delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/1997/06/15/23:42:20

From: Andrew Crabtree <andrewc AT typhoon DOT rose DOT hp DOT com>
Message-Id: <199706160342.AA051232523@typhoon.rose.hp.com>
Subject: Re: names of FPU registers in inline asm?
To: jasonp AT Glue DOT umd DOT edu (Jason Stratos Papadopoulos)
Date: Sun, 15 Jun 1997 20:42:03 PDT
Cc: djgpp AT delorie DOT com
In-Reply-To: <5nqddg$2e2$2@hecate.umd.edu>; from "Jason Stratos Papadopoulos" at Jun 13, 97 3:05 am

 
> Hello. There are ample resources on the web for inline assembly in
> DJGPP, but very little regarding floating point. I was wondering:
> what are the FPU registers named? st(0),st(1),... or something else?

The compiler can be a great aid at figuring things like this out.

Try the following 

test.c

double f(double x)
{
return x+2.54*x;
}

Compile it with the following command line

gcc -S -o - test.c

Now look at what is displayed on screen.  You should see references to

fstp %st(0)
fmulp %st,%st(1)

HTH

Andrew

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019