From: Robert Jarzmik <robert.jarzmik@free.fr>
To: Sascha Hauer <s.hauer@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH 2/4] introduce region_overlap() function
Date: Sat, 06 Oct 2012 21:44:54 +0200 [thread overview]
Message-ID: <87obkfxu4p.fsf@free.fr> (raw)
In-Reply-To: <20121005213302.GZ1322@pengutronix.de> (Sascha Hauer's message of "Fri, 5 Oct 2012 23:33:02 +0200")
Sascha Hauer <s.hauer@pengutronix.de> writes:
> You made me curious. I tried to compile both and here is the result on
> ARM (I swapped the arguments left and right of the &&):
>
...zip...
>
> Maybe gcc isn't so clever on other architectures, I don't know ;)
You're right.
Same conclusion on x86 with gcc 4.7. I had tried that a long time ago (maybe 10
years or so) on x86, benchmarking both pure C and Java on this very function (it
was for aircrafts timeslots conflicts discovery).
At that time, the "startA <= endB && endA >= startB" was fastest. So compilation
technique have improved enough to write maintainable code after all :)
Cheers.
--
Robert
_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox
next prev parent reply other threads:[~2012-10-06 19:45 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-05 16:45 [PATCH] cleanup arm startup a bit Sascha Hauer
2012-10-05 16:45 ` [PATCH 1/4] ARM: add assembly function for setting up C environment Sascha Hauer
2012-10-05 16:45 ` [PATCH 2/4] introduce region_overlap() function Sascha Hauer
2012-10-05 19:55 ` Robert Jarzmik
2012-10-05 21:33 ` Sascha Hauer
2012-10-06 19:44 ` Robert Jarzmik [this message]
2012-10-07 6:59 ` Antony Pavlov
2012-10-05 16:45 ` [PATCH 3/4] ARM: cleanup piggydata copy check Sascha Hauer
2012-10-05 16:45 ` [PATCH 4/4] ARM: simplify start.c Sascha Hauer
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=87obkfxu4p.fsf@free.fr \
--to=robert.jarzmik@free.fr \
--cc=barebox@lists.infradead.org \
--cc=s.hauer@pengutronix.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.