* 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.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@168659 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e565b2e..b372b6c 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+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

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 64f7ad0..710431c 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+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

diff --git a/gcc/testsuite/gcc.dg/pr47086.c b/gcc/testsuite/gcc.dg/pr47086.c
new file mode 100644 (file)
index 0000000..71743fe
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr47086.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fexceptions -fnon-call-exceptions -ftrapv" } */
+
+void
+foo ()
+{
+  int n = 0;
+  while (1)
+    {
+      int i[n % 1];
+      n++;
+    }
+}
+

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 59e2fef..479b46f 100644 (file)
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -1,5 +1,5 @@
 /* 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;
 }