Hi, this patch fixes if (deref) that is reversed in merge_call_lhs_flags. I re-run stats on cc1plus that seems comparable to last run.
Bootstrapped/regtested x86_64-linux. Alias oracle query stats: refs_may_alias_p: 66575703 disambiguations, 76462658 queries ref_maybe_used_by_call_p: 364568 disambiguations, 67280898 queries call_may_clobber_ref_p: 217587 disambiguations, 221304 queries nonoverlapping_component_refs_p: 0 disambiguations, 36514 queries nonoverlapping_refs_since_match_p: 17351 disambiguations, 61127 must overlaps, 79253 queries aliasing_component_refs_p: 64537 disambiguations, 2076259 queries TBAA oracle: 24082735 disambiguations 57590168 queries 11651231 are in alias set 0 10865812 queries asked about the same object 132 queries asked about the same alias set 0 access volatile 9473619 are dependent in the DAG 1516639 are aritificially in conflict with void * Modref stats: modref use: 13892 disambiguations, 409262 queries modref clobber: 1358267 disambiguations, 15950909 queries 3287388 tbaa queries (0.206094 per modref query) 519328 base compares (0.032558 per modref query) PTA query stats: pt_solution_includes: 11809203 disambiguations, 19340135 queries pt_solutions_intersect: 1217666 disambiguations, 13770732 queries gcc/ChangeLog: 2021-03-29 Jan Hubicka <hubi...@ucw.cz> * ipa-modref.c (merge_call_lhs_flags): Correct handling of deref. (analyze_ssa_name_flags): Fix typo in comment. gcc/testsuite/ChangeLog: 2021-03-29 Jan Hubicka <hubi...@ucw.cz> * gcc.c-torture/compile/pr99751.c: New test. diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c index 7aaf53be8f4..5f33bb5b410 100644 --- a/gcc/ipa-modref.c +++ b/gcc/ipa-modref.c @@ -1545,9 +1545,9 @@ merge_call_lhs_flags (gcall *call, int arg, int index, bool deref, tree lhs = gimple_call_lhs (call); analyze_ssa_name_flags (lhs, lattice, depth + 1, ipa); if (deref) - lattice[index].merge (lattice[SSA_NAME_VERSION (lhs)]); - else lattice[index].merge_deref (lattice[SSA_NAME_VERSION (lhs)], false); + else + lattice[index].merge (lattice[SSA_NAME_VERSION (lhs)]); } /* In the case of memory store we can do nothing. */ else @@ -1621,7 +1621,7 @@ analyze_ssa_name_flags (tree name, vec<modref_lattice> &lattice, int depth, else if (gcall *call = dyn_cast <gcall *> (use_stmt)) { tree callee = gimple_call_fndecl (call); - /* Return slot optiomization would require bit of propagation; + /* Return slot optimization would require bit of propagation; give up for now. */ if (gimple_call_return_slot_opt_p (call) && gimple_call_lhs (call) != NULL_TREE diff --git a/gcc/testsuite/gcc.c-torture/compile/pr99751.c b/gcc/testsuite/gcc.c-torture/compile/pr99751.c new file mode 100644 index 00000000000..f1d5101c359 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr99751.c @@ -0,0 +1,20 @@ +int *ptr1 = 0, **ptr2 = &ptr1; + +int *identity(int *p) +{ + return p; +} + +void store_to_c(int *p) +{ + *ptr2 = identity(p); +} + +int main() +{ + int f; + store_to_c(&f); + if (ptr1 != &f) + __builtin_abort(); + return 0; +}