diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 2 | ||||
| -rw-r--r-- | lib/hweight.c | 10 |
2 files changed, 9 insertions, 3 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 2869307ca3e4..f1ac3184dc08 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -225,7 +225,7 @@ config LOCKDEP bool depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT select STACKTRACE - select FRAME_POINTER + select FRAME_POINTER if !X86 select KALLSYMS select KALLSYMS_ALL diff --git a/lib/hweight.c b/lib/hweight.c index 438257671708..360556a7803d 100644 --- a/lib/hweight.c +++ b/lib/hweight.c @@ -1,5 +1,6 @@ #include <linux/module.h> #include <asm/types.h> +#include <asm/bitops.h> /** * hweightN - returns the hamming weight of a N-bit word @@ -40,14 +41,19 @@ unsigned long hweight64(__u64 w) #if BITS_PER_LONG == 32 return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); #elif BITS_PER_LONG == 64 +#ifdef ARCH_HAS_FAST_MULTIPLIER + w -= (w >> 1) & 0x5555555555555555ul; + w = (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul); + w = (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful; + return (w * 0x0101010101010101ul) >> 56; +#else __u64 res = w - ((w >> 1) & 0x5555555555555555ul); res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul); res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful; res = res + (res >> 8); res = res + (res >> 16); return (res + (res >> 32)) & 0x00000000000000FFul; -#else -#error BITS_PER_LONG not defined +#endif #endif } EXPORT_SYMBOL(hweight64); |