This started off as a build time analysis (#130090 (comment) ), but since I now have the infrastructure, I tried -flto=thin, too:
faster in building 520.6 vs 651.2 seconds
is neutral on the pyperformance benchmarks
would bring us in sync with Linux, because there CONFIGURE_CFLAGS_NODIST and CONFIGURE_LDFLAGS_NOLTO both use -flto=thin when I configure for clang in WSL Ubuntu-24.04. See also the discussion why not to use full -flto in Revert to default fullLTO on Clang #130048
Benchmark
clang.pgo.20.1.0-rc2
clang.pgo.thin.20.1.0-rc2
Geometric mean
(ref)
1.00x faster
Detailed pybenchmark results
Benchmark
clang.pgo.20.1.0-rc2
clang.pgo.thin.20.1.0-rc2
float
95.0 ms
89.7 ms: 1.06x faster
json_loads
29.8 us
28.6 us: 1.04x faster
mdp
2.86 sec
2.77 sec: 1.03x faster
html5lib
68.3 ms
66.2 ms: 1.03x faster
async_tree_none_tg
330 ms
320 ms: 1.03x faster
pyflate
518 ms
505 ms: 1.03x faster
sqlite_synth
3.21 us
3.13 us: 1.03x faster
pidigits
228 ms
223 ms: 1.02x faster
bench_mp_pool
168 ms
165 ms: 1.02x faster
async_tree_eager_io
742 ms
727 ms: 1.02x faster
generators
34.5 ms
33.8 ms: 1.02x faster
comprehensions
18.3 us
17.9 us: 1.02x faster
async_tree_cpu_io_mixed
641 ms
629 ms: 1.02x faster
scimark_sparse_mat_mult
4.51 ms
4.43 ms: 1.02x faster
async_tree_memoization
425 ms
417 ms: 1.02x faster
sympy_expand
538 ms
529 ms: 1.02x faster
unpack_sequence
57.0 ns
56.0 ns: 1.02x faster
regex_dna
209 ms
205 ms: 1.02x faster
async_generators
465 ms
458 ms: 1.02x faster
scimark_sor
140 ms
137 ms: 1.02x faster
sympy_str
319 ms
314 ms: 1.02x faster
async_tree_io_tg
751 ms
740 ms: 1.01x faster
regex_effbot
3.14 ms
3.10 ms: 1.01x faster
async_tree_eager_tg
272 ms
268 ms: 1.01x faster
pickle_dict
27.3 us
27.0 us: 1.01x faster
async_tree_eager_memoization_tg
363 ms
359 ms: 1.01x faster
sympy_integrate
22.5 ms
22.2 ms: 1.01x faster
sympy_sum
181 ms
179 ms: 1.01x faster
2to3
390 ms
386 ms: 1.01x faster
hexiom
6.68 ms
6.61 ms: 1.01x faster
docutils
3.03 sec
3.00 sec: 1.01x faster
sqlglot_normalize
121 ms
120 ms: 1.01x faster
async_tree_memoization_tg
392 ms
389 ms: 1.01x faster
async_tree_cpu_io_mixed_tg
614 ms
609 ms: 1.01x faster
tomli_loads
2.20 sec
2.18 sec: 1.01x faster
spectral_norm
102 ms
101 ms: 1.01x faster
python_startup_no_site
34.4 ms
34.2 ms: 1.01x faster
genshi_text
24.6 ms
24.5 ms: 1.01x faster
dulwich_log
119 ms
118 ms: 1.00x faster
go
128 ms
128 ms: 1.00x faster
deltablue
3.62 ms
3.63 ms: 1.00x slower
unpickle_pure_python
247 us
248 us: 1.00x slower
xml_etree_generate
107 ms
107 ms: 1.01x slower
django_template
39.2 ms
39.4 ms: 1.01x slower
coroutines
24.8 ms
25.0 ms: 1.01x slower
mako
13.3 ms
13.5 ms: 1.01x slower
unpickle
15.9 us
16.1 us: 1.01x slower
nbody
119 ms
121 ms: 1.01x slower
fannkuch
465 ms
472 ms: 1.01x slower
