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| author | Jan Hubicka <hubicka@ucw.cz> | 2021-10-31 23:14:29 +0100 |
|---|---|---|
| committer | Jan Hubicka <hubicka@ucw.cz> | 2021-10-31 23:14:29 +0100 |
| commit | ca84f39399fda80c770306465276ffd66d3766ed (patch) | |
| tree | 6bb38a6cd317c43716c251388b7aa9b10c5302b8 /gcc/ipa-modref.c | |
| parent | d41092ec52f46d2f4b08fff8d1519e50354331b0 (diff) | |
| download | gcc-ca84f39399fda80c770306465276ffd66d3766ed.zip gcc-ca84f39399fda80c770306465276ffd66d3766ed.tar.gz gcc-ca84f39399fda80c770306465276ffd66d3766ed.tar.bz2 | |
Improve handling of return slot in ipa-pure-const and modref.
while preparing testcase for return slot tracking I noticed that both
ipa-pure-const and modref treat return slot writes as non-local which prevents
detecting functions as pure or not modifying global state. Fixed by making
points_to_local_or_readonly_memory_p to special case return slot. This is bit
of a side case, but presently at all uses of
points_to_local_or_readonly_memory_p we want to handle return slot this way.
I also noticed that we handle gimple copy unnecesarily pesimistically. This
does not make difference right now since we do no not track non-scalars, but
I fixed it anyway.
Bootstrapped/regtested x86_64-linux, comitted.
gcc/ChangeLog:
* ipa-fnsummary.c: Include tree-dfa.h.
(points_to_local_or_readonly_memory_p): Return true on return
slot writes.
* ipa-modref.c (analyze_ssa_name_flags): Fix handling of copy
statement.
gcc/testsuite/ChangeLog:
* g++.dg/ipa/modref-1.C: New test.
Diffstat (limited to 'gcc/ipa-modref.c')
| -rw-r--r-- | gcc/ipa-modref.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c index 3539cb4..d866d9e 100644 --- a/gcc/ipa-modref.c +++ b/gcc/ipa-modref.c @@ -1841,7 +1841,7 @@ analyze_ssa_name_flags (tree name, vec<modref_lattice> &lattice, int depth, We do not track memory locations, so assume that value is used arbitrarily. */ if (memory_access_to (gimple_assign_rhs1 (assign), name)) - lattice[index].merge (0); + lattice[index].merge (deref_flags (0, false)); /* Handle *name = *exp. */ else if (memory_access_to (gimple_assign_lhs (assign), name)) lattice[index].merge_direct_store (); |