From: Richard Biener <rguenther@suse.de>
Date: Thu, 20 Dec 2012 12:45:48 +0000 (+0000)
Subject: re PR rtl-optimization/55740 (ICE in verify_loop_structure, at cfgloop.c:1582, error... 
X-Git-Tag: releases/gcc-4.8.0~1297
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=63f2ff0f23d633aad769997ec617ce2177c311ec;p=thirdparty%2Fgcc.git

re PR rtl-optimization/55740 (ICE in verify_loop_structure, at cfgloop.c:1582, error: loop 2's header does not belong directly to it)

2012-12-20  Richard Biener  <rguenther@suse.de>

	PR middle-end/55740
	* cfghooks.c (merge_blocks): Properly handle merging of
	two loop headers.

	* g++.dg/torture/pr55740.C: New testcase.

From-SVN: r194633
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6d385605b629..01ed19b18258 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-12-20  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/55740
+	* cfghooks.c (merge_blocks): Properly handle merging of
+	two loop headers.
+
 2012-12-20  Roland Stigge  <stigge@debian.org>
 	    Matthias Klose  <doko@ubuntu.com>
 
diff --git a/gcc/cfghooks.c b/gcc/cfghooks.c
index f09573160625..b729ae00504e 100644
--- a/gcc/cfghooks.c
+++ b/gcc/cfghooks.c
@@ -724,11 +724,23 @@ merge_blocks (basic_block a, basic_block b)
 
   cfg_hooks->merge_blocks (a, b);
 
-  /* If we merge a loop header into its predecessor, update the loop
-     structure.  */
   if (current_loops != NULL)
     {
-      if (b->loop_father->header == b)
+      /* If the block we merge into is a loop header do nothing unless ... */
+      if (a->loop_father->header == a)
+	{
+	  /* ... we merge two loop headers, in which case we kill
+	     the inner loop.  */
+	  if (b->loop_father->header == b)
+	    {
+	      b->loop_father->header = NULL;
+	      b->loop_father->latch = NULL;
+	      loops_state_set (LOOPS_NEED_FIXUP);
+	    }
+	}
+      /* If we merge a loop header into its predecessor, update the loop
+	 structure.  */
+      else if (b->loop_father->header == b)
 	{
 	  remove_bb_from_loops (a);
 	  add_bb_to_loop  (a, b->loop_father);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 1b7c851df383..1f401cd7ac77 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-12-20  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/55740
+	* g++.dg/torture/pr55740.C: New testcase.
+
 2012-12-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/55619
diff --git a/gcc/testsuite/g++.dg/torture/pr55740.C b/gcc/testsuite/g++.dg/torture/pr55740.C
new file mode 100644
index 000000000000..cdd84254399a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr55740.C
@@ -0,0 +1,19 @@
+// { dg-do compile }
+
+static bool st_IsPathDelimiter( char c ) { return c == '/'; }
+bool IsValidPath( char const * filename )
+{
+  if ( !filename || filename[0] == 0 )     
+    return false;
+  char const * run = filename;
+  while ( run && *run )       
+    {
+      if ( run[0] == '.' )   
+	if ( run[1] != '.' || ( !st_IsPathDelimiter( run[2] ) && run[2] != 0 ) )   
+	  return false;   
+      while ( *run && !st_IsPathDelimiter( *run ) )
+	++run;
+      if ( *run ) 
+	++run;
+    }
+}