From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jamie Lokier <egcs@tantalophile.demon.co.uk>
To: Edward Jason Riedy <ejr@CS.Berkeley.EDU>, Joe Buck <jbuck@synopsys.com>
Cc: hjstein@bfr.co.il, egcs@cygnus.com
Subject: Re: FWD: FLOATING-POINT CONSISTENCY, -FFLOAT-STORE, AND X86
Date: Tue, 15 Dec 1998 17:11:00 -0000
Message-id: <19981216010546.F7806@tantalophile.demon.co.uk>
References: <199812150119.RAA03420@yamato.synopsys.com> <199812150251.SAA11628@lotus.CS.Berkeley.EDU>
X-SW-Source: 1998-12/msg00556.html

On Mon, Dec 14, 1998 at 06:51:28PM -0800, Edward Jason Riedy wrote:
> Using 80-bit spills is a quick approximation to extending the FP stack
> into memory, and it should give some of the benefit with very little 
> (hopefully) hassle.  Of course, 80 bits is wider than the normal spill,
> so it eats more memory bandwidth, cache space, etc.  Anyone who's that
> concerned will bend over backwards to avoid spills anyways.

I like this 80-bit spills idea.

But given that you can just put the FPU into 64-bit precision mode
anyway to get predictable arithmetic, I would like to see the option to
use just 64-bit spills for those programs that do run the FPU in 64-bit
precision mode.

Maybe that option could be implied by -ffast-math.

-- Jamie