Inlining of runtime/internal/atomic.Cas

[Timur Celik]

Why is it that changes in the runtime package's atomic.Cas don't land in
my build? I suspect it has something to do with inlining of the
function, but even with `-gcflags=-l` the atomic.Cas original
implementation seems to get inlined. Functions that aren't inlined,
like atomic.Or have my changes incorporated. I tried deleting all
caches and rebuilt the compiler without success.

Thank you.

[Ian Lance Taylor]

It's because in general the compiler internally implements all the
functions that appear in runtime/internal/atomic. The implementations
in that package are not normally used at all, though they may be used
when optimizations are disabled (-gcflags=-N). For the internal
compiler implementations you can start by looking for
OpAtomicCompareAndSwap32 in cmd/compile/internal/ssa.

Ian

[Timur Celik]

Thank you so much, this solves my issue. Really appreciate your work for the Go project, Ian. Cheers