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: 103376,c6128af70f6d02c8
X-Google-Attributes: gid103376,public
From: tmoran@bix.com (Tom Moran)
Subject: Re: Timing things.
Date: 1999/06/16
Message-ID: <3767f26f.840466@news.pacbell.net>#1/1
X-Deja-AN: 490363113
References: <3767E18A.1904F5AF@acm.org>
X-Complaints-To: abuse@pacbell.net
X-Trace: typhoon-sf.snfc21.pbi.net 929559516 207.214.211.175 (Wed,
 16 Jun 1999 11:58:36 PDT)
Organization: SBC Internet Services
NNTP-Posting-Date: Wed, 16 Jun 1999 11:58:36 PDT
Newsgroups: comp.lang.ada
Date: 1999-06-16T00:00:00+00:00
List-Id: <comp.lang.ada>

>Windows98 PC using Gnat 3.11p
>...
>I am getting either end_time and start_time are the same or
>num_micros is 110_000
  Sounds like it's using the standard PC clock that tickes every 55
milliseconds.  You can get a different compiler, or a different OS or
machine, or make a direct OS call to QueryPerformanceCounter (sp?)
or
> start_time := ada.real_time.clock;
    for trial in 1 .. 100 loop
>do operations ( e.g. build 10_000 element heap in at least 23_000
>               comparisons)
   end loop;
>end_time := ada.real_time.clock;
>num_micros := ada.real_time."/"(ada.real_time."-"(end_time,start_time),

ada.real_time.microseconds(1))/100; ie, run the test long enough to
get multiple clock ticks, then divide the elapsed time by the number
of trials you used.