closure iterators are much slower with ARC/ORC #20177
Description
What happened?
here I get 8x slow down when I switch to --mm:arc.
import std/sugar
import benchy
proc toIter*[T](s: Slice[T]): iterator: T =
iterator it: T {.closure.} =
for x in s.a..s.b:
yield x
return it
proc filter*[T](i: iterator: T, f: proc(x: T): bool): iterator: T =
iterator it: T {.closure.} =
for x in i():
if f(x):
yield x
result = it
iterator filter*[T](i: iterator: T, f: proc(x: T): bool): T =
for x in i():
if f(x):
yield x
timeIt "closure iterator":
var acc = 0
for i in (1..100_000).
toIter.
filter(x => x mod 2 == 0).
filter(x => x mod 4 == 0).
filter(x => x mod 8 == 0).
filter(x => x mod 16 == 0).
filter(x => x mod 32 == 0).
filter(x => x mod 64 == 0).
filter(x => x mod 128 == 0).
filter(x => x mod 256 == 0).
filter(x => x mod 512 == 0):
acc.inc iNim Version
Nim Compiler Version 1.7.1 [Windows: amd64]
Compiled at 2022-07-17
Copyright (c) 2006-2022 by Andreas Rumpf
active boot switches: -d:release
Current Standard Output Logs
with ARC: nim --mm:arc -d:release r .\play.nim:
min time avg time std dv runs name
4.022 ms 4.352 ms ±0.207 x1000 closure iterator
with refC: nim -d:release r .\play.nim:
min time avg time std dv runs name
0.841 ms 0.924 ms ±0.045 x1000 closure iterator
Expected Standard Output Logs
almost the same numbers
Additional Information
the numbers are almost the same with version 1.6.6, I will try to bisect the regression