Re: [Mingw-users] Really slow executables generated by Msys/Mingw

[Michael G. <mg...@te...>]

> Malloc is not the problem.

Right -- I added another time() and it shows that the malloc calls
do usually add 0 sec and occasionally 1 sec.

> I wouldn't know enough about the assembled code to know what was going=20
> on and decipher it.  I would have thought though that gcc would create=20
> similar code.

I have tried your code and the gcc invocations on Linux with both
3.3.5 as well as 4.0.2.

3.3.5 mostly reflects your results (about 23 sec on my machine).
However the -ffast-math version with 4.0.2 results in about 9 sec
on my machine which is pretty similar to your 8.9 sec using .NET

I have not bothered to check on the generated assembly however
all but the -ffast-math version requires -lm on Linux which probably
implies there is a subroutine call involved.

Therefor I guess Greg Chicares assumption that the difference in
speed is due to FSIN inline (or something similar) as opposed to
actually calling a subroutine has some probability.

However according to the gcc docs -ffast-math option impacts
reproduceability of the results on different platforms etc.

Best,
Michael
=2D-=20
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 Michael Gerdau       email: mg...@te...
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