《汇编语言 基于x86处理器》第九章字符串与数组部分的代码
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? 书中第九章的程序，主要讲了
● 代码，Irvine32 中的字符串库函数代码范例
1 INCLUDE Irvine32.inc 2 3 .data 4 str1 BYTE "abcde////", 0 5 str2 BYTE "ABCDE", 0 6 msg0 BYTE "Upper case: ", 0 7 msg1 BYTE "str1 == str2", 0 8 msg2 BYTE "str1 < str2", 0 9 msg3 BYTE "str1 > str2", 0 10 msg4 BYTE "Length of str1: ", 0 11 msg5 BYTE "Trimming: ", 0 12 13 .code 14 main PROC 15 mov edx, OFFSET str1 16 call WriteString 17 call crlf 18 19 call trim_string 20 call upper_case 21 call compare_strings 22 call print_length 23 call waitmsg 24 exit 25 main ENDP 26 27 trim_string PROC ; 去掉结尾的指定字符 28 INVOKE Str_trim, ADDR str1, ‘/‘ 29 mov edx, OFFSET msg5 30 call WriteString 31 mov edx, OFFSET str1 32 call WriteString 33 call Crlf 34 ret 35 trim_string ENDP 36 37 upper_case PROC ; 小写转大写 38 mov edx, OFFSET msg0 39 call WriteString 40 INVOKE Str_ucase, ADDR str1 41 mov edx, OFFSET str1 42 call WriteString 43 call Crlf 44 ret 45 upper_case ENDP 46 47 compare_strings PROC ; 比较 str1 和 str2 48 INVOKE Str_compare, ADDR str1, ADDR str2 49 .IF ZERO? 50 mov edx, OFFSET msg1 ; str1 = str2 51 .ELSEIF CARRY? 52 mov edx, OFFSET msg2 ; str1 < str2 53 .ELSE 54 mov edx, OFFSET msg3 ; str1 > str2 55 .ENDIF 56 call WriteString 57 call Crlf 58 ret 59 compare_strings ENDP 60 61 print_length PROC ; 获取字符串长度 62 mov edx, OFFSET msg4 63 call WriteString 64 INVOKE Str_length, ADDR str1 65 call WriteDec 66 call Crlf 67 ret 68 print_length ENDP 69 70 END main
■ 输出结果
abcde//// Trimming: abcde Upper case: ABCDE str1 == str2 Length of str1: 5
● 二维表下标引用
1 INCLUDE Irvine32.inc 2 3 .data 4 tableB BYTE 10h, 20h, 30h, 40h, 50h ; 数组定义能断开，中间插入一个用于计算数组行宽的常量 5 Rowsize = ($ - tableB) 6 BYTE 60h, 70h, 80h, 90h, 0A0h 7 BYTE 0B0h, 0C0h, 0D0h, 0E0h, 0F0h 8 9 tableW WORD 10h, 20h, 30h, 40h, 50h 10 RowsizeW = ($ - tableW) 11 WORD 60h, 70h, 80h, 90h, 0A0h 12 WORD 0B0h, 0C0h, 0D0h, 0E0h, 0F0h 13 14 tableD DWORD 10000h, 20000h, 30000h, 40000h, 50000h 15 RowSizeD = ($ - tableD) 16 DWORD 60000h, 70000h, 80000h, 90000h, 0A0000h 17 DWORD 0B0000h, 0C0000h, 0D0000h, 0E0000h, 0F0000h 18 19 .code 20 main PROC 21 22 row = 1 ; 目标元素的下标 23 col = 2 24 25 mov ebx, OFFSET tableB ; 指向数组首元素 26 add ebx, RowSize * row ; 计算行偏移 27 mov esi, col ; 列偏移 28 mov al, [ebx + esi] ; 取目标元素 29 call DumpRegs ; AL = 80h 30 31 mov ebx, OFFSET tableW ; 相同的过程 32 add ebx, RowSizeW * row 33 mov esi, col 34 mov ax, [ebx + esi*TYPE tableW] ; 元素不是 BYTE 时要乘以比例因子 35 call DumpRegs ; AX = 0080h 36 37 mov eax, row 38 mov esi, col 39 call get_tableDval ; 使用函数寻找目标元素 40 call WriteHex ; 目标元素在 eax 中 41 call Crlf 42 call WaitMsg 43 exit 44 main ENDP 45 46 get_tableDval PROC uses ebx 47 mov ebx, RowSizeD 48 mul ebx ; eax *= RowSizeD，行偏移 49 mov eax, tableD[eax + esi*TYPE tableD] ; 加上列偏移再寻址 50 ret ; eax = 80000h 51 get_tableDval ENDP 52 53 END main
● 代码，冒泡排序，二分搜索
