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[PATCH] Fix RPO VN region boundary check
- From: Richard Biener <rguenther at suse dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Wed, 29 Aug 2018 17:01:24 +0200 (CEST)
- Subject: [PATCH] Fix RPO VN region boundary check
The following moves the region boundary check for alias stmt walking
where it is effective.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2018-08-29 Richard Biener <rguenther@suse.de>
* tree-ssa-sccvn.c (vuse_ssa_val): Return NULL for unvisited
virtual operands that are not default defs to honor region
boundaries.
(rpo_vn_valueize): Remove ineffective code here.
Index: gcc/tree-ssa-sccvn.c
===================================================================
--- gcc/tree-ssa-sccvn.c (revision 263945)
+++ gcc/tree-ssa-sccvn.c (working copy)
@@ -475,12 +474,16 @@ vuse_ssa_val (tree x)
do
{
- tree tem = SSA_VAL (x);
- /* stmt walking can walk over a backedge and reach code we didn't
- value-number yet. */
- if (tem == VN_TOP)
+ if (SSA_NAME_IS_DEFAULT_DEF (x))
return x;
- x = tem;
+ vn_ssa_aux_t tem
+ = vn_ssa_aux_hash->find_with_hash (x, SSA_NAME_VERSION (x));
+ /* For region-based VN this makes walk_non_aliased_vuses stop walking
+ when we are about to look at a def outside of the region. */
+ if (!tem || !tem->visited)
+ return NULL_TREE;
+ gcc_assert (tem->valnum != VN_TOP);
+ x = tem->valnum;
}
while (SSA_NAME_IN_FREE_LIST (x));
@@ -5797,11 +5755,6 @@ rpo_vn_valueize (tree name)
if (TREE_CODE (name) == SSA_NAME)
{
vn_ssa_aux_t val = VN_INFO (name);
- /* For region-based VN this makes walk_non_aliased_vuses stop walking
- when we are about to look at a def outside of the region. */
- if (SSA_NAME_IS_VIRTUAL_OPERAND (name)
- && !val->visited)
- return NULL_TREE;
if (val)
{
tree tem = val->valnum;