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crotetoday at 12:06 PM2 repliesview on HN

Another thing to keep in mind is that CPU processing of denormals tends to be extremely slow - I vaguely recall running into something like a 10x slowdown a decade ago.

For a lot of applications the difference between a denormal and zero is small enough to be irrelevant, so if you expect near-zero values to be common, enabling a denormals-to-zero compiler flag might give you a pretty nice performance boost for free.


Replies

adgjlsfhk1today at 2:43 PM

cpus that aren't Intel are plenty fast on denormals. Intel is the only one where denormals are 100x slower. (and Intel has fixed that on their new cpus, but only on their e cores)

andrepdtoday at 3:18 PM

More like 100x, but not sure how true that is nowadays.