global setjmp
; int setjmp(jmp_buf env);
setjmp:
    mov ecx, [esp + 4]  ; ecx = env
    mov edx, [esp + 0]  ; edx = ret addr
    mov [ecx + 0], edx
    mov [ecx + 4], ebx
    mov [ecx + 8], esp
    mov [ecx + 12], ebp
    mov [ecx + 16], esi
    mov [ecx + 20], edi
    mov [ecx + 24], eax ; eax = trigblock()'s ret val

    xor eax, eax    ; setjmp ret val = 0
    ret

global longjmp
; void longjmp(jmp_buf env, int val)
longjmp:

    mov edx, [esp + 4]  ; edx = env
    mov eax, [esp + 8]  ; eax = val
    mov ecx, [edx + 0]  ; ecx = setjmp()'s ret val
    mov ebx, [edx + 4]
    mov esp, [edx + 8]
    mov ebp, [edx + 12]
    mov esi, [edx + 16]
    mov edi, [edx + 20]

    ; make sure longjmp's ret val not 0
    test eax, eax   ; if eax == 0:
    jnz .1          ;   eax += 1
    inc eax         ; else: goto lable 1
.1: ; let longjmp's ret addr as setjmp's ret addr
    mov [esp + 0], ecx ; ret addr = ecx = setjmp's next code
    ret