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Re: PATCH: HUGE_VAL should be Infinity
- To: dave at hiauly1 dot hia dot nrc dot ca (John David Anglin)
- Subject: Re: PATCH: HUGE_VAL should be Infinity
- From: "John David Anglin" <dave at hiauly1 dot hia dot nrc dot ca>
- Date: Thu, 30 Nov 2000 15:16:25 -0500 (EST)
- Cc: law at redhat dot com, meissner at cygnus dot com, gcc-patches at gcc dot gnu dot org
> > Nyet. Recent HP chips (all PA2.0 variants) have fneg which provides an
> > ieee compliant negation.
>
> Wrong. I tried fneg on a C200 and again negation of +0. yielded +0. The
> behaviour was identical to that of the 735. Thus, I don't believe that
> all the new PA2.0 chips provide an ieee compliant negation. HP is usually
> pretty good about this kind of thing which was why I wondered if there
> was some debate about the standard.
I retested this and it appears that I made a mistake in my original testing.
The fneg instruction on PA2.0 gear does negate +0. correctly. Thus, there
is only a problem with PA1.0 and PA1.1 hardware which uses fsub. The HP
compiler doesn't have the problem since it multiplies by -1. instead.
Dave
--
J. David Anglin dave.anglin@nrc.ca
National Research Council of Canada (613) 990-0752 (FAX: 952-6605)