?? check-shift.c
字號(hào):
/* code "borrowed" from JPEG-5 config code*/#include <stdio.h>int is_shifting_signed (arg) long arg;/* See whether right-shift on a long is signed or not. */{ long res = arg >> 4; if (res == -0x7F7E80CL) { /* expected result for signed shift */ return 1; /* right shift is signed */ } /* see if unsigned-shift hack will fix it. */ /* we can't just test exact value since it depends on width of long... */ res |= (~0L) << (32-4); if (res == -0x7F7E80CL) { /* expected result now? */ return 0; /* right shift is unsigned */ } fprintf(stderr, "Right shift isn't acting as I expect it to.\n"); fprintf(stderr, "I fear the DCT software will not work at all.\n\n"); exit(1);}main(){ if (is_shifting_signed(-0x7F7E80B1L)) { printf("do not define RIGHT_SHIFT_IS_UNSIGNED\n"); } else { printf("define RIGHT_SHIFT_IS_UNSIGNED\n"); }}
?? 快捷鍵說(shuō)明
復(fù)制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號(hào)
Ctrl + =
減小字號(hào)
Ctrl + -