Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!uunet!taumet!steve
From: steve@taumet.com (Stephen Clamage)
Newsgroups: comp.lang.c
Subject: Re: Log Library - How is it done in the library code?
Message-ID: <628@taumet.com>
Date: 21 Mar 91 17:21:26 GMT
References: <1991Mar20.173249.3819@zoo.toronto.edu> <1991Mar20.204034.28931@bingvaxu.cc.binghamton.edu> <1991Mar20.223644.16769@zoo.toronto.edu> <1991Mar21.000655.28999@bingvaxu.cc.binghamton.edu>
Organization: Taumetric Corporation, San Diego
Lines: 25

kym@bingvaxu.cc.binghamton.edu (R. Kym Horsell) writes:

>Yes I may be confused. The following comes from the man page...

>Floating-point code generation option.  Can be one of:

>-f68881   Generate  in-line  code   for   Motorola
>		 MC68881  floating-point  processor (sup-
>		 ported only on Sun-3 systems).

>what does this mean? :-)

The Sun-3 has three options for floating point calculations.  It can
use the MC68881 co-processor directly, use subroutines to do
floating-point calculations, or use subroutines which choose one of
the other two options based on the presence or absence of the MC68881.

If you know your code will only be run on machines with the MC68881,
you can tell the compiler this with the -f68881 switch.  When you then
write a floating-point expression, the compiler will generate code to
use the coprocessor directly (in line) instead of calling a subroutine
to determine how to perform the calculations.
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com