1 files changed, 113 insertions, 0 deletions
diff --git a/gcc/tree-loop-linear.c b/gcc/tree-loop-linear.c
new file mode 100644
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--- /dev/null
+++ b/gcc/tree-loop-linear.c
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+/* Linear Loop transforms
+   Copyright (C) 2003, 2004 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
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+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
+along with GCC; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA.  */
+
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "errors.h"
+#include "ggc.h"
+#include "tree.h"
+#include "target.h"
+
+#include "rtl.h"
+#include "basic-block.h"
+#include "diagnostic.h"
+#include "tree-flow.h"
+#include "tree-dump.h"
+#include "timevar.h"
+#include "cfgloop.h"
+#include "tree-fold-const.h"
+#include "expr.h"
+#include "optabs.h"
+#include "tree-chrec.h"
+#include "tree-data-ref.h"
+#include "tree-scalar-evolution.h"
+#include "tree-pass.h"
+#include "varray.h"
+#include "lambda.h"
+
+/* Linear loop transforms include any composition of interchange,
+   scaling, skewing, and reversal.  They are used to change the
+   iteration order of loop nests in order to optimize data locality of
+   traversals, or remove dependences that prevent
+   parallelization/vectorization/etc.  
+
+   TODO: Determine reuse vectors/matrix and use it to determine optimal
+   transform matrix for locality purposes.
+   TODO: Add dependence matrix collection and approriate matrix
+   calculations so we can determine if a given transformation matrix
+   is legal for a loop. 
+   TODO: Completion of partial transforms.
+*/
+
+/* Perform a set of linear transforms on LOOPS.  */
+
+void
+linear_transform_loops (struct loops *loops)
+{
+  unsigned int i;  
+  for (i = 1; i < loops->num; i++)
+    {
+      struct loop *loop_nest = loops->parray[i];
+      varray_type oldivs;
+      varray_type invariants;
+      lambda_loopnest before, after;
+      lambda_trans_matrix trans;
+
+      if (!loop_nest->inner)
+	continue;
+      flow_loop_scan (loop_nest, LOOP_ALL);
+      flow_loop_scan (loop_nest->inner, LOOP_ALL);
+#if 0
+      if (loop_nest->num_pre_header_edges != 1 
+	  || loop_nest->inner->num_pre_header_edges != 1)
+	  continue;
+#endif 
+      before = gcc_loopnest_to_lambda_loopnest (loop_nest, &oldivs, &invariants);
+      if (!before)
+	continue;
+      if (dump_file)
+	{
+	  fprintf (dump_file, "Before:\n");
+	  print_lambda_loopnest (dump_file, before, 'i');
+	}
+      trans = lambda_trans_matrix_new (LN_DEPTH (before), LN_DEPTH (before));
+#if 1
+      lambda_matrix_id (LTM_MATRIX (trans), LN_DEPTH (before));
+#else
+      /* This is a 2x2 interchange matrix.  */
+      LTM_MATRIX (trans)[0][0] = 0;
+      LTM_MATRIX (trans)[0][1] = 1;
+      LTM_MATRIX (trans)[1][0] = 1;
+      LTM_MATRIX (trans)[1][1] = 0;
+#endif
+      after = lambda_loopnest_transform (before, trans);
+      if (dump_file)
+	{
+	  fprintf (dump_file, "After:\n");
+	  print_lambda_loopnest (dump_file, after, 'u');
+	}
+      lambda_loopnest_to_gcc_loopnest (loop_nest, oldivs, invariants,
+				       after, trans);
+    }
+}