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Re: Bug with g77 and -mieee on Alpha Linux


Richard Henderson wrote:
> 
> On Mon, Jul 12, 1999 at 11:57:55PM +0200, Toon Moene wrote:
> > I think it's *either* -mieee *or* 80-bit spills.

> Eh?  One is proposed for Alpha, the other for IA-32.

Yes, but it still might not be totally transparent to everyone that *on
the ia32* you have to specify *either* -mieee *or* 80-bit spills.

> > This still has two limitations w.r.t. to true IEEE conformance:
> >
> > 1. It only works correctly for doubles, because floats still get
> >    extended to 64 bits and are therefore not equal to their stored
> >    value.
> 
> No, you can set the rounding mode to 24, 53, or 64 bits.

OK, but the point is you have to set it to *one* value for the complete
compilation (unless you want to call this routine after every
calculation to set the default right for the next one).

> > 2. [This one is from hearsay, on comp.arch]  One can only set the
> >    rounding mode on the ix86, not the range.  That means that the
> >    register values still will not have the same non-finite behaviour
> >    as stored values.
> 
> True.
> 
> r~

-- 
Toon Moene (toon@moene.indiv.nluug.nl)
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
Phone: +31 346 214290; Fax: +31 346 214286
GNU Fortran: http://world.std.com/~burley/g77.html


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