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void p1 (p) int *p; { *p &= ~0xff; } void p2 (p) int *p; { *p &= ~0xff00; } void p3 (p) int *p; { *p &= ~0xffff0000; } void p4 (p) int *p; { *p &= ~0xffff; } main () { int a; a = 0x12345678; p1 (&a); printf ("%x\n", a); a = 0x12345678; p2 (&a); printf ("%x\n", a); a = 0x12345678; p3 (&a); printf ("%x\n", a); a = 0x12345678; p4 (&a); printf ("%x\n", a); }