re PR tree-optimization/18792 (ICE with -O1 -ftree-loop-linear on small test case)

2005-01-06  Daniel Berlin <dberlin@dberlin.org>

	Fix PR tree-optimization/18792

	* tree-data-ref.c (build_classic_dist_vector): Change first_loop
	to first_loop_depth, and use loop depth instead of loop number.
	(build_classic_dir_vector): Ditto.
	(compute_data_dependences_for_loop): Use depth, not loop number.
	* tree-loop-linear.c (try_interchange_loops): Use loop depth, not loop
	number. Pass in loops, instead of loop numbers.
	(gather_interchange_stats): Ditto.
	(linear_transform_loops): Ditto.

From-SVN: r93008

gcc/ChangeLog

+2005-01-06  Daniel Berlin <dberlin@dberlin.org>
+	
+	Fix PR tree-optimization/18792
+
+	* tree-data-ref.c (build_classic_dist_vector): Change first_loop
+	to first_loop_depth, and use loop depth instead of loop number.
+	(build_classic_dir_vector): Ditto.
+	(compute_data_dependences_for_loop): Use depth, not loop number.
+	* tree-loop-linear.c (try_interchange_loops): Use loop depth, not loop 
+	number. Pass in loops, instead of loop numbers.
+	(gather_interchange_stats): Ditto.
+	(linear_transform_loops): Ditto.
+
 2005-01-06  Richard Sandiford  <rsandifo@redhat.com>
 
 	PR rtl-opt/13299

gcc/testsuite/gcc.dg/pr18792.c

+/* PR tree-optimization/18792 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -ftree-loop-linear" } */
+void put_atoms_in_triclinic_unitcell(float x[][3])
+{
+	int i=0,d;
+
+	while (x[i][3] < 0)
+		for (d=0; d<=3; d++)
+			x[i][d] = 0;
+
+	while (x[i][3] >= 0)
+		for (d=0; d<=3; d++)
+			x[i][d] = 0;
+
+}

gcc/tree-loop-linear.c

@@ -55,19 +55,19 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
    transform matrix for locality purposes.
    TODO: Completion of partial transforms.  */
 
-/* Gather statistics for loop interchange.  LOOP_NUMBER is a relative
-   index in the considered loop nest.  The first loop in the
-   considered loop nest is FIRST_LOOP, and consequently the index of
-   the considered loop is obtained by FIRST_LOOP + LOOP_NUMBER.
+/* Gather statistics for loop interchange.  LOOP is the loop being
+   considered. The first loop in the considered loop nest is
+   FIRST_LOOP, and consequently, the index of the considered loop is
+   obtained by LOOP->DEPTH - FIRST_LOOP->DEPTH
    
    Initializes:
    - DEPENDENCE_STEPS the sum of all the data dependence distances
-   carried by loop LOOP_NUMBER,
+   carried by loop LOOP,
 
    - NB_DEPS_NOT_CARRIED_BY_LOOP the number of dependence relations
-   for which the loop LOOP_NUMBER is not carrying any dependence,
+   for which the loop LOOP is not carrying any dependence,
 
-   - ACCESS_STRIDES the sum of all the strides in LOOP_NUMBER.
+   - ACCESS_STRIDES the sum of all the strides in LOOP.
 
    Example: for the following loop,
 
@@ -93,8 +93,8 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 static void
 gather_interchange_stats (varray_type dependence_relations, 
 			  varray_type datarefs,
-			  unsigned int loop_number, 
-			  unsigned int first_loop,
+			  struct loop *loop,
+			  struct loop *first_loop,
 			  unsigned int *dependence_steps, 
 			  unsigned int *nb_deps_not_carried_by_loop, 
 			  unsigned int *access_strides)
@@ -123,7 +123,7 @@ gather_interchange_stats (varray_type dependence_relations,
       
 
       
