在Microsoft Visual C ++ 2010中将汇编合并转换为C ++中的内联汇编
您好。我正在尝试转换我在 Github上找到的汇编代码使用C ++进行内联汇编。我已经将asm函数添加到代码中,但代码中断并且不能编译。我使用Microsoft Visual C ++编译器来执行此操作。这是一个个人项目,因此代码仅供我学习。非常感谢任何帮助。
这是代码:
Hello. I am trying to convert this assembly code that I found on Github into inline assembly in C++. I have already added the asm function to the code, but the code breaks and won''t compile. I am using Microsoft Visual C++ compiler to do this. This is a personal project so the code is only for my learning experience. I greatly appreciate any help.
Here is the code:
#include <iostream>
#include <cmath>
#include <stdio.h>
using namespace std;
const int ARRAYSIZE = 30;
int main()
{
int arr[ARRAYSIZE];
int temp_arr[ARRAYSIZE];
int number;
for(int x = 0; x < ARRAYSIZE; x++)
{
number = (rand() % 99) + 1;
arr[x] = number;
}
/*
READ_ARR_LEN:
__asm
{
// Read the length of the array
//GetLInt [30] // Size of input array
//PutLInt [30]
}
GET_ARRAY:
__asm
{
//intel_syntax
// Get values in arr from the user
mov EAX, arr
mov ECX, ARR_LEN
call Read_Arr
// Run Merge Sort on the array
mov EAX, arr
mov EBX, temp_arr
mov ECX, ARR_LEN
call Merge_Sort
// EXIT
}//
*/
Merge_Sort:
__asm
{
// EAX - Array start
// ECX - array length
// Arrays of size 0 or 1 are already sorted
cmp ECX, 2
jl Trivial_Merge_Sort
// Merge_Sort (first half)
// Length of the first half
// ECX /= 2
push ECX
shr ECX, 1
call Merge_Sort
pop ECX
// Merge_Sort (second half)
push EAX
push EBX
push ECX
// Length of the second half
// ECX = ECX - ECX/2
mov EDX, ECX
shr EDX, 1
sub ECX, EDX
imul EDX, 4
// Start index of the second half
// EAX = EAX + (ECX/2) * 4
add EAX, EDX
push EDX
call Merge_Sort
pop EDX
pop ECX
pop EBX
pop EAX
pushad
// Merge (first half, second half)
// Length of first half = ECX/2
// Length of second half = ECX - ECX/2
mov EDX, ECX
shr ECX, 1
sub EDX, ECX
// Start of second half = EAX + (ECX/2) * 4
mov EBX, EAX
mov EDI, ECX
imul EDI, 4
add EBX, EDI
// Index of temp array = 0
sub EDI, EDI
call Merge
popad
// Copy back the merged array from temp_arr to arr
call Merge_Copy_Back_Temp
ret
};
Trivial_Merge_Sort:
__asm
{
// In case of arrays of length 0 or 1
ret
};
Merge:
__asm
{
// Merge two arrays contents.
// The final merged array will be in temp_arr
// Merging is done recursively.
// Arguments:
// EAX - First array's start
// EBX - Second array's start
// ECX - Length of first array
// EDX - Length of second array
// EDI - Index in temp array
pushad
// Handle the cases where one array is empty
cmp ECX, 0
jz First_Array_Over
cmp EDX, 0
jz Second_Array_Over
// Compare first elements of both the arrays
push EDX
push EDI
mov EDX, [EAX]
mov EDI, [EBX]
cmp EDX, EDI
pop EDI
pop EDX
// Pick which ever is the least and update that array
jl Update_First_Array
jmp Update_Second_Array
};
Update_First_Array:
__asm
{
// min_elem = min (first elements of first array and second array)
// Put min_elem into the temp array
push dword ptr [EAX]
pop dword ptr [temp_arr + EDI * 4]
add EAX, 4
dec ECX
inc EDI
// Recursively call Merge on the updated array and the
// other array
call Merge
popad
ret
};
Update_Second_Array:
__asm
{
// min_elem = min (first elements of first array and second array)
// Put min_elem into the temp array
push dword ptr [EBX]
pop dword ptr [temp_arr + EDI * 4]
add EBX, 4
dec EDX
inc EDI
// Recursively call Merge on the updated array and the
// other array
call Merge
popad
ret
};
Merge_Copy_Back_Temp:
__asm
{
// Copy back the temp array into original array
// Arguments:
// EAX - original array address
// ECX - original array length
pushad
// For copying back, the destination array is EAX
mov EBX, EAX
// Now, the source array is temp_arr
mov EAX, temp_arr
call Copy_Array
popad
ret
};
Trivial_Merge:
__asm
{
// Note: One array is empty means no need to merge.
popad
ret
};
First_Array_Over:
__asm
{
// Copy the rest of the second array to the temp arr
// because the first array is empty
pushad
mov EAX, EBX
mov ECX, EDX
mov EBX, temp_arr
imul EDI, 4
add EBX, EDI
call Copy_Array
popad
popad
ret
};
Second_Array_Over:
__asm
{
// Copy the rest of the first array to the temp arr
// because the second array is empty
pushad
mov EBX, temp_arr
imul EDI, 4
add EBX, EDI
call Copy_Array
popad
popad
ret
};
Copy_Array:
__asm
{
// Copy array to destination array
// EAX - Array start
// EBX - Destination array
// ECX - Array length
// Trivial case
cmp ECX, 0
jz Copy_Empty_Array
push ECX
sub EDI, EDI
};
copy_loop:
__asm
{
// Copy each element
push dword ptr [EAX + EDI * 4]
pop dword ptr [EBX + EDI * 4]
inc EDI
loop copy_loop
pop ECX
ret
};
Copy_Empty_Array:
__asm
{
ret
};
Read_Arr:
__asm
{
// EAX - array start
// ECX - array length
mov ESI, EAX
sub EDI, EDI
};
loop1:
__asm
{
// Read each element
lea eax,[esi+edx*4]
inc EDI
loop loop1
ret
};
return 0;
}
您好
您的代码在我的win7上编译得很好/ x64 / vs2010系统,但它崩溃了,我认为这是因为你在寄存器上使用的是间接的,这些寄存器没有加载正确的地址。
我带了例子通过初始化来生活
Hi
your code compiles fine on my win7/x64/vs2010 system, but it crashes and I think this is because you are using indirections on registers which aren''t loaded with proper addresses.
I brought the example to life by initializing with
Init:
__asm
{
//instead of mov EAX, arr
lea EAX, arr
//instead of mov EBX, temp_arr
lea EBX, temp_arr
mov ECX, ARRAYSIZE
call Merge_Sort
jmp finish
};
在初始for循环之后,用随机数填充数组,
然后替换所有出现
right after the initial for loop which fills the array with random numbers,
then replacing all occurences of
mov <reg>, <c-array-name></c-array-name></reg>
with
with
lea <reg>, <c-array-name></c-array-name></reg>
和最后添加一个
and finally adding a
finish:
标签之前
label right before
return 0;
}