There is no blog post
If there was a blog post written in markdown it would be here (but there isn't one).
Instead here is some assembly code:
%include "x86inc.asm"
SECTION .text
;static void add_values(uint8_t *src, const uint8_t *src2)
INIT_XMM sse2
cglobal add_values, 2, 2, 2, src, src2
movu m0, [srcq]
movu m1, [src2q]
paddb m0, m1
movu [srcq], m0
RET