From 92562f8869378b0fd06de4e1d695d89d8a6ca0b4 Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Wed, 23 Apr 2014 08:23:33 +0000
Subject: [PATCH] re PR tree-optimization/60891 (ICE: SIGSEGV (Invalid
 write/read) in pre_and_rev_post_order_compute_fn with -O -fno-tree-ch
 -fno-tree-cselim -fno-tree-dominator-opts)

2014-04-23  Richard Biener  <rguenther@suse.de>

	PR middle-end/60891
	* loop-init.c (loop_optimizer_init): Make sure to apply
	LOOPS_MAY_HAVE_MULTIPLE_LATCHES before fixing up loops.

	* gcc.dg/torture/pr60891.c: New testcase.

From-SVN: r209673
---
 gcc/ChangeLog                          |  6 ++++++
 gcc/loop-init.c                        | 17 ++++++++++-------
 gcc/testsuite/ChangeLog                |  5 +++++
 gcc/testsuite/gcc.dg/torture/pr60891.c | 23 +++++++++++++++++++++++
 4 files changed, 44 insertions(+), 7 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr60891.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 10980896060..bac9f35fa7e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2014-04-23  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/60891
+	* loop-init.c (loop_optimizer_init): Make sure to apply
+	LOOPS_MAY_HAVE_MULTIPLE_LATCHES before fixing up loops.
+
 2014-04-22  Jakub Jelinek  <jakub@redhat.com>
 
 	PR sanitizer/60275
diff --git a/gcc/loop-init.c b/gcc/loop-init.c
index 90453f67eca..59f52d0f29b 100644
--- a/gcc/loop-init.c
+++ b/gcc/loop-init.c
@@ -94,20 +94,15 @@ loop_optimizer_init (unsigned flags)
   else
     {
       bool recorded_exits = loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS);
+      bool needs_fixup = loops_state_satisfies_p (LOOPS_NEED_FIXUP);
 
       gcc_assert (cfun->curr_properties & PROP_loops);
 
       /* Ensure that the dominators are computed, like flow_loops_find does.  */
       calculate_dominance_info (CDI_DOMINATORS);
 
-      if (loops_state_satisfies_p (LOOPS_NEED_FIXUP))
-	{
-	  loops_state_clear (~0U);
-	  fix_loop_structure (NULL);
-	}
-
 #ifdef ENABLE_CHECKING
-      else
+      if (!needs_fixup)
 	verify_loop_structure ();
 #endif
 
@@ -115,6 +110,14 @@ loop_optimizer_init (unsigned flags)
       if (recorded_exits)
 	release_recorded_exits ();
       loops_state_clear (~0U);
+
+      if (needs_fixup)
+	{
+	  /* Apply LOOPS_MAY_HAVE_MULTIPLE_LATCHES early as fix_loop_structure
+	     re-applies flags.  */
+	  loops_state_set (flags & LOOPS_MAY_HAVE_MULTIPLE_LATCHES);
+	  fix_loop_structure (NULL);
+	}
     }
 
   /* Apply flags to loops.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index abbd1cfee87..8f1bfc6bee3 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2014-04-23  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/60891
+	* gcc.dg/torture/pr60891.c: New testcase.
+
 2014-04-22  Jakub Jelinek  <jakub@redhat.com>
 
 	PR sanitizer/60275
diff --git a/gcc/testsuite/gcc.dg/torture/pr60891.c b/gcc/testsuite/gcc.dg/torture/pr60891.c
new file mode 100644
index 00000000000..c8fec87ea8c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr60891.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-fno-tree-ch -fno-tree-cselim -fno-tree-dominator-opts" } */
+
+int a, b, c, d, e, f;
+
+void foo (int x)
+{
+  for (;;)
+    {
+      int g = c;
+      if (x)
+	{
+	  if (e)
+	    while (a)
+	      --f;
+	}
+      for (b = 5; b; b--)
+	{
+	}
+      if (!g)
+	x = 0;
+    }
+}