./:

[pf3gnuchains/gcc-fork.git] / gcc / tree-loop-linear.c

diff --git a/gcc/tree-loop-linear.c b/gcc/tree-loop-linear.c
index f0dfa7a..cc2440d 100644 (file)
--- a/gcc/tree-loop-linear.c
+++ b/gcc/tree-loop-linear.c
@@ -1,12 +1,13 @@
 /* Linear Loop transforms
 /* Linear Loop transforms

-   Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009
+   Free Software Foundation, Inc.

    Contributed by Daniel Berlin <dberlin@dberlin.org>.
 
 This file is part of GCC.
 
 GCC is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free
    Contributed by Daniel Berlin <dberlin@dberlin.org>.
 
 This file is part of GCC.
 
 GCC is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free

-Software Foundation; either version 2, or (at your option) any later
+Software Foundation; either version 3, or (at your option) any later

 version.
 
 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
 version.
 
 GCC is distributed in the hope that it will be useful, but WITHOUT ANY


@@ -15,9 +16,8 @@ FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 for more details.
 
 You should have received a copy of the GNU General Public License
 for more details.
 
 You should have received a copy of the GNU General Public License

-along with GCC; see the file COPYING.  If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA.  */
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */

 
 
 #include "config.h"
 
 
 #include "config.h"


@@ -31,6 +31,7 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
 #include "rtl.h"
 #include "basic-block.h"
 #include "diagnostic.h"
 #include "rtl.h"
 #include "basic-block.h"
 #include "diagnostic.h"

+#include "obstack.h"

 #include "tree-flow.h"
 #include "tree-dump.h"
 #include "timevar.h"
 #include "tree-flow.h"
 #include "tree-dump.h"
 #include "timevar.h"


@@ -89,13 +90,13 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
 */
 
 static void
 */
 
 static void

-gather_interchange_stats (VEC (ddr_p, heap) *dependence_relations,
-                         VEC (data_reference_p, heap) *datarefs,
-                         struct loop *loop,
-                         struct loop *first_loop,
-                         unsigned int *dependence_steps, 
-                         unsigned int *nb_deps_not_carried_by_loop, 
-                         double_int *access_strides)
+gather_interchange_stats (VEC (ddr_p, heap) *dependence_relations ATTRIBUTE_UNUSED,
+                         VEC (data_reference_p, heap) *datarefs ATTRIBUTE_UNUSED,
+                         struct loop *loop ATTRIBUTE_UNUSED,
+                         struct loop *first_loop ATTRIBUTE_UNUSED,
+                         unsigned int *dependence_steps ATTRIBUTE_UNUSED, 
+                         unsigned int *nb_deps_not_carried_by_loop ATTRIBUTE_UNUSED, 
+                         double_int *access_strides ATTRIBUTE_UNUSED)

 {
   unsigned int i, j;
   struct data_dependence_relation *ddr;
 {
   unsigned int i, j;
   struct data_dependence_relation *ddr;


@@ -135,7 +136,7 @@ gather_interchange_stats (VEC (ddr_p, heap) *dependence_relations,
     {
       unsigned int it;
       tree ref = DR_REF (dr);
     {
       unsigned int it;
       tree ref = DR_REF (dr);

-      tree stmt = DR_STMT (dr);
+      gimple stmt = DR_STMT (dr);

       struct loop *stmt_loop = loop_containing_stmt (stmt);
       struct loop *inner_loop = first_loop->inner;
 
       struct loop *stmt_loop = loop_containing_stmt (stmt);
       struct loop *inner_loop = first_loop->inner;
 


@@ -146,19 +147,17 @@ gather_interchange_stats (VEC (ddr_p, heap) *dependence_relations,
       for (it = 0; it < DR_NUM_DIMENSIONS (dr); 
           it++, ref = TREE_OPERAND (ref, 0))
        {
       for (it = 0; it < DR_NUM_DIMENSIONS (dr); 
           it++, ref = TREE_OPERAND (ref, 0))
        {

