I don't think 32-bit compilers generally offer builtins for 64-bit atomics. Frankly, they can't really unless the underlying ISA provides some additional support for this in particular.
To implement a 64-bit atomic on a 32-bit architecture, you generally needs some additional state somewhere -- typically some sort of mutex or spinlock. That has to live somewhere. (You *might* be able to have a compiler builtin that provides this along with a compiler runtime which provides an instance of the spinlock somewhere in the program's data section. I think this sort of "builtin" (which isn't really builtin at all) generally can't be used in operating system kernels -- e.g. with --freestanding.) On 10/9/2019 11:26:40 AM, Richard Elling <richard.ell...@richardelling.com> wrote: If it is possible to specify a compiler version, it might be easier to use the compiler builtin atomics. Just sayin' -- richard ------------------------------------------ openzfs: openzfs-developer Permalink: https://openzfs.topicbox.com/groups/developer/T3ee8a81d5f09f2ec-Me9f5c4a72346d54fcfcd775f Delivery options: https://openzfs.topicbox.com/groups/developer/subscription
