1 ; fltarith_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 fltarith_64.lst fltarith_64.asm
5 ; link gcc -m64 -o fltarith_64 fltarith_64.o
6 ; run ./fltarith_64
7 ;
8 ; the output from running fltarith and fltarithc is:
9 ; c=5.0, a=3.000000e+00, b=4.000000e+00, c=5.000000e+00
10 ; c=a+b, a=3.000000e+00, b=4.000000e+00, c=7.000000e+00
11 ; c=a-b, a=3.000000e+00, b=4.000000e+00, c=-1.000000e+00
12 ; c=a*b, a=3.000000e+00, b=4.000000e+00, c=1.200000e+01
13 ; c=c/a, a=3.000000e+00, b=4.000000e+00, c=4.000000e+00
14 ; a=i , a=8.000000e+00, b=1.600000e+01, c=1.600000e+01
15 ; a<=b , a=8.000000e+00, b=1.600000e+01, c=1.600000e+01
16 ; b==c , a=8.000000e+00, b=1.600000e+01, c=1.600000e+01
17 ;The file fltarith.c is:
18 ; #include <stdio.h>
19 ; int main()
20 ; {
21 ; double a=3.0, b=4.0, c;
22 ; long int i=8;
23 ;
24 ; c=5.0;
25 ; printf("%s, a=%e, b=%e, c=%e\n","c=5.0", a, b, c);
26 ; c=a+b;
27 ; printf("%s, a=%e, b=%e, c=%e\n","c=a+b", a, b, c);
28 ; c=a-b;
29 ; printf("%s, a=%e, b=%e, c=%e\n","c=a-b", a, b, c);
30 ; c=a*b;
31 ; printf("%s, a=%e, b=%e, c=%e\n","c=a*b", a, b, c);
32 ; c=c/a;
33 ; printf("%s, a=%e, b=%e, c=%e\n","c=c/a", a, b, c);
34 ; a=i;
35 ; b=a+i;
36 ; i=b;
37 ; c=i;
38 ; printf("%s, a=%e, b=%e, c=%e\n","c=c/a", a, b, c);
39 ; if(a<b) printf("%s, a=%e, b=%e, c=%e\n","a<=b ", a, b, c);
40 ; else printf("%s, a=%e, b=%e, c=%e\n","a>b ", a, b, c);
41 ; if(b==c)printf("%s, a=%e, b=%e, c=%e\n","b==c ", a, b, c);
42 ; else printf("%s, a=%e, b=%e, c=%e\n","b!=c ", a, b, c);
43 ; return 0;
44 ; }
45
46 extern printf ; the C function to be called
47
48 %macro pabc 1 ; a "simple" print macro
49 section .data
50 .str db %1,0 ; %1 is macro call first actual parameter
51 section .text
52 ; push onto stack backwards
53 mov rdi, fmt ; address of format string
54 mov rsi, .str ; string passed to macro
55 movq xmm0, qword [a] ; first floating point in fmt
56 movq xmm1, qword [b] ; second floating point
57 movq xmm2, qword [c] ; third floating point
58 mov rax, 3 ; 3 floating point arguments to printf
59 call printf ; Call C function
60 %endmacro
61
62 section .data ; preset constants, writeable
63 00000000 0000000000000840 a: dq 3.0 ; 64-bit variable a initialized to 3.0
64 00000008 0000000000001040 b: dq 4.0 ; 64-bit variable b initializes to 4.0
65 00000010 0800000000000000 i: dq 8 ; a 64 bit integer
66 00000018 0000000000001440 five: dq 5.0 ; constant 5.0
67 00000020 25732C20613D25652C- fmt: db "%s, a=%e, b=%e, c=%e",10,0 ; format string for printf
68 00000029 20623D25652C20633D-
69 00000032 25650A00
70
71 section .bss ; unitialized space
72 00000000 <res 00000008> c: resq 1 ; reserve a 64-bit word
73
74 section .text ; instructions, code segment
75 global main ; for gcc standard linking
76 main: ; label
77
78 00000000 55 push rbp ; set up stack
79 lit5: ; c=5.0;
80 00000001 DD0425[18000000] fld qword [five] ; 5.0 constant
81 00000008 DD1C25[00000000] fstp qword [c] ; store into c
82 pabc "c=5.0" ; invoke the print macro
83 <1> section .data
84 00000036 633D352E3000 <1> .str db %1,0
85 <1> section .text
86 <1>
87 0000000F 48BF- <1> mov rdi, fmt
88 00000011 [2000000000000000] <1>
89 00000019 48BE- <1> mov rsi, .str
90 0000001B [3600000000000000] <1>
91 00000023 F30F7E0425- <1> movq xmm0, qword [a]
92 00000028 [00000000] <1>
93 0000002C F30F7E0C25- <1> movq xmm1, qword [b]
94 00000031 [08000000] <1>
95 00000035 F30F7E1425- <1> movq xmm2, qword [c]
96 0000003A [00000000] <1>
97 0000003E B803000000 <1> mov rax, 3
98 00000043 E8(00000000) <1> call printf
99
100 addb: ; c=a+b;
101 00000048 DD0425[00000000] fld qword [a] ; load a (pushed on flt pt stack, st0)
102 0000004F DC0425[08000000] fadd qword [b] ; floating add b (to st0)
