From: Alviro Iskandar Setiawan <[email protected]>
To: Ammar Faizi <[email protected]>
Cc: "Willy Tarreau" <[email protected]>,
"Thomas Weißschuh" <[email protected]>,
"Nicholas Rosenberg" <[email protected]>,
"Michael William Jonathan" <[email protected]>,
"GNU/Weeb Mailing List" <[email protected]>,
"Linux Kernel Mailing List" <[email protected]>
Subject: Re: [RFC PATCH v1 2/5] tools/nolibc: x86-64: Use `rep stosb` for `memset()`
Date: Wed, 30 Aug 2023 21:08:05 +0700 [thread overview]
Message-ID: <CAOG64qMkQJ-znXbeBz=zubhbonzEKtzJ5y6xQZPvXUpkC-=TDg@mail.gmail.com> (raw)
In-Reply-To: <[email protected]>
On Wed, Aug 30, 2023 at 8:57 PM Ammar Faizi wrote:
> +".section .text.nolibc_memset\n"
> +".weak memset\n"
> +"memset:\n"
> + "movq %rsi, %rax\n"
> + "movq %rdx, %rcx\n"
> + "movq %rdi, %rdx\n"
> + "rep stosb\n"
> + "movq %rdx, %rax\n"
> + "retq\n"
The first instruction could be:
movl %esi, %eax
That's smaller. Also, the second argument of memset() is an int
anyway, so there is no need to have a full 64-bit copy of %rsi in
%rax.
-- Viro
next prev parent reply other threads:[~2023-08-30 14:08 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-30 13:57 [RFC PATCH v1 0/5] nolibc x86-64 string functions Ammar Faizi
2023-08-30 13:57 ` [RFC PATCH v1 1/5] tools/nolibc: x86-64: Use `rep movsb` for `memcpy()` and `memmove()` Ammar Faizi
2023-08-30 13:57 ` [RFC PATCH v1 2/5] tools/nolibc: x86-64: Use `rep stosb` for `memset()` Ammar Faizi
2023-08-30 14:08 ` Alviro Iskandar Setiawan [this message]
2023-08-30 14:13 ` Ammar Faizi
2023-08-30 14:24 ` Alviro Iskandar Setiawan
2023-08-30 15:09 ` Ammar Faizi
2023-08-30 15:23 ` Willy Tarreau
2023-08-30 15:44 ` Ammar Faizi
2023-08-30 15:51 ` Willy Tarreau
2023-08-30 16:08 ` Ammar Faizi
2023-08-30 16:11 ` Alviro Iskandar Setiawan
2023-08-30 13:57 ` [RFC PATCH v1 3/5] tools/nolibc: x86-64: Use `rep cmpsb` for `memcmp()` Ammar Faizi
2023-08-30 21:26 ` Willy Tarreau
2023-09-01 3:24 ` Ammar Faizi
2023-09-01 3:35 ` Willy Tarreau
2023-09-01 7:27 ` Ammar Faizi
2023-09-04 8:26 ` David Laight
2023-08-30 13:57 ` [RFC PATCH v1 4/5] tools/nolibc: string: Remove the `_nolibc_memcpy_down()` function Ammar Faizi
2023-08-30 21:27 ` Willy Tarreau
2023-08-30 13:57 ` [RFC PATCH v1 5/5] tools/nolibc: string: Remove the `_nolibc_memcpy_up()` function Ammar Faizi
2023-08-30 21:32 ` [RFC PATCH v1 0/5] nolibc x86-64 string functions Willy Tarreau
2023-09-01 11:34 ` David Laight
2023-09-01 11:46 ` Willy Tarreau
2023-09-01 13:06 ` Ammar Faizi
2023-09-01 14:23 ` David Laight
2023-09-01 14:41 ` Ammar Faizi
2023-09-01 14:54 ` David Laight
2023-09-01 15:20 ` Ammar Faizi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAOG64qMkQJ-znXbeBz=zubhbonzEKtzJ5y6xQZPvXUpkC-=TDg@mail.gmail.com' \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox