1 ; printf2_64.asm use "C" printf on char, string, int, long int, float, double
2 ;
3 ; Assemble: nasm -f elf64 -l printf2_64.lst printf2_64.asm
4 ; Link: gcc -m64 -o printf2_64 printf2_64.o
5 ; Run: ./printf2_64 > printf2_64.out
6 ; Output: cat printf2_64.out
7 ;
8 ; A similar "C" program printf2_64.c
9 ; #include <stdio.h>
10 ; int main()
11 ; {
12 ; char char1='a'; /* sample character */
13 ; char str1[]="mystring"; /* sample string */
14 ; int len=9; /* sample string */
15 ; int inta1=12345678; /* sample integer 32-bit */
16 ; long int inta2=12345678900; /* sample long integer 64-bit */
17 ; long int hex1=0x123456789ABCD; /* sample hexadecimal 64-bit*/
18 ; float flt1=5.327e-30; /* sample float 32-bit */
19 ; double flt2=-123.4e300; /* sample double 64-bit*/
20 ;
21 ; printf("printf2_64: flt2=%e\n", flt2);
22 ; printf("char1=%c, srt1=%s, len=%d\n", char1, str1, len);
23 ; printf("char1=%c, srt1=%s, len=%d, inta1=%d, inta2=%ld\n",
24 ; char1, str1, len, inta1, inta2);
25 ; printf("hex1=%lX, flt1=%e, flt2=%e\n", hex1, flt1, flt2);
26 ; return 0;
27 ; }
28 extern printf ; the C function to be called
29
30 SECTION .data ; Data section
31
32 ; format strings for printf
33 00000000 7072696E7466323A20- fmt2: db "printf2: flt2=%e", 10, 0
34 00000009 666C74323D25650A00
35 00000012 63686172313D25632C- fmt3: db "char1=%c, str1=%s, len=%d", 10, 0
36 0000001B 20737472313D25732C-
37 00000024 206C656E3D25640A00
38 0000002D 63686172313D25632C- fmt4: db "char1=%c, str1=%s, len=%d, inta1=%d, inta2=%ld", 10, 0
39 00000036 20737472313D25732C-
40 0000003F 206C656E3D25642C20-
41 00000048 696E7461313D25642C-
42 00000051 20696E7461323D256C-
43 0000005A 640A00
44 0000005D 686578313D256C582C- fmt5: db "hex1=%lX, flt1=%e, flt2=%e", 10, 0
45 00000066 20666C74313D25652C-
46 0000006F 20666C74323D25650A-
47 00000078 00
48
49 00000079 61 char1: db 'a' ; a character
50 0000007A 6D79737472696E6700 str1: db "mystring",0 ; a C string, "string" needs 0
51 len: equ $-str1 ; len has value, not an address
52 00000083 4E61BC00 inta1: dd 12345678 ; integer 12345678, note dd
53 00000087 341CDCDF02000000 inta2: dq 12345678900 ; long integer 12345678900, note dq
54 0000008F CDAB896745230100 hex1: dq 0x123456789ABCD ; long hex constant, note dq
55 00000097 BB16D80E flt1: dd 5.327e-30 ; 32-bit floating point, note dd
56 0000009B 6ED768D3250BA7FE flt2: dq -123.456789e300 ; 64-bit floating point, note dq
57
58 SECTION .bss
59
60 00000000 <res 00000008> flttmp: resq 1 ; 64-bit temporary for printing flt1
61
62 SECTION .text ; Code section.
63
64 global main ; "C" main program
65 main: ; label, start of main program
66 00000000 55 push rbp ; set up stack frame
67 00000001 D90425[97000000] fld dword [flt1] ; need to convert 32-bit to 64-bit
68 00000008 DD1C25[00000000] fstp qword [flttmp] ; floating load makes 80-bit,
69 ; store as 64-bit
70 0000000F 48BF- mov rdi,fmt2
71 00000011 [0000000000000000]
72 00000019 F30F7E0425- movq xmm0, qword [flt2]
73 0000001E [9B000000]
74 00000022 B801000000 mov rax, 1 ; 1 xmm register
75 00000027 E8(00000000) call printf
76
77 0000002C 48BF- mov rdi, fmt3 ; first arg, format
78 0000002E [1200000000000000]
79 00000036 488B3425[79000000] mov rsi, [char1] ; second arg, char
80 0000003E 48BA- mov rdx, str1 ; third arg, string
81 00000040 [7A00000000000000]
82 00000048 B909000000 mov rcx, len ; fourth arg, int
83 0000004D B800000000 mov rax, 0 ; no xmm used
84 00000052 E8(00000000) call printf
85
86 00000057 48BF- mov rdi, fmt4 ; first arg, format
87 00000059 [2D00000000000000]
88 00000061 488B3425[79000000] mov rsi, [char1] ; second arg, char
89 00000069 48BA- mov rdx, str1 ; third arg, string
90 0000006B [7A00000000000000]
91 00000073 B909000000 mov rcx, len ; fourth arg, int
92 00000078 4C8B0425[83000000] mov r8, [inta1] ; fifth arg, inta1 32->64
93 00000080 4C8B0C25[87000000] mov r9, [inta2] ; sixth arg, inta2
94 00000088 B800000000 mov rax, 0 ; no xmm used
95 0000008D E8(00000000) call printf
96
97 00000092 48BF- mov rdi, fmt5 ; first arg, format
98 00000094 [5D00000000000000]
99 0000009C 488B3425[8F000000] mov rsi, [hex1] ; second arg, char
100 000000A4 F30F7E0425- movq xmm0, qword [flttmp] ; first double
101 000000A9 [00000000]
102 000000AD F30F7E0C25- movq xmm1, qword [flt2] ; second double
103 000000B2 [9B000000]
104 000000B6 B802000000 mov rax, 2 ; 2 xmm used
105 000000BB E8(00000000) call printf
106
107 000000C0 5D pop rbp ; restore stack
108 000000C1 B800000000 mov rax, 0 ; exit code, 0=normal
109 000000C6 C3 ret ; main returns to operating system