From efa26eaae377bf2a5ce9b02b84f3963a0166e280 Mon Sep 17 00:00:00 2001
From: Richard Guenther <rguenther@suse.de>
Date: Tue, 17 Apr 2012 13:42:48 +0000
Subject: [PATCH] re PR rtl-optimization/53011 (ice in verify_loop_structure:
 bad sizes)

2012-04-17  Richard Guenther  <rguenther@suse.de>

	PR middle-end/53011
	* tree-eh.c (cleanup_empty_eh_merge_phis): Properly discard
	loops when redirecting an entry or latch edge.

	* g++.dg/torture/pr53011.C: New testcase.

From-SVN: r186529
---
 gcc/ChangeLog                          |  6 +++
 gcc/testsuite/ChangeLog                |  5 ++
 gcc/testsuite/g++.dg/torture/pr53011.C | 66 ++++++++++++++++++++++++++
 gcc/tree-eh.c                          | 15 ++++++
 4 files changed, 92 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/torture/pr53011.C

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7de0e0bdcf5..e09d6724b6f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-04-17  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/53011
+	* tree-eh.c (cleanup_empty_eh_merge_phis): Properly discard
+	loops when redirecting an entry or latch edge.
+
 2012-04-17  Bernd Schmidt  <bernds@codesourcery.com>
 
 	* sel-sched.c (sel_global_init): Revert previous change.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0b6fcf50317..e1862c65b8f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-04-17  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/53011
+	* g++.dg/torture/pr53011.C: New testcase.
+
 2012-04-16  Jason Merrill  <jason@redhat.com>
 
 	PR c++/38543
diff --git a/gcc/testsuite/g++.dg/torture/pr53011.C b/gcc/testsuite/g++.dg/torture/pr53011.C
new file mode 100644
index 00000000000..2cd8a60332d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr53011.C
@@ -0,0 +1,66 @@
+// { dg-do compile }
+
+extern "C" class WvFastString;
+typedef WvFastString& WvStringParm;
+struct WvFastString {
+  ~WvFastString();
+  operator char* () {}
+};
+class WvString : WvFastString {};
+class WvAddr {};
+class WvIPAddr : WvAddr {};
+struct WvIPNet : WvIPAddr {
+  bool is_default() {}
+};
+template<class T, bool> struct WvTraits_Helper {
+  static void release(T *obj) {
+    delete obj;
+  }
+};
+template<class From> struct WvTraits {
+  static void release(From *obj) {
+    WvTraits_Helper<From, 0>::release(obj);
+  }
+};
+struct WvLink {
+  void   *data;
+  WvLink *next;
+  bool    autofree;
+  WvLink(bool, int) : autofree() {}
+  bool get_autofree() {}
+
+  void unlink() {
+    delete this;
+  }
+};
+struct WvListBase {
+  WvLink head, *tail;
+  WvListBase() : head(0, 0) {}
+};
+template<class T> struct WvList : WvListBase {
+  ~WvList() {
+    zap();
+  }
+
+  void zap(bool destroy = 1) {
+    while (head.next) unlink_after(&head, destroy);
+  }
+
+  void unlink_after(WvLink *after, bool destroy) {
+    WvLink *next = 0;
+    T *obj       = (destroy && next->get_autofree()) ? 
+                   static_cast<T*>(next->data) : 0;
+
+    if (tail) tail = after;
+    next->unlink();
+    WvTraits<T>::release(obj);
+  }
+};
+typedef WvList<WvString>WvStringListBase;
+class WvStringList : WvStringListBase {};
+class WvSubProc {
+  WvStringList last_args, env;
+};
+void addroute(WvIPNet& dest, WvStringParm table) {
+  if (dest.is_default() || (table != "default")) WvSubProc checkProc;
+}
diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c
index ba188d85a77..0241a5f1bc4 100644
--- a/gcc/tree-eh.c
+++ b/gcc/tree-eh.c
@@ -3916,6 +3916,21 @@ cleanup_empty_eh_merge_phis (basic_block new_bb, basic_block old_bb,
   for (ei = ei_start (old_bb->preds); (e = ei_safe_edge (ei)); )
     if (e->flags & EDGE_EH)
       {
+	/* ???  CFG manipluation routines do not try to update loop
+	   form on edge redirection.  Do so manually here for now.  */
+	/* If we redirect a loop entry or latch edge that will either create
+	   a multiple entry loop or rotate the loop.  If the loops merge
+	   we may have created a loop with multiple latches.
+	   All of this isn't easily fixed thus cancel the affected loop
+	   and mark the other loop as possibly having multiple latches.  */
+	if (current_loops
+	    && e->dest == e->dest->loop_father->header)
+	  {
+	    e->dest->loop_father->header = NULL;
+	    e->dest->loop_father->latch = NULL;
+	    new_bb->loop_father->latch = NULL;
+	    loops_state_set (LOOPS_NEED_FIXUP|LOOPS_MAY_HAVE_MULTIPLE_LATCHES);
+	  }
 	redirect_eh_edge_1 (e, new_bb, change_region);
 	redirect_edge_succ (e, new_bb);
 	flush_pending_stmts (e);