diff options
Diffstat (limited to 'arch/s390/include/asm/bitops.h')
| -rw-r--r-- | arch/s390/include/asm/bitops.h | 88 |
1 files changed, 27 insertions, 61 deletions
diff --git a/arch/s390/include/asm/bitops.h b/arch/s390/include/asm/bitops.h index a5ca0a947691..ec945fb60c02 100644 --- a/arch/s390/include/asm/bitops.h +++ b/arch/s390/include/asm/bitops.h @@ -122,6 +122,8 @@ static inline bool test_bit_inv(unsigned long nr, return test_bit(nr ^ (BITS_PER_LONG - 1), ptr); } +#ifndef CONFIG_CC_HAS_BUILTIN_FFS + /** * __flogr - find leftmost one * @word - The word to search @@ -130,11 +132,12 @@ static inline bool test_bit_inv(unsigned long nr, * where the most significant bit has bit number 0. * If no bit is set this function returns 64. */ -static inline unsigned char __flogr(unsigned long word) +static __always_inline __attribute_const__ unsigned long __flogr(unsigned long word) { - if (__builtin_constant_p(word)) { - unsigned long bit = 0; + unsigned long bit; + if (__builtin_constant_p(word)) { + bit = 0; if (!word) return 64; if (!(word & 0xffffffff00000000UL)) { @@ -163,86 +166,49 @@ static inline unsigned char __flogr(unsigned long word) } return bit; } else { - union register_pair rp; + union register_pair rp __uninitialized; rp.even = word; - asm volatile( - " flogr %[rp],%[rp]\n" - : [rp] "+d" (rp.pair) : : "cc"); - return rp.even; + asm("flogr %[rp],%[rp]" + : [rp] "+d" (rp.pair) : : "cc"); + bit = rp.even; + /* + * The result of the flogr instruction is a value in the range + * of 0..64. Let the compiler know that the AND operation can + * be optimized away. + */ + __assume(bit <= 64); + return bit & 127; } } /** - * __ffs - find first bit in word. - * @word: The word to search - * - * Undefined if no bit exists, so code should check against 0 first. - */ -static inline unsigned long __ffs(unsigned long word) -{ - return __flogr(-word & word) ^ (BITS_PER_LONG - 1); -} - -/** * ffs - find first bit set * @word: the word to search * * This is defined the same way as the libc and * compiler builtin ffs routines (man ffs). */ -static inline int ffs(int word) +static __always_inline __flatten __attribute_const__ int ffs(int word) { - unsigned long mask = 2 * BITS_PER_LONG - 1; unsigned int val = (unsigned int)word; - return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask; -} - -/** - * __fls - find last (most-significant) set bit in a long word - * @word: the word to search - * - * Undefined if no set bit exists, so code should check against 0 first. - */ -static inline unsigned long __fls(unsigned long word) -{ - return __flogr(word) ^ (BITS_PER_LONG - 1); + return BITS_PER_LONG - __flogr(-val & val); } -/** - * fls64 - find last set bit in a 64-bit word - * @word: the word to search - * - * This is defined in a similar way as the libc and compiler builtin - * ffsll, but returns the position of the most significant set bit. - * - * fls64(value) returns 0 if value is 0 or the position of the last - * set bit if value is nonzero. The last (most significant) bit is - * at position 64. - */ -static inline int fls64(unsigned long word) -{ - unsigned long mask = 2 * BITS_PER_LONG - 1; +#else /* CONFIG_CC_HAS_BUILTIN_FFS */ - return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask; -} +#include <asm-generic/bitops/builtin-ffs.h> -/** - * fls - find last (most-significant) bit set - * @word: the word to search - * - * This is defined the same way as ffs. - * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. - */ -static inline int fls(unsigned int word) -{ - return fls64(word); -} +#endif /* CONFIG_CC_HAS_BUILTIN_FFS */ +#include <asm-generic/bitops/builtin-__ffs.h> +#include <asm-generic/bitops/ffz.h> +#include <asm-generic/bitops/builtin-__fls.h> +#include <asm-generic/bitops/builtin-fls.h> +#include <asm-generic/bitops/fls64.h> #include <asm/arch_hweight.h> #include <asm-generic/bitops/const_hweight.h> -#include <asm-generic/bitops/ffz.h> #include <asm-generic/bitops/sched.h> #include <asm-generic/bitops/le.h> #include <asm-generic/bitops/ext2-atomic-setbit.h> |