Use clz / dclz on MIPS32 / MIPS64 processors. (65903265) · Commits · e / devices / android_kernel_oneplus_sm8150

include/asm-mips/bitops.h

+115 −22

Original line number	Diff line number	Diff line
		@@ -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
		@@ -727,17 +831,6 @@ static inline int sched_find_first_bit(const unsigned long *b)
		#endif
		}

		/*
		* 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