On 16/04/14 17:57, Peter Schneider wrote:
Hi David,
Sorry, I had included more information in an earlier draft which I
edited out for brevity.
(Sorry for the late reply - Easter is a /serious/ holiday in Norway.)
> You cannot learn useful timing
> information from a single run of a short
On April 16, 2014 7:45:55 PM CEST, Peter Schneider wrote:
>In order to see what difference a different processor makes I also
>tried
>the same code on a fairly old 32 bit "AMD Athlon(tm) XP 3000+" with the
>
>current stable gcc (4.7.2). The difference is even more striking
>(dereferencing is muc
In order to see what difference a different processor makes I also tried
the same code on a fairly old 32 bit "AMD Athlon(tm) XP 3000+" with the
current stable gcc (4.7.2). The difference is even more striking
(dereferencing is much faster). I see that the size of the code inside
the loop for t
Hi David,
Sorry, I had included more information in an earlier draft which I
edited out for brevity.
> You cannot learn useful timing
> information from a single run of a short
> test like this - there are far too many
> other factors that come into play.
I didn't mention that I have run it d
Hello,
I completely agree with David.
Note that your results will greatly vary depending on the machine you
run the tests on. Performance on such tests it is very
machine-dependant, so the conclusion cannot be generalized.
David
2014-04-16 16:49 GMT+02:00 David Brown :
>
> Hi,
>
> You cannot lea
Hi,
You cannot learn useful timing information from a single run of a short
test like this - there are far too many other factors that come into play.
You cannot learn useful timing information from unoptimised code.
There is too much luck involved in a test like this to be useful. You
need op
I have made a curious performance observation with gcc under 64 bit
cygwin on a corei7. I'm genuinely puzzled and couldn't find any
information about it. Perhaps this is only indirectly a gcc question
though, bear with me.
I have two trivial programs which assign a loop variable to a local
va
