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Re: [PATCH v3 0/5] bswap.h: Rework ntohl handling

From
Junio C Hamano <gitster@pobox.com>
Date
Jul 15, 2025, 21:52 UTC
Message-ID
<xmqqple1f7ge.fsf@gitster.g>
In-Reply-To
<20250715191230.12081-1-sebastian@breakpoint.cc>
Sebastian Andrzej Siewior <sebastian@breakpoint.cc> writes:
Show 20 quoted lines
> this series continues the rework of the bswap32/64()/ nothl() handling. 
>
> I've been looking at recent compiler and they manage to recognize the
> manual shifting and use an optimize opcode if available. The ntohl
> version provided by glibc already provides an "optimized" version which
> makes an optimisation in git almost not needed.
> One of the motivation behind overwriting/ providing an optimized
> version was to provide a macro instead of using a function call. One
> libc that is still providing ntohl as a function call is musl.
>
> While ntohl() is provided by the libc, the ntohll() is not. I found it
> only on Windows provided by winsock.h.
>
> I haven't touched the put/get_be*() macros. gcc & clang are both smart
> enough to swap the content accordingly and perform a single store/ load.
> Only the msvc seems to strugle here and performs multiple bytes stores/
> loads and shifts.
>
> v2…v3 https://lore.kernel.org/all/20250611221444.1567638-1-sebastian@breakpoint.cc/
>   - Fixed typos in the patch description

Thanks for updating the proposed log messages with typofixes. I understand the patch text has no changes?

Cc'ed those who gave comments on the previous round. How does this version look to you folks?

Thanks.
Previous: Sebastian Andrzej SiewiorNext: brian m. carlson
Message 7 of 9 in “bswap.h: Rework ntohl handling”
  1. 0/5 bswap.h: Rework ntohl handlingSebastian Andrzej Siewior, Jul 15, 2025
  2. 1/5 bswap.h: Add support for __BYTE_ORDER__Sebastian Andrzej Siewior, Jul 15, 2025
  3. 4/5 bswap.h: Remove optimized x86 version of bswap32/64Sebastian Andrzej Siewior, Jul 15, 2025
  4. 5/5 bswap.h: Provide a built-in based version of bswap32/64 if possibleSebastian Andrzej Siewior, Jul 15, 2025
  5. 2/5 bswap.h: Define GIT_LITTLE_ENDIAN on msvc as little endianSebastian Andrzej Siewior, Jul 15, 2025
  6. 3/5 bswap.h: Always overwrite ntohl/ ntohll macrosSebastian Andrzej Siewior, Jul 15, 2025
  7. Junio C HamanoJul 15, 2025
  8. brian m. carlsonJul 15, 2025
  9. Sebastian Andrzej SiewiorJul 16, 2025

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