diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index af48a1cb5c5..cb041e05585 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-17  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/46498
+	* tree-ssa-dce.c (perform_tree_ssa_dce): Compute dominator info.
+
 2010-11-16  Nathan Froyd  <froydnj@codesourcery.com>
 
 	* config/xtensa/xtensa.c (function_arg_boundary): Really rename to...
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index a1a51914fa6..a9c886f0a8f 100644
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -1408,6 +1408,8 @@ perform_tree_ssa_dce (bool aggressive)
   struct edge_list *el = NULL;
   bool something_changed = 0;
 
+  calculate_dominance_info (CDI_DOMINATORS);
+
   /* Preheaders are needed for SCEV to work.
      Simple lateches and recorded exits improve chances that loop will
      proved to be finite in testcases such as in loop-15.c and loop-24.c  */