Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site noao.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!astrovax!noao!grandi From: grandi@noao.UUCP Newsgroups: net.lang.f77 Subject: Re: xf77 compiler ? Message-ID: <357@noao.UUCP> Date: Fri, 22-Jun-84 11:50:32 EDT Article-I.D.: noao.357 Posted: Fri Jun 22 11:50:32 1984 Date-Received: Sat, 23-Jun-84 03:47:45 EDT References: <32400001@uiucuxc.UUCP> Organization: Natl. Optical Astronomy Obs. Tucson AZ USA Lines: 39 * My understanding of the LINPACK Benchmark is that xf77 represents the BSD 4.2 f77 compiler (with optimization on). However, as regular readers of this newsgroup know, the 4.2 f77 optimizer is FULL of bugs. Thank the Gods of Fortran for Donn Seeley and his bugfixes that at least seem to make the compiler reliable with the optimizer off. SO, if all the bugs can be rooted out, the 4.2 f77 compiler is at least close to the VMS compiler in execution speed. But it is sure slow when compiling! HOWEVER, DEC has just announced that the f77 compiler that will come with version 4.0 of VMS will increase execution performance by 10 - 50%. For those of you interested in the actual benchmarks, they are taken from "Performance of Various Computers Using Standard Linear Equation Software in a Fortran Environment," Jack J. Dougarra, Mathematics and Computer Science Division, Argonne National Laboratory, 10 Jan. 1984. Unfortunately, I have misplaced my copy of this report and can only quote from a bowderlized version reprinted in the Astronomical Image Processing Circular (#10). Linpack routines SGEFA and SGESL were used for problems of order 100. Computer/Compiler Double-Precision Mflops Single-Precision Mflops -------------------------------------------------------------------------------- Cray X-MP/CFT 21.0 CDC Cyber 205/FTN 8.4 Amdahl 5860/H enhan (opt=3) 3.9 5.5 IBM 3081K/H enhan (opt=3) 2.1 2.4 DG MV-10000/f77 (opt=3) 0.30 0.39 VAX 11/780 + FPA/VMS-f77 0.13 0.21 VAX 11/780 + FPA/UNIX(4.2)-f77 opt 0.11 0.20 Ridge 32/f77 0.12 0.20 VAX 11/750 + FPA/VMS-f77 0.10 0.14 IBM 4331/H (opt=3) 0.038 0.088 VAX 11/730 + FPA/VMS-f77 0.036 0.047 IBM PC-XT/370/H (opt=3) 0.031 0.040 Sun 2 + FPA/UNIX(4.2)-f77 opt 0.022 0.039 -- Steve Grandi, National Optical Astronomy Observatories, Tucson, AZ, 602-325-9228 {allegra,arizona,astrovax,decvax,hao,ihnp4,lbl-csam} !noao!grandi