Re: C compilers with at least C11 threads, atomics and membars?

On 8/5/2024 11:51 AM, Blue-Maned_Hawk wrote:

Scott Lurndal wrote:
 

Blue-Maned_Hawk <bluemanedhawk@invalid.invalid> writes:

Standard C threading and atomics are part of the standard library, not
the compiler.  I don't know what you mean by the term ‘membars’, but if
you could define that, i might be able to answer.
>
>

They are referring to various forms of barrier instructions used to
synchronize memory accesses between independent processors.
>
I think you'll find that the compilers do have a role to play with
respect to standard C threading and atomics.

 Standard C threading and atomics are accomplished through subroutines
defined in the standard library in headers that need not be supported by
freestanding implementations.

You sound like the past, pre C11. Actually, the compiler plays a fairly "major" role in in such things, indeed! Heck even pre C11 if a compiler wanted to support POSIX it has to do certain things... This is why I had to code the "sensitive" parts of my lock/wait free algorithms in pure ASM. Aka, externally assembled libraries. Iirc, even then LTO could be a potential problem way back then...