Re: [PATCH 2/5] bitops: compile time optimization forhweight_long(CONSTANT)

[Peter Zijlstra]

On Wed, 2010-02-03 at 19:14 +0100, Borislav Petkov wrote:

> alternative("call hweightXX", "popcnt", X86_FEATURE_POPCNT)

Make sure to apply a 0xff bitmask to the popcnt r16 call for hweight8(),
and hweight64() needs a bit of magic for 32bit, but yes, something like
that ought to work nicely.

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