1 ; fib_64m.asm using 64 bit memory more like C code
2 ; // fib.c same as computation as fib_64m.asm
3 ; #include <stdio.h>
4 ; int main(int argc, char *argv[])
5 ; {
6 ; long int c = 95; // loop counter
7 ; long int a = 1; // current number, becomes next
8 ; long int b = 2; // next number, becomes sum a+b
9 ; long int d; // temp
10 ; printf("fibinachi numbers\n");
11 ; for(c=c; c!=0; c--)
12 ; {
13 ; printf("%21ld\n",a);
14 ; d = a;
15 ; a = b;
16 ; b = d+b;
17 ; }
18 ; }
19 global main
20 extern printf
21
22 section .bss
23 00000000 <res 00000008> d: resq 1 ; temp unused, kept in register rdx
24
25 section .data
26 00000000 5F00000000000000 c: dq 95 ; loop counter
27 00000008 0100000000000000 a: dq 1 ; current number, becomes next
28 00000010 0200000000000000 b: dq 2 ; next number, becomes sum a+b
29
30
31 00000018 2531356C640A00 format: db '%15ld', 10, 0
32 0000001F 666962696E61636869- title: db 'fibinachi numbers', 10, 0
33 00000028 206E756D626572730A-
34 00000031 00
35
36 section .text
37 main:
38 00000000 55 push rbp ; set up stack
39 00000001 48BF- mov rdi, title ; arg 1 is a pointer
40 00000003 [1F00000000000000]
41 0000000B B800000000 mov rax, 0 ; no vector registers in use
42 00000010 E8(00000000) call printf
43
44 print:
45 ; We need to call printf, but we are using rax, rbx, and rcx.
46 00000015 48BF- mov rdi, format ; arg 1 is a pointer
47 00000017 [1800000000000000]
48 0000001F 488B3425[08000000] mov rsi,[a] ; arg 2 is the current number
49 00000027 B800000000 mov rax, 0 ; no vector registers in use
50 0000002C E8(00000000) call printf
51
52 00000031 488B1425[08000000] mov rdx,[a] ; save the current number, in register
53 00000039 488B1C25[10000000] mov rbx,[b] ;
54 00000041 48891C25[08000000] mov [a],rbx ; next number is now current, in ram
55 00000049 4801D3 add rbx, rdx ; get the new next number
56 0000004C 48891C25[10000000] mov [b],rbx ; store in ram
57 00000054 488B0C25[00000000] mov rcx,[c] ; get loop count
58 0000005C 48FFC9 dec rcx ; count down
59 0000005F 48890C25[00000000] mov [c],rcx ; save in ram
60 00000067 75AC jnz print ; if not done counting, do some more
61
62 00000069 5D pop rbp ; restore stack
63 0000006A B800000000 mov rax, 0 ; normal exit
64 0000006F C3 ret ; return to operating system