters (struct loop *, tree);
+extern tree instantiate_scev (struct loop *, struct loop *, tree);
 extern tree resolve_mixers (struct loop *, tree);
 extern void gather_stats_on_scev_database (void);
 extern void scev_analysis (void);
@@ -38,6 +38,16 @@ unsigned int scev_const_prop (void);
 
 extern bool simple_iv (struct loop *, tree, tree, affine_iv *, bool);
 
+/* Analyze all the parameters of the chrec that were left under a
+   symbolic form.  LOOP is the loop in which symbolic names have to
+   be analyzed and instantiated.  */
+
+static inline tree
+instantiate_parameters (struct loop *loop, tree chrec)
+{
+  return instantiate_scev (loop, loop, chrec);
+}
+
 /* Returns the loop of the polynomial chrec CHREC.  */
 
 static inline struct loop *