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: 114669,94472ba0fa186a8d X-Google-Attributes: gid114669,public X-Google-Thread: 1147fc,94472ba0fa186a8d X-Google-Attributes: gid1147fc,public X-Google-Thread: 103376,94472ba0fa186a8d X-Google-Attributes: gid103376,public From: mfb@mbunix.mitre.org (Michael F Brenner) Subject: Re: ADA on the super Date: 1998/04/20 Message-ID: <6hfjmg$hvt@top.mitre.org>#1/1 X-Deja-AN: 345948421 Distribution: inet References: <6h7v0c$r68$1@bambi.zdv.Uni-Mainz.DE> <6ha2lu$5cb$1@nnrp1.dejanews.com> Organization: The MITRE Corporation, Bedford Mass. Newsgroups: comp.sys.super,comp.parallel.mpi,comp.lang.ada Date: 1998-04-20T00:00:00+00:00 List-Id: > Yes, Robert I agree, but ... [it] shares the back end of GCC, > which isn't famous for its optimization. Robert > ... the backend of GCC, actually it is well known for high > code quality and extensive optimization. On a number of machines, > GCC is the most efficient code generator available. ... > A number of customers chose gnat ... after extensive benchmarking > *because* it was the most effective compiler *for their application*. I would like to confirm what Robert says in the following cases: (a) tsgreat, an extensive arithmetic with no I/O, is timed as follows: (first run tsgreat 1001 and tsgreat 1, then subtract the two numbers to get the time for 1000 iterations): 90 MHz Pentium DOS Alsys-83 32-bit Compiler: 25 sec 90 MHZ Pentium DOS Meridian-83 32 bit Compiler: 49 sec 90 MHz Pentium DOS Janus-83 16 bit Compiler: 39 sec 90 MHz Pentium DOS gnat-95 3.10 from GWU: 21 sec 90 MHz Pentium DOS Turbo Pascal 7.0 32 bit Compiler: 78 sec (b) Lighting up things dot by dot on the SVGA memory mapped screen goes about twice as fast in gnat3.10 than in Alsys-83. (c) Lighting up things by moving large blocks or whole lines at a time to the SVGA memory mapped screen goes about twice as fast in Alsys-83 than in gnat3.10. CONCLUSION: Gnat has good optimization. Gnat has good code generation except for packed arrays. Robert is right about bench marking your application with ALL of your data before deciding what is fast and what is slow. Mike Brenner