-         tree chrec = DR_ACCESS_FN (dr, it);
-         tree tstride = evolution_part_in_loop_num (chrec, loop->num);
+         int num = am_vector_index_for_loop (DR_ACCESS_MATRIX (dr), loop->num);
+         int istride = AM_GET_ACCESS_MATRIX_ELEMENT (DR_ACCESS_MATRIX (dr), it, num);

          tree array_size = TYPE_SIZE (TREE_TYPE (ref));
          double_int dstride;
 
          tree array_size = TYPE_SIZE (TREE_TYPE (ref));
          double_int dstride;
 

-         if (tstride == NULL_TREE
-             || array_size == NULL_TREE 
-             || TREE_CODE (tstride) != INTEGER_CST
+         if (array_size == NULL_TREE 

              || TREE_CODE (array_size) != INTEGER_CST)
            continue;
 
          dstride = double_int_mul (tree_to_double_int (array_size), 
              || TREE_CODE (array_size) != INTEGER_CST)
            continue;
 
          dstride = double_int_mul (tree_to_double_int (array_size), 

-                                   tree_to_double_int (tstride));
+                                   shwi_to_double_int (istride));

          (*access_strides) = double_int_add (*access_strides, dstride);
        }
     }
          (*access_strides) = double_int_add (*access_strides, dstride);
        }
     }


@@ -179,10 +178,14 @@ try_interchange_loops (lambda_trans_matrix trans,
                       VEC (data_reference_p, heap) *datarefs,
                       struct loop *first_loop)
 {
                       VEC (data_reference_p, heap) *datarefs,
                       struct loop *first_loop)
 {

+  bool res;

   struct loop *loop_i;
   struct loop *loop_j;
   unsigned int dependence_steps_i, dependence_steps_j;
   double_int access_strides_i, access_strides_j;
   struct loop *loop_i;
   struct loop *loop_j;
   unsigned int dependence_steps_i, dependence_steps_j;
   double_int access_strides_i, access_strides_j;

+  double_int small, large, nb_iter;
+  double_int l1_cache_size, l2_cache_size;
+  int cmp;

   unsigned int nb_deps_not_carried_by_i, nb_deps_not_carried_by_j;
   struct data_dependence_relation *ddr;
 
   unsigned int nb_deps_not_carried_by_i, nb_deps_not_carried_by_j;
   struct data_dependence_relation *ddr;
 


@@ -194,7 +197,10 @@ try_interchange_loops (lambda_trans_matrix trans,
   ddr = VEC_index (ddr_p, dependence_relations, 0);
   if (ddr == NULL || DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
     return trans;
   ddr = VEC_index (ddr_p, dependence_relations, 0);
   if (ddr == NULL || DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
     return trans;

-  
+
+  l1_cache_size = uhwi_to_double_int (L1_CACHE_SIZE * 1024);
+  l2_cache_size = uhwi_to_double_int (L2_CACHE_SIZE * 1024);
+

   /* LOOP_I is always the outer loop.  */
   for (loop_j = first_loop->inner; 
        loop_j; 
   /* LOOP_I is always the outer loop.  */
   for (loop_j = first_loop->inner; 
        loop_j; 


@@ -216,18 +222,38 @@ try_interchange_loops (lambda_trans_matrix trans,
        
        /* Heuristics for loop interchange profitability:
 
        
        /* Heuristics for loop interchange profitability:
 

+          0. Don't transform if the smallest stride is larger than
+             the L2 cache, or if the largest stride multiplied by the
+             number of iterations is smaller than the L1 cache.
+

           1. (spatial locality) Inner loops should have smallest
               dependence steps.
 
           2. (spatial locality) Inner loops should contain more
           dependence relations not carried by the loop.
 
           1. (spatial locality) Inner loops should have smallest
               dependence steps.
 
           2. (spatial locality) Inner loops should contain more
           dependence relations not carried by the loop.
 

