Faster popcnt_i32
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d6b7a232ac
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@ -182,14 +182,12 @@ do
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local bit_countrz = bit32.countrz
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local bit_countrz = bit32.countrz
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local function popcnt_i32(num)
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local function popcnt_i32(num)
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local count = 0
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num = bit_and(num, 0x55555555) + bit_and(bit_rshift(num, 1), 0x55555555)
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num = bit_and(num, 0x33333333) + bit_and(bit_rshift(num, 2), 0x33333333)
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while num ~= 0 do
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num = bit_and(num, 0x0f0f0f0f) + bit_and(bit_rshift(num, 4), 0x0f0f0f0f)
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num = bit_and(num, num - 1)
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num = bit_and(num, 0x00ff00ff) + bit_and(bit_rshift(num, 8), 0x00ff00ff)
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count = count + 1
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num = bit_and(num, 0x0000ffff) + bit_and(bit_rshift(num, 16), 0x0000ffff)
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end
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return num
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return count
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end
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end
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popcnt.i32 = popcnt_i32
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popcnt.i32 = popcnt_i32
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