Fix alignment issues with double-wide atomics on i386 #102
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…atforms We used to use Int64 on 32-bit architectures, but the inconsistency is bothering me. (Even ignoring alignment issues on SysV-derived ABIs on i386.)
… types The SysV ABI defined uint64_t with 4 byte alignment on i386 — so we can’t just assume that the integer types will have the right alignment by default for atomics. Emulate the original `_Atomic<Width>Storage` types in the C shims even in native atomics configuration, so that they can carry a custom `@_alignment` attribute.
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Azoy
approved these changes
Sep 22, 2023
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The SysV ABI defined
uint64_twith 4 byte alignment on i386 — so we can’t just assume that the integer types will have the right alignment for atomics out of the box.Emulate the original
_Atomic<Width>Storagetypes from the old C shims even in native atomics configuration, so that they can carry a custom@_alignmentattribute.Change things up so that these storage types define atomic operations taking and returning themselves, rather than some standard scalar type. This gets things a little closer in spirit to what we're planning to do in the stdlib, and it really cuts down the size of the gyb output for the native definitions.
Resolves #99.
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