asm 计算一个数（8bit）乘以2的n次方（n<128）

用汇编计算一个数（8bit）乘以2的n次方（n<128）

TITLE shifting_number
include irvine32.inc
.data
value dword 4 DUP(0)        ;128位
n_2 byte 0                  ;0-128
nt_2 byte 0                 ;临时变量
result dword 8 DUP(0)       ;256位
str0 byte "用移位做一个数乘以2的n次方",0
str1 byte "[该数由128位二进制数组成(已预设)；2的次方数在0到128之间]",0
str2 byte "请输入2的次方数:",0
str3 byte "*2^",0
str4 byte "2的次方数输入有误导致结果溢出",0
bo byte 0                   ;溢出标志
.code
input proc
;设置value的值
mov eax,12345678h
mov dword ptr value,eax
mov eax,0fea99321h
mov dword ptr value+4,eax
mov eax,12345678h
mov dword ptr value+8,eax
mov eax,0fea99321h
mov dword ptr value+12,eax
;==============
mov edx,offset str0
call writestring
call crlf
mov edx,offset str1
call writestring
call crlf
mov edx,offset str2
call writestring
call readint
mov n_2,al
mov nt_2,al
ret
input endp
;====================
calculate proc
mov al,n_2
;=====================
cmp al,32   ;大于32位时跳后
ja NEXT_1
;=============================
mov ebx,dword ptr value+12
mov edx,0      ;每次使用时都将edx清零
mov cl,nt_2
shld edx,ebx,cl ;每次edx都"不会被"清0后再进行移动，且每次移动后"后面的寄存器"值不变
shl ebx,cl
add dword ptr result+16,edx
add dword ptr result+12,ebx

mov ebx,dword ptr value+8
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+12,edx
add dword ptr result+8,ebx

mov ebx,dword ptr value+4
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+8,edx
add dword ptr result+4,ebx

mov ebx,dword ptr value
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+4,edx
add dword ptr result,ebx
;================================
jmp OVER
NEXT_1:
cmp al,64   ;大于64跳
ja NEXT_2
mov bl,32
sub nt_2,bl
;===============================
mov ebx,dword ptr value+12
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+20,edx
add dword ptr result+16,ebx

mov ebx,dword ptr value+8
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+16,edx
add dword ptr result+12,ebx

mov ebx,dword ptr value+4
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+12,edx
add dword ptr result+8,ebx

mov ebx,dword ptr value
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+8,edx
add dword ptr result+4,ebx
;===============================
jmp OVER
NEXT_2:
cmp al,96   ;大于96跳
ja NEXT_3
mov bl,64
sub nt_2,bl
;================================
mov ebx,dword ptr value+12
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+24,edx
add dword ptr result+20,ebx

mov ebx,dword ptr value+8
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+20,edx
add dword ptr result+16,ebx

mov ebx,dword ptr value+4
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+16,edx
add dword ptr result+12,ebx

mov ebx,dword ptr value
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+12,edx
add dword ptr result+8,ebx
;===========================
jmp OVER
NEXT_3:
cmp al,128  ;大于128跳
jae NEXT_4
mov bl,96
sub nt_2,bl
;===========================
mov ebx,dword ptr value+12
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+28,edx
add dword ptr result+24,ebx

mov ebx,dword ptr value+8
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+24,edx
add dword ptr result+20,ebx

mov ebx,dword ptr value+4
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+20,edx
add dword ptr result+16,ebx

mov ebx,dword ptr value
mov edx,0
mov cl,nt_2
shld edx,ebx,cl
shl ebx,cl
add dword ptr result+16,edx
add dword ptr result+12,ebx
;============================
jmp OVER
NEXT_4:
cmp al,128  ;等于128跳
jne NEXT_5
mov eax,dword ptr value+12
mov dword ptr result+28,eax
mov eax,dword ptr value+8
mov dword ptr result+24,eax
mov eax,dword ptr value+4
mov dword ptr result+20,eax
mov eax,dword ptr value
mov dword ptr result+16,eax
;===========================
jmp OVER
NEXT_5:
;========================
mov bl,1                  ;溢出标志为1，表示输入有误
mov bo,bl
OVER:
ret
calculate endp
;====================
output proc;输出函数
mov bl,bo
cmp bl,0
jnz NEXT2_1
mov eax,dword ptr value+12
call writeHex
mov eax,dword ptr value+8
call writeHex
mov eax,dword ptr value+4
call writeHex
mov eax,dword ptr value
call writeHex
mov edx,offset str3
call writestring
movzx eax,n_2
call writedec
mov al,"="
call writechar
call crlf

