re PR middle-end/21846 (segfault in fold_binary compiling vpr with -O2 -funroll-loops)

	PR tree-optimization/21846
	* tree-cfg.c (replace_uses_by): Update information stored at loops.
	* tree-flow.h (substitute_in_loop_info): Declare.
	* tree-scalar-evolution.c (initialize_scalar_evolutions_analyzer):
	Ensure that chrec_dont_know and chrec_known have a type.
	* tree-ssa-loop-niter.c (substitute_in_loop_info): New function.

From-SVN: r100631

5 files changed, 43 insertions, 2 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d0a38c6..50916ee 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2005-06-05  Zdenek Dvorak  <dvorakz@suse.cz>
+
+	PR tree-optimization/21846
+	* tree-cfg.c (replace_uses_by): Update information stored at loops.
+	* tree-flow.h (substitute_in_loop_info): Declare.
+	* tree-scalar-evolution.c (initialize_scalar_evolutions_analyzer):
+	Ensure that chrec_dont_know and chrec_known have a type.
+	* tree-ssa-loop-niter.c (substitute_in_loop_info): New function.
+
 2005-06-05  Steven Bosscher  <stevenb@suse.de>
 
 	* config/i386/i386.c (x86_use_loop): Remove.
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 2776f21..6108dd8 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -1264,6 +1264,19 @@ replace_uses_by (tree name, tree val)
     }
 
   VEC_free (tree, heap, stmts);
+
+  /* Also update the trees stored in loop structures.  */
+  if (current_loops)
+    {
+      struct loop *loop;
+
+      for (i = 0; i < current_loops->num; i++)
+	{
+	  loop = current_loops->parray[i];
+	  if (loop)
+	    substitute_in_loop_info (loop, name, val);
+	}
+    }
 }
 
 /* Merge block B into block A.  */
diff --git a/gcc/tree-flow.h b/gcc/tree-flow.h
index 584e42b..51a2051 100644
--- a/gcc/tree-flow.h
+++ b/gcc/tree-flow.h
@@ -679,6 +679,7 @@ bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
 				    basic_block *);
 tree expand_simple_operations (tree);
+void substitute_in_loop_info (struct loop *, tree, tree);
 
 /* In tree-ssa-loop-im.c  */
 /* The possibilities of statement movement.  */
diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c
index 82cbc2f..2753186 100644
--- a/gcc/tree-scalar-evolution.c
+++ b/gcc/tree-scalar-evolution.c
@@ -2503,8 +2503,8 @@ initialize_scalar_evolutions_analyzer (void)
       chrec_not_analyzed_yet = NULL_TREE;
       chrec_dont_know = make_node (SCEV_NOT_KNOWN);
       chrec_known = make_node (SCEV_KNOWN);
-      TREE_TYPE (chrec_dont_know) = NULL_TREE;
-      TREE_TYPE (chrec_known) = NULL_TREE;
+      TREE_TYPE (chrec_dont_know) = void_type_node;
+      TREE_TYPE (chrec_known) = void_type_node;
     }
 }
 
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index 38f7b42..78f14e9 100644
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -1600,3 +1600,21 @@ free_numbers_of_iterations_estimates (struct loops *loops)
 	free_numbers_of_iterations_estimates_loop (loop);
     }
 }
+
+/* Substitute value VAL for ssa name NAME inside expressions held
+   at LOOP.  */
+
+void
+substitute_in_loop_info (struct loop *loop, tree name, tree val)
+{
+  struct nb_iter_bound *bound;
+
+  loop->nb_iterations = simplify_replace_tree (loop->nb_iterations, name, val);
+  loop->estimated_nb_iterations
+	  = simplify_replace_tree (loop->estimated_nb_iterations, name, val);
+  for (bound = loop->bounds; bound; bound = bound->next)
+    {
+      bound->bound = simplify_replace_tree (bound->bound, name, val);
+      bound->additional = simplify_replace_tree (bound->additional, name, val);
+    }
+}