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From: Terry Lambert <terry@lambert.org>
Message-Id: <199610232122.OAA10485@phaeton.artisoft.com>
Subject: Re: Is profiling code broken?
To: sgk@troutmask.apl.washington.edu (Steven G. Kargl)
Date: Wed, 23 Oct 1996 14:22:19 -0700 (MST)
Cc: freebsd-current@FreeBSD.org
In-Reply-To: <199610232042.NAA05182@troutmask.apl.washington.edu> from "Steven G. Kargl" at Oct 23, 96 01:42:54 pm
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>       program t
>       implicit none
>       double precision x, f
>       integer i, j
>       external f
> 
>       do 1 i =1, 1000
>          do 2 j = 1, 1000
>             x = f(dble(i))
> 2        continue
> 1     continue
>       end

I would expect the second do loop to be removed by a decent optimizer;
ij is not a dependent variable.  Maybe the back end changed to 2.7.2 or
the default optimization flags have changed in the compilation script?

>       double precision function f(x)
>       double precision x
>       integer i
>       do 3 i = 1, 100
>          f = x / 2.d0
> 3     continue
>       return
>       end

I would expect this second do loop to fall out as well.

> There appears to be about 11 seconds missing from the time command
> that should be accounted for by gprof.

Inline functions for which exported symbols aren't generated will
be static.  This could be hidden in your dble() call...

> Additionally, I noticed that the profiled libraries built during a
> make world use a -p flag instead of -pg.  Why? We do not currently
> have prof(1) in the source tree.

g is debugging information; you don't need it for profiling?


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.