STAMP_MASK         72 dev/rasops/rasops15.c #define STAMP_MASK		(15 << 3)
STAMP_MASK         77 dev/rasops/rasops24.c #define STAMP_MASK		(0xf << 4)
STAMP_MASK         71 dev/rasops/rasops8.c #define STAMP_MASK		(0xf << 2)