Re: comparing gnat/Ada95 and g77

From: "David C. Hoos, Sr." <david.c.hoos.sr@ada95.com>
Subject: Re: comparing gnat/Ada95 and g77
Date: Thu, 14 Mar 2002 05:41:06 -0600
Date: 2002-03-14T05:41:06-06:00	[thread overview]
Message-ID: <mailman.1016106122.24675.comp.lang.ada@ada.eu.org> (raw)
In-Reply-To: 5s%j8.55660$yc2.6017500@news2-win.server.ntlworld.com

Or how about
 x := x * 0.5 + 2.0 + sin_x*cos_x + sin_x + cos_x;
which is faster still, unless the compiler optimizes to this
same thing.

----- Original Message -----
From: "chris.danx" <chris.danx@ntlworld.com>
Newsgroups: comp.lang.ada
To: <comp.lang.ada@ada.eu.org>
Sent: March 14, 2002 5:04 AM
Subject: Re: comparing gnat/Ada95 and g77

>
> "Martin Dowie" <martin.dowie@nospam.baesystems.com> wrote in message
> news:3c9081f5$1@pull.gecm.com...
> > >          x := x*0.5 + 1.0 + sin(x)*cos(x) + sin(x) + cos(x) +
> > >                             sin(x)*sin(x) + cos(x)*cos(x);
> >
> > Try changing this line to:
> >
> >          Sin_X := Sin(X);
> >          Cos_X := Cos(X);
> >          X := X*0.5 + 1.0 + Sin_X*Cos_X + Sin_X + Cos_X +
> >             Sin_X*Sin_X + Cos_X*Cos_X;
>
> what is the point of calculating sin(x)*sin(x) + cos(x)*cos(x)?  It is equal
> to (sin(x))^2 + (cos(x)^2) which is always 1.0 so you can do
>
> x := x * 0.5 + 1.0 + sin_x*cos_x + sin_x + cos_x + 1.0;
>
> and that'll be even faster.
>
>
>
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