On Mon, Sep 30, 2019 at 11:50 PM Nick Desaulniers
[off-list ref] wrote:
So __attribute__((always_inline)) doesn't guarantee that code will be
inlined. [...] inline and __attribute__((always_inline))
are a heuristic laden mess and should not be relied upon.
Small note: in GCC, __attribute__((always_inline)) is documented as
actually guaranteeing to either inline or error otherwise (although
see the remark for indirect calls):
"Failure to inline such a function is diagnosed as an error. Note
that if such a function is called indirectly the compiler may or may
not inline it depending on optimization level and a failure to inline
an indirect call may or may not be diagnosed."
As for LLVM/Clang, no idea, since it does not say anything about it in
the docs -- but from what you say, it is a weaker guarantee.
Cheers,
Miguel