由于使用宏,还是有要引入几个int类型的临时变量及指针,没有完全发挥xor操作的速度,改用块汇编实现。
只是替换了三处,测试与用C实现的结果一样。速度及空间应该都有改良。
#include <stdio.h>
#include <stdlib.h>
#define SWAP(a,b) { a=a^0xFFFFFFFF; b=b^a; a=a^b; b=b^0xFFFFFFFF; b=b^a; }
#define SWAP_POINT(pA,pB) { int h,t; pLinkList ph,pt; h=(int)pA; t=(int)pB; ph = (pLinkList)h; pt = (pLinkList)t; SWAP(h,t); pA = (pLinkList)h; pB = (pLinkList)t; }
typedef struct tagLinkList
{
int data;
struct tagLinkList *next;
} LinkList , *pLinkList ;
int main(int argc, char* argv[])
{
/*
int a=10,b=99;
_asm {
mov eax,a
mov ebx,b
xor ebx,eax
xor eax,ebx
xor ebx,eax
mov a,eax
mov b,ebx
}
printf("a=%d , b=%d \n",a,b);
*/
int count,i;
pLinkList Head,tmpNode,Tail;
Head=NULL;
// Construct LinkList.
printf("Enter count:"); scanf("%d",&count);
if(count <= 1)
{
printf("Count error,must large than 1.\n");
exit(1);
}
for(i=1;i<=count;++i)
{
tmpNode=(LinkList *)malloc(sizeof(LinkList));
tmpNode->data=i;
printf("No.=%d\t Address:%X , Data:%d\n",i,tmpNode,tmpNode->data);
if(!Head)
Tail=Head=tmpNode;
else{
Tail->next=tmpNode;
Tail=tmpNode;
}
}
Tail->next=NULL;
// Reverse LinkList.
if(2 == count) {
//N=2
//SWAP_POINT(Head,Tail->next);
_asm {
mov eax,DWORD PTR Head
mov edx,DWORD PTR Tail
mov esi,4
mov ebx,[edx][esi]
xor ebx,eax
xor eax,ebx
xor ebx,eax
mov Head,eax
mov [edx][esi],ebx
}
SWAP_POINT(Head,Tail);
SWAP_POINT(Head->next->next,Tail);
}else if(3 == count) {
//N=3
SWAP_POINT(Head->next,Tail->next);
SWAP_POINT(Head,Tail);
SWAP_POINT(Head->next->next,Tail);
}else{
//N>=4
SWAP_POINT(Head->next,Tail->next);
SWAP_POINT(Head,Tail);
SWAP_POINT(Head->next->next,Tail);
SWAP_POINT(Head->next,Tail->next);
SWAP_POINT(Head->next->next,Tail);
for(i=6;i<=count;++i)
{
//SWAP_POINT(Head->next,Tail);
_asm {
mov edx,DWORD PTR Head
mov ebx,DWORD PTR Tail
mov esi,4
mov eax,[edx][esi]
xor ebx,eax
xor eax,ebx
xor ebx,eax
mov Tail,ebx
mov [edx][esi],eax
}
//SWAP_POINT(Head->next->next,Tail);
_asm {
mov eax,DWORD PTR Head
mov ebx,DWORD PTR Tail
mov esi,4
mov edx,[edx][esi]
mov eax,[edx][esi]
xor ebx,eax
xor eax,ebx
xor ebx,eax
mov Tail,ebx
mov [edx][esi],eax
}
}
}
//Output reversed LinkList.
tmpNode=Head;
printf("After reverse.\n");
for(i=1;i<=count;++i)
{
printf("No.=%d\t Address:%X , Data:%d\n",i,tmpNode,tmpNode->data);
tmpNode = tmpNode->next;
}
printf("Tail->data = %d\n",Tail->data);
//Release LinkList
printf("Release LinkList.\n");
for(i=1;i<=count;++i)
{
tmpNode=Head;
Head = Head->next;
free(tmpNode);
}
return 0;
}