2008-02-04 Richard Guenther <rguenther@suse.de>

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

diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index fdce4be..40e7051 100644 (file)
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -5,7 +5,7 @@ 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
+Free 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
@@ -14,9 +14,8 @@ 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
-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 "system.h"
@@ -1674,7 +1673,7 @@ simplify_using_outer_evolutions (struct loop *loop, tree expr)
 /* Returns true if EXIT is the only possible exit from LOOP.  */
 
 static bool
-loop_only_exit_p (struct loop *loop, edge exit)
+loop_only_exit_p (const struct loop *loop, const_edge exit)
 {
   basic_block *body;
   block_stmt_iterator bsi;
@@ -2172,7 +2171,7 @@ find_loop_niter_by_eval (struct loop *loop, edge *exit)
    be nonnegative.  */
  
 static double_int
-derive_constant_upper_bound (tree val)
+derive_constant_upper_bound (const_tree val)
 {
   tree type = TREE_TYPE (val);
   tree op0, op1, subtype, maxt;
@@ -2970,8 +2969,7 @@ scev_probably_wraps_p (tree base, tree step,
      2032, 2040, 0, 8, ..., but the code is still legal.  */
 
   if (chrec_contains_undetermined (base)
-      || chrec_contains_undetermined (step)
-      || TREE_CODE (step) != INTEGER_CST)
+      || chrec_contains_undetermined (step))
     return true;
 
   if (integer_zerop (step))
@@ -2982,6 +2980,11 @@ scev_probably_wraps_p (tree base, tree step,
   if (use_overflow_semantics && nowrap_type_p (type))
     return false;
 
+  /* To be able to use estimates on number of iterations of the loop,
+     we must have an upper bound on the absolute value of the step.  */
+  if (TREE_CODE (step) != INTEGER_CST)
+    return true;
+
   /* Don't issue signed overflow warnings.  */
   fold_defer_overflow_warnings ();