汇编语言-016（SCASB 、STOSB 、LODSD 、数组中的取值、二维数组操作、冒泡排序和二分查找、CMPSW ）

1： SCASB : (字节)将AL的值与EDI寻址的一个字比较。进行在一个字符串检索特定的字符

.386
.model flat,stdcall.stack 4096
ExitProcess PROTO,dwExitCode:DWORD.data 
alpha BYTE "ABCDEFGH",0.code
main PROCmov edi,OFFSET alpha  ;EDI指向字符串mov al,'F'            ;检索字符Fmov ecx,LENGTHOF alpha ;设置检索计数器cld                   ;方向为正向repne scasb            ;不相等则重复jnz  quit               ;若未发现字符则退出dec edi       ;发现字符，EDI减1，因为执行scasb后,edi增加1了quit:INVOKE ExitProcess,0 
main ENDP
END main

2：STOSB : (字节)将AL的值复制到EDI寻址的位置上，可以加上rep重复操作

.386
.model flat,stdcall.stack 4096
ExitProcess PROTO,dwExitCode:DWORD.data
Count =100
string1 BYTE Count DUP(?).code
main PROCmov al,0FFh   ;要保存的数值mov edi,OFFSET string1 ;EDI指向目标字符串mov ecx,Countcldrep stosb  ;用AL的内容实现填充INVOKE ExitProcess,0
main ENDP
END main

3：LODSD : (双字)交一个双字数组中的每个元素都乘以同一个常数

.386
.model flat,stdcall.stack 4096
ExitProcess PROTO,dwExitCode:DWORD.data
array DWORD 1,2,3,4,5,6,7,8,9,10
multiplier DWORD 10  ;将一个32位整数数组中的每个元素都乘以一个常数.code
main PROCcld mov esi,OFFSET array  ;源数组索引mov edi,esi   ;目标数组索引mov ecx,LENGTHOF array  ;循环计数器
L1:lodsd   ;将[ESI]加载到EAXmul multiplier  ;与常数相乘stosd    ;将EAX保存到[EDI]loop L1  INVOKE ExitProcess,0
main ENDP
END main

4：数组中的取值，基址——变址操作数，将两个寄存器（称为基址和变址）相加，生成一个偏移地址

.386
.model flat,stdcall.stack 4096
ExitProcess PROTO,dwExitCode:DWORD.data
array WORD 1000h,2000h,3000h.code
main PROCmov ebx,OFFSET arraymov esi,2mov ax,[ebx+esi]  ;AX=2000hmov edi,OFFSET arraymov ecx,4mov ax,[edi+ecx]   ;AX = 3000hmov ebp,OFFSET arraymov esi,0mov ax,[ebp+esi]INVOKE ExitProcess,0
main ENDP
END main

5：二维数组中取值

.386
.model flat,stdcall.stack 4096
ExitProcess PROTO,dwExitCode:DWORD.data
tableB BYTE 10h,20h,30h,40h,50h
RowSize = ($ - tableB)BYTE 60h,70h,80h,90h,0A0hBYTE 0B0h,0C0h,0D0h,0E0h,0F0h.code
main PROCrow_index = 1column_index = 2mov ebx,OFFSET tableB ;表的偏移量add ebx,RowSize * row_index  ;行的偏移量mov esi,column_indexmov al,[ebx+esi]     ;AL = 80hINVOKE ExitProcess,0
main ENDP
END main

6：计算二维数组中某一行的之和

.386
.model flat,stdcall.stack 4096
ExitProcess PROTO,dwExitCode:DWORD.data
tableB BYTE 10h,20h,30h,40h,50h
RowSize = ($ - tableB)BYTE 60h,70h,80h,90h,0A0hBYTE 0B0h,0C0h,0D0h,0E0h,0F0h.code
main PROCrow_index = 1column_index = 2mov ebx,OFFSET tableB ;表的偏移量add ebx,RowSize * row_index  ;行的偏移量mov esi,column_indexmov al,[ebx+esi]     ;AL = 80hINVOKE ExitProcess,0
main ENDP;计算字节矩阵中一行的和数
;接收：EBX=表偏移量，EAX=行索引
;ECX=按字节计的行大小
;返回：EAX为和数
calc_row_sum PROC USES ebx ecx edx esimul ecx   ;行索引 * 行大小add ebx,eax ;行偏移量mov eax,0   ;累加器mov esi,0   ;列索引
L1:movzx edx,BYTE PTR[ebx + esi] ;取一个字节add eax,edx          ;与累加器相加inc esi            ;行中下一个字节loop L1ret
calc_row_sum ENDP
END main