103 00000056 DD1C25[00000000] fstp qword [c] ; store into c (pop flt pt stack)
104 pabc "c=a+b" ; invoke the print macro
105 <1> section .data
106 0000003C 633D612B6200 <1> .str db %1,0
107 <1> section .text
108 <1>
109 0000005D 48BF- <1> mov rdi, fmt
110 0000005F [2000000000000000] <1>
111 00000067 48BE- <1> mov rsi, .str
112 00000069 [3C00000000000000] <1>
113 00000071 F30F7E0425- <1> movq xmm0, qword [a]
114 00000076 [00000000] <1>
115 0000007A F30F7E0C25- <1> movq xmm1, qword [b]
116 0000007F [08000000] <1>
117 00000083 F30F7E1425- <1> movq xmm2, qword [c]
118 00000088 [00000000] <1>
119 0000008C B803000000 <1> mov rax, 3
120 00000091 E8(00000000) <1> call printf
121
122 subb: ; c=a-b;
123 00000096 DD0425[00000000] fld qword [a] ; load a (pushed on flt pt stack, st0)
124 0000009D DC2425[08000000] fsub qword [b] ; floating subtract b (to st0)
125 000000A4 DD1C25[00000000] fstp qword [c] ; store into c (pop flt pt stack)
126 pabc "c=a-b" ; invoke the print macro
127 <1> section .data
128 00000042 633D612D6200 <1> .str db %1,0
129 <1> section .text
130 <1>
131 000000AB 48BF- <1> mov rdi, fmt
132 000000AD [2000000000000000] <1>
133 000000B5 48BE- <1> mov rsi, .str
134 000000B7 [4200000000000000] <1>
135 000000BF F30F7E0425- <1> movq xmm0, qword [a]
136 000000C4 [00000000] <1>
137 000000C8 F30F7E0C25- <1> movq xmm1, qword [b]
138 000000CD [08000000] <1>
139 000000D1 F30F7E1425- <1> movq xmm2, qword [c]
140 000000D6 [00000000] <1>
141 000000DA B803000000 <1> mov rax, 3
142 000000DF E8(00000000) <1> call printf
143
144 mulb: ; c=a*b;
145 000000E4 DD0425[00000000] fld qword [a] ; load a (pushed on flt pt stack, st0)
146 000000EB DC0C25[08000000] fmul qword [b] ; floating multiply by b (to st0)
147 000000F2 DD1C25[00000000] fstp qword [c] ; store product into c (pop flt pt stack)
148 pabc "c=a*b" ; invoke the print macro
149 <1> section .data
150 00000048 633D612A6200 <1> .str db %1,0
151 <1> section .text
152 <1>
153 000000F9 48BF- <1> mov rdi, fmt
154 000000FB [2000000000000000] <1>
155 00000103 48BE- <1> mov rsi, .str
156 00000105 [4800000000000000] <1>
157 0000010D F30F7E0425- <1> movq xmm0, qword [a]
158 00000112 [00000000] <1>
159 00000116 F30F7E0C25- <1> movq xmm1, qword [b]
160 0000011B [08000000] <1>
161 0000011F F30F7E1425- <1> movq xmm2, qword [c]
162 00000124 [00000000] <1>
163 00000128 B803000000 <1> mov rax, 3
164 0000012D E8(00000000) <1> call printf
165
166 diva: ; c=c/a;
167 00000132 DD0425[00000000] fld qword [c] ; load c (pushed on flt pt stack, st0)
168 00000139 DC3425[00000000] fdiv qword [a] ; floating divide by a (to st0)
169 00000140 DD1C25[00000000] fstp qword [c] ; store quotient into c (pop flt pt stack)
170 pabc "c=c/a" ; invoke the print macro
171 <1> section .data
172 0000004E 633D632F6100 <1> .str db %1,0
173 <1> section .text
174 <1>
175 00000147 48BF- <1> mov rdi, fmt
176 00000149 [2000000000000000] <1>
177 00000151 48BE- <1> mov rsi, .str
178 00000153 [4E00000000000000] <1>
179 0000015B F30F7E0425- <1> movq xmm0, qword [a]
180 00000160 [00000000] <1>
181 00000164 F30F7E0C25- <1> movq xmm1, qword [b]
182 00000169 [08000000] <1>
183 0000016D F30F7E1425- <1> movq xmm2, qword [c]
184 00000172 [00000000] <1>
185 00000176 B803000000 <1> mov rax, 3
186 0000017B E8(00000000) <1> call printf
187
188 intflt: ; a=i;
189 00000180 DB0425[10000000] fild dword [i] ; load integer as floating point
190 00000187 DD1425[00000000] fst qword [a] ; store the floating point (no pop)
191 0000018E D8C0 fadd st0 ; b=a+i; 'a' as 'i' already on flt stack
192 00000190 DD1425[08000000] fst qword [b] ; store sum (no pop) 'b' still on stack
