Subject: Re: [boost] Fixed point integer proposal
From: Soren Holstebroe (holstebroe_at_[hidden])
Date: 2009-06-25 19:34:59
2009/6/25 Christian Schladetsch <christian.schladetsch_at_[hidden]>:
> In fact, fixed point is not faster on many architectures than floating
> point. One assumes that it is mainly PSP, DS and Gamecube guys that want
> fixed-point just for speed these days (I'm looking at you, Kenny ;).
On my quad core desktop there is a difference between ints and floats.
I just wrote a quick test with the following loop for some random
for (int i = 0; i < iterations; ++i)
sum += a * b;
a += b;
I used MSVC++ to compile.
I set iterations to a billion. When I used ints I got around 800
ticks. When I used floats I got around 3700 ticks.
That is almost a factor five. For my purposes, that's an optimization
I am willing to sacrifice a lot for.
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