This re-instantiates the patch I had to revert earlier, doing it in
a safer way. We record the original ref so we can do an additional
disambiguation during vn_reference_lookup_3.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
Richard.
2019-07-08 Richard Biener <rguent...@suse.de>
* tree-ssa-sccvn.c (struct vn_walk_cb_data): Add orig_ref member.
(vn_reference_lookup_3): If the main ref has no access path recorded
but orig_ref has use it to do access-path based disambiguation.
(vn_reference_lookup_pieces): Adjust.
(vn_reference_lookup): Pass down original ref if we valueized.
* gcc.dg/tree-ssa/alias-access-path-1.c: Scan fre1 dump.
* gcc.dg/tree-ssa/alias-access-path-2.c: Likewise.
* gcc.dg/tree-ssa/alias-access-path-8.c: Likewise.
Index: gcc/tree-ssa-sccvn.c
===================================================================
--- gcc/tree-ssa-sccvn.c (revision 273232)
+++ gcc/tree-ssa-sccvn.c (working copy)
@@ -1670,15 +1670,18 @@ struct pd_data
struct vn_walk_cb_data
{
- vn_walk_cb_data (vn_reference_t vr_, tree *last_vuse_ptr_,
+ vn_walk_cb_data (vn_reference_t vr_, tree orig_ref_, tree *last_vuse_ptr_,
vn_lookup_kind vn_walk_kind_, bool tbaa_p_)
- : vr (vr_), last_vuse_ptr (last_vuse_ptr_), vn_walk_kind (vn_walk_kind_),
- tbaa_p (tbaa_p_), known_ranges (NULL)
- {}
+ : vr (vr_), last_vuse_ptr (last_vuse_ptr_),
+ vn_walk_kind (vn_walk_kind_), tbaa_p (tbaa_p_), known_ranges (NULL)
+ {
+ ao_ref_init (&orig_ref, orig_ref_);
+ }
~vn_walk_cb_data ();
void *push_partial_def (const pd_data& pd, tree, HOST_WIDE_INT);
vn_reference_t vr;
+ ao_ref orig_ref;
tree *last_vuse_ptr;
vn_lookup_kind vn_walk_kind;
bool tbaa_p;
@@ -2246,6 +2249,28 @@ vn_reference_lookup_3 (ao_ref *ref, tree
lhs_ref_ok = true;
}
+ /* Besides valueizing the LHS we can also use access-path based
+ disambiguation on the original non-valueized ref. */
+ if (!ref->ref
+ && lhs_ref_ok
+ && data->orig_ref.ref)
+ {
+ /* We want to use the non-valueized LHS for this, but avoid redundant
+ work. */
+ ao_ref *lref = &lhs_ref;
+ ao_ref lref_alt;
+ if (valueized_anything)
+ {
+ ao_ref_init (&lref_alt, lhs);
+ lref = &lref_alt;
+ }
+ if (!refs_may_alias_p_1 (&data->orig_ref, lref, data->tbaa_p))
+ {
+ *disambiguate_only = true;
+ return NULL;
+ }
+ }
+
/* If we reach a clobbering statement try to skip it and see if
we find a VN result with exactly the same value as the
possible clobber. In this case we can ignore the clobber
@@ -2983,7 +3008,7 @@ vn_reference_lookup_pieces (tree vuse, a
{
ao_ref r;
unsigned limit = PARAM_VALUE (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS);
- vn_walk_cb_data data (&vr1, NULL, kind, true);
+ vn_walk_cb_data data (&vr1, NULL_TREE, NULL, kind, true);
if (ao_ref_init_from_vn_reference (&r, set, type, vr1.operands))
*vnresult =
(vn_reference_t)walk_non_aliased_vuses (&r, vr1.vuse, true,
@@ -3040,7 +3065,8 @@ vn_reference_lookup (tree op, tree vuse,
|| !ao_ref_init_from_vn_reference (&r, vr1.set, vr1.type,
vr1.operands))
ao_ref_init (&r, op);
- vn_walk_cb_data data (&vr1, last_vuse_ptr, kind, tbaa_p);
+ vn_walk_cb_data data (&vr1, r.ref ? NULL_TREE : op,
+ last_vuse_ptr, kind, tbaa_p);
wvnresult =
(vn_reference_t)walk_non_aliased_vuses (&r, vr1.vuse, tbaa_p,
vn_reference_lookup_2,
Index: gcc/testsuite/gcc.dg/tree-ssa/alias-access-path-1.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/alias-access-path-1.c (revision 273232)
+++ gcc/testsuite/gcc.dg/tree-ssa/alias-access-path-1.c (working copy)
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-fre3" } */
+/* { dg-options "-O2 -fdump-tree-fre1" } */
struct foo
{
int val;
@@ -18,4 +18,4 @@ test ()
return barptr->val2;
}
-/* { dg-final { scan-tree-dump-times "return 123" 1 "fre3"} } */
+/* { dg-final { scan-tree-dump-times "return 123" 1 "fre1"} } */
Index: gcc/testsuite/gcc.dg/tree-ssa/alias-access-path-2.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/alias-access-path-2.c (revision 273232)
+++ gcc/testsuite/gcc.dg/tree-ssa/alias-access-path-2.c (working copy)
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-fre3" } */
+/* { dg-options "-O2 -fdump-tree-fre1" } */
struct a {
int val;
};
@@ -19,4 +19,4 @@ test (int i, int j, int k, int l)
dptr->c.b[k].a2[l].val=2;
return cptr->b[i].a[j].val;
}
-/* { dg-final { scan-tree-dump-times "return 123" 1 "fre3"} } */
+/* { dg-final { scan-tree-dump-times "return 123" 1 "fre1"} } */
Index: gcc/testsuite/gcc.dg/tree-ssa/alias-access-path-8.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/alias-access-path-8.c (revision 273232)
+++ gcc/testsuite/gcc.dg/tree-ssa/alias-access-path-8.c (working copy)
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-fre3" } */
+/* { dg-options "-O2 -fdump-tree-fre1" } */
struct a {
int val;
};
@@ -18,4 +18,4 @@ test (int i, int j, int k, int l)
cptr2->b[k].a2[l].val=2;
return cptr->b[i].a[j].val;
}
-/* { dg-final { scan-tree-dump-times "return 123" 1 "fre3"} } */
+/* { dg-final { scan-tree-dump-times "return 123" 1 "fre1"} } */
