【高速化】ビット演算　0x02

【高速化】ビット演算　0x02 at TECH

465:デフォルトの名無しさん
07/09/30 00:34:50
>>464のソース (VC6SP4)
----------------------------
#include <windows.h>
#include <stdio.h>
int rotate_0_9_457_1(int a){a++;return(a+(((a+6)>>4)+(((a+6)>>4)<<1))<<1)&15;}
int rotate_0_9_457_2(int a){a++;return(a+((a+6)>>4)*6)&15;}
int rotate_0_9_458(int a){return ++a%9;}
int rotate_0_9_460(int a){return a<9?a+1:0;}
//#define COUNT_TIMES 0x7fffffff
#define COUNT_TIMES 0x7ffffff
#define TEST(func) \
dwTime = GetTickCount(); \
for(i = 0, count = 0; count < COUNT_TIMES ; count++) { \
i=func(i); \
} \
printf( # func " %d msec\n", GetTickCount() - dwTime);
main() {
int i, count;
DWORD dwTime;
SetPriorityClass(GetCurrentProcess(), HIGH_PRIORITY_CLASS);
Sleep(100);
TEST(rotate_0_9_457_1)
Sleep(100);
TEST(rotate_0_9_457_2)
Sleep(100);
TEST(rotate_0_9_458)
Sleep(100);
TEST(rotate_0_9_460)
return 0;
}
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