Please reconsider implementing the standard memory functions yourself about mcfgthread HOT 3 CLOSED

rep movsb/stosb is fast ( with large and aligned memory ) because of the ERMSB optimization.

Yes; and for small blocks of memory it has a huge startup overhead.
Those functions have been designed to be small and inlineable. They are not presumed to be fast.

But repz cmpsb is not the case. It's not optimized.

That does not matter. It is there only because GCC requires it. At the moment we make no use of it at all.

RtlCompareMemory is slow because it uses repz cmpsb too. We can use memcmp in ntdll, which results in both less code and better performance.

memcmp() does not exist in NTDLL.DEF from mingw-w64 and would cause undefined references if it was called.

from mcfgthread.

We dont use cmpsb but we use memmove

https://github.com/lhmouse/mcfgthread/blob/ac3cf22f602a15796992d72e52c49e91eb0b38d0/src/dtor_queue.c

Add GCC use these functions internally, that's why GCC requires it.

https://gcc.godbolt.org/z/f889cYc6e

And

They are exported from the DLL for external use

memcmp() does not exist in NTDLL.DEF from mingw-w64 and would cause undefined references if it was called.

What about kernel*.dll? No

from mcfgthread.

The fact that 'we make no use of it' does not mean we make no use of all of them.

from mcfgthread.