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

1 files changed, 18 insertions, 0 deletions

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);
+    }
+}