我正在使用Visual Studio 2010.我编写了一个执行简单二进制搜索算法的程序。我正在尝试将其转换为汇编代码。我使用反汇编程序来获取汇编代码。我正在尝试将其粘贴到_asm中。我已经尝试了很多方法而且它不起作用。
我试过
_asm(" . . . .");
_asm( );
_asm{ } <--- -Currently going with this way for c++. seems to work well.
这是代码。我会评论错误的位置。好吧，我现在有13个。有些我不会列出，因为它们与其他错误相同。一旦我修复了一个或两个，我应该能够解决所有问题。该函数的原始c ++代码也在那里。它被注释掉了。
bool binarySearch(int searchNum,int myArray[],int size){
_asm{
push ebp
mov ebp,esp
sub esp,0F0h
push ebx
push esi
push edi
lea edi,[ebp-0F0h]
mov ecx,3Ch
mov eax,0CCCCCCCCh
rep stos dword ptr es:[edi]
// 217: int first=0,last=size-1,middle;
mov dword ptr [first],0
mov eax,dword ptr [size] // ERROR! Error 2 error C2400: inline assembler syntax error in 'second operand'; found ']'
sub eax,1
mov dword ptr [last],eax
// 218: bool found = false;
mov byte ptr [found],0
// 220: while (first <= last)
mov eax,dword ptr [first]
cmp eax,dword ptr [last]
jg binarySearch+80h (0B51970h) //ERROR! Error 4 error C2400: inline assembler syntax error in 'second operand'; found '('
// 222: middle = (first + last)/2;
mov eax,dword ptr [first] ; // Error 5 error C2400: inline assembler syntax error in 'opcode'; found '('
add eax,dword ptr [last] ;
cdq
sub eax,edx
sar eax,1
mov dword ptr [middle],eax
// 224: if(searchNum > myArray[middle])
mov eax,dword ptr [middle]
mov ecx,dword ptr [myArray]
mov edx,dword ptr [searchNum]
cmp edx,dword ptr [ecx+eax*4]
jle binarySearch+61h (0B51951h) // Error 8 error C2400: inline assembler syntax error in 'opcode'; found '('
// 226: first = middle +1;
mov eax,dword ptr [middle]
add eax,1
mov dword ptr [first],eax
jmp binarySearch+7Eh (0B5196Eh)
// 228: else if (searchNum < myArray[middle])
mov eax,dword ptr [middle]
mov ecx,dword ptr [myArray]
mov edx,dword ptr [searchNum]
cmp edx,dword ptr [ecx+eax*4]
jge binarySearch+7Ah (0B5196Ah)
// 230: last = middle -1;
mov eax,dword ptr [middle]
sub eax,1
mov dword ptr [last],eax
// 232: else
jmp binarySearch+7Eh (0B5196Eh) // Error 18 error C2400: inline assembler syntax error in 'second operand'; found '('
// 233: return true;
mov al,1 // Error 19 error C2400: inline assembler syntax error in 'opcode'; found '('
jmp binarySearch+82h (0B51972h)
jmp binarySearch+32h (0B51922h) // Error 22 error C2400: inline assembler syntax error in 'opcode'; found '('
// 236: return false;
xor al,al
pop edi
pop esi
pop ebx
mov esp,ebp
pop ebp
ret
};
/*
int first=0,last=size-1,middle;
bool found = false;
while (first <= last)
{
middle = (first + last)/2;
if(searchNum > myArray[middle])
{
first = middle +1;
}
else if (searchNum < myArray[middle])
{
last = middle -1;
}
else
return true;
}
return false;
*/
}
答案 0 :(得分：2)
以下是您为独立程序集发布的（几乎1：1）工作代码。
binsearch.cpp
extern "C"
{
bool BinSearch(int searchNum, int myArray[], int arraySize);
};
// This is the inlined version.
bool BinSearchInline(int searchNum, int myArray[], int arraySize)
{
int middle;
int first;
int last;
char found;
_asm
{
push ebx
push esi
push edi
mov first,0
mov eax, arraySize
sub eax,1
mov last ,eax
mov found,0
LocalLoop:
mov eax, first
cmp eax, last
jg NotFound
mov eax, first
add eax, last
cdq
sub eax,edx
sar eax,1
mov middle,eax
mov eax,middle
mov ecx,myArray
mov edx,searchNum
cmp edx, dword ptr [ecx+eax*4]
jle MaybeLower
mov eax, middle
add eax,1
mov first, eax
jmp WhileLoop
MaybeLower:
mov eax, middle
mov ecx, myArray
mov edx, searchNum
cmp edx,dword ptr [ecx+eax*4]
jge Found
mov eax, middle
sub eax,1
mov last, eax
jmp WhileLoop
Found:
mov al,1
jmp Done
WhileLoop:
jmp LocalLoop
NotFound:
xor al,al
Done:
pop edi
pop esi
pop ebx
};
}
int main(int argc, char*arg[])
{
int testvalues[7];
for(int i = 0; i < 7; i++)
testvalues[i] = i;
bool b = BinSearch(8, testvalues, 7); // false, value not in array
b = BinSearch(3, testvalues, 7); // true, value is in array.
b = BinSearchInline(8, testvalues, 7); // false
b = BinSearchInline(3, testvalues, 7); // true
return 0;
}
binsearch.asm
.486
.model flat, C
option casemap :none
.code
BinSearch PROC, searchNum:DWORD, myArray:PTR DWORD, arraySize:DWORD
LOCAL first:DWORD
LOCAL middle:DWORD
LOCAL last:DWORD
LOCAL found:BYTE
push ebx
push esi
push edi
; This block is only for debugging stack errors and should be removed.
; lea edi,[ebp-0F0h]
; mov ecx,3Ch
; mov eax,0CCCCCCCCh
; rep stos dword ptr es:[edi]
mov dword ptr [first],0
mov eax,dword ptr [arraySize]
sub eax,1
mov dword ptr [last],eax
mov byte ptr [found],0 ; not even used.
@@Loop:
mov eax,dword ptr [first]
cmp eax,dword ptr [last]
jg @@NotFound
mov eax,dword ptr [first]
add eax,dword ptr [last]
cdq
sub eax,edx
sar eax,1
mov dword ptr [middle],eax
mov eax,dword ptr [middle]
mov ecx,dword ptr [myArray]
mov edx,dword ptr [searchNum]
cmp edx,dword ptr [ecx+eax*4]
jle @@MaybeLower
mov eax,dword ptr [middle]
add eax,1
mov dword ptr [first],eax
jmp @@WhileLoop
@@MaybeLower:
mov eax,dword ptr [middle]
mov ecx,dword ptr [myArray]
mov edx,dword ptr [searchNum]
cmp edx,dword ptr [ecx+eax*4]
jge @@Found
mov eax,dword ptr [middle]
sub eax,1
mov dword ptr [last],eax
jmp @@WhileLoop
@@Found:
mov al,1
jmp @@Done
@@WhileLoop:
jmp @@Loop
@@NotFound:
xor al,al
@@Done:
pop edi
pop esi
pop ebx
ret
BinSearch ENDP
END