From 256b8b105850ed2121753037193b72d583373777 Mon Sep 17 00:00:00 2001 From: law Date: Fri, 6 Sep 2013 17:41:48 +0000 Subject: * tree-ssa-dom.c (cprop_into_successor_phis): Also propagate edge implied equivalences into successor phis. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@202345 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/tree-ssa-dom.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'gcc/tree-ssa-dom.c') diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c index 691e6f905a2..f999a648e26 100644 --- a/gcc/tree-ssa-dom.c +++ b/gcc/tree-ssa-dom.c @@ -1642,6 +1642,28 @@ cprop_into_successor_phis (basic_block bb) if (gsi_end_p (gsi)) continue; + /* We may have an equivalence associated with this edge. While + we can not propagate it into non-dominated blocks, we can + propagate them into PHIs in non-dominated blocks. */ + + /* Push the unwind marker so we can reset the const and copies + table back to its original state after processing this edge. */ + const_and_copies_stack.safe_push (NULL_TREE); + + /* Extract and record any simple NAME = VALUE equivalences. + + Don't bother with [01] = COND equivalences, they're not useful + here. */ + struct edge_info *edge_info = (struct edge_info *) e->aux; + if (edge_info) + { + tree lhs = edge_info->lhs; + tree rhs = edge_info->rhs; + + if (lhs && TREE_CODE (lhs) == SSA_NAME) + record_const_or_copy (lhs, rhs); + } + indx = e->dest_idx; for ( ; !gsi_end_p (gsi); gsi_next (&gsi)) { @@ -1667,6 +1689,8 @@ cprop_into_successor_phis (basic_block bb) && may_propagate_copy (orig_val, new_val)) propagate_value (orig_p, new_val); } + + restore_vars_to_original_value (); } } -- cgit v1.2.1