7：二维数组中使用比例因子寻址取值

.386
.model flat,stdcall.stack 4096
ExitProcess PROTO,dwExitCode:DWORD.data
tableW WORD 10h,20h,30h,40h,50h
RowSizeW = ($ - tableW)WORD 60h,70h,80h,90h,0A0hWORD 0B0h,0C0h,0D0h,0E0h,0F0h.code
main PROCrow_index = 1column_index = 2mov ebx,OFFSET tableW   ;表偏移量add ebx,RowSizeW * row_index ;行偏移量mov esi,column_indexmov ax,[ebx + esi*TYPE tableW]  ;AX = 0080hINVOKE ExitProcess,0
main ENDPEND main

8：基址——变址——偏移量操作数，用一个偏移量、一个基址寄存器、一个变址寄存器和一个可选的比例因子生成有效地址

.386
.model flat,stdcall.stack 4096
ExitProcess PROTO,dwExitCode:DWORD.data
tableD DWORD 10h,20h,30h,40h,50h
RowSizeD = ($ - tableD)DWORD 60h,70h,80h,90h,0A0hDWORD 0B0h,0C0h,0D0h,0E0h,0F0h.code
main PROCrow_index = 1column_index = 2mov ebx,RowSizeD * row_index   ;行索引mov esi,column_index           ;列索引mov eax,tableD[ebx + esi*TYPE tableD]  ;AX = 00000080hINVOKE ExitProcess,0
main ENDPEND main

9：64位基址——变址——偏移量操作数做法

BinarySearch.asm

include BinarySearch.inc.codeBinarySearch PROC USES ebx edx esi edi,pArray:PTR DWORD, ;数组指针Count:DWORD,      ;数组大小searchVal:DWORD   ;给定查找数值LOCAL first:DWORD,;first的位置last:DWORD, ;last的位置mid:DWORD   ;中点mov first,0        ;first = 0mov eax,Count      ;last = (Count - 1)dec eaxmov last,eaxmov edi,searchVal  ;EDI = searchValmov ebx,pArray     ;EBX 为 数组指针
L1:;当first<=last时mov eax,firstcmp eax,lastjg L5              ;退出查找;mid = (last+first)/2mov eax,lastadd eax,firstshr eax,1mov mid,eax;EDX = values[mid]mov esi,midshl esi,2            ;将mid 值乘4mov edx,[ebx+esi]    ;EDX = values[mid];若EDX < searchVal(EDI)cmp edx,edijge L2;first = mid +1mov eax,midinc eaxmov first,eaxjmp L4;否则，若EDX>searchVal(EDI)
L2:cmp edx,edijle L3    ;可选项;last=mid - 1mov eax,middec eaxmov last,eaxjmp L4;否则返回mid
L3:mov eax,mid   ;发现数值jmp L9        ;返回mid
L4: jmp L1         ;继续循环
L5:mov eax,-1     ;查找失败
L9:retBinarySearch ENDPEND

BinarySearch.inc

.386
.model flat,stdcall.stack 4096;冒泡排序/对半查找程序中使用的过程原型;在32位有符号整数数组中查找一个数
BinarySearch PROTO,pArray:PTR DWORD,     ;指向数组Count:DWORD,          ;数组大小searchVal:DWORD       ;查找数值;用32位有符号随机整数填充数组
FillArray PROTO,pArray:PTR DWORD,       ;指向数组Count:DWORD,            ;元素个数LowerRange:SDWORD,      ;随机数的下限UpperRange:SDWORD       ;随机数的上限;将32位有符号整数数组定到标准输出
PrintArray PROTO,pArray:PTR DWORD,Count:DWORD,;将数组按升序排列
BubbleSort PROTO,pArray:PTR DWORD,Count:DWORD

