Linux-kernel mailing list archive 1998-31,: Re: floating-point abuse in 2.1.113

# Re: floating-point abuse in 2.1.113

Andreas Schwab (schwab@issan.informatik.uni-dortmund.de)
07 Aug 1998 11:33:31 +0200

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"H. Peter Anvin" <hpa@transmeta.com> writes:

|> > >
|> > > > I don't think this is a big problem anymore with mostly all CPUs supporting
|> > > > standard IEEE floating point arithmetic. Is there any Linux target that has
|> > > > non-IEEE FP? I doubt it.
|> > >
|> > > VAX. Also, for example i386 has 80-bit floating point, which no other
|> > > system have, and I think Alpha and Sparc64 have 128-bit.
|> >
|> > Sparc32 has 128-bit as well. But both 80-bit and 128-bit floating point are
|> > IEEE as well... So a generic emulator could help.
|> >
|>
|> Only it is arbitrary-precision, which is very slow (it may or may not
|> matter, of course.)

It doesn't matter for the compiler. And by the way, gcc *does* emulate
floating point by default if XFmode (80/96 bits) or TFmode (128 bits) is
to be supported, in order to get precise, consistent results on all
platforms, whether cross compiling or not. Look for REAL_ARITHMETIC in
the gcc sources.

    --
    Andreas Schwab                                      "And now for something
    schwab@issan.informatik.uni-dortmund.de              completely different"
    schwab@gnu.org

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