The following implements the gist of the PR100923 fix in a leaner
(and more complete) way by realizing that all ao_ref_init_from_vn_reference
uses need to have an SSA name in the base valueized with availability
in mind. Instead of re-valueizing the whole chain of operands we can
simply only and always valueize the SSA name we put in the base.
This handles also two omitted places in vn_reference_lookup_3.
Bootstrapped and tested on x86_64-unknown-linux-gnu, will push later.
Richard.
PR tree-optimization/100923
* tree-ssa-sccvn.cc (ao_ref_init_from_vn_reference): Valueize
base SSA_NAME.
(vn_reference_lookup_3): Adjust vn_context_bb around calls
to ao_ref_init_from_vn_reference.
(vn_reference_lookup_pieces): Revert original PR100923 fix.
(vn_reference_lookup): Likewise.
---
gcc/tree-ssa-sccvn.cc | 58 +++++++++++++++++++------------------------
1 file changed, 25 insertions(+), 33 deletions(-)
diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
index fbbfa557833..726e9d88b8f 100644
--- a/gcc/tree-ssa-sccvn.cc
+++ b/gcc/tree-ssa-sccvn.cc
@@ -1201,11 +1201,17 @@ ao_ref_init_from_vn_reference (ao_ref *ref,
case STRING_CST:
/* This can show up in ARRAY_REF bases. */
case INTEGER_CST:
- case SSA_NAME:
*op0_p = op->op0;
op0_p = NULL;
break;
+ case SSA_NAME:
+ /* SSA names we have to get at one available since it contains
+ flow-sensitive info. */
+ *op0_p = vn_valueize (op->op0);
+ op0_p = NULL;
+ break;
+
/* And now the usual component-reference style ops. */
case BIT_FIELD_REF:
offset += wi::to_poly_offset (op->op1);
@@ -2725,7 +2731,6 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void
*data_,
copy_reference_ops_from_ref (lhs, &lhs_ops);
valueize_refs_1 (&lhs_ops, &valueized_anything, true);
}
- vn_context_bb = saved_rpo_bb;
ao_ref_init (&lhs_ref, lhs);
lhs_ref_ok = true;
if (valueized_anything
@@ -2734,9 +2739,11 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void
*data_,
ao_ref_base_alias_set (&lhs_ref), TREE_TYPE (lhs), lhs_ops)
&& !refs_may_alias_p_1 (ref, &lhs_ref, data->tbaa_p))
{
+ vn_context_bb = saved_rpo_bb;
*disambiguate_only = TR_VALUEIZE_AND_DISAMBIGUATE;
return NULL;
}
+ vn_context_bb = saved_rpo_bb;
/* When the def is a CLOBBER we can optimistically disambiguate
against it since any overlap it would be undefined behavior.
@@ -3634,13 +3641,19 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void
*data_,
/* Adjust *ref from the new operands. */
ao_ref rhs1_ref;
ao_ref_init (&rhs1_ref, rhs1);
+ basic_block saved_rpo_bb = vn_context_bb;
+ vn_context_bb = gimple_bb (def_stmt);
if (!ao_ref_init_from_vn_reference (&r,
force_no_tbaa ? 0
: ao_ref_alias_set (&rhs1_ref),
force_no_tbaa ? 0
: ao_ref_base_alias_set (&rhs1_ref),
vr->type, vr->operands))
- return (void *)-1;
+ {
+ vn_context_bb = saved_rpo_bb;
+ return (void *)-1;
+ }
+ vn_context_bb = saved_rpo_bb;
/* This can happen with bitfields. */
if (maybe_ne (ref->size, r.size))
{
@@ -3839,8 +3852,14 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void
*data_,
return data->finish (0, 0, val);
/* Adjust *ref from the new operands. */
+ basic_block saved_rpo_bb = vn_context_bb;
+ vn_context_bb = gimple_bb (def_stmt);
if (!ao_ref_init_from_vn_reference (&r, 0, 0, vr->type, vr->operands))
- return (void *)-1;
+ {
+ vn_context_bb = saved_rpo_bb;
+ return (void *)-1;
+ }
+ vn_context_bb = saved_rpo_bb;
/* This can happen with bitfields. */
if (maybe_ne (ref->size, r.size))
return (void *)-1;
@@ -3928,31 +3947,13 @@ vn_reference_lookup_pieces (tree vuse, alias_set_type
set,
unsigned limit = param_sccvn_max_alias_queries_per_access;
vn_walk_cb_data data (&vr1, NULL_TREE, NULL, kind, true, NULL_TREE,
false);
- vec<vn_reference_op_s> ops_for_ref;
- if (!valueized_p)
- ops_for_ref = vr1.operands;
- else
- {
- /* For ao_ref_from_mem we have to ensure only available SSA names
- end up in base and the only convenient way to make this work
- for PRE is to re-valueize with that in mind. */
- ops_for_ref.create (operands.length ());
- ops_for_ref.quick_grow (operands.length ());
- memcpy (ops_for_ref.address (),
- operands.address (),
- sizeof (vn_reference_op_s)
- * operands.length ());
- valueize_refs_1 (&ops_for_ref, &valueized_p, true);
- }
if (ao_ref_init_from_vn_reference (&r, set, base_set, type,
- ops_for_ref))
+ vr1.operands))
*vnresult
= ((vn_reference_t)
walk_non_aliased_vuses (&r, vr1.vuse, true, vn_reference_lookup_2,
vn_reference_lookup_3, vuse_valueize,
limit, &data));
- if (ops_for_ref != shared_lookup_references)
- ops_for_ref.release ();
gcc_checking_assert (vr1.operands == shared_lookup_references);
if (*vnresult
&& data.same_val
@@ -4053,18 +4054,9 @@ vn_reference_lookup (tree op, tree vuse, vn_lookup_kind
kind,
vn_reference_t wvnresult;
ao_ref r;
unsigned limit = param_sccvn_max_alias_queries_per_access;
- auto_vec<vn_reference_op_s> ops_for_ref;
- if (valueized_anything)
- {
- copy_reference_ops_from_ref (op, &ops_for_ref);
- bool tem;
- valueize_refs_1 (&ops_for_ref, &tem, true);
- }
- /* Make sure to use a valueized reference if we valueized anything.
- Otherwise preserve the full reference for advanced TBAA. */
if (!valueized_anything
|| !ao_ref_init_from_vn_reference (&r, vr1.set, vr1.base_set,
- vr1.type, ops_for_ref))
+ vr1.type, vr1.operands))
{
ao_ref_init (&r, op);
/* Record the extra info we're getting from the full ref. */
--
2.35.3
