Files
Nim/lib/system/sets.nim
flywind c8dda867f2 close #11330 sets uses optimized countSetBits (#17334)
* Update lib/pure/bitops.nim
* Update lib/system/sets.nim
* Apply suggestions from code review

Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
2021-03-22 00:36:48 +01:00

27 lines
562 B
Nim

#
#
# Nim's Runtime Library
# (c) Copyright 2012 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
# set handling
type
NimSet = array[0..4*2048-1, uint8]
proc cardSet(s: NimSet, len: int): int {.compilerproc, inline.} =
var i = 0
result = 0
when defined(x86) or defined(amd64):
while i < len - 8:
inc(result, countBits64((cast[ptr uint64](s[i].unsafeAddr))[]))
inc(i, 8)
while i < len:
inc(result, countBits32(uint32(s[i])))
inc(i, 1)