From: C H Forsyth <forsyth@vitanuova.com>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] brucee's 8c on sources?
Date: Fri, 14 May 2004 06:30:50 +0100 [thread overview]
Message-ID: <8f2a08f3fdef3a1a5ab430265782f80f@vitanuova.com> (raw)
In-Reply-To: <40A435AA.3030908@chunder.com>
>>another good speedup is a simple vlong assignment,
>>which used to be MOVL; CLD; REP; MOVSL; and is now
another example is conversion between 32-bit and 64-bit values.
loading vlong as long from memory as in
g((ulong)x); /* x vlong */
should just be loading the correct half of the vlong, shouldn't it,
but it was
MOVL x+-8(SP),CX
MOVL CX,(SP)
MOVL x+-4(SP),CX
MOVL CX,4(SP)
CALL ,_v2ul+0(SB)
MOVL AX,.safe+-16(SP)
MOVL .safe+-16(SP),AX
MOVL AX,(SP)
CALL ,g+0(SB)
and now is
MOVL x+-8(SP),AX
MOVL AX,(SP)
CALL ,g+0(SB)
ie, it does the obvious thing
the original scheme was easy to implement and was adequate
when there were few 64-bit values in sight,
but once offsets were vlong everywhere, and Qid.path was vlong,
they began to spread fairly widely through the code.
prev parent reply other threads:[~2004-05-14 5:30 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-05-13 19:27 andrey mirtchovski
2004-05-13 20:00 ` jmk
2004-05-13 20:02 ` boyd, rounin
2004-05-13 20:13 ` Russ Cox
2004-05-14 2:57 ` Bruce Ellis
2004-05-14 5:30 ` C H Forsyth [this message]
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=8f2a08f3fdef3a1a5ab430265782f80f@vitanuova.com \
--to=forsyth@vitanuova.com \
--cc=9fans@cse.psu.edu \
/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;
as well as URLs for NNTP newsgroup(s).