Proposal for CPU dispatching in libc

[Agner Fog]

Petr Baudis wrote:
>   This work is already being done in glibc git tree by Ulrich Drepper
> and H.J. Lu; a new ELF symbol type STT_GNU_IFUNC is used; if symbol
> of this type is called, the function returns address of the actual
> function that should be called on this and subsequent calls.
>
>   Currently, SSE4.2-optimized strcmp() is already committed.
>   
I see that an optimized strcpy has also been committed. What a 
coincidence that our offer to do this work comes at just the time where 
others have begun to do the same work. Some of the most important 
functions to optimize, in my opinion, are memset, memcpy and memmove. 
The latter two will use the same principles as strcpy for SSSE3, so I 
guess you will be making these functions as well.

Do you need our help optimizing other functions or is our offer to help 
coming too late?