Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!cbosgd!gwspc!cbcsta!n8emr!oink!jep From: jep@oink.UUCP Newsgroups: comp.lang.c Subject: Re: Dhrystones Message-ID: <204@oink.UUCP> Date: Fri, 4-Dec-87 13:19:22 EST Article-I.D.: oink.204 Posted: Fri Dec 4 13:19:22 1987 Date-Received: Wed, 9-Dec-87 20:16:46 EST References: <3368@rosevax.Rosemount.COM> Reply-To: jep@oink.UUCP (James E. Prior) Organization: Random Prime Research Institute Columbus, Ohio Lines: 35 Keywords: C, performance In article <3368@rosevax.Rosemount.COM> richw@rosevax.Rosemount.COM (Rich Wagenknecht) writes: >Could somemone tell me what a 'Dhrystone' (<-sp.?) is? >Why is it used so often to evaluate compiler performance? >Is it a good overall indicator of compiler peformance? > >Thanks in advance, >Rich W. First there was the Whetstone benchmark. It is rich in floating point calculations, and as such is handy for comparing systems when you are concerned about scientific calculations. Most operating system programming doesn't use any floating point math. Same goes for programs such as text editors, compilers, assemblers, linkers, and any other program primarily dealing with integers instead of of floating point data. On machines without floating point hardware, the Whetstone benchmark will report that the machine is very pokey, even though it might scream when doing operating system stuff or any other non-floating point calculations. The Dhrystone benchmark program attempts to measure to speed of non-floating point code. As such, it is much better for comparing compilers that the Whetstone benchmark. Its name is a pun on "Whet", since it measures the opposite kind of calculation. In spite of the above, I am leery of benchmarks. The is a saying: "There are lies, damn lies, and benchmarks." The correct way to compare systems, is to run the programs that *you* are interested in, on them. Make sure you are doing emprical bench- marks, not just paper calculations of how much time it "should" take. -- Jim Prior jep@oink.UUCP {ihnp4|cbosgd}!n8emr!oink!jep