Article View: comp.arch
Article #12292Re: IEEE arithmetic (Goldberg paper)
From: Jon Krueger
Date: Sat, 29 Jun 1991 02:14
Date: Sat, 29 Jun 1991 02:14
24 lines
1401 bytes
1401 bytes
I wrote: >>It is a good thing for compilers to expose broken programs. Stan wrote: >Many vector machines do summations in different than program order; thus >optimization on vs. off can and does produce different answers. They >can be very different depending upon the actual numbers. Not what I was referring to. Such compilers are broken. The meaning of some programs depends on the ordering of some of their steps. To change the ordering is to change the meaning -- an impermissible optimization. A program in a sequential language may reasonably depend on the sequential ordering of its steps. Such programs are not broken. A program in a language where order of expression evaluation is undefined may not reasonably depend on left-to-right evaluation. Such programs are broken. -- Jon Jon Krueger, jpk@ingres.com
Technical Details
Message-ID:
<1991Jun29.021450.18391@ingres.Ingres.COM>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!pacbell.com!pacbell!rtech!ingres!Ingres.COM!jpkReferences:
<9106210542.AA21933@ucbvax.Berkeley.EDU> <1991Jun24.211407.17389@ingres.Ingres.COM> <64885@bbn.BBN.COM>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!pacbell.com!pacbell!rtech!ingres!Ingres.COM!jpk From: jpk@Ingres.COM (Jon Krueger) Newsgroups: comp.arch Subject: Re: IEEE arithmetic (Goldberg paper) Message-ID: <1991Jun29.021450.18391@ingres.Ingres.COM> Date: 29 Jun 91 02:14:49 GMT References: <9106210542.AA21933@ucbvax.Berkeley.EDU> <1991Jun24.211407.17389@ingres.Ingres.COM> <64885@bbn.BBN.COM> Reply-To: jpk@Ingres.COM (Jon Krueger) Organization: Ingres Division, ASK Computer Systems. Lines: 24