In theory there could be a "fixed-layout" enum that's not exhaustive
but promises not to add any more cases with payloads, but we don't
need that distinction today.
(Note that @objc enums are still "fixed-layout" in the actual sense of
"having a compile-time known layout". There's just no special way to
spell that.)
In response to [SR-3334], which pointed out a large cost to iteration over
ReversedRandomAccessCollections at optimization level -Onone. By adding
iteration through a.reversed() in the _Prespecialize struct, we can get to
about the same performance as forward iteration.
Pre-specializations were only used by Onone builds, but were kept inside the standard library dylyb anyways. This commit moves all the pre-specializations into a dedicated Swift module and a dynamic library, which are only used by Onone builds.
This reduces the code size of libswiftCore.dylib by 4%-5%.
Pre-specializations were only used by Onone builds, but were kept inside the standard library dylyb anyways. This commit moves all the pre-specializations into a dedicated Swift module and a dynamic library, which are only used by Onone builds.
This reduces the code size of libswiftCore.dylib by 5%.
