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ryujinx-fork/Ryujinx.Common/BitUtils.cs

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namespace Ryujinx.Common
{
public static class BitUtils
{
public static int AlignUp(int Value, int Size)
{
return (Value + (Size - 1)) & -Size;
}
public static ulong AlignUp(ulong Value, int Size)
{
return (ulong)AlignUp((long)Value, Size);
}
public static long AlignUp(long Value, int Size)
{
return (Value + (Size - 1)) & -(long)Size;
}
public static int AlignDown(int Value, int Size)
{
return Value & -Size;
}
public static ulong AlignDown(ulong Value, int Size)
{
return (ulong)AlignDown((long)Value, Size);
}
public static long AlignDown(long Value, int Size)
{
return Value & -(long)Size;
}
public static ulong DivRoundUp(ulong Value, uint Dividend)
{
return (Value + Dividend - 1) / Dividend;
}
public static long DivRoundUp(long Value, int Dividend)
{
return (Value + Dividend - 1) / Dividend;
}
public static bool IsPowerOfTwo32(int Value)
{
return Value != 0 && (Value & (Value - 1)) == 0;
}
public static bool IsPowerOfTwo64(long Value)
{
return Value != 0 && (Value & (Value - 1)) == 0;
}
public static int CountLeadingZeros32(int Value)
{
return (int)CountLeadingZeros((ulong)Value, 32);
}
public static int CountLeadingZeros64(long Value)
{
return (int)CountLeadingZeros((ulong)Value, 64);
}
private static readonly byte[] ClzNibbleTbl = { 4, 3, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0 };
private static ulong CountLeadingZeros(ulong Value, int Size) // Size is 8, 16, 32 or 64 (SIMD&FP or Base Inst.).
{
if (Value == 0ul)
{
return (ulong)Size;
}
int NibbleIdx = Size;
int PreCount, Count = 0;
do
{
NibbleIdx -= 4;
PreCount = ClzNibbleTbl[(Value >> NibbleIdx) & 0b1111];
Count += PreCount;
}
while (PreCount == 4);
return (ulong)Count;
}
public static long ReverseBits64(long Value)
{
return (long)ReverseBits64((ulong)Value);
}
private static ulong ReverseBits64(ulong Value)
{
Value = ((Value & 0xaaaaaaaaaaaaaaaa) >> 1 ) | ((Value & 0x5555555555555555) << 1 );
Value = ((Value & 0xcccccccccccccccc) >> 2 ) | ((Value & 0x3333333333333333) << 2 );
Value = ((Value & 0xf0f0f0f0f0f0f0f0) >> 4 ) | ((Value & 0x0f0f0f0f0f0f0f0f) << 4 );
Value = ((Value & 0xff00ff00ff00ff00) >> 8 ) | ((Value & 0x00ff00ff00ff00ff) << 8 );
Value = ((Value & 0xffff0000ffff0000) >> 16) | ((Value & 0x0000ffff0000ffff) << 16);
return (Value >> 32) | (Value << 32);
}
}
}