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16:30:46
sjl
is it safe to assume characters and fixnums will always work with eq in sbcl? I can't find it documented in the manual anywhere
16:31:33
sjl
I'm considering adding some key hooks into stumpwm, which only supports sbcl, but since they'll be looked up on every single keypress I'd like the lookups (probably in an eq hashtable) to be as fast as possible
17:02:27
sjl
pkhuong: it would work, I was just wondering if I could reduce latency even further with a faster test. I should actually implement it with eql and just see how much time it takes before worrying about it though.
17:50:53
stassats
SB-KERNEL:POINTER-HASH claims to "shift the whole address into a positive fixnum.", yet it does (inst shr res 1)
17:52:10
stassats
i wonder what would be the effect if i fix it, would actually improve or worsen collisions
18:17:05
stassats
x86: (loop for i to 16 collect (sb-impl::index-for-hashing (sb-impl::eq-hash i) 16)) => (7 7 6 6 5 5 4 4 3 3 2 2 1 1 0 0 0)
18:38:11
stassats
doing (inst shr res 1) (inst and res (lognot n-fixnum-tag-bits)) => (8 8 7 7 6 6 5 5 4 4 3 3 2 2 2 2)
19:31:37
stassats
(inst and res (constantize (dpb -1 (byte (- n-word-bits n-fixnum-tag-bits 1) n-fixnum-tag-bits) 0))) =>
19:45:43
corci
Project sbcl-master-windows build #2716: FAILURE in 35 min: http://ci.cor-lab.de/job/sbcl-master-windows/2716/
20:23:30
corci
Project sbcl-master-windows build #2717: FIXED in 37 min: http://ci.cor-lab.de/job/sbcl-master-windows/2717/
1:54:32
pfdietz_
I wonder if fibonacci hashing could help with that https://probablydance.com/2018/06/16/fibonacci-hashing-the-optimization-that-the-world-forgot-or-a-better-alternative-to-integer-modulo/