re PR tree-optimization/47086 (ICE: verify_flow_info failed: BB 3 can not throw…

re PR tree-optimization/47086 (ICE: verify_flow_info failed: BB 3 can not throw but has an EH edge with -O -fexceptions -fnon-call-exceptions -ftrapv)


	* PR tree-optimization/47086
	* tree-ssa-loop-ivopts.c (find_givs_in_stmt_scev): Do not record
	IVs from statements that might throw.

	* PR tree-optimization/47086
	* gcc.dg/pr47086.c: New test.

From-SVN: r168659

gcc/ChangeLog

+2011-01-11  Jeff Law  <law@redhat.com>
+
+	* PR tree-optimization/47086
+	* tree-ssa-loop-ivopts.c (find_givs_in_stmt_scev): Do not record
+	IVs from statements that might throw.
+
 2011-01-10  Jan Hubicka  <jh@suse.cz>
 
 	PR lto/45375

gcc/testsuite/ChangeLog

+2011-01-11  Jeff Law <law@redhat.com>
+
+	* PR tree-optimization/47086
+	* gcc.dg/pr47086.c: New test.
+
 2011-01-11  Jason Merrill  <jason@redhat.com>
 
 	PR c++/46658

gcc/testsuite/gcc.dg/pr47086.c

+/* { dg-do compile } */
+/* { dg-options "-O -fexceptions -fnon-call-exceptions -ftrapv" } */
+
+void
+foo ()
+{
+  int n = 0;
+  while (1)
+    {
+      int i[n % 1];
+      n++;
+    }
+}
+

gcc/tree-ssa-loop-ivopts.c

 /* Induction variable optimizations.
-   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -1102,6 +1102,12 @@ find_givs_in_stmt_scev (struct ivopts_data *data, gimple stmt, affine_iv *iv)
       || contains_abnormal_ssa_name_p (iv->step))
     return false;
 
+  /* If STMT could throw, then do not consider STMT as defining a GIV.  
+     While this will suppress optimizations, we can not safely delete this
+     GIV and associated statements, even if it appears it is not used.  */
+  if (stmt_could_throw_p (stmt))
+    return false;
+
   return true;
 }