Messages in this thread | | | Subject | Re: [PATCH V3] blackfin: optimize ffz, __ffs, ffs, __fls, and fls functions | From | Zhaoxiu Zeng <> | Date | Sat, 16 Apr 2016 00:18:43 +0800 |
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在 2016/4/16 0:08, Joe Perches 写道: > On Fri, 2016-04-15 at 23:20 +0800, zengzhaoxiu@163.com wrote: >> From: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com> >> >> blackfin has popcount instruction (ONES), we can do the efficient >> computing (ffz, __ffs, ffs, __fls, and fls) use this instruction. > [] >> diff --git a/arch/blackfin/include/asm/bitops.h b/arch/blackfin/include/asm/bitops.h > [] >> +static inline unsigned int __arch_hweight64(__u64 w) >> +{ >> + return __arch_hweight32((unsigned int)(w >> 32)) + >> + __arch_hweight32((unsigned int)w); >> +} > trivia: perhaps this is more readable as: > > return __arch_hweight32(upper_32_bits(w)) + > __arch_hweight32(lower_32_bits(w)); > >
Yes. I just moved these codes from the bottom of bitops.h, didn't change anything.
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