GeezerVison

Background

Experimental optimization techniques using LLVM-BOLT have been applied in CPython 3.12, but in order to provide this as an official feature, it must be ensured that the optimized binary does not change the expected behavior.

It has been confirmed that the peephole optimization provided by LLVM-BOLT re-raises the #53093 issue, and it passes the unit tests normally when this is disabled.

A detailed explanation of LLVM_BOLT will be shared at this year's Python Language Summit lightning talk, and materials will be published after the presentation.
(Also, I already shared the draft material at Discord of Python core team)

Performance Impact

I measured that enabling or disabling peephole optimization of LLVM-BOLT has almost no impact on performance, and it shows only noise-level results in the pyperformance benchmarks also.

pyperformance

Benchmark hidden because not significant (31): 2to3, async_tree_none, async_tree_io, async_tree_memoization, bench_mp_pool, deepcopy, deepcopy_memo, docutils, genshi_xml, html5lib, json_dumps, mdp, pickle, pickle_dict, pickle_pure_python, pyflate, regex_dna, regex_v8, sqlglot_parse, sqlglot_transpile, sympy_integrate, sympy_sum, sympy_str, telco, tornado_http, unpack_sequence, unpickle, unpickle_pure_python, xml_etree_parse, xml_etree_iterparse, xml_etree_process

• Issue: Make BOLT as stable feature #101525