crypto_pyaes
81.3 ms
82.6 ms: 1.02x slower
json_dumps
11.5 ms
11.7 ms: 1.02x slower
deepcopy
285 us
291 us: 1.02x slower
pprint_safe_repr
858 ms
876 ms: 1.02x slower
xml_etree_iterparse
136 ms
139 ms: 1.02x slower
gc_traversal
5.03 ms
5.14 ms: 1.02x slower
meteor_contest
115 ms
117 ms: 1.02x slower
deepcopy_memo
33.8 us
34.7 us: 1.03x slower
richards_super
51.1 ms
52.6 ms: 1.03x slower
scimark_fft
327 ms
337 ms: 1.03x slower
richards
44.9 ms
46.3 ms: 1.03x slower
pickle_list
4.83 us
4.99 us: 1.03x slower
deepcopy_reduce
2.93 us
3.03 us: 1.03x slower
pprint_pformat
1.74 sec
1.80 sec: 1.03x slower
logging_simple
10.9 us
11.4 us: 1.05x slower
logging_format
12.1 us
12.6 us: 1.05x slower
xml_etree_parse
197 ms
208 ms: 1.05x slower
Geometric mean
(ref)
1.00x faster
pgo_clang_20.1.0-rc2
pgo_clang_thin_20.1.0-rc2
pginstr
297.2
219.3
pgo
70.0
69.0
kill
1.2
0.5
pgupd
282.8
231.7
total time
651.2
520.6
Details pginstrument
pgo_clang_20.1.0-rc2
pgo_clang_thin_20.1.0-rc2
_freeze_module
38.5
40.0
python314
141.5
81.3
pyexpat
52.7
3.9
_elementtree
51.8
5.3
sqlite3
46.0
42.4
liblzma
18.2
16.5
_decimal
12.4
7.7
_testcapi
8.3
7.1
_bz2
7.0
4.9
_ctypes
6.9
7.5
_testlimitedcapi
4.9
4.3
_wmi
4.5
3.0
_overlapped
4.5
3.2
_asyncio
4.0
5.2
_lzma
3.8
1.8
_ssl
3.7
5.5
_ctypes_test
3.7
3.4
_multiprocessing
3.5
2.7
_sqlite3
3.4
2.8
venvwlauncher
3.3
2.7
_zoneinfo
3.1
3.4
unicodedata
2.7
3.0
pyshellext
2.7
2.6
pyw
2.7
2.7
py
2.6
2.5
_socket
2.4
3.7
_testinternalcapi
2.4
2.2
_tkinter
2.2
4.1
_testclinic
2.0
1.9
_hashlib
1.8
3.1
select
1.8
2.2
venvlauncher
1.8
1.7
winsound
1.7
3.3
_uuid
1.6
3.2
_queue
1.6
2.3
_testembed
1.5
1.5
_testbuffer
1.4
1.3
pythonw
1.1
1.1
_testconsole
1.1
1.1
_testmultiphase
1.0
1.0
_testsinglephase
1.0
1.0
python
1.0
0.9
_testclinic_limited
0.9
0.9
_testimportmultiple
0.9
0.9
python3
0.5
0.5
total
465.8
303.3
Details pgupdate
pgo_clang_20.1.0-rc2
pgo_clang_thin_20.1.0-rc2
_freeze_module
38.0
39.5
python314
141.9
95.4
sqlite3
44.4
42.9
liblzma
17.3
16.5
_decimal
11.2
8.7
_testcapi
8.6
7.3
_ctypes
8.0
7.2
_bz2
7.8
5.5
_ssl
5.2
5.6
_testlimitedcapi
5.0
4.2
pyexpat
4.6
3.6
_asyncio
4.5
4.6
_socket
4.3
3.5
_tkinter
4.0
4.2
_ctypes_test
3.7
3.4
_overlapped
3.5
3.7
_elementtree
3.5
4.5
_wmi
3.5
3.1
_zoneinfo
3.2
3.2
_lzma
3.2
1.9
unicodedata
3.2
3.0
_sqlite3
3.1
2.7
_hashlib
3.1
3.3
venvwlauncher
3.1
3.0
_multiprocessing
2.8
2.6
pyshellext
2.7
2.6
pyw
2.6
2.6
_uuid
2.6
2.8
py
2.6
2.7
_testinternalcapi
2.4
2.2
_testclinic
2.0
1.9
_queue
1.9
2.2
winsound
1.8
3.0
venvlauncher
1.7
1.5
select
1.6
2.0
_testembed
1.5
1.4
_testbuffer
1.4
1.3
_testconsole
1.1
1.0
pythonw
1.1
1.1
_testmultiphase
1.0
1.1
_testsinglephase
1.0
1.0
python
1.0
0.9
_testclinic_limited
0.9
0.9
_testimportmultiple
0.9
0.9
python3
0.5
0.5
total
372.9
316.8
Linked PRs
