Subject: Re: one program, one machine, two wildly different execution times
To: None <firstname.lastname@example.org>
From: Ben Elliston <email@example.com>
Date: 04/20/2003 10:14:30
Jim Bernard <firstname.lastname@example.org> writes:
> My guess is that the two different execution times represent runs
> in which the program was loaded with different alignments of
> double-precision variables, one efficient and the other not. I
> tried compiling with -malign-double, but that made no difference.
> I've tried a large number of variations in compile-time optimization
> flags, including no optimization, and nothing made much of a
I doubt that would make any difference; your variables should be bound
to the same address in every run. Try compiling your program with -pg
and see if gprof gives you any insight into where the extra time is
being spent. That might be a good starting point.