PrimeOrderCalculator.Cpu optimizations.

PerfectNumbers.Core/IntArrayPool.cs

@@ -1,40 +1,103 @@
+using System;
+using System.Numerics;
 using System.Runtime.CompilerServices;
 
 namespace PerfectNumbers.Core
 {
 	public struct IntArrayPool(int poolCapacity)
 	{
-        private readonly int[][] _arrays = new int[poolCapacity][];
+        private const int MinBucketPower = 1;
-        private int _count = 0;
+        private static readonly int MaxBucketPower = CalculateMaxBucketPower();
+        private static readonly int MaxBucketLength = 1 << MaxBucketPower;
+        private static readonly int BucketCount = MaxBucketPower - MinBucketPower + 1;
+
+        private readonly int[][] _arrays = new int[poolCapacity * BucketCount][];
+        private readonly int[] _counts = new int[BucketCount];
+        private readonly int _bucketCapacity = poolCapacity;
 
 		[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-        public int[] Rent(int length)
+        public readonly int[] Rent(int length)
         {
-            int available = _count;
+            int bucketIndex = GetBucketIndex(length);
-            if (available == 0)
+            if (bucketIndex < 0)
             {
                 return new int[length];
             }
 
-            int[][] arrays = _arrays;
+            int[] counts = _counts;
-            available--;
+            int available = counts[bucketIndex];
-            _count = available;
+            int bucketLength = GetBucketLength(bucketIndex);
 
-            int[] candidate = arrays[available];
+            if (available == 0)
-			return candidate.Length >= length ? candidate : new int[length];
+            {
+                return new int[bucketLength];
+            }
+
+            int offset = (bucketIndex * _bucketCapacity) + (available - 1);
+            counts[bucketIndex] = available - 1;
+            return _arrays[offset];
 		}
 
 		[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-        public void Return(int[] array)
+        public readonly void Return(int[] array)
         {
-            int[][] arrays = _arrays;
+			int capacity = array.Length;
-            int available = _count;
+            int bucketIndex = GetBucketIndex(capacity);
-
+            if (bucketIndex < 0)
-            if (available < arrays.Length)
             {
-				arrays[available] = array;
+                return;
-				_count = available + 1;
             }
+
+            int bucketLength = GetBucketLength(bucketIndex);
+            if (capacity < bucketLength)
+            {
+                return;
+            }
+
+            int[] counts = _counts;
+            int available = counts[bucketIndex];
+            int bucketCapacity = _bucketCapacity;
+            if (available >= bucketCapacity)
+            {
+                return;
+            }
+
+            int offset = (bucketIndex * bucketCapacity) + available;
+            _arrays[offset] = array;
+            counts[bucketIndex] = available + 1;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+        private static int GetBucketIndex(int length)
+        {
+            if (length <= 0 || length > MaxBucketLength)
+            {
+                return -1;
+            }
+
+            if (length <= (1 << MinBucketPower))
+            {
+                return 0;
+            }
+
+            int power = 32 - BitOperations.LeadingZeroCount((uint)(length - 1));
+            if (power > MaxBucketPower)
+            {
+                return -1;
+            }
+
+            return power - MinBucketPower;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+        private static int GetBucketLength(int bucketIndex) => 1 << (bucketIndex + MinBucketPower);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+        private static int CalculateMaxBucketPower()
+        {
+            int maxLength = Math.Min(int.MaxValue, Array.MaxLength);
+            int leadingZeros = BitOperations.LeadingZeroCount((uint)maxLength);
+            return 31 - leadingZeros;
         }
     }
 }

