[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

Alexey Izbyshev added the comment: Thank you for benchmarking and merging, Victor! -- resolution: -> fixed stage: patch review -> resolved status: open -> closed ___ Python tracker

[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

miss-islington added the comment: New changeset 945771b3c7a08f0b2b875905d517a1566477bfaf by Miss Islington (bot) in branch '3.6': bpo-34436: Fix check that disables overallocation for the last fmt specifier (GH-8826)

[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

miss-islington added the comment: New changeset 042082692b7fab7361a8c9d0fb792532bb77e293 by Miss Islington (bot) in branch '3.7': bpo-34436: Fix check that disables overallocation for the last fmt specifier (GH-8826)

[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

Change by miss-islington : -- pull_requests: +8340 ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

STINNER Victor added the comment: New changeset ccd99752675042bd5f67d332c5b0ed85ba1f2da3 by Victor Stinner (Alexey Izbyshev) in branch 'master': bpo-34436: Fix check that disables overallocation for the last fmt specifier (GH-8826)

[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

Change by miss-islington : -- pull_requests: +8339 ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

STINNER Victor added the comment: I ran a microbenchmark on PR 8826: ./python -m perf timeit -s 'fmt=b"%s%s"; args=(b"1", b"x"*(1024*1024))' 'fmt % args' -v -o patch.json $ python3 -m perf compare_to ref.json patch.json Mean +- std dev: [ref] 325 us +- 7 us -> [patch] 36.2 us +- 1.1 us:

[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

STINNER Victor added the comment: bytes % args has been optimized using the _PyBytesWriter API in bpo-25349: commit fa7762ec066aa3632a25b6a52bb7597b8f17c2f3. I converted my old benchmark from bpo-25349 to my new perf module:

[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

Change by Alexey Izbyshev : -- keywords: +patch pull_requests: +8305 stage: -> patch review ___ Python tracker ___ ___

[issue34436] Overallocation is never disabled in _PyBytes_FormatEx()

New submission from Alexey Izbyshev : The condition for disabling overallocation at 225b055/Objects/bytesobject.c:822 is always false. Reported by Svace static analyzer. -- components: Interpreter Core messages: 323763 nosy: inada.naoki, izbyshev, serhiy.storchaka, vstinner priority: