2007-05-30 Frank Ch. Eigler <fche@redhat.com>

	PR 4567.
	* staptree.cxx (varuse_collecting_visitor): Add side-effect
	result query functions.
	* elaborate.cxx (dead_stmtexpr_remover::visit_expr_statement):
	Switch to it.
	(dead_assignment_remover::visit_assignment): Skip elision of
	lvalues with side-effects in index exprs.
	* staptree.h: Corresponding changes.

2007-05-30  Frank Ch. Eigler  <fche@redhat.com>

	PR 4567.
	* systemtap.base/optim.stp, optim.exp: New test.

1 files changed, 3 insertions, 1 deletions

diff --git a/staptree.h b/staptree.h
index b63c6c33..0ba8c657 100644
--- a/staptree.h
+++ b/staptree.h
@@ -723,8 +723,10 @@ struct varuse_collecting_visitor: public functioncall_traversing_visitor
   void visit_pre_crement (pre_crement *e);
   void visit_post_crement (post_crement *e);
   void visit_foreach_loop (foreach_loop *s);
-};
 
+  bool side_effect_free ();
+  bool side_effect_free_wrt (const std::set<vardecl*>& vars);
+};