-      dist = DDR_DIST_VECT (ddr)[loop_number];
+      dist = DDR_DIST_VECT (ddr)[loop->depth - first_loop->depth];
       if (dist == 0)
 	(*nb_deps_not_carried_by_loop) += 1;
       else if (dist < 0)
@@ -139,17 +139,16 @@ gather_interchange_stats (varray_type dependence_relations,
       struct data_reference *dr = VARRAY_GENERIC_PTR (datarefs, i);
       tree stmt = DR_STMT (dr);
       struct loop *stmt_loop = loop_containing_stmt (stmt);
-      struct loop *inner_loop = current_loops->parray[first_loop + 1];
-
-      if (!flow_loop_nested_p (inner_loop, stmt_loop)
-	  && inner_loop->num != stmt_loop->num)
+      struct loop *inner_loop = first_loop->inner;
+      
+      if (inner_loop != stmt_loop 
+	  && !flow_loop_nested_p (inner_loop, stmt_loop))
 	continue;
-
       for (it = 0; it < DR_NUM_DIMENSIONS (dr); it++)
 	{
 	  tree chrec = DR_ACCESS_FN (dr, it);
 	  tree tstride = evolution_part_in_loop_num 
-	    (chrec, first_loop + loop_number);
+	    (chrec, loop->num);
 	  
 	  if (tstride == NULL_TREE
 	      || TREE_CODE (tstride) != INTEGER_CST)
@@ -173,9 +172,10 @@ try_interchange_loops (lambda_trans_matrix trans,
 		       unsigned int depth,		       
 		       varray_type dependence_relations,
 		       varray_type datarefs, 
-		       unsigned int first_loop)
+		       struct loop *first_loop)
 {
-  unsigned int loop_i, loop_j;
+  struct loop *loop_i;
+  struct loop *loop_j;
   unsigned int dependence_steps_i, dependence_steps_j;
   unsigned int access_strides_i, access_strides_j;
   unsigned int nb_deps_not_carried_by_i, nb_deps_not_carried_by_j;
@@ -189,8 +189,12 @@ try_interchange_loops (lambda_trans_matrix trans,
     return trans;
   
   /* LOOP_I is always the outer loop.  */
-  for (loop_j = 1; loop_j < depth; loop_j++)
-    for (loop_i = 0; loop_i < loop_j; loop_i++)
+  for (loop_j = first_loop->inner; 
+       loop_j; 
+       loop_j = loop_j->inner)
+    for (loop_i = first_loop; 
+	 loop_i->depth < loop_j->depth; 
+	 loop_i = loop_i->inner)
       {
 	gather_interchange_stats (dependence_relations, datarefs,
 				  loop_i, first_loop,
@@ -218,11 +222,15 @@ try_interchange_loops (lambda_trans_matrix trans,
 	    || nb_deps_not_carried_by_i > nb_deps_not_carried_by_j
 	    || access_strides_i < access_strides_j)
 	  {
-	    lambda_matrix_row_exchange (LTM_MATRIX (trans), loop_i, loop_j);
+	    lambda_matrix_row_exchange (LTM_MATRIX (trans),
+					loop_i->depth - first_loop->depth,
+					loop_j->depth - first_loop->depth);
 	    /* Validate the resulting matrix.  When the transformation
 	       is not valid, reverse to the previous transformation.  */
 	    if (!lambda_transform_legal_p (trans, depth, dependence_relations))
-	      lambda_matrix_row_exchange (LTM_MATRIX (trans), loop_i, loop_j);
+	      lambda_matrix_row_exchange (LTM_MATRIX (trans), 
+					  loop_i->depth - first_loop->depth, 
+					  loop_j->depth - first_loop->depth);
 	  }
       }
 
@@ -318,7 +326,7 @@ linear_transform_loops (struct loops *loops)
       lambda_matrix_id (LTM_MATRIX (trans), depth);
 
       trans = try_interchange_loops (trans, depth, dependence_relations,
-				     datarefs, loop_nest->num);
+				     datarefs, loop_nest);
 
       if (lambda_trans_matrix_id_p (trans))
 	{