mem.asm_x86_64 699 B raw

section .text
​
global memcpy
memcpy:
    mov rcx, rdx
    mov rax, rdi
    rep movsb
    ret
​
global memset
memset:
    push rdi
    mov rax, rsi
    mov rcx, rdx
    rep stosb
    pop rax
    ret
​
global memmove
memmove:
    mov rcx, rdx
    mov rax, rdi
​
    cmp rdi, rsi
    ja .copy_backwards
​
    rep movsb
    jmp .done
​
  .copy_backwards:
    lea rdi, [rdi+rcx-1]
    lea rsi, [rsi+rcx-1]
    std
    rep movsb
    cld
​
  .done:
    ret
​
global memcmp
memcmp:
    mov rcx, rdx
    repe cmpsb
    je .equal
​
    mov al, byte [rdi-1]
    sub al, byte [rsi-1]
    movsx rax, al
    jmp .done
​
  .equal:
    xor eax, eax
​
  .done:
    ret
​
section .note.GNU-stack noalloc noexec nowrite progbits

tab: 2 4 8 wrap: off on

1	section .text
2
3	global memcpy
4	memcpy:
5	mov rcx, rdx
6	mov rax, rdi
7	rep movsb
8	ret
9
10	global memset
11	memset:
12	push rdi
13	mov rax, rsi
14	mov rcx, rdx
15	rep stosb
16	pop rax
17	ret
18
19	global memmove
20	memmove:
21	mov rcx, rdx
22	mov rax, rdi
23
24	cmp rdi, rsi
25	ja .copy_backwards
26
27	rep movsb
28	jmp .done
29
30	.copy_backwards:
31	lea rdi, [rdi+rcx-1]
32	lea rsi, [rsi+rcx-1]
33	std
34	rep movsb
35	cld
36
37	.done:
38	ret
39
40	global memcmp
41	memcmp:
42	mov rcx, rdx
43	repe cmpsb
44	je .equal
45
46	mov al, byte [rdi-1]
47	sub al, byte [rsi-1]
48	movsx rax, al
49	jmp .done
50
51	.equal:
52	xor eax, eax
53
54	.done:
55	ret
56
57	section .note.GNU-stack noalloc noexec nowrite progbits