From: Alessandro Rubini <rubini-list@gnudd.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH V2 0/3] make memcpy and memset faster
Date: Thu, 8 Oct 2009 13:29:51 +0200 [thread overview]
Message-ID: <cover.1255000877.git.rubini@unipv.it> (raw)
I've added 32-bit lcd to the Nomadik (not submitted yet), and I found
the scroll to be very slow, as the screen is big.
Instead of activating the "if 0" stanza for 32-bit scroll in lcd.c,
I'd better have a faster memcpy/memset globally. So this patch set
adds ulong-wide memcpy and memset, then removes the "#if 0" part in the
scroll function. For me scrolling is 4 times faster on a 32 bit system.
V2: I incorporated most of the comments, but I didn't change the for
loops to help the compiler optimizing it, since nowadays gcc is
already doing the loops his own way irrespective of what i write.
Similarly, I'm not interested in "4 bytes at a time, then 1 at a time"
as it's quite a corner case. If such optimizations are really useful,
then we'd better have hand-crafted assembly for each arch, possibly
lifted from glibc.
Alessandro Rubini (3):
memcpy: copy one word at a time if possible
memset: fill one word at a time if possible
lcd: remove '#if 0' 32-bit scroll, now memcpy does it
common/lcd.c | 21 ---------------------
lib_generic/string.c | 34 +++++++++++++++++++++++++++++-----
2 files changed, 29 insertions(+), 26 deletions(-)
next reply other threads:[~2009-10-08 11:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-08 11:29 Alessandro Rubini [this message]
2009-10-08 11:30 ` [U-Boot] [PATCH V2 1/3] memcpy: copy one word at a time if possible Alessandro Rubini
2009-10-08 15:12 ` Peter Tyser
2009-10-08 16:00 ` Alessandro Rubini
2009-10-08 16:30 ` Peter Tyser
2009-10-08 18:23 ` Alessandro Rubini
2009-10-08 19:09 ` Peter Tyser
2009-10-08 19:17 ` Alessandro Rubini
2009-10-08 20:40 ` Wolfgang Denk
2009-10-08 20:47 ` Wolfgang Denk
2009-10-08 19:14 ` Mike Frysinger
2009-10-08 20:44 ` Wolfgang Denk
2009-10-09 4:42 ` Chris Moore
2009-10-09 10:11 ` Mark Jackson
2009-10-09 10:26 ` Mike Frysinger
2009-10-11 7:06 ` Chris Moore
2009-10-09 11:12 ` Wolfgang Denk
2009-10-08 11:30 ` [U-Boot] [PATCH V2 2/3] memset: fill " Alessandro Rubini
2009-10-08 20:46 ` Wolfgang Denk
2009-10-08 11:30 ` [U-Boot] [PATCH V2 3/3] lcd: remove '#if 0' 32-bit scroll, now memcpy does it Alessandro Rubini
2009-11-22 22:34 ` Wolfgang Denk
2009-11-24 23:04 ` Anatolij Gustschin
2009-10-08 20:36 ` [U-Boot] [PATCH V2 0/3] make memcpy and memset faster Wolfgang Denk
2009-10-08 21:30 ` Mike Frysinger
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=cover.1255000877.git.rubini@unipv.it \
--to=rubini-list@gnudd.com \
--cc=u-boot@lists.denx.de \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.