Advanced Micro Devices Inc (AMD)

[dacaw]

Thinking about rgb->bgr

the best way is probably the simplest:

;esi ->src & dst
;ecx -> # triplets

;*************************************************

top:
mov al,[esi+0]
xchg al,[esi+2]
mov [esi+0],al
add si,3
dec ecx
jnz top

Only problem is that xchg locks the bus, so you may wish to do:

top:
mov al,[esi+0]
mov ah,[esi+2]
mov [esi+2],al
mov [esi+0],ah
add si,3
dec ecx
jnz top

Isn't that easier? And write allocation takes care of the memory accesses for you.