diff options
Diffstat (limited to 'include/asm-mips/bitops.h')
| -rw-r--r-- | include/asm-mips/bitops.h | 137 |
1 files changed, 115 insertions, 22 deletions
diff --git a/include/asm-mips/bitops.h b/include/asm-mips/bitops.h index d9c02bd0b18..2ba20730a3e 100644 --- a/include/asm-mips/bitops.h +++ b/include/asm-mips/bitops.h @@ -546,17 +546,60 @@ static inline int test_bit(unsigned long nr, const volatile unsigned long *addr) return 1UL & (addr[nr >> SZLONG_LOG] >> (nr & SZLONG_MASK)); } +#ifdef CONFIG_CPU_MIPS32_R1 /* - * ffz - find first zero in word. + * Return the bit position (0..31) of the most significant 1 bit in a word + * Returns -1 if no 1 bit exists + */ +static __inline__ int __ilog2(unsigned long x) +{ + int lz; + + __asm__ ( + " .set push \n" + " .set mips32 \n" + " clz %0, %1 \n" + " .set pop \n" + : "=r" (lz) + : "r" (x)); + + return 31 - lz; +} +#elif defined(CONFIG_CPU_MIPS64_R1) +/* + * Return the bit position (0..63) of the most significant 1 bit in a word + * Returns -1 if no 1 bit exists + */ +static __inline__ int __ilog2(unsigned long x) +{ + int lz; + + __asm__ ( + " .set push \n" + " .set mips64 \n" + " dclz %0, %1 \n" + " .set pop \n" + : "=r" (lz) + : "r" (x)); + + return 63 - lz; +} +#endif + +/* + * __ffs - find first bit in word. * @word: The word to search * - * Undefined if no zero exists, so code should check against ~0UL first. + * Returns 0..SZLONG-1 + * Undefined if no bit exists, so code should check against 0 first. */ -static inline unsigned long ffz(unsigned long word) +static inline unsigned long __ffs(unsigned long word) { +#if defined(CONFIG_CPU_MIPS32_R1) || defined(CONFIG_CPU_MIPS64_R1) + return __ilog2(word & -word); +#else int b = 0, s; - word = ~word; #ifdef CONFIG_32BIT s = 16; if (word << 16 != 0) s = 0; b += s; word >>= s; s = 8; if (word << 24 != 0) s = 0; b += s; word >>= s; @@ -572,26 +615,87 @@ static inline unsigned long ffz(unsigned long word) s = 2; if (word << 62 != 0) s = 0; b += s; word >>= s; s = 1; if (word << 63 != 0) s = 0; b += s; #endif - return b; +#endif } /* - * __ffs - find first bit in word. + * ffs - find first bit set. * @word: The word to search * - * Undefined if no bit exists, so code should check against 0 first. + * Returns 1..SZLONG + * Returns 0 if no bit exists */ -static inline unsigned long __ffs(unsigned long word) + +static inline unsigned long ffs(unsigned long word) { - return ffz(~word); + if (!word) + return 0; + + return __ffs(word) + 1; } /* - * fls: find last bit set. + * ffz - find first zero in word. + * @word: The word to search + * + * Undefined if no zero exists, so code should check against ~0UL first. */ +static inline unsigned long ffz(unsigned long word) +{ + return __ffs (~word); +} + +/* + * flz - find last zero in word. + * @word: The word to search + * + * Returns 0..SZLONG-1 + * Undefined if no zero exists, so code should check against ~0UL first. + */ +static inline unsigned long flz(unsigned long word) +{ +#if defined(CONFIG_CPU_MIPS32_R1) || defined(CONFIG_CPU_MIPS64_R1) + return __ilog2(~word); +#else +#if defined(CONFIG_32BIT) + int r = 31, s; + word = ~word; + s = 16; if ((word & 0xffff0000)) s = 0; r -= s; word <<= s; + s = 8; if ((word & 0xff000000)) s = 0; r -= s; word <<= s; + s = 4; if ((word & 0xf0000000)) s = 0; r -= s; word <<= s; + s = 2; if ((word & 0xc0000000)) s = 0; r -= s; word <<= s; + s = 1; if ((word & 0x80000000)) s = 0; r -= s; +#endif +#if defined(CONFIG_64BIT) + int r = 63, s; + word = ~word; + s = 32; if ((word & 0xffffffff00000000UL)) s = 0; r -= s; word <<= s; + s = 16; if ((word & 0xffff000000000000UL)) s = 0; r -= s; word <<= s; + s = 8; if ((word & 0xff00000000000000UL)) s = 0; r -= s; word <<= s; + s = 4; if ((word & 0xf000000000000000UL)) s = 0; r -= s; word <<= s; + s = 2; if ((word & 0xc000000000000000UL)) s = 0; r -= s; word <<= s; + s = 1; if ((word & 0x8000000000000000UL)) s = 0; r -= s; +#endif + return r; +#endif +} + +/* + * fls - find last bit set. + * @word: The word to search + * + * Returns 1..SZLONG + * Returns 0 if no bit exists + */ +static inline unsigned long fls(unsigned long word) +{ + if (word == 0) + return 0; + + return flz(~word) + 1; +} -#define fls(x) generic_fls(x) /* * find_next_zero_bit - find the first zero bit in a memory region @@ -728,17 +832,6 @@ static inline int sched_find_first_bit(const unsigned long *b) } /* - * ffs - find first bit set - * @x: the word to search - * - * This is defined the same way as - * the libc and compiler builtin ffs routines, therefore - * differs in spirit from the above ffz (man ffs). - */ - -#define ffs(x) generic_ffs(x) - -/* * hweightN - returns the hamming weight of a N-bit word * @x: the word to weigh * |