This caches alias info avoiding repeated (expensive)
get_ref_base_and_extent. It doesn't address the unlimited quadraticness
in this function the PR93199 testcase runs into.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2020-01-10 Richard Biener <rguent...@suse.de>
* gimple-ssa-store-merging
(pass_store_merging::terminate_all_aliasing_chains): Cache alias info.
Index: gcc/gimple-ssa-store-merging.c
===================================================================
--- gcc/gimple-ssa-store-merging.c (revision 280096)
+++ gcc/gimple-ssa-store-merging.c (working copy)
@@ -2219,6 +2219,8 @@ pass_store_merging::terminate_all_aliasi
return false;
tree store_lhs = gimple_store_p (stmt) ? gimple_get_lhs (stmt) : NULL_TREE;
+ ao_ref store_lhs_ref;
+ ao_ref_init (&store_lhs_ref, store_lhs);
for (imm_store_chain_info *next = m_stores_head, *cur = next; cur; cur =
next)
{
next = cur->next;
@@ -2233,9 +2235,12 @@ pass_store_merging::terminate_all_aliasi
FOR_EACH_VEC_ELT (cur->m_store_info, i, info)
{
tree lhs = gimple_assign_lhs (info->stmt);
- if (ref_maybe_used_by_stmt_p (stmt, lhs)
- || stmt_may_clobber_ref_p (stmt, lhs)
- || (store_lhs && refs_output_dependent_p (store_lhs, lhs)))
+ ao_ref lhs_ref;
+ ao_ref_init (&lhs_ref, lhs);
+ if (ref_maybe_used_by_stmt_p (stmt, &lhs_ref)
+ || stmt_may_clobber_ref_p_1 (stmt, &lhs_ref)
+ || (store_lhs && refs_may_alias_p_1 (&store_lhs_ref,
+ &lhs_ref, false)))
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
