[Mono-dev] mono numerical performance
Konrad M. Kruczyński
konrad.kruczynski at gmail.com
Sun Nov 20 11:38:10 EST 2011
I'd like to add that you may gain something on MS JIT compiler using
for (int i = 0 ; i < x.Length ; i++)
for (int i = 0 ; i < len ; i++)
This may seem counter intuitive, however that's the scenario in which
JIT eliminates array bound checking for the x array (however not for the
second one) as arrays have constant length. I am not sure whether Mini
recognizes that. I'm pretty sure that Hotspot is much smarter here ;)
As Zoltan wrote in the bug comments, enabling LLVM improves the results
a lot. This is, I guess, due to much better register allocation in which
domain Mini isn't too good - and probably other optimizations like
better loop unrolling.
If I remember correctly, there once was a branch of LLVM with array
bounds check elimination, is it still developed?
I am also curious which code patterns enable ABC elimination in Mini.
On Sun, 2011-11-20 at 08:01 -0500, Jonathan Shore wrote:
> Here is a link to and entry in bugzilla with attached code. I could
> not send to the list:
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