PR tree-optimization/51683

[thirdparty/gcc.git] / gcc / tree-ssa-propagate.c

diff --git a/gcc/tree-ssa-propagate.c b/gcc/tree-ssa-propagate.c
index 80b33e11d80ec16a77de893a5c29756f991559a7..a057ad72bed58bf5b020b7d5973b812383b647e9 100644 (file)
--- a/gcc/tree-ssa-propagate.c
+++ b/gcc/tree-ssa-propagate.c
@@ -1,5 +1,5 @@
 /* Generic SSA value propagation engine.
-   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
+   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
    Free Software Foundation, Inc.
    Contributed by Diego Novillo <dnovillo@redhat.com>
 
@@ -1056,6 +1056,12 @@ substitute_and_fold (ssa_prop_get_value_fn get_value_fn,
          }
        else if (is_gimple_call (def_stmt))
          {
+           int flags = gimple_call_flags (def_stmt);
+
+           /* Don't optimize away calls that have side-effects.  */
+           if ((flags & (ECF_CONST|ECF_PURE)) == 0
+               || (flags & ECF_LOOPING_CONST_OR_PURE))
+             continue;
            if (update_call_from_tree (&gsi, val)
                && maybe_clean_or_replace_eh_stmt (def_stmt, gsi_stmt (gsi)))
              gimple_purge_dead_eh_edges (gimple_bb (gsi_stmt (gsi)));