alt Hacker Newsnth_set_bit_u64: wouldn't that be __builtin_ctzll(_pdep_u64(1<<n, v)) with BMI2?
Replies
SkiFire13 • 11/20/2024
That's assuming you're ok with your program not running on some older cpus.
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stouset • 11/21/2024
I believe the equivalent ARM64 instructions are in SVE2 which isn’t yet supported on Apple’s M-series chips as of M4, sadly.
That's my guess as well.
Bitstring rank/select is a well-known problem, and the BMI and non-BMI (Hacker's Delight) versions are available as a reference.