BitContradiction improvements.

PerfectNumbers.Core.Tests/BitContradictionSolverTests.cs

@@ -1,3 +1,4 @@
+using System.Numerics;
 using FluentAssertions;
 using PerfectNumbers.Core.ByDivisor;
 using Xunit;
@@ -34,6 +35,30 @@ public class BitContradictionSolverTests
         carry.Max.Should().Be(0);
     }
 
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void ShouldPruneWithFinalPow2Shift_ReturnsTrue_WhenShiftedResidueStaysBelowModulusAndResidueIsNotOne()
+    {
+        bool shouldPrune = ShouldPruneWithFinalPow2Shift(
+            prefixResidue: new BigInteger(3),
+            modulus: new BigInteger(1000),
+            tailShift: 8);
+
+        shouldPrune.Should().BeTrue();
+    }
+
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void ShouldPruneWithFinalPow2Shift_ReturnsFalse_WhenResidueIsOne()
+    {
+        bool shouldPrune = ShouldPruneWithFinalPow2Shift(
+            prefixResidue: BigInteger.One,
+            modulus: new BigInteger(1000),
+            tailShift: 8);
+
+        shouldPrune.Should().BeFalse();
+    }
+
     [Fact]
     public void TryPropagateCarry_ComputesNextCarryRange()
     {

PerfectNumbers.Core/Cpu/MersenneNumberDivisorByDivisorCpuTesterWithTemplate.cs

@@ -1,4 +1,4 @@
-// #define DivisorSet_BitContradiction
+// #define DivisorSet_BitContradiction
 // #define DivisorSet_BitTree
 // #define DEVICE_GPU
 
@@ -5108,8 +5108,10 @@ public struct MersenneNumberDivisorByDivisorCpuTesterWithTemplate() : IMersenneN
 		while (true)
 		{
 			int remainder8 = (stepMod8 * kRem8 + 1) & 7;
+#if DETAILED_LOG
 			if (prime == 138000001UL && divisor == 1209708008767)
 				Console.WriteLine("[HIT] enumerated target q before remainder8 check");
+#endif
 
 			if (remainder8 != 1 && remainder8 != 7)
 			{
@@ -5152,17 +5154,20 @@ public struct MersenneNumberDivisorByDivisorCpuTesterWithTemplate() : IMersenneN
 				}
 			}
 
+#if DETAILED_LOG
 			if (prime == 138000001UL && divisor == 1209708008767)
 			{
 				Console.WriteLine("[HIT] processed target q. Stopping.");
 				Environment.Exit(1);
 			}
+#endif
 
+			RecordState(currentK);
 		MOVE_NEXT:
 		ContinueOuter:
-			RecordState(currentK);
 			if (hasLimit && currentK >= maxK)
 			{
+				RecordState(currentK);
 				break;
 			}
 
@@ -5357,9 +5362,9 @@ public struct MersenneNumberDivisorByDivisorCpuTesterWithTemplate() : IMersenneN
 		ReadOnlySpan<int> oneOffsetsSlice = oneOffsets[..oneCount];
 		// BitContradictionSolverWithQMultiplier.SetDebugEnabled(true);
 #if DETAILED_LOG
-			bool decided = BitContradictionSolverWithAMultiplier.TryCheckDivisibilityFromOneOffsets(oneOffsetsSlice, prime, currentK, isPowerOfTwo, out divides, out var reason);
+			bool decided = BitContradictionSolverWithAMultiplier.TryCheckDivisibilityFromOneOffsets(oneOffsetsSlice, prime, divisor, currentK, isPowerOfTwo, out divides, out var reason);
 #else
-			bool decided = BitContradictionSolverWithAMultiplier.TryCheckDivisibilityFromOneOffsets(oneOffsetsSlice, prime, currentK, isPowerOfTwo, out divides);
+			bool decided = BitContradictionSolverWithAMultiplier.TryCheckDivisibilityFromOneOffsets(oneOffsetsSlice, prime, divisor, currentK, isPowerOfTwo, out divides);
 #endif
 		// BitContradictionSolverWithQMultiplier.SetDebugEnabled(false);
 		if (decided && divides)

PerfectNumbers.Core/PerfectNumberConstants.cs

@@ -21,12 +21,14 @@ public static class PerfectNumberConstants
 	public const int PooledArrayThreshold = 64;
 	public const int Pow2WindowSize = 8;
 	public const int RollingAccelerators = 298;
-	public const int ThreadsByAccelerator = 128;
+	public const int ThreadsByAccelerator = 4;
-	public const int ByDivisorStateSaveInterval = 1_000;
+	public const int ByDivisorFlushAndEvictInterval = 5;
+	public const int ByDivisorStateSaveInterval = 10_000_000;
 	public const string ByDivisorStateDirectory = "Checks";
 	public const int PollardRhoMilliseconds = 100;
 	public const int ByDivisorMersenneTailCount = 8;
 	public const int ByDivisorMersenneBitLimit = 4096;
+	public const int BitContradictionForcedALowBits = 4096;
 	public const int BitContradictionGpuBatchCount = 16;
 	// public const int BitContradictionGpuBatchCount = 512;
 	// public const int BitContradictionGpuBatchCount = 131_072;

PerfectNumbers.Core/PerfectNumbers.Core.csproj

@@ -13,6 +13,7 @@
 	<!-- <DefineConstants>$(DefineConstants);OVERRIDE_MIN_K</DefineConstants> -->
 	<!-- <DefineConstants>$(DefineConstants);SELF_TEST</DefineConstants> -->
 	<!-- <DefineConstants>$(DefineConstants);EXPORT_STAGE</DefineConstants> -->
+  	<!-- <DefineConstants>$(DefineConstants);WITH_PRUNE_STATS</DefineConstants> -->
   </PropertyGroup>
 
   <ItemGroup>

PerfectNumbers.Core/Persistence/KStateRepository.cs

@@ -68,12 +68,15 @@ public sealed class KStateRepository : IDisposable
         session.Upsert(keyString, valueString);
         session.CompletePending(true);
 		var flushCount = ++_flushCount;
-		if (flushCount >= PerfectNumberConstants.ByDivisorStateSaveInterval)
+		if (flushCount >= PerfectNumberConstants.ByDivisorFlushAndEvictInterval)
 		{
 			_flushCount = 0;
 			_store.Log.FlushAndEvict(wait: true);
 		}
-		
+		else
+        {
+            _store.Log.Flush(wait: false);
+        }
     }
 
     public bool TryGet(ulong prime, out BigInteger value)

PerfectNumbers.Core/Pow2Provider.cs

@@ -70,6 +70,7 @@ namespace PerfectNumbers.Core
 			61 => BigIntegerNumbers.Pow2Exact61,
 			62 => BigIntegerNumbers.Pow2Exact62,
 			63 => BigIntegerNumbers.Pow2Exact63,
+			_ when i >= 0 => System.Numerics.BigInteger.One << i,
 			_ => throw new ArgumentOutOfRangeException(nameof(i), $"Parameter value {i} is incorrect"),
 		};
 
@@ -140,6 +141,7 @@ namespace PerfectNumbers.Core
 			62 => BigIntegerNumbers.Pow2MinusOne62,
 			63 => BigIntegerNumbers.Pow2MinusOne63,
 			1024 => BigIntegerNumbers.Pow2MinusOne1024,
+			_ when i >= 0 => (System.Numerics.BigInteger.One << i) - System.Numerics.BigInteger.One,
 			_ => throw new ArgumentOutOfRangeException(nameof(i), $"Parameter value {i} is incorrect"),
 		};
     }