Mail Archives: djgpp/1999/08/17/12:19:31
I think you are right about the bad luck. I found this:
gcc 2.81 gcc 2.95 CBuilder 4.0
- old version of chess program 123a 112a 132a
- new version of chess program - 550b 500b
a = Positions searched per Second (x1000)
b = Times a sec that all legal moves in a pos are generated (x1000)
The new version of the program uses a lot of 64 bit integers.
The strange thing is for program a) gcc 2.95 is slowest, while for b)
it is fastest. Borland other way round.
So it could very well be that gcc 2.95 is overall faster than 2.81.
optimation options used:
-o6 -fomit_frame_pointer
>On Thu, Aug 12, 1999 at 10:58:39AM +0300, Eli Zaretskii wrote:
>>
>> On Wed, 11 Aug 1999, "Bas Hamstra" <bas.hamstra wrote:
>>
>> > I donwloaded some components of GCC 2.95 (binaries of gcc, gxx and the libs,
>> > I believe) and copied them onto the old djgpp package (latest official
>> > version). It works, but now my programs run slower, regardless of the
>> > optimation options.
>There are many changes in 2.95, so it is possible that you have just bad luck
>and some of new features hurts your program. At the average 2.95 is a win
>(pretty noticeable).
>I would recommend you to try -mpreferred-stack-boundary=2 option. It turns off
>stack alignment code and makes executable smaller, function calling faster
>and may reduce performance of fp code, if some of the temporaries spilled to
>stack in internal loop gets missaligned.
>Honza
Jan Hubicka <hubicka AT tabor DOT ta DOT jcu DOT cz> wrote:
>On Thu, Aug 12, 1999 at 10:58:39AM +0300, Eli Zaretskii wrote:
>>
>> On Wed, 11 Aug 1999, "Bas Hamstra" <bas.hamstra wrote:
>>
>> > I donwloaded some components of GCC 2.95 (binaries of gcc, gxx and the libs,
>> > I believe) and copied them onto the old djgpp package (latest official
>> > version). It works, but now my programs run slower, regardless of the
>> > optimation options.
>There are many changes in 2.95, so it is possible that you have just bad luck
>and some of new features hurts your program. At the average 2.95 is a win
>(pretty noticeable).
>I would recommend you to try -mpreferred-stack-boundary=2 option. It turns off
>stack alignment code and makes executable smaller, function calling faster
>and may reduce performance of fp code, if some of the temporaries spilled to
>stack in internal loop gets missaligned.
>Honza
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