PR middle-end/44777

	* profile.c (branch_prob): Split bbs that have exit edge
	and need a fake entry edge too.

	* gcc.dg/tree-prof/pr44777.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@182920 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 90 insertions, 1 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1e612427ebf..9cbe9c0ffb6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-01-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/44777
+	* profile.c (branch_prob): Split bbs that have exit edge
+	and need a fake entry edge too.
+
 2012-01-05  Jan Hubicka  <jh@suse.cz>
 
 	PR middle-end/49710
diff --git a/gcc/profile.c b/gcc/profile.c
index 201f6cd3c32..10ab756d567 100644
--- a/gcc/profile.c
+++ b/gcc/profile.c
@@ -1,6 +1,6 @@
 /* Calculate branch probabilities, and basic block execution counts.
    Copyright (C) 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998, 1999,
-   2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
+   2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012
    Free Software Foundation, Inc.
    Contributed by James E. Wilson, UC Berkeley/Cygnus Support;
    based on some ideas from Dain Samples of UC Berkeley.
@@ -1040,6 +1040,41 @@ branch_prob (void)
 	    fprintf (dump_file, "Adding fake entry edge to bb %i\n",
 		     bb->index);
 	  make_edge (ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
+	  /* Avoid bbs that have both fake entry edge and also some
+	     exit edge.  One of those edges wouldn't be added to the
+	     spanning tree, but we can't instrument any of them.  */
+	  if (have_exit_edge || need_exit_edge)
+	    {
+	      gimple_stmt_iterator gsi;
+	      gimple first;
+	      tree fndecl;
+
+	      gsi = gsi_after_labels (bb);
+	      gcc_checking_assert (!gsi_end_p (gsi));
+	      first = gsi_stmt (gsi);
+	      if (is_gimple_debug (first))
+		{
+		  gsi_next_nondebug (&gsi);
+		  gcc_checking_assert (!gsi_end_p (gsi));
+		  first = gsi_stmt (gsi);
+		}
+	      /* Don't split the bbs containing __builtin_setjmp_receiver
+		 or __builtin_setjmp_dispatcher calls.  These are very
+		 special and don't expect anything to be inserted before
+		 them.  */
+	      if (!is_gimple_call (first)
+		  || (fndecl = gimple_call_fndecl (first)) == NULL
+		  || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL
+		  || (DECL_FUNCTION_CODE (fndecl) != BUILT_IN_SETJMP_RECEIVER
+		      && (DECL_FUNCTION_CODE (fndecl)
+			  != BUILT_IN_SETJMP_DISPATCHER)))
+		{
+		  if (dump_file)
+		    fprintf (dump_file, "Splitting bb %i after labels\n",
+			     bb->index);
+		  split_block_after_labels (bb);
+		}
+	    }
 	}
     }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d324db6a2e3..d35dab996b5 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-01-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/44777
+	* gcc.dg/tree-prof/pr44777.c: New test.
+
 2012-01-05  Jan Hubicka  <jh@suse.cz>
 
 	PR middle-end/49710
diff --git a/gcc/testsuite/gcc.dg/tree-prof/pr44777.c b/gcc/testsuite/gcc.dg/tree-prof/pr44777.c
new file mode 100644
index 00000000000..1c4da7f5f7d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-prof/pr44777.c
@@ -0,0 +1,43 @@
+/* PR middle-end/44777 */
+/* { dg-options "-O0" } */
+/* A variant of gcc.c-torture/execute/comp-goto-2.c.  */
+
+extern void abort (void);
+extern void exit (int);
+
+#ifdef STACK_SIZE
+#define DEPTH ((STACK_SIZE) / 512 + 1)
+#else
+#define DEPTH 1000
+#endif
+
+#if ! defined (NO_LABEL_VALUES) && !defined (NO_TRAMPOLINES)
+int
+x (int a)
+{
+  __label__ xlab;
+  void y (int a)
+    {
+      void *x = &&llab;
+      if (a==-1)
+	goto *x;
+      if (a==0)
+	goto xlab;
+    llab:
+      y (a-1);
+    }
+  y (a);
+ xlab:;
+  return a;
+}
+#endif
+
+int
+main ()
+{
+#if ! defined (NO_LABEL_VALUES) && !defined (NO_TRAMPOLINES)
+  if (x (DEPTH) != DEPTH)
+    abort ();
+#endif
+  exit (0);
+}