26 Apr
2013
26 Apr
'13
5:59 a.m.
On Thu, Apr 25, 2013 at 10:32 PM, Johan Tibell
If you remember where it would be great to see an example.
I'm afraid I don't remember. I spend a lot of time optimising things down to the last memory allocation, and this was one of those cases where I could keep heap allocation constant by unboxing an unpacked field repeatedly, whereas if I packed the field I was allocating a little on every iteration of whatever the loop was.
There's also NOUNPACK nowadays so you can opt out in these specific cases.
Oh yes, I have no problem with this becoming the default behaviour. All I was doing was confirming that it is not always a win "in the wild".