mlemanczyk/even-perfect-numbers-scanner
1
0 Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Reapply modulo helpers and inline fast remainders

Browse Source
This commit is contained in:
Marek Lemańczyk committed 2025-09-22 19:26:07 +02:00
1 parent 5db0c4fa95
commit ca866ffc5b
43 files changed
+982 -134
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

PerfectNumbers.Core/Gpu/MersenneNumberLucasLehmerGpuTester.cs
+4 -4
View File
@@ -51,7 +51,7 @@ public class MersenneNumberLucasLehmerGpuTester
// Early rejections aligned with incremental/order sieves, but safe for small p:
// - If 3 | p and p != 3, then 7 | M_p -> composite.
// - If p ≡ 1 (mod 4) and p shares a factor with (p-1), reject fast.
if ((exponent % 3UL) == 0UL && exponent != 3UL)
if (exponent % 3UL == 0UL && exponent != 3UL)
{
return false;
}
@@ -548,7 +548,7 @@ public class MersenneNumberLucasLehmerGpuTester
}
}
int topBits = (int)(exponent % 128UL);
int topBits = (int)exponent.Mod128();
if (topBits == 0)
{
topBits = 128;
@@ -672,7 +672,7 @@ public class MersenneNumberLucasLehmerGpuTester
}
}
int topBits = (int)(exponent % 128UL);
int topBits = (int)exponent.Mod128();
if (topBits == 0)
{
topBits = 128;
@@ -803,7 +803,7 @@ public class MersenneNumberLucasLehmerGpuTester
vLow.Add(vHigh);
// Mask to keep only p low bits and fold the carry bits (v >> p)
int topBits = (int)(p % 128UL);
int topBits = (int)p.Mod128();
if (topBits == 0)
{
topBits = 128;
PerfectNumbers.Core/Gpu/MersenneNumberOrderGpuTester.cs
+3 -3
View File
@@ -27,10 +27,10 @@ public class MersenneNumberOrderGpuTester(GpuKernelType kernelType, bool useGpuO
var foundBuffer = accelerator.Allocate1D<int>(1);
UInt128 exponent128 = exponent;
exponent128.Mod10_8_5_3(out ulong exponentMod10, out ulong exponentMod8, out ulong exponentMod5, out ulong exponentMod3);
ulong step10 = (exponentMod10 << 1).Mod10();
ulong step10 = (exponentMod10 << 1) % 10UL;
ulong step8 = (exponentMod8 << 1) & 7UL;
ulong step3 = (exponentMod3 << 1) % 3UL;
ulong step5 = (exponentMod5 << 1) % 5UL;
ulong step3 = (exponentMod3 << 1) % 3UL;
ulong step5 = (exponentMod5 << 1) % 5UL;
try
{
UInt128 remaining;