#ifndef _ASM_WORD_AT_A_TIME_H #define _ASM_WORD_AT_A_TIME_H /* * This says "generic", but it's actually big-endian only. * Little-endian can use more efficient versions of these * interfaces, see for example * arch/x86/include/asm/word-at-a-time.h * for those. */ #include <linux/kernel.h> struct word_at_a_time { const unsigned long high_bits, low_bits; }; #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0xfe) + 1, REPEAT_BYTE(0x7f) } /* Bit set in the bytes that have a zero */ static inline long prep_zero_mask(unsigned long val, unsigned long rhs, const struct word_at_a_time *c) { unsigned long mask = (val & c->low_bits) + c->low_bits; return ~(mask | rhs); } #define create_zero_mask(mask) (mask) static inline long find_zero(unsigned long mask) { long byte = 0; #ifdef CONFIG_64BIT if (mask >> 32) mask >>= 32; else byte = 4; #endif if (mask >> 16) mask >>= 16; else byte += 2; return (mask >> 8) ? byte : byte + 1; } static inline bool has_zero(unsigned long val, unsigned long *data, const struct word_at_a_time *c) { unsigned long rhs = val | c->low_bits; *data = rhs; return (val + c->high_bits) & ~rhs; } #ifndef zero_bytemask #define zero_bytemask(mask) (~1ul << __fls(mask)) #endif #endif /* _ASM_WORD_AT_A_TIME_H */