1 ; BinarySearchTest.asm，测试函数 2 INCLUDE Irvine32.inc 3 INCLUDE BinarySearch.inc 4 5 LOWVAL = -5000 6 HIGHVAL = +5000 7 ARRAY_SIZE = 50 8 9 .data 10 array DWORD ARRAY_SIZE DUP(?) 11 12 .code 13 main PROC 14 call Randomize ; 初始化随机数种子 15 INVOKE FillArray, ADDR array, ARRAY_SIZE, LOWVAL, HIGHVAL ; 用随机数填充数组 16 INVOKE PrintArray, ADDR array, ARRAY_SIZE ; 显示数组内容 17 call WaitMsg 18 call Crlf 19 20 INVOKE BubbleSort, ADDR array, ARRAY_SIZE ; 冒泡排序 21 INVOKE PrintArray, ADDR array, ARRAY_SIZE 22 call WaitMsg 23 call Crlf 24 25 call AskForSearchVal ; 输入待查找的数字 26 INVOKE BinarySearch, ADDR array, ARRAY_SIZE, eax ; 二叉搜索 27 call ShowResults ; 输出搜索结果 28 call WaitMsg 29 30 exit 31 main ENDP 32 33 AskForSearchVal PROC 34 .data 35 prompt BYTE "Signed integer to find: ",0 36 .code 37 call Crlf 38 mov edx, OFFSET prompt 39 call WriteString 40 call ReadInt 41 ret 42 AskForSearchVal ENDP 43 44 ShowResults PROC 45 .data 46 msg1 BYTE "Not found.",0 47 msg2 BYTE "Found at index：",0 48 .code 49 .IF eax == -1 50 mov edx, OFFSET msg1 51 call WriteString 52 .ELSE 53 mov edx, OFFSET msg2 54 call WriteString 55 call WriteDec 56 .ENDIF 57 call Crlf 58 ret 59 ShowResults ENDP 60 61 END main
1 ; FillArray.asm，用 [LowerRange, UpperRange - 1] 之间随机的整数来填充数组 2 INCLUDE Irvine32.inc 3 4 .code 5 FillArray PROC USES eax edi ecx edx, pArray:PTR DWORD, Count:DWORD, LowerRange:SDWORD, UpperRange:SDWORD 6 7 mov edi, pArray 8 mov ecx, Count 9 mov edx, UpperRange 10 sub edx, LowerRange 11 cld ; 清除方向标志位 12 13 L1: 14 mov eax, edx 15 call RandomRange 16 add eax, LowerRange 17 stosd ; eax 的值保存到 [edi] 18 loop L1 19 20 ret 21 FillArray ENDP 22 23 END
1 ; PrintArray.asm，打印数组 2 INCLUDE Irvine32.inc 3 4 .code 5 PrintArray PROC USES eax ecx edx esi, pArray:PTR DWORD, Count:DWORD 6 7 .data 8 comma BYTE ", ",0 ; 逗号 9 .code 10 mov esi, pArray 11 mov ecx, Count 12 cld 13 14 L1: 15 lodsd ; 读取 [ESI] 给 eax 16 call WriteInt 17 mov edx, OFFSET comma 18 call Writestring 19 loop L1 20 21 call Crlf 22 ret 23 PrintArray ENDP 24 25 END
1 ; BubbleSort.asm，冒泡排序 2 INCLUDE Irvine32.inc 3 4 .code 5 BubbleSort PROC USES eax ecx esi, pArray:PTR DWORD, Count:DWORD 6 7 mov ecx, Count 8 dec ecx ; 外层循环 ecx -->0 9 10 L1: 11 push ecx ; 内层循环，保存 ecx 12 mov esi, pArray 13 14 L2: 15 mov eax, [esi] ; 取出相邻两个元素作比较 16 cmp [esi + 4] ,eax 17 jge L3 ; pArray[esi] < pArray[esi + 1] 跳转，不发生交换 18 xchg eax, [esi+4] 19 mov [esi], eax 20 21 L3: 22 add esi, 4 ; 后移一位 23 loop L2 24 25 pop ecx ; 退到外层循环以前恢复 ecx 26 loop L1 27 28 L4: 29 ret 30 BubbleSort ENDP 31 32 END
1 ; BinarySearch.asm，二分搜索 2 INCLUDE Irvine32.inc 3 4 .code 5 BinarySearch PROC USES ebx edx esi edi, pArray:PTR DWORD, Count:DWORD, searchVal:DWORD 6 7 LOCAL first:DWORD, last:DWORD, mid:DWORD 8 9 mov first, 0 10 mov eax, Count 11 dec eax 12 mov last, eax 13 mov edi, searchVal 14 mov ebx, pArray 15 16 L1: ; first <= last 17 mov eax, first 18 cmp eax, last 19 jg L5 ; first > last，退出搜索 20 21 mov eax, last ; 计算 mid 22 add eax, first 23 shr eax, 1 24 mov mid, eax 25 26 mov esi, mid 27 shl esi, 2 ; 下标乘以 4，变成数组偏移量 28 mov edx, [ebx + esi] ; EDX = pArray[mid] 29 30 cmp edx, edi ; 比较 edx 和 查找的值 31 jge L2 ; edx >= searchval 跳转 32 mov eax, mid ; first = mid + 1 33 inc eax 34 mov first, eax 35 jmp L4 36 37 L2: 38 cmp edx,edi ; 比较 edx 和 查找的值 39 jle L3 ; edx <= searchval 跳转 40 mov eax, mid ; last = mid - 1 41 dec eax 42 mov last, eax 43 jmp L4 44 45 L3: 46 mov eax, mid ; edx == searchval 47 jmp L9 ; 返回，eax即为找到的下标 48 49 L4: 50 jmp L1 ; 调整过 first 或 last，继续搜索 51 52 L5: 53 mov eax, -1 ; 没找到 54 L9: 55 ret 56 BinarySearch ENDP 57 58 END
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