mov eax,dword ptr result+28
call writeHex
mov eax,dword ptr result+24
call writeHex
mov eax,dword ptr result+20
call writeHex
mov eax,dword ptr result+16
call writeHex
mov eax,dword ptr result+12
call writeHex
mov eax,dword ptr result+8
call writeHex
mov eax,dword ptr result+4
call writeHex
mov eax,dword ptr result
call writeHex

jmp NEXT2_2
NEXT2_1:
mov edx,offset str4
call writestring
NEXT2_2:
call crlf
call readchar
ret
output endp
;====================
main proc
call input
call calculate
call output
exit
main endp
end main
  

 

  
1
  
2
  
3
  
4
  
5
  
6
  
7
  
8
  
9
  
10
  
11
  
12
  
13
  
14
  
15
  
16
  
17
  
18
  
19
  
20
  
21
  
22
  
23
  
24
  
25
  
26
  
27
  
28
  
29
  
30
  
31
  
32
  
33
  
34
  
35
  
36
  
37
  
38
  
39
  
40
  
41
  
42
  
43
  
44
  
45
  
46
  
47
  
48
  
49
  
50
  
51
  
52
  
53
  
54
  
55
  
56
  
57
  
58
  
59
  
60
  
61
  
62
  
63
  
64
  
65
  
66
  
67
  
68
  
69
  
70
  
71
  
72
  
73
  
74
  
75
  
76
  
77
  
78
  
79
  
80
  
81
  
82
  
83
  
84
  
85
  
86
  
87
  
88
  
89
  
90
  
91
  
92
  
93
  
94
  
95
  
96
  
97
  
98
  
99
  
100
  
101
  
102
  
103
  
104
  
105
  
106
  
107
  
108
  
109
  
110
  
111
  
112
  
113
  
114
  
115
  
116
  
117
  
118
  
119
  
120
  
121
  
122
  
123
  
124
  
125
  
126
  
127
  
128
  
129
  
130
  
131
  
132
  
133
  
134
  
135
  
136
  
137
  
138
  
139
  
140
  
141
  
142
  
143
  
144
  
145
  
146
  
147
  
148
  
149
  
150
  
151
  
152
  
153
  
154
  
155
  
156
  
157
  
158
  
159
  
160
  
161
  
162
  
163
  
164
  
165
  
166
  
167
  
168
  
169
  
170
  
171
  
172
  
173
  
174
  
175
  
176
  
177
  
178
  
179
  
180
  
181
  
182
  
183
  
184
  
185
  
186
  
187
  
188
  
189
  
190
  
191
  
192
  
193
  
194
  
195
  
196
  
197
  
198
  
199
  
200
  
201
  
202
  
203
  
204
  
205
  
206
  
207
  
208
  
209
  
210
  
211
  
212
  
213
  
214
  
215
  
216
  
217
  
218
  
219
  
220
  
221
  
222
  
223
  
224
  
225
  
226
  
227
  
228
  
229
  
230
  
231
  
232
  
233
  
234
  
235
  
236
  
237
  
238
  
239
  
240
  
241
  
242
  
243
  
244
  
245
  
246
  
247
  
248
  
249
  
250
  
251
  
252
  
253
  
254
  
255
  
256
  
257
  
258
  
259
  
260
  
261
  
262
  
263
  
264
  
265
  
266
  
267
  
268
  
269
  
270
 

文章来源: blog.csdn.net，作者：福州-司马懿，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/chy555chy/article/details/52145355