Deutsch English Français Italiano |
<jwva5kj9c0j.fsf-monnier+comp.arch@gnu.org> View for Bookmarking (what is this?) Look up another Usenet article |
Path: ...!2.eu.feeder.erje.net!feeder.erje.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Stefan Monnier <monnier@iro.umontreal.ca> Newsgroups: comp.arch Subject: Re: Making Lemonade (Floating-point format changes) Date: Tue, 21 May 2024 15:56:47 -0400 Organization: A noiseless patient Spider Lines: 19 Message-ID: <jwva5kj9c0j.fsf-monnier+comp.arch@gnu.org> References: <abe04jhkngt2uun1e7ict8vmf1fq8p7rnm@4ax.com> <memo.20240512203459.16164W@jgd.cix.co.uk> <v1rab7$2vt3u$1@dont-email.me> <20240513151647.0000403f@yahoo.com> <v1to2h$3km86$1@dont-email.me> <20240514221659.00001094@yahoo.com> <v234nr$12p27$1@dont-email.me> <20240516001628.00001031@yahoo.com> <v2cn4l$3bpov$1@dont-email.me> <v2d9sv$3fda0$1@dont-email.me> <20240519203403.00003e9b@yahoo.com> <v2etr0$3s9r0$1@dont-email.me> <20240520113045.000050c5@yahoo.com> <v2ff99$3vq7q$1@dont-email.me> <20240520153630.00000b5a@yahoo.com> <v2g7js$4vi9$1@dont-email.me> <20240521104659.00003fa0@yahoo.com> <e6f23396245cccf5a852718d100d044a@www.novabbs.org> MIME-Version: 1.0 Content-Type: text/plain Injection-Date: Tue, 21 May 2024 21:56:54 +0200 (CEST) Injection-Info: dont-email.me; posting-host="ff98a5a52c24689404a2aa94c510823c"; logging-data="800546"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19RlXe77rnprRu8Eb4wVYjUEofY8xu0N8s=" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:3bVrnp3uKybCVVsc94knykfS98Y= sha1:Y0kVH4RO6ed1p8EP47CvpSCL5rw= Bytes: 2427 >> I think, we were discussing multiplication stage of FMA rather than >> multiplication proper. >> In case of FMA, zeroness (zeroity ?) and sign of tiny product matter in >> all standard IEEE rounding mode except default (RNE). > Imagine, instead, if IEEE 754 had defined positive underflow with the > result of positive tiny, negative underflow with negative tiny, > positive overflow with positive infinity-epsilon and negative > overflow with negative infinity+epsilon. > Here, the fact overflow or underflow happened is recorded in the > result, and these results remain identifiable from real infinities > or real zeros. > But that ship sailed 50 years ago. Wouldn't that just kick the problem down the street? For example, what should `x < y` return when both `x` and `y` are "infinity+epsilon"? Stefan