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Code Issues

Fix ulong.PopCount for .NET < Core 3.1 fallback

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Previous implementation copied the uint version
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Oliver Booth 2022-07-08 13:24:07 +01:00
parent b1eadf61f4
commit efa5145836
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1 changed files with 5 additions and 5 deletions
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10
X10D/src/Numerics/UInt64Extensions.cs
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@ -30,14 +30,14 @@ public static class UInt64Extensions
#if NETCOREAPP3_1_OR_GREATER
return BitOperations.PopCount(value);
#else
const uint c1 = 0x_55555555u;
const uint c2 = 0x_33333333u;
const uint c3 = 0x_0F0F0F0Fu;
const uint c4 = 0x_01010101u;
const ulong c1 = 0x_55555555_55555555ul;
const ulong c2 = 0x_33333333_33333333ul;
const ulong c3 = 0x_0F0F0F0F_0F0F0F0Ful;
const ulong c4 = 0x_01010101_01010101ul;
value -= (value >> 1) & c1;
value = (value & c2) + ((value >> 2) & c2);
value = (((value + (value >> 4)) & c3) * c4) >> 24;
value = (((value + (value >> 4)) & c3) * c4) >> 56;
return (int)value;
#endif