尝试通过 eax 从 asm proc 返回一个 long int,然后尝试通过 dx:ax。两者都对我不起作用,因为 C printf 打印的数字与所需的 320L 不同。
x.asm:
.model SMALL
.stack 100h
.code
.386
; extern int get_buffered_long(long int **arr, int num_of_elements, int i);
; [BP+4] [BP+6] [BP+8]
PUBLIC _get_bufferred_long
_get_bufferred_long PROC NEAR
push BP
mov BP,SP
push SI
push DI
push BX
call locate_slot
;mov EAX, DWORD PTR [DI] ;something here doesn't work. the way i return a long int to borland C, or other issue.
mov ax,[DI]
mov dx,[DI+2]
pop BX
pop DI
pop SI
pop BP
ret
_get_bufferred_long ENDP
; extern void set_bufferred_long(long int *arr[], int buff_size, int i,long int value);
; [BP+4] [BP+6] [BP+8] [BP+10]
PUBLIC _set_bufferred_long
_set_bufferred_long PROC NEAR
push BP
mov BP,SP
pushad
call locate_slot
mov EAX,[BP+10]
mov DWORD PTR [DI],EAX
popad
pop BP
ret
_set_bufferred_long ENDP
; helper function that makes DI point to the slot wanted.
locate_slot PROC NEAR
calc_slot:
mov SI,[BP+4]
mov AX,[BP+8]
mov BX,[BP+6]
xor DX,DX
div BX
locate_slot_in_array:
shl AX,1
add SI,AX
mov DI,[SI]
shl DX,2
add DI,DX
ret
locate_slot ENDP
end
yc:
#include "stdio.h"
#include "stdlib.h"
extern int get_bufferred_long(long int**,int,int);
extern void set_bufferred_long(long int**,int,int,long int);
int main(){
long int **arr;
int i,j,n,m;
n = 5;
m = 4;
arr=(long int**)malloc(n*sizeof(long int*));
for(i=0; i < n; i = i + 2) arr[i] = malloc( m*sizeof(long int));
for(i=1; i < n; i = i + 2) arr[i] = malloc( m*sizeof(long int));
for(i=0; i < n; i++)
for(j=0; j < m; j++)
set_bufferred_long(arr, m, i*m+j, i*100+j*10);
printf("get_bufferred_long(arr, %d, %d) = %ld\n", m, 14, get_bufferred_long(arr,m, 14));
return 0;
}
set 函数有效(数组看起来与需要的完全一样)。get 函数也可以工作,它在 asm 中获取 320L,但是当传递给 C 时,出现了问题。
没有编译错误或警告。borland c++ 5.02