PerfectNumbers.Core/PartialFactorResult.cs

@@ -11,6 +11,10 @@ namespace PerfectNumbers.Core
 		public readonly int[] Exponents = new int[PrimeOrderConstants.GpuSmallPrimeFactorSlots];
 		public readonly FixedCapacityStack<ulong> CompositeStack = new (PrimeOrderConstants.GpuSmallPrimeFactorSlots);
 		public readonly List<PartialFactorPendingEntry> PendingFactors = new (PrimeOrderConstants.GpuSmallPrimeFactorSlots);
+		public readonly ulong[] TempFactorsArray = new ulong[PrimeOrderConstants.GpuSmallPrimeFactorSlots << 3];
+		public readonly int[] TempExponentsArray = new int[PrimeOrderConstants.GpuSmallPrimeFactorSlots << 3];
+		public readonly ulong[] StackCandidates = new ulong[PrimeOrderConstants.GpuSmallPrimeFactorSlots << 3];
+		public readonly bool[] StackEvaluations = new bool[PrimeOrderConstants.GpuSmallPrimeFactorSlots << 3];
 		private PartialFactorResult? _next;
 		public ulong Cofactor;
 		public bool FullyFactored;

PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs

@@ -545,12 +545,12 @@ internal static partial class PrimeOrderCalculator
 	private static ulong ExponentLoweringCpu(ulong order, ulong prime, PartialFactorResult factors, in MontgomeryDivisorData divisorData)
 	{
 		int length = factors.Count;
-		ReadOnlySpan<ulong> factorSpan = factors.Factors.AsSpan(0, length);
+		ReadOnlySpan<ulong> factorSpan = new(factors.Factors, 0, length);
-		ReadOnlySpan<int> exponentsSpan = factors.Exponents.AsSpan(0, length);
+		ReadOnlySpan<int> exponentsSpan = new(factors.Exponents, 0, length);
 
 		int newLength = length + 1;
-		ulong[] tempFactorsArray = FixedCapacityPools.ExclusiveUlongArray.Rent(newLength);
+		ulong[] tempFactorsArray = factors.TempFactorsArray;
-		int[] tempExponentsArray = FixedCapacityPools.ExclusiveIntArray.Rent(newLength);
+		int[] tempExponentsArray = factors.TempExponentsArray;
 
 		Span<ulong> ulongBuffer = tempFactorsArray;
 		factorSpan.CopyTo(ulongBuffer);
@@ -568,14 +568,8 @@ internal static partial class PrimeOrderCalculator
 
 		ExponentRemainderStepperCpu stepper = ThreadStaticPools.RentExponentStepperCpu(divisorData);
 
-		const int StackExponentCapacity = 16;
+		Span<ulong> stackCandidates = new(factors.StackCandidates);
-		const int ExponentHardLimit = 256;
+		Span<bool> stackEvaluations = new(factors.StackEvaluations);
-
-		Span<ulong> stackCandidates = stackalloc ulong[StackExponentCapacity];
-		Span<bool> stackEvaluations = stackalloc bool[StackExponentCapacity];
-
-		ulong[]? heapCandidateArray = null;
-		bool[]? heapEvaluationArray = null;
 
 		for (int i = 0; i < length; i++)
 		{
@@ -587,31 +581,10 @@ internal static partial class PrimeOrderCalculator
 			// 	continue;
 			// }
 
-			if (exponent > ExponentHardLimit)
-			{
-				throw new InvalidOperationException($"Prime factor exponent {exponent} exceeds the supported limit of {ExponentHardLimit}.");
-			}
-
-			if (exponent <= StackExponentCapacity)
-			{
 			ProcessExponentLoweringPrime(stackCandidates[..exponent], stackEvaluations[..exponent], ref order, primeFactor, exponent, ref stepper);
-				continue;
-			}
-
-			heapCandidateArray ??= FixedCapacityPools.ExclusiveUlongArray.Rent(ExponentHardLimit);
-			heapEvaluationArray ??= ThreadStaticPools.BoolPool.Rent(ExponentHardLimit);
-			ProcessExponentLoweringPrime(heapCandidateArray.AsSpan(0, exponent), heapEvaluationArray.AsSpan(0, exponent), ref order, primeFactor, exponent, ref stepper);
 		}
 
