From: rog@vitanuova.com
To: 9fans@cse.psu.edu
Subject: Re: [9fans] fp: stack underflow error
Date: Thu, 1 Jul 2004 20:24:23 +0100 [thread overview]
Message-ID: <d66164ffbf07b27c99685ea41599f1a3@vitanuova.com> (raw)
In-Reply-To: <b974470c3e357a7efd16b8345fb68e94@orthanc.cc.titech.ac.jp>
> I encountered a "sys: fp: stack underflow" error in my program.
looks like a compiler bug.
here's a simpler version of the code that does the same thing.
who'd've thought that a2b() would generate such
convoluted code? what's that comparison for?
TEXT a2b+0(SB),0,$12
MOVL tb+4(FP),CX
SUBL fb+0(FP),CX
MOVL CX,.safe+-4(SP)
FMOVL .safe+-4(SP),F0
CMPL CX,$0
JGE ,2(PC)
FADDD $(4.29496729600000000e+09),F0
FMULD dis+8(FP),F0
FSTCW ,.safe+-8(SP)
MOVW $3967,.safe+-6(SP)
FLDCW .safe+-6(SP),
FMOVLP F0,.safe+-4(SP)
FLDCW .safe+-8(SP),
MOVL .safe+-4(SP),AX
RET ,
#include <u.h>
#include <libc.h>
int
a2b(int fb, uint tb, double dis)
{
return (tb - fb)*dis;
}
void
main(void)
{
a2b(1, 0, 65);
a2b(1, 0, 66);
}
next prev parent reply other threads:[~2004-07-01 19:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-07-01 4:50 YAMANASHI Takeshi
2004-07-01 8:55 ` Kenji Okamoto
2004-07-01 19:24 ` rog [this message]
2004-07-01 20:32 ` Charles Forsyth
2004-07-01 20:38 ` boyd, rounin
2004-07-02 9:34 ` Charles Forsyth
2004-07-02 10:25 ` Geoff Collyer
2004-07-02 10:53 ` Charles Forsyth
2004-07-02 0:35 YAMANASHI Takeshi
2004-07-02 1:02 ` Kenji Okamoto
2004-07-02 1:04 ` Kenji Okamoto
2004-07-02 1:05 ` Kenji Okamoto
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=d66164ffbf07b27c99685ea41599f1a3@vitanuova.com \
--to=rog@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).