4 ms·

There's a critical instruction for Objective C handling (I forget exactly what it is) but it's faster than intel's chips even in Rosetta 2's x86 emulation.

• wvenable 1y ago
  I believe it's the `lock xadd` instruction. It's faster when combined with x86 Total Store Ordering mode that the Rosetta emulation runs under.
  • saagarjha 1y ago
    Looking at objc_retain apparently it's a lock cmpxchg these days