Assembly Language Rep Movsd The use of detailed _c languages

MOV Esi,offset @s1
MOV Edi,offset @s2
MOV ecx,10
Cld
Rep Movsd

1.Rep Movsd every ecx! =0 executes Movsd, then ecx=ecx-1 movsd move Ds:[si] to Es:[di], in 32-bit assembler can replace the Si,edi with ESI instead of Di

2. at the same time because in general exe DS = ES program starting position so another ESI = offset @s1 can find the variable s1, edi= offset @s2 can find the variable s2

3.Movsd Such directives are of a nature and perform a esi = ESI +1,edi= edi+ 1 when the flag bit d=0

d=1 when performing esi = esi +1,edi= edi+ 1

So the meaning of this instruction is to copy ecx from S1 to S2