bitops: Provide compile time HWEIGHT{8,16,32,64} (9f41699e) · Commits · 戴 / test

Provide compile time versions of hweight. Signed-off-by:

Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20100122155535.797688466@chello.nl> [ Remove some whitespace damage while we are at it ] Signed-off-by:

Ingo Molnar <mingo@elte.hu>

include/linux/bitops.h

+16 −2

Original line number	Diff line number	Diff line
		@@ -45,6 +45,20 @@ static inline unsigned long hweight_long(unsigned long w)
		return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
		}

		#define HWEIGHT8(w) \
		( (!!((w) & (1ULL << 0))) + \
		(!!((w) & (1ULL << 1))) + \
		(!!((w) & (1ULL << 2))) + \
		(!!((w) & (1ULL << 3))) + \
		(!!((w) & (1ULL << 4))) + \
		(!!((w) & (1ULL << 5))) + \
		(!!((w) & (1ULL << 6))) + \
		(!!((w) & (1ULL << 7))) )

		#define HWEIGHT16(w) (HWEIGHT8(w) + HWEIGHT8(w >> 8))
		#define HWEIGHT32(w) (HWEIGHT16(w) + HWEIGHT16(w >> 16))
		#define HWEIGHT64(w) (HWEIGHT32(w) + HWEIGHT32(w >> 32))

		/**
		* rol32 - rotate a 32-bit value left
		* @word: value to rotate

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