Index: gcc/tree-ssa-dom.c
===================================================================
--- gcc/tree-ssa-dom.c	(revision 195530)
+++ gcc/tree-ssa-dom.c	(working copy)
@@ -3006,7 +3006,12 @@ eliminate_degenerate_phis (void)
     }
 
   if (cfg_altered)
-    free_dominance_info (CDI_DOMINATORS);
+    {
+      free_dominance_info (CDI_DOMINATORS);
+      /* If we changed the CFG schedule loops for fixup by cfgcleanup.  */
+      if (current_loops)
+	loops_state_set (LOOPS_NEED_FIXUP);
+    }
 
   /* Propagation of const and copies may make some EH edges dead.  Purge
      such edges from the CFG as needed.  */
Index: gcc/testsuite/gcc.dg/torture/pr55270.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr55270.c	(revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr55270.c	(working copy)
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+
+unsigned a, b, c;
+
+void f(void)
+{
+  for(; a; a++)
+    {
+      long *p1 = (long *)&b;
+
+      if(*p1)
+	return;
+
+      if(b && (*p1 = b) || c && ++*p1)
+	{
+	  unsigned *p2 = &b;
+
+	  for(*p2 = 0; *p2 < 1;)
+	    for(; b; b++);
+	}
+    }
+}