GH-98831: Remove all remaining DISPATCH() calls from bytecodes.c #99271

gvanrossum · 2022-11-09T01:33:09Z

Also mark those opcodes that have no stack effect as such (inst(FOO) -> inst(FOO, (--))).

Issue: Generate the interpreter #98831

Also mark those opcodes that have no stack effect as such.

gvanrossum · 2022-11-10T02:35:58Z

@brandtbucher When you have the benchmark results can you just post them here? So Mark won't have to ask for them.

brandtbucher · 2022-11-10T05:20:27Z

Here you go:

All benchmarks:
===============

Slower (21):
- nbody: 93.3 ms +- 1.6 ms -> 96.8 ms +- 1.9 ms: 1.04x slower
- unpickle_list: 4.91 us +- 0.06 us -> 5.04 us +- 0.20 us: 1.03x slower
- scimark_fft: 309 ms +- 4 ms -> 315 ms +- 8 ms: 1.02x slower
- sqlglot_normalize: 106 ms +- 1 ms -> 108 ms +- 1 ms: 1.02x slower
- pickle: 10.1 us +- 0.1 us -> 10.2 us +- 0.1 us: 1.02x slower
- chameleon: 6.50 ms +- 0.09 ms -> 6.60 ms +- 0.08 ms: 1.02x slower
- telco: 6.31 ms +- 0.12 ms -> 6.39 ms +- 0.16 ms: 1.01x slower
- fannkuch: 366 ms +- 3 ms -> 371 ms +- 3 ms: 1.01x slower
- crypto_pyaes: 74.5 ms +- 1.6 ms -> 75.4 ms +- 0.5 ms: 1.01x slower
- sqlglot_optimize: 51.5 ms +- 0.4 ms -> 52.0 ms +- 0.2 ms: 1.01x slower
- pycparser: 1.08 sec +- 0.02 sec -> 1.09 sec +- 0.02 sec: 1.01x slower
- json_dumps: 9.33 ms +- 0.13 ms -> 9.39 ms +- 0.14 ms: 1.01x slower
- regex_v8: 21.2 ms +- 0.2 ms -> 21.3 ms +- 0.0 ms: 1.01x slower
- scimark_sor: 104 ms +- 1 ms -> 104 ms +- 1 ms: 1.01x slower
- nqueens: 83.2 ms +- 1.0 ms -> 83.7 ms +- 1.3 ms: 1.01x slower
- sqlglot_transpile: 1.65 ms +- 0.02 ms -> 1.66 ms +- 0.02 ms: 1.01x slower
- python_startup: 8.63 ms +- 0.01 ms -> 8.67 ms +- 0.01 ms: 1.00x slower
- python_startup_no_site: 6.31 ms +- 0.01 ms -> 6.33 ms +- 0.01 ms: 1.00x slower
- coroutines: 25.4 ms +- 0.1 ms -> 25.5 ms +- 0.3 ms: 1.00x slower
- mako: 9.68 ms +- 0.05 ms -> 9.71 ms +- 0.05 ms: 1.00x slower
- sympy_integrate: 20.5 ms +- 0.1 ms -> 20.6 ms +- 0.1 ms: 1.00x slower

Faster (34):
- regex_dna: 208 ms +- 1 ms -> 199 ms +- 1 ms: 1.05x faster
- logging_simple: 6.03 us +- 0.08 us -> 5.80 us +- 0.08 us: 1.04x faster
- pickle_list: 4.19 us +- 0.03 us -> 4.04 us +- 0.04 us: 1.04x faster
- pidigits: 199 ms +- 0 ms -> 193 ms +- 0 ms: 1.03x faster
- django_template: 33.5 ms +- 1.0 ms -> 32.6 ms +- 0.4 ms: 1.03x faster
- logging_format: 6.58 us +- 0.09 us -> 6.40 us +- 0.09 us: 1.03x faster
- sqlite_synth: 2.65 us +- 0.04 us -> 2.59 us +- 0.04 us: 1.02x faster
- generators: 73.6 ms +- 0.4 ms -> 72.1 ms +- 0.3 ms: 1.02x faster
- regex_compile: 130 ms +- 2 ms -> 128 ms +- 1 ms: 1.02x faster
- richards: 43.5 ms +- 1.1 ms -> 42.8 ms +- 0.6 ms: 1.02x faster
- mdp: 2.56 sec +- 0.01 sec -> 2.52 sec +- 0.04 sec: 1.02x faster
- chaos: 68.0 ms +- 0.6 ms -> 66.9 ms +- 0.7 ms: 1.02x faster
- json: 4.64 ms +- 0.15 ms -> 4.57 ms +- 0.11 ms: 1.02x faster
- pickle_pure_python: 287 us +- 4 us -> 283 us +- 5 us: 1.01x faster
- deepcopy_reduce: 3.01 us +- 0.04 us -> 2.97 us +- 0.04 us: 1.01x faster
- pyflate: 405 ms +- 8 ms -> 400 ms +- 4 ms: 1.01x faster
- deepcopy: 334 us +- 5 us -> 329 us +- 3 us: 1.01x faster
- xml_etree_generate: 77.0 ms +- 0.8 ms -> 76.1 ms +- 0.8 ms: 1.01x faster
- pprint_pformat: 1.42 sec +- 0.02 sec -> 1.41 sec +- 0.02 sec: 1.01x faster
- xml_etree_process: 53.0 ms +- 0.6 ms -> 52.4 ms +- 0.6 ms: 1.01x faster
- pprint_safe_repr: 692 ms +- 7 ms -> 684 ms +- 8 ms: 1.01x faster
- sympy_expand: 460 ms +- 7 ms -> 456 ms +- 6 ms: 1.01x faster
- coverage: 96.5 ms +- 1.2 ms -> 95.6 ms +- 1.8 ms: 1.01x faster
- genshi_xml: 47.4 ms +- 0.8 ms -> 47.1 ms +- 0.5 ms: 1.01x faster
- deepcopy_memo: 34.4 us +- 0.6 us -> 34.2 us +- 0.3 us: 1.01x faster
- raytrace: 287 ms +- 3 ms -> 284 ms +- 7 ms: 1.01x faster
- deltablue: 3.34 ms +- 0.05 ms -> 3.32 ms +- 0.05 ms: 1.01x faster
- genshi_text: 20.7 ms +- 0.3 ms -> 20.6 ms +- 0.3 ms: 1.01x faster
- sympy_str: 285 ms +- 4 ms -> 283 ms +- 3 ms: 1.01x faster
- go: 138 ms +- 1 ms -> 137 ms +- 1 ms: 1.01x faster
- unpickle_pure_python: 205 us +- 2 us -> 204 us +- 2 us: 1.01x faster
- xml_etree_parse: 148 ms +- 2 ms -> 147 ms +- 1 ms: 1.01x faster
- json_loads: 24.0 us +- 0.1 us -> 23.9 us +- 0.2 us: 1.00x faster
- pickle_dict: 30.9 us +- 0.1 us -> 30.8 us +- 0.1 us: 1.00x faster

