Implement Intrinsics.pause for aarch64
#11742
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@lbguilherme Thanks for knocking this out. Super appreciated! |
straight-shoota
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Jan 12, 2022
jhass
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Jan 18, 2022
straight-shoota
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Intrinsics.pause for aarch64
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This was made by @jgaskins, full credits to him. Taken from https://forum.crystal-lang.org/t/intrinsics-pause-no-op-on-non-intel-cpus/4199.
Implements
Intrinsics.pausefor ARM. This is useful for busy loops inside a spinlock or a mutex implementation. Doesn't change correctness, but should provide some speedup in very high contention cases.Update: Only AArch64 is supported because the plain ARM variant (
llvm.arm.hint) seems to require ARMv7 at least and I don't see a way to select it.