From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 109fba,dad65365cb2b3396 X-Google-Attributes: gid109fba,public X-Google-Thread: 103376,dad65365cb2b3396 X-Google-Attributes: gid103376,public X-Google-Thread: 1014db,dad65365cb2b3396 X-Google-Attributes: gid1014db,public X-Google-Thread: 106c43,dad65365cb2b3396 X-Google-Attributes: gid106c43,public X-Google-Thread: fac41,dad65365cb2b3396 X-Google-Attributes: gidfac41,public From: jhd@herold.franken.de (Joachim Durchholz) Subject: Re: The disturbing myth of Eiffel portability Date: 1996/11/25 Message-ID: <6LW663dk3RB@herold.franken.de>#1/1 X-Deja-AN: 200707604 references: <3294e64b.74799475@news2.ibm.net> <56t1m4$nis@bcrkh13.bnr.ca> newsgroups: comp.lang.eiffel,comp.lang.ada,comp.lang.c,comp.lang.c++,comp.lang.object Date: 1996-11-25T00:00:00+00:00 List-Id: fred@genesis.demon.co.uk wrote 24.11.96: > Financial calculations within (fairly generous) limits can use IEEE > floating point and be *proven* correct barring bugs in the implementation. > But bugs can affect integer calculations as well. However, integer bugs are less likely. After all, IEEE format is much more complicated (at least in comparison to two's-complement integer). For IEEE format, there is room for interpretation (really there isn't, but some implementors behave as if there were). E.g. the infamous Pentium bug was in the FPU, not in the ALU. Of course this is jumping to conclusions from a statistically insignificant sample... > No > format can represent general irrational quantities precisely. There is one - storing formulae instead of quantities :) Actually this is feasible - Mathematica and Co. do exactly this. This allows them to compute as many digits as required on the fly, without loss of precision from intermediate results. (Of course there is still a round-off error, but it is always on the last printed digits.) Anybody on his way implementing a FORMULA class for unlimited-precision math? Regards, -Joachim -- Looking for a new job. Resume available on request. WWW version of resume available under http://www.franken.de/users/herold/jhd/resume/index.html