1 ; intlogic_64.asm show some simple C code and corresponding nasm code
2 ; the nasm code is one sample, not unique
3 ;
4 ; compile: nasm -f elf64 -l intlogic_64.lst intlogic_64.asm
5 ; link: gcc -m64 -o intlogic_64 intlogic_64.o
6 ; run: ./intlogic_64 > intlogic_64.out
7 ;
8 ; the output from running intlogic_64.asm and intlogic.c is
9 ; c=5 , a=3, b=5, c=15
10 ; c=a&b, a=3, b=5, c=1
11 ; c=a|b, a=3, b=5, c=7
12 ; c=a^b, a=3, b=5, c=6
13 ; c=~a , a=3, b=5, c=-4
14 ;
15 ;The file intlogic.c is:
16 ; /* intlogic.c */
17 ; #include <stdio.h>
18 ; int main()
19 ; {
20 ; long int a=3, b=5, c;
21 ;
22 ; c=15;
23 ; printf("%s, a=%d, b=%d, c=%d\n","c=5 ", a, b, c);
24 ; c=a&b; /* and */
25 ; printf("%s, a=%d, b=%d, c=%d\n","c=a&b", a, b, c);
26 ; c=a|b; /* or */
27 ; printf("%s, a=%d, b=%d, c=%d\n","c=a|b", a, b, c);
28 ; c=a^b; /* xor */
29 ; printf("%s, a=%d, b=%d, c=%d\n","c=a^b", a, b, c);
30 ; c=~a; /* not */
31 ; printf("%s, a=%d, b=%d, c=%d\n","c=~a", a, b, c);
32 ; return 0;
33 ; }
34
35 extern printf ; the C function to be called
36
37 %macro pabc 1 ; a "simple" print macro
38 section .data
39 .str db %1,0 ; %1 is first actual in macro call
40 section .text
41 mov rdi, fmt ; address of format string
42 mov rsi, .str ; users string
43 mov rdx, [a] ; long int a
44 mov rcx, [b] ; long int b
45 mov r8, [c] ; long int c
46 mov rax, 0 ; no xmm used
47 call printf ; Call C function
48 %endmacro
49
50 section .data ; preset constants, writeable
51 00000000 0300000000000000 a: dq 3 ; 64-bit variable a initialized to 3
52 00000008 0500000000000000 b: dq 5 ; 64-bit variable b initializes to 4
53 00000010 25732C20613D256C64- fmt: db "%s, a=%ld, b=%ld, c=%ld",10,0 ; format string for printf
54 00000019 2C20623D256C642C20-
55 00000022 633D256C640A00
56
57 section .bss ; unitialized space
58 00000000 <res 00000008> c: resq 1 ; reserve a 64-bit word
59
60 section .text ; instructions, code segment
61 global main ; for gcc standard linking
62 main: ; label
63 00000000 55 push rbp ; set up stack
64
65 lit5: ; c=5;
66 00000001 B80F000000 mov rax,15 ; 5 is a literal constant
67 00000006 48890425[00000000] mov [c],rax ; store into c
68 pabc "c=5 " ; invoke the print macro
69 <1> section .data
70 00000029 633D35202000 <1> .str db %1,0
71 <1> section .text
72 0000000E 48BF- <1> mov rdi, fmt
73 00000010 [1000000000000000] <1>
74 00000018 48BE- <1> mov rsi, .str
75 0000001A [2900000000000000] <1>
76 00000022 488B1425[00000000] <1> mov rdx, [a]
77 0000002A 488B0C25[08000000] <1> mov rcx, [b]
78 00000032 4C8B0425[00000000] <1> mov r8, [c]
79 0000003A B800000000 <1> mov rax, 0
80 0000003F E8(00000000) <1> call printf
81
82 andb: ; c=a&b;
83 00000044 488B0425[00000000] mov rax,[a] ; load a
84 0000004C 48230425[08000000] and rax,[b] ; and with b
85 00000054 48890425[00000000] mov [c],rax ; store into c
86 pabc "c=a&b" ; invoke the print macro
87 <1> section .data
88 0000002F 633D61266200 <1> .str db %1,0
89 <1> section .text
90 0000005C 48BF- <1> mov rdi, fmt
91 0000005E [1000000000000000] <1>
92 00000066 48BE- <1> mov rsi, .str
93 00000068 [2F00000000000000] <1>
94 00000070 488B1425[00000000] <1> mov rdx, [a]
95 00000078 488B0C25[08000000] <1> mov rcx, [b]
96 00000080 4C8B0425[00000000] <1> mov r8, [c]
97 00000088 B800000000 <1> mov rax, 0
98 0000008D E8(00000000) <1> call printf
99
100 orw: ; c=a-b;
101 00000092 488B0425[00000000] mov rax,[a] ; load a
102 0000009A 480B0425[08000000] or rax,[b] ; logical or with b
103 000000A2 48890425[00000000] mov [c],rax ; store into c
104 pabc "c=a|b" ; invoke the print macro
105 <1> section .data
106 00000035 633D617C6200 <1> .str db %1,0
107 <1> section .text
108 000000AA 48BF- <1> mov rdi, fmt
109 000000AC [1000000000000000] <1>
110 000000B4 48BE- <1> mov rsi, .str
111 000000B6 [3500000000000000] <1>
112 000000BE 488B1425[00000000] <1> mov rdx, [a]
113 000000C6 488B0C25[08000000] <1> mov rcx, [b]
114 000000CE 4C8B0425[00000000] <1> mov r8, [c]
115 000000D6 B800000000 <1> mov rax, 0
116 000000DB E8(00000000) <1> call printf
117
118 xorw: ; c=a^b;
119 000000E0 488B0425[00000000] mov rax,[a] ; load a
120 000000E8 48330425[08000000] xor rax,[b] ; exclusive or with b
121 000000F0 48890425[00000000] mov [c],rax ; store result in c
122 pabc "c=a^b" ; invoke the print macro
123 <1> section .data
124 0000003B 633D615E6200 <1> .str db %1,0
125 <1> section .text
126 000000F8 48BF- <1> mov rdi, fmt
127 000000FA [1000000000000000] <1>
128 00000102 48BE- <1> mov rsi, .str
129 00000104 [3B00000000000000] <1>
130 0000010C 488B1425[00000000] <1> mov rdx, [a]
131 00000114 488B0C25[08000000] <1> mov rcx, [b]
132 0000011C 4C8B0425[00000000] <1> mov r8, [c]
133 00000124 B800000000 <1> mov rax, 0
134 00000129 E8(00000000) <1> call printf
135
136 notw: ; c=~a;
137 0000012E 488B0425[00000000] mov rax,[a] ; load c
138 00000136 48F7D0 not rax ; not, complement
139 00000139 48890425[00000000] mov [c],rax ; store result into c
140 pabc "c=~a " ; invoke the print macro
141 <1> section .data
142 00000041 633D7E612000 <1> .str db %1,0
143 <1> section .text
144 00000141 48BF- <1> mov rdi, fmt
145 00000143 [1000000000000000] <1>
146 0000014B 48BE- <1> mov rsi, .str
147 0000014D [4100000000000000] <1>
148 00000155 488B1425[00000000] <1> mov rdx, [a]
149 0000015D 488B0C25[08000000] <1> mov rcx, [b]
150 00000165 4C8B0425[00000000] <1> mov r8, [c]
151 0000016D B800000000 <1> mov rax, 0
152 00000172 E8(00000000) <1> call printf
153
154 00000177 5D pop rbp ; restore stack
155 00000178 B800000000 mov rax,0 ; exit code, 0=normal
156 0000017D C3 ret ; main returns to operating system