Benchmark hidden because not significant (27): 2to3, aiohttp, async_tree_none, async_tree_cpu_io_mixed, async_tree_io, async_tree_memoization, dulwich_log, float, gunicorn, hexiom, html5lib, logging_silent, meteor_contest, mypy, pathlib, regex_effbot, scimark_lu, scimark_monte_carlo, scimark_sparse_mat_mult, spectral_norm, sqlglot_parse, sympy_sum, thrift, tornado_http, unpack_sequence, unpickle, xml_etree_iterparse

Geometric mean: 1.00x faster

markshannon · 2022-11-10T12:11:38Z

Python/bytecodes.c

-            /* Use BASIC_PUSH as NULL is not a valid object pointer */
-            BASIC_PUSH(NULL);
+        inst(PUSH_NULL, (-- res)) {
+            res = NULL;


I feel that this ought to fail, as we should have NULL checks in debug mode.

Yeah, but we never had those. In debug mode we check for stack overflow/underflow but not for NULL-ness. (Of course the NULL will wreak havoc if it gets popped by the wrong opcode, bu that's also nothing new.) The code generator still checks for stack over/underflow by calling STACK_SHRINK()/GROW(), so nothing is really changed.

Once we have typed stack effects, we can auto-generate those sorts of assertions. That would be really nice.

Python/bytecodes.c

brandtbucher · 2022-11-10T16:33:55Z

Python/bytecodes.c

@@ -2642,14 +2631,15 @@ dummy_func(
                    PyObject *next = PyList_GET_ITEM(seq, it->it_index++);
                    PUSH(Py_NewRef(next));
                    JUMPBY(INLINE_CACHE_ENTRIES_FOR_ITER);
-                    DISPATCH();
+                    goto end_for_iter_list;  // End of this instruction


Yeah, I'm really counting on the compiler to optimize this for us.

Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

python#99271) Also mark those opcodes that have no stack effect as such. Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

Remove all remaining DISPATCH() calls from bytecodes.c

d453fcc

Also mark those opcodes that have no stack effect as such.

bedevere-bot mentioned this pull request Nov 9, 2022

Generate the interpreter #98831

Closed

bedevere-bot added the awaiting core review label Nov 9, 2022

gvanrossum added the skip news label Nov 9, 2022

gvanrossum marked this pull request as ready for review November 10, 2022 02:35

gvanrossum requested review from markshannon and brandtbucher November 10, 2022 02:35

markshannon reviewed Nov 10, 2022

View reviewed changes

gvanrossum added 4 commits November 10, 2022 07:50

Merge commit 'c7f57087149968e9a72f6dee73514ff18fee78e8' into rm-dispatch

14d60fd

Merge commit '2e343fc465ed0206340cf139ba485f9004bbdd41' into rm-dispatch

089b508

Merge remote-tracking branch 'origin/main' into rm-dispatch

3f57751

Merge branch 'main' into rm-dispatch

f4ebe70

brandtbucher approved these changes Nov 10, 2022

View reviewed changes

bedevere-bot added awaiting merge and removed awaiting core review labels Nov 10, 2022

gvanrossum and others added 3 commits November 10, 2022 09:04

Whitespace/braces from Brandt's review

67200bf

Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

Merge remote-tracking branch 'origin/main' into rm-dispatch

a419b2b

Regen cases

ed64309

gvanrossum merged commit 694cdb2 into python:main Nov 10, 2022

bedevere-bot removed the awaiting merge label Nov 10, 2022

gvanrossum deleted the rm-dispatch branch November 10, 2022 20:43

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GH-98831: Remove all remaining DISPATCH() calls from bytecodes.c #99271

GH-98831: Remove all remaining DISPATCH() calls from bytecodes.c #99271

gvanrossum commented Nov 9, 2022 •

edited

gvanrossum commented Nov 10, 2022

brandtbucher commented Nov 10, 2022

markshannon Nov 10, 2022

gvanrossum Nov 10, 2022

brandtbucher Nov 10, 2022

brandtbucher Nov 10, 2022

gvanrossum Nov 10, 2022

GH-98831: Remove all remaining DISPATCH() calls from bytecodes.c #99271

GH-98831: Remove all remaining DISPATCH() calls from bytecodes.c #99271

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gvanrossum commented Nov 9, 2022 • edited

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gvanrossum commented Nov 9, 2022 •

edited