 		ThreadStaticPools.ReturnExponentStepperCpu(stepper);
-
-		if (heapCandidateArray is not null)
-		{
-			FixedCapacityPools.ExclusiveUlongArray.Return(heapCandidateArray);
-			ThreadStaticPools.BoolPool.Return(heapEvaluationArray!);
-		}
-
-		FixedCapacityPools.ExclusiveUlongArray.Return(tempFactorsArray);
 		return order;
 	}
 
@@ -1945,4 +1918,3 @@ internal static partial class PrimeOrderCalculator
 }
 
 
-

PerfectNumbers.Core/UlongArrayPool.cs

@@ -1,40 +1,102 @@
+using System.Numerics;
 using System.Runtime.CompilerServices;
 
 namespace PerfectNumbers.Core
 {
     public struct UlongArrayPool(int poolCapacity)
     {
-        private readonly ulong[][] _arrays = new ulong[poolCapacity][];
+        private const int MinBucketPower = 1;
-        private int _count = 0;
+        private static readonly int MaxBucketPower = CalculateMaxBucketPower();
+        private static readonly int MaxBucketLength = 1 << MaxBucketPower;
+        private static readonly int BucketCount = MaxBucketPower - MinBucketPower + 1;
+
+        private readonly ulong[][] _arrays = new ulong[poolCapacity * BucketCount][];
+        private readonly int[] _counts = new int[BucketCount];
+        private readonly int _bucketCapacity = poolCapacity;
 
         [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-        public ulong[] Rent(int length)
+        public readonly ulong[] Rent(int length)
         {
-            int available = _count;
+            int bucketIndex = GetBucketIndex(length);
-            if (available == 0)
+            if (bucketIndex < 0)
             {
                 return new ulong[length];
             }
 
-            ulong[][] arrays = _arrays;
+            int[] counts = _counts;
-            available--;
+            int available = counts[bucketIndex];
-            _count = available;
+            int bucketLength = GetBucketLength(bucketIndex);
 
-            ulong[] candidate = arrays[available];
+            if (available == 0)
-			return candidate.Length >= length ? candidate : new ulong[length];
+            {
+                return new ulong[bucketLength];
+            }
+
+            int offset = (bucketIndex * _bucketCapacity) + (available - 1);
+            counts[bucketIndex] = available - 1;
+            return _arrays[offset];
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-        public void Return(ulong[] array)
+        public readonly void Return(ulong[] array)
         {
-            ulong[][] arrays = _arrays;
+			int capacity = array.Length;
-            int available = _count;
+			int bucketIndex = GetBucketIndex(capacity);
-
+            if (bucketIndex < 0)
-            if (available < arrays.Length)
             {
-				arrays[available] = array;
+                return;
-				_count = available + 1;
             }
+
+            int bucketLength = GetBucketLength(bucketIndex);
+            if (capacity < bucketLength)
+            {
+                return;
+            }
+
+            int[] counts = _counts;
+            int available = counts[bucketIndex];
+			int bucketCapacity = _bucketCapacity;
+			if (available >= bucketCapacity)
+            {
+                return;
+            }
+
+            int offset = (bucketIndex * bucketCapacity) + available;
+            _arrays[offset] = array;
+            counts[bucketIndex] = available + 1;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+        private static int GetBucketIndex(int length)
+        {
+            if (length <= 0 || length > MaxBucketLength)
+            {
+                return -1;
+            }
+
+			if (length <= (1 << MinBucketPower))
+            {
+                return 0;
+            }
+
+            int power = 32 - BitOperations.LeadingZeroCount((uint)(length - 1));
+            if (power > MaxBucketPower)
+            {
+                return -1;
+            }
+
+            return power - MinBucketPower;
+        }
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+		private static int GetBucketLength(int bucketIndex) => 1 << (bucketIndex + MinBucketPower);
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+		private static int CalculateMaxBucketPower()
+        {
+            int maxLength = Math.Min(int.MaxValue, Array.MaxLength);
+            int leadingZeros = BitOperations.LeadingZeroCount((uint)maxLength);
+            return 31 - leadingZeros;
         }
     }
 }