193 00000197 DB1C25[10000000] fistp dword [i] ; i=b; store floating point as integer
194 0000019E DB0425[10000000] fild dword [i] ; c=i; load again from ram (redundant)
195 000001A5 DD1C25[00000000] fstp qword [c]
196 pabc "a=i " ; invoke the print macro
197 <1> section .data
198 00000054 613D69202000 <1> .str db %1,0
199 <1> section .text
200 <1>
201 000001AC 48BF- <1> mov rdi, fmt
202 000001AE [2000000000000000] <1>
203 000001B6 48BE- <1> mov rsi, .str
204 000001B8 [5400000000000000] <1>
205 000001C0 F30F7E0425- <1> movq xmm0, qword [a]
206 000001C5 [00000000] <1>
207 000001C9 F30F7E0C25- <1> movq xmm1, qword [b]
208 000001CE [08000000] <1>
209 000001D2 F30F7E1425- <1> movq xmm2, qword [c]
210 000001D7 [00000000] <1>
211 000001DB B803000000 <1> mov rax, 3
212 000001E0 E8(00000000) <1> call printf
213
214 000001E5 D90425[08000000] cmpflt: fld dword [b] ; into st0, then pushed to st1
215 000001EC D90425[00000000] fld dword [a] ; in st0
216 000001F3 DFF1 fcomip st0,st1 ; a compare b, pop a
217 000001F5 7F3B jg cmpfl2
218 pabc "a<=b "
219 <1> section .data
220 0000005A 613C3D622000 <1> .str db %1,0
221 <1> section .text
222 <1>
223 000001F7 48BF- <1> mov rdi, fmt
224 000001F9 [2000000000000000] <1>
225 00000201 48BE- <1> mov rsi, .str
226 00000203 [5A00000000000000] <1>
227 0000020B F30F7E0425- <1> movq xmm0, qword [a]
228 00000210 [00000000] <1>
229 00000214 F30F7E0C25- <1> movq xmm1, qword [b]
230 00000219 [08000000] <1>
231 0000021D F30F7E1425- <1> movq xmm2, qword [c]
232 00000222 [00000000] <1>
233 00000226 B803000000 <1> mov rax, 3
234 0000022B E8(00000000) <1> call printf
235 00000230 EB39 jmp cmpfl3
236 cmpfl2:
237 pabc "a>b "
238 <1> section .data
239 00000060 613E62202000 <1> .str db %1,0
240 <1> section .text
241 <1>
242 00000232 48BF- <1> mov rdi, fmt
243 00000234 [2000000000000000] <1>
244 0000023C 48BE- <1> mov rsi, .str
245 0000023E [6000000000000000] <1>
246 00000246 F30F7E0425- <1> movq xmm0, qword [a]
247 0000024B [00000000] <1>
248 0000024F F30F7E0C25- <1> movq xmm1, qword [b]
249 00000254 [08000000] <1>
250 00000258 F30F7E1425- <1> movq xmm2, qword [c]
251 0000025D [00000000] <1>
252 00000261 B803000000 <1> mov rax, 3
253 00000266 E8(00000000) <1> call printf
254 cmpfl3:
255 0000026B D90425[00000000] fld dword [c] ; should equal [b]
256 00000272 DFF1 fcomip st0,st1
257 00000274 753B jne cmpfl4
258 pabc "b==c "
259 <1> section .data
260 00000066 623D3D632000 <1> .str db %1,0
261 <1> section .text
262 <1>
263 00000276 48BF- <1> mov rdi, fmt
264 00000278 [2000000000000000] <1>
265 00000280 48BE- <1> mov rsi, .str
266 00000282 [6600000000000000] <1>
267 0000028A F30F7E0425- <1> movq xmm0, qword [a]
268 0000028F [00000000] <1>
269 00000293 F30F7E0C25- <1> movq xmm1, qword [b]
270 00000298 [08000000] <1>
271 0000029C F30F7E1425- <1> movq xmm2, qword [c]
272 000002A1 [00000000] <1>
273 000002A5 B803000000 <1> mov rax, 3
274 000002AA E8(00000000) <1> call printf
275 000002AF EB39 jmp cmpfl5
276 cmpfl4:
277 pabc "b!=c "
278 <1> section .data
279 0000006C 62213D632000 <1> .str db %1,0
280 <1> section .text
281 <1>
282 000002B1 48BF- <1> mov rdi, fmt
283 000002B3 [2000000000000000] <1>
284 000002BB 48BE- <1> mov rsi, .str
285 000002BD [6C00000000000000] <1>
286 000002C5 F30F7E0425- <1> movq xmm0, qword [a]
287 000002CA [00000000] <1>
288 000002CE F30F7E0C25- <1> movq xmm1, qword [b]
289 000002D3 [08000000] <1>
290 000002D7 F30F7E1425- <1> movq xmm2, qword [c]
291 000002DC [00000000] <1>
292 000002E0 B803000000 <1> mov rax, 3
293 000002E5 E8(00000000) <1> call printf
294 cmpfl5:
295
296 000002EA 5D pop rbp ; pop stack
297 000002EB B800000000 mov rax,0 ; exit code, 0=normal
298 000002F0 C3 ret ; main returns to operating system