-          3. (temporal locality) Inner loops should have smallest 
+          3. (temporal locality) Inner loops should have smallest

              array access strides.
        */
              array access strides.
        */

+
+       cmp = double_int_ucmp (access_strides_i, access_strides_j);
+       small = cmp < 0 ? access_strides_i : access_strides_j;
+       large = cmp < 0 ? access_strides_j : access_strides_i;
+
+       if (double_int_ucmp (small, l2_cache_size) > 0)
+         continue;
+
+       res = cmp < 0 ?
+         estimated_loop_iterations (loop_j, false, &nb_iter):
+         estimated_loop_iterations (loop_i, false, &nb_iter);
+       large = double_int_mul (large, nb_iter);
+
+       if (res && double_int_ucmp (large, l1_cache_size) < 0)
+         continue;
+

        if (dependence_steps_i < dependence_steps_j 
            || nb_deps_not_carried_by_i > nb_deps_not_carried_by_j
        if (dependence_steps_i < dependence_steps_j 
            || nb_deps_not_carried_by_i > nb_deps_not_carried_by_j

-           || double_int_ucmp (access_strides_i, access_strides_j) < 0)
+           || cmp < 0)

          {
            lambda_matrix_row_exchange (LTM_MATRIX (trans),
                                        loop_depth (loop_i) - loop_depth (first_loop),
          {
            lambda_matrix_row_exchange (LTM_MATRIX (trans),
                                        loop_depth (loop_i) - loop_depth (first_loop),


@@ -244,6 +270,46 @@ try_interchange_loops (lambda_trans_matrix trans,
   return trans;
 }
 
   return trans;
 }
 

+/* Return the number of nested loops in LOOP_NEST, or 0 if the loops
+   are not perfectly nested.  */
+
+unsigned int
+perfect_loop_nest_depth (struct loop *loop_nest)
+{
+  struct loop *temp;
+  unsigned int depth = 1;
+
+  /* If it's not a loop nest, we don't want it.  We also don't handle
+     sibling loops properly, which are loops of the following form:
+
+     | for (i = 0; i < 50; i++)
+     |   {
+     |     for (j = 0; j < 50; j++)
+     |       {
+     |        ...
+     |       }
+     |     for (j = 0; j < 50; j++)
+     |       {
+     |        ...
+     |       }
+     |   }
+  */
+
+  if (!loop_nest->inner || !single_exit (loop_nest))
+    return 0;
+
+  for (temp = loop_nest->inner; temp; temp = temp->inner)
+    {
+      /* If we have a sibling loop or multiple exit edges, jump ship.  */
+      if (temp->next || !single_exit (temp))
+       return 0;
+
+      depth++;
+    }
+
+  return depth;
+}
+

 /* Perform a set of linear transforms on loops.  */
 
 void
 /* Perform a set of linear transforms on loops.  */
 
 void


@@ -253,55 +319,46 @@ linear_transform_loops (void)
   loop_iterator li;
   VEC(tree,heap) *oldivs = NULL;
   VEC(tree,heap) *invariants = NULL;
   loop_iterator li;
   VEC(tree,heap) *oldivs = NULL;
   VEC(tree,heap) *invariants = NULL;

+  VEC(tree,heap) *lambda_parameters = NULL;
+  VEC(gimple,heap) *remove_ivs = VEC_alloc (gimple, heap, 3);

   struct loop *loop_nest;
   struct loop *loop_nest;

-  
+  gimple oldiv_stmt;
+  unsigned i;
+

   FOR_EACH_LOOP (li, loop_nest, 0)
     {
       unsigned int depth = 0;
       VEC (ddr_p, heap) *dependence_relations;
       VEC (data_reference_p, heap) *datarefs;
   FOR_EACH_LOOP (li, loop_nest, 0)
     {
       unsigned int depth = 0;
       VEC (ddr_p, heap) *dependence_relations;
       VEC (data_reference_p, heap) *datarefs;

-      struct loop *temp;
+      

       lambda_loopnest before, after;
       lambda_trans_matrix trans;
       lambda_loopnest before, after;
       lambda_trans_matrix trans;

-      bool problem = false;
-      /* If it's not a loop nest, we don't want it.
-         We also don't handle sibling loops properly, 
-         which are loops of the following form:
-         for (i = 0; i < 50; i++)
-           {
-             for (j = 0; j < 50; j++)
-               {
-               ...
-               }
-             for (j = 0; j < 50; j++)
-               {
-                ...
-               }
-           } */
-      if (!loop_nest->inner || !single_exit (loop_nest))
+      struct obstack lambda_obstack;
+      struct loop *loop;
+      VEC(loop_p,heap) *nest;
+
+      depth = perfect_loop_nest_depth (loop_nest);
+      if (depth == 0)

        continue;
        continue;

