[PATCH] x86-64: Implement strcpy family IFUNC selectors in C

[Florian Weimer]

On 06/11/2017 03:50 PM, H.J. Lu wrote:
> All internal calls within libc.so can use IFUNC on x86-64 since unlike
> x86, x86-64 doesn't need to reserve a register to make a PLT call.

Shouldn't this rather say, “because, unlike x86, x86-64 supports 
PC-relative addressing to access the GOT entry”?  That's probably the 
root cause of the performance difference.

Thanks,
Florian