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Benchmarks extended. Small optimizations.

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Marek Lemańczyk committed 2025-09-21 06:15:14 +02:00
1 parent 53554ffd3d
commit 1499f6abe1
5 files changed
+181 -79
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PerfectNumbers.Core/PerfectNumbersMath.cs
+21
View File
@@ -0,0 +1,21 @@
using System.Runtime.CompilerServices;
namespace PerfectNumbers.Core;
public static class PerfectNumbersMath
{
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint FastRemainder3(uint value)
{
uint quotient = (uint)(((ulong)value * 0xAAAAAAABUL) >> 33);
return value - quotient * 3U;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint FastRemainder5(uint value)
{
uint quotient = (uint)(((ulong)value * 0xCCCCCCCDUL) >> 34);
return value - quotient * 5U;
}
}
PerfectNumbers.Core/UInt128Extensions.cs
+58 -72
View File
@@ -120,87 +120,73 @@ public static class UInt128Extensions
return true;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void Mod10_8_5_3(this UInt128 value, out ulong mod10, out ulong mod8, out ulong mod5, out ulong mod3)
{
UInt128 temp = value;
uint byteSum = 0U;
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void Mod10_8_5_3(this UInt128 value, out ulong mod10, out ulong mod8, out ulong mod5, out ulong mod3)
{
UInt128 temp = value;
uint byteSum = 0U;
do
{
byteSum += (uint)(byte)temp;
temp >>= 8;
}
while (temp != UInt128.Zero);
do
{
byteSum += (byte)temp;
temp >>= 8;
}
while (temp != UInt128.Zero);
mod8 = (ulong)value & 7UL;
mod8 = (ulong)value & 7UL;
uint mod5Value = FastRemainder5(byteSum);
uint mod3Value = FastRemainder3(byteSum);
uint mod5Value = PerfectNumbersMath.FastRemainder5(byteSum);
uint mod3Value = PerfectNumbersMath.FastRemainder3(byteSum);
ulong parity = mod8 & 1UL;
mod10 = parity == 0UL
? mod5Value switch
{
0U => 0UL,
1U => 6UL,
2U => 2UL,
3U => 8UL,
_ => 4UL,
}
: mod5Value switch
{
0U => 5UL,
1U => 1UL,
2U => 7UL,
3U => 3UL,
_ => 9UL,
};
ulong parity = mod8 & 1UL;
mod10 = parity == 0UL
? mod5Value switch
{
0U => 0UL,
1U => 6UL,
2U => 2UL,
3U => 8UL,
_ => 4UL,
}
: mod5Value switch
{
0U => 5UL,
1U => 1UL,
2U => 7UL,
3U => 3UL,
_ => 9UL,
};
mod5 = mod5Value;
mod3 = mod3Value;
}
mod5 = mod5Value;
mod3 = mod3Value;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static uint FastRemainder3(uint value)
{
uint quotient = (uint)(((ulong)value * 0xAAAAAAABUL) >> 33);
return value - quotient * 3U;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static UInt128 Pow(this UInt128 value, ulong exponent)
{
UInt128 result = UInt128.One;
UInt128 baseValue = value;
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static uint FastRemainder5(uint value)
{
uint quotient = (uint)(((ulong)value * 0xCCCCCCCDUL) >> 34);
return value - quotient * 5U;
}
while (exponent != 0UL)
{
if ((exponent & 1UL) != 0UL)
{
result *= baseValue;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static UInt128 Pow(this UInt128 value, ulong exponent)
{
UInt128 result = UInt128.One;
UInt128 baseValue = value;
baseValue *= baseValue;
exponent >>= 1;
}
while (exponent != 0UL)
{
if ((exponent & 1UL) != 0UL)
{
result *= baseValue;
}
return result;
}
baseValue *= baseValue;
exponent >>= 1;
}
return result;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static UInt128 ModPow(this UInt128 value, UInt128 exponent, UInt128 modulus)
{
UInt128 result, one = result = UInt128.One,
zero = UInt128.Zero,
baseValue = value % modulus;
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static UInt128 ModPow(this UInt128 value, UInt128 exponent, UInt128 modulus)
{
UInt128 result, one = result = UInt128.One,
zero = UInt128.Zero,
baseValue = value % modulus;
while (exponent != zero)
{
@@ -284,7 +270,7 @@ public static class UInt128Extensions
{
a -= modulus;
}
b >>= 1;
}
PerfectNumbers.Core/ULongExtensions.cs
+41
View File
@@ -57,6 +57,47 @@ public static class ULongExtensions
return q;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void Mod10_8_5_3(this ulong value, out ulong mod10, out ulong mod8, out ulong mod5, out ulong mod3)
{
ulong temp = value;
uint byteSum = 0U;
do
{
byteSum += (byte)temp;
temp >>= 8;
}
while (temp != 0UL);
mod8 = value & 7UL;
uint mod5Value = PerfectNumbersMath.FastRemainder5(byteSum);
uint mod3Value = PerfectNumbersMath.FastRemainder3(byteSum);
ulong parity = mod8 & 1UL;
mod10 = parity == 0UL
? mod5Value switch
{
0U => 0UL,
1U => 6UL,
2U => 2UL,
3U => 8UL,
_ => 4UL,
}
: mod5Value switch
{
0U => 5UL,
1U => 1UL,
2U => 7UL,
3U => 3UL,
_ => 9UL,
};
mod5 = mod5Value;
mod3 = mod3Value;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static bool IsPrimeCandidate(this ulong n)
{