Date: Fri, 2 Oct 1998 16:36:44 +0200 (WET)
From: Andris Pavenis <pavenis AT lanet DOT lv>
To: Bradley Walker <Brad DOT Walker AT Eng DOT Sun DOT COM>
cc: nate AT cartsys DOT com, djgpp AT delorie DOT com
Subject: Re: question about libm
In-Reply-To: <199810012318.QAA09752@boofoo.Eng>
Message-ID: <Pine.A32.3.91.981002163050.71398B-100000@ieva05.lanet.lv>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII



On Thu, 1 Oct 1998, Bradley Walker wrote:

> > From: Nate Eldredge <nate AT cartsys DOT com>
> > To: Bradley Walker <bwalker AT boofoo DOT Eng DOT Sun DOT COM>
> > CC: djgpp AT delorie DOT com
> > Subject: Re: question about libm
> > References: <ywjd67e5jmtq DOT fsf AT boofoo DOT Eng DOT Sun DOT COM>
> > 
> > Bradley Walker wrote:
> > > 
> > > When I use the libm.a that is included with djgcc, is this a software
> > > implementation of the the transcendental functions or is there any inlining
> > > to take advantage of a math coprocessor?
> > 
> > No; libm is probably slower with respect to math functions; it doesn't
> > use the coprocessor as much as it might.  It is, however, more compliant
> > to ANSI in such areas as setting `errno' on errors.  But there are some
> > functions that only libm provides, like gamma.
> > -- 
> > 
> 
> My application is an extremely heavy user of pow() and log(). What
> I'm interested is will the libm use a math coprocessor for these
> functions or will it run them in s/w..
> 

I think the best would be to have 2 versions of libm.a to choose.
Poeple that wants more ANSI compliant version will then be able
to use version that now is in alpha versions of DJDEV202 and poeple
who want faster library will be able to use it.

Only question is which one should be default (in DJDEV and DJLSR). The 
second one perhaps should be in a separate package.

Using functions from libc.a is not enough as for example g77
generates "-lg2f -lm" in ld command line.  

Andris