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Re: FWD: FLOATING-POINT CONSISTENCY, -FFLOAT-STORE, AND X86
- To: pcg at goof dot com (Marc Lehmann)
- Subject: Re: FWD: FLOATING-POINT CONSISTENCY, -FFLOAT-STORE, AND X86
- From: Tim Hollebeek <tim at wagner dot princeton dot edu>
- Date: Wed, 16 Dec 1998 15:50:22 -0500 (EST)
- Cc: egcs at cygnus dot com
Marc Lehmann writes ...
>
> I still don't see what the 64 bit precision idea gives us, in terms of
> performance. First, it doesn't give us full ieee, second, it kills
> performance, depending on where the rounding mode is set (before each
> assignment? resetting it to normal before each long double assignment?)
64 bit rounding is a wonderful solution .... assuming the only
floating point type you ever use is 'double'. As such, it makes sense
as a practical user level solution, but I'm afraid it's almost useless
as a general purpose solution.
---------------------------------------------------------------------------
Tim Hollebeek | "Everything above is a true
email: tim@wfn-shop.princeton.edu | statement, for sufficiently
URL: http://wfn-shop.princeton.edu/~tim | false values of true."