+
+      nest = VEC_alloc (loop_p, heap, 3);
+      for (loop = loop_nest; loop; loop = loop->inner)
+       VEC_safe_push (loop_p, heap, nest, loop);
+
+      gcc_obstack_init (&lambda_obstack);

       VEC_truncate (tree, oldivs, 0);
       VEC_truncate (tree, invariants, 0);
       VEC_truncate (tree, oldivs, 0);
       VEC_truncate (tree, invariants, 0);

-      depth = 1;
-      for (temp = loop_nest->inner; temp; temp = temp->inner)
-       {
-         /* If we have a sibling loop or multiple exit edges, jump ship.  */
-         if (temp->next || !single_exit (temp))
-           {
-             problem = true;
-             break;
-           }
-         depth ++;
-       }
-      if (problem)
-       continue;
+      VEC_truncate (tree, lambda_parameters, 0);

 
 

-      /* Analyze data references and dependence relations using scev.  */      
- 

       datarefs = VEC_alloc (data_reference_p, heap, 10);
       dependence_relations = VEC_alloc (ddr_p, heap, 10 * 10);
       datarefs = VEC_alloc (data_reference_p, heap, 10);
       dependence_relations = VEC_alloc (ddr_p, heap, 10 * 10);

-      compute_data_dependences_for_loop (loop_nest, true, &datarefs,
-                                        &dependence_relations);
+      if (!compute_data_dependences_for_loop (loop_nest, true, &datarefs,
+                                             &dependence_relations))
+       goto free_and_continue;
+      
+      lambda_collect_parameters (datarefs, &lambda_parameters);
+      if (!lambda_compute_access_matrices (datarefs, lambda_parameters, nest))
+       goto free_and_continue;

 
       if (dump_file && (dump_flags & TDF_DETAILS))
        dump_ddrs (dump_file, dependence_relations);
 
       if (dump_file && (dump_flags & TDF_DETAILS))
        dump_ddrs (dump_file, dependence_relations);


@@ -328,7 +385,7 @@ linear_transform_loops (void)
        }
 
       before = gcc_loopnest_to_lambda_loopnest (loop_nest, &oldivs,
        }
 
       before = gcc_loopnest_to_lambda_loopnest (loop_nest, &oldivs,

-                                               &invariants);
+                                                &invariants, &lambda_obstack);

 
       if (!before)
        goto free_and_continue;
 
       if (!before)
        goto free_and_continue;


@@ -339,7 +396,7 @@ linear_transform_loops (void)
          print_lambda_loopnest (dump_file, before, 'i');
        }
   
          print_lambda_loopnest (dump_file, before, 'i');
        }
   

-      after = lambda_loopnest_transform (before, trans);
+      after = lambda_loopnest_transform (before, trans, &lambda_obstack);

 
       if (dump_file)
        {
 
       if (dump_file)
        {


@@ -348,19 +405,26 @@ linear_transform_loops (void)
        }
 
       lambda_loopnest_to_gcc_loopnest (loop_nest, oldivs, invariants,
        }
 
       lambda_loopnest_to_gcc_loopnest (loop_nest, oldivs, invariants,

-                                      after, trans);
+                                      &remove_ivs,
+                                       after, trans, &lambda_obstack);

       modified = true;
 
       if (dump_file)
        fprintf (dump_file, "Successfully transformed loop.\n");
 
     free_and_continue:
       modified = true;
 
       if (dump_file)
        fprintf (dump_file, "Successfully transformed loop.\n");
 
     free_and_continue:

+      obstack_free (&lambda_obstack, NULL);

       free_dependence_relations (dependence_relations);
       free_data_refs (datarefs);
       free_dependence_relations (dependence_relations);
       free_data_refs (datarefs);

+      VEC_free (loop_p, heap, nest);

     }
 
     }
 

+  for (i = 0; VEC_iterate (gimple, remove_ivs, i, oldiv_stmt); i++)
+    remove_iv (oldiv_stmt);
+

   VEC_free (tree, heap, oldivs);
   VEC_free (tree, heap, invariants);
   VEC_free (tree, heap, oldivs);
   VEC_free (tree, heap, invariants);

+  VEC_free (gimple, heap, remove_ivs);

   scev_reset ();
 
   if (modified)
   scev_reset ();
 
   if (modified)