Use clz / dclz on MIPS32 / MIPS64 processors.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle
parent
e5de3b4687
commit
6590326505
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@ -546,17 +546,60 @@ static inline int test_bit(unsigned long nr, const volatile unsigned long *addr)
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return 1UL & (addr[nr >> SZLONG_LOG] >> (nr & SZLONG_MASK));
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}
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#ifdef CONFIG_CPU_MIPS32_R1
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/*
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* ffz - find first zero in word.
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* Return the bit position (0..31) of the most significant 1 bit in a word
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* Returns -1 if no 1 bit exists
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*/
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static __inline__ int __ilog2(unsigned long x)
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{
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int lz;
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__asm__ (
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" .set push \n"
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" .set mips32 \n"
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" clz %0, %1 \n"
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" .set pop \n"
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: "=r" (lz)
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: "r" (x));
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return 31 - lz;
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}
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#elif defined(CONFIG_CPU_MIPS64_R1)
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/*
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* Return the bit position (0..63) of the most significant 1 bit in a word
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* Returns -1 if no 1 bit exists
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*/
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static __inline__ int __ilog2(unsigned long x)
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{
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int lz;
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__asm__ (
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" .set push \n"
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" .set mips64 \n"
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" dclz %0, %1 \n"
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" .set pop \n"
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: "=r" (lz)
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: "r" (x));
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return 63 - lz;
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}
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#endif
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/*
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* __ffs - find first bit in word.
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* @word: The word to search
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*
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* Undefined if no zero exists, so code should check against ~0UL first.
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* Returns 0..SZLONG-1
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* Undefined if no bit exists, so code should check against 0 first.
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*/
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static inline unsigned long ffz(unsigned long word)
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static inline unsigned long __ffs(unsigned long word)
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{
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#if defined(CONFIG_CPU_MIPS32_R1) || defined(CONFIG_CPU_MIPS64_R1)
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return __ilog2(word & -word);
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#else
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int b = 0, s;
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word = ~word;
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#ifdef CONFIG_32BIT
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s = 16; if (word << 16 != 0) s = 0; b += s; word >>= s;
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s = 8; if (word << 24 != 0) s = 0; b += s; word >>= s;
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@ -572,26 +615,87 @@ static inline unsigned long ffz(unsigned long word)
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s = 2; if (word << 62 != 0) s = 0; b += s; word >>= s;
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s = 1; if (word << 63 != 0) s = 0; b += s;
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#endif
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return b;
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#endif
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}
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/*
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* __ffs - find first bit in word.
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* ffs - find first bit set.
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* @word: The word to search
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*
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* Undefined if no bit exists, so code should check against 0 first.
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* Returns 1..SZLONG
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* Returns 0 if no bit exists
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*/
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static inline unsigned long __ffs(unsigned long word)
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static inline unsigned long ffs(unsigned long word)
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{
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return ffz(~word);
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if (!word)
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return 0;
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return __ffs(word) + 1;
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}
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/*
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* fls: find last bit set.
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* ffz - find first zero in word.
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* @word: The word to search
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*
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* Undefined if no zero exists, so code should check against ~0UL first.
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*/
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static inline unsigned long ffz(unsigned long word)
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{
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return __ffs (~word);
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}
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/*
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* flz - find last zero in word.
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* @word: The word to search
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*
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* Returns 0..SZLONG-1
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* Undefined if no zero exists, so code should check against ~0UL first.
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*/
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static inline unsigned long flz(unsigned long word)
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{
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#if defined(CONFIG_CPU_MIPS32_R1) || defined(CONFIG_CPU_MIPS64_R1)
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return __ilog2(~word);
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#else
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#if defined(CONFIG_32BIT)
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int r = 31, s;
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word = ~word;
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s = 16; if ((word & 0xffff0000)) s = 0; r -= s; word <<= s;
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s = 8; if ((word & 0xff000000)) s = 0; r -= s; word <<= s;
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s = 4; if ((word & 0xf0000000)) s = 0; r -= s; word <<= s;
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s = 2; if ((word & 0xc0000000)) s = 0; r -= s; word <<= s;
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s = 1; if ((word & 0x80000000)) s = 0; r -= s;
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#endif
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#if defined(CONFIG_64BIT)
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int r = 63, s;
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word = ~word;
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s = 32; if ((word & 0xffffffff00000000UL)) s = 0; r -= s; word <<= s;
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s = 16; if ((word & 0xffff000000000000UL)) s = 0; r -= s; word <<= s;
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s = 8; if ((word & 0xff00000000000000UL)) s = 0; r -= s; word <<= s;
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s = 4; if ((word & 0xf000000000000000UL)) s = 0; r -= s; word <<= s;
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s = 2; if ((word & 0xc000000000000000UL)) s = 0; r -= s; word <<= s;
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s = 1; if ((word & 0x8000000000000000UL)) s = 0; r -= s;
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#endif
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return r;
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#endif
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}
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/*
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* fls - find last bit set.
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* @word: The word to search
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*
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* Returns 1..SZLONG
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* Returns 0 if no bit exists
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*/
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static inline unsigned long fls(unsigned long word)
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{
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if (word == 0)
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return 0;
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return flz(~word) + 1;
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}
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#define fls(x) generic_fls(x)
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/*
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* find_next_zero_bit - find the first zero bit in a memory region
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@ -727,17 +831,6 @@ static inline int sched_find_first_bit(const unsigned long *b)
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#endif
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}
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/*
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* ffs - find first bit set
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* @x: the word to search
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*
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* This is defined the same way as
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* the libc and compiler builtin ffs routines, therefore
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* differs in spirit from the above ffz (man ffs).
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*/
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#define ffs(x) generic_ffs(x)
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/*
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* hweightN - returns the hamming weight of a N-bit word
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* @x: the word to weigh
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