BinarySearchTest.asm

include Irvine32.inc
include BinarySearch.incLOWVAL = -5000       ;最小值
HIGHVAL = +5000      ;最大值
ARRAY_SIZE = 50      ;数组大小.data
array DWORD ARRAY_SIZE DUP(?).code
main PROCcall Randomize;用有符号随机整数填充数组INVOKE FillArray,ADDR array,ARRAY_SIZE,LOWVAL,HIGHVAL;显示数组INVOKE PrintArray,ADDR array,ARRAY_SIZEcall WaitMsg;执行冒泡排序并再次显示数组INVOKE BubbleSort ,ADDR array,ARRAY_SIZEINVOKE PrintArray,ADDR array,ARRAY_SIZE;实现对半查找call AskForSearchVal   ;用EAX返回INVOKE BinarySearch,ADDR array,ARRAY_SIZE,eaxcall ShowResultsexit
main ENDP;请求用户输入一个有符号整数
;接收：无
;返回：EAX = 用户输入的数值
AskForSearchVal PROC
.data
prompt BYTE "Enter a signed decimal integer "BYTE "in the range of -5000 to +5000 "BYTE "to find in the array: ",0
.codecall Crlfmov edx,OFFSET promptcall WriteStringcall ReadIntret
AskForSearchVal ENDP;显示对半查找的结果值
;接收：EAX = 被显示数的位置
;返回：无
ShowResults PROC
.data
msg1 BYTE "The value was not found,",0
msg2 BYTE "The value was found at position ",0
.code
.IF eax == -1mov  edx,OFFSET msg1call WriteString
.ELSEmov edx,OFFSET msg2call WriteStringcall WriteDec
.ENDIFcall Crlfcall Crlfret
ShowResults ENDP
END main

BubbleSort.asm

include BinarySearch.inc.code;使用冒泡算法，将一个32位有符号整数数组升序进行排列
;接收：数组指针，数组大小
;返回：无
BubbleSort PROC USES eax ecx esi,pArray:PTR DWORD,        ;数组指针Count:DWORD              ;数组大小mov ecx,Countdec ecx        ;计数值减1
L1:push ecx       ;保存外循环计数值mov esi,pArray; 指向第一个数值
L2:mov eax,[esi]   ;取数组元素值cmp [esi+4],eax ;比较两个数值jg L3           ;如果[ESI]<=[ESI+4],不交换xchg eax,[esi+4];交换两数mov [esi],eax
L3:add esi,4   ;两个指针都向前移动一个元素loop L2     ;内循环pop ecx     ;恢复外循环计数值loop L1     ;若计数值不等于0，则继续外循环
L4:ret
BubbleSort ENDP
END

FillArray.asm

include Irvine32.inc.code
;用LowerRange到(UpperRange-1之间的32位随机有符号整数序列填充数组)
;返回：无
FillArray PROC USES eax edi ecx edx,pArray:PTR DWORD,      ;数组指针Count:DWORD,          ;元素个数LowerRange:SDWORD,     ;范围下限UpperRange:SDWORD     ;范围上限mov edi,pArray    ;EDI为数组指针mov ecx,Count     ;循环计数器mov edx,UpperRangesub edx,LowerRange   ;EDX = 绝对范围0..ncld   ;方向标志位清零
L1:mov eax,edx   ;偏移处理结果call RandomRangeadd eax,LowerRange  ;偏移处理结果stosd    ;将EAX 保存到[edi]loop L1ret
FillArray ENDP
END

PrintArray.asm

include Irvine32.inc.code
;将32位有符号十进制整数数组写到标准输出，数值用逗号隔开
;接收：数组指针，数组大小
;返回：无
PrintArray PROC USES eax ecx edx esi,pArray:PTR DWORD,  Count:DWORD
.data
comma BYTE ", ",0
.codemov esi,pArraymov ecx,Countcld
L1:lodsd       ;加载[ESI]到EAXcall WriteInt  ;发送到输出mov edx,OFFSET commacall WriteStringloop L1call Crlfret
PrintArray ENDPEND

10：CMPSW : 比较两个16位数组，找出第一个相同的值

.386
.model flat,stdcall.stack 4096
ExitProcess PROTO,dwEixtCode:DWORD.data
sourceW WORD 1,2,3,4,5
targetW WORD 5,4,3,2,1.code
main PROCmov esi,OFFSET sourceWmov edi,OFFSET targetWcldmov ecx,LENGTHOF sourceWrepne cmpswsub esi,TYPE WORDmov ax,[esi]INVOKE ExitProcess,0
main ENDP
END main