IsProbablePrime/IsLikelyPrime methods

build.vc11/mpir.net/mpir.net-tests/mpir.net-tests.csproj

@@ -118,6 +118,9 @@
     <Compile Include="..\..\..\mpir.net\mpir.net-tests\HugeIntTests\Math.cs">
       <Link>HugeIntTests\Math.cs</Link>
     </Compile>
+    <Compile Include="..\..\..\mpir.net\mpir.net-tests\HugeIntTests\NumberTheoretic.cs">
+      <Link>HugeIntTests\NumberTheoretic.cs</Link>
+    </Compile>
     <Compile Include="..\..\..\mpir.net\mpir.net-tests\HugeIntTests\XmlCommentsTests.cs">
       <Link>IntegrationTests\XmlCommentsTests.cs</Link>
     </Compile>

mpir.net/mpir.net-tests/HugeIntTests/NumberTheoretic.cs

@@ -0,0 +1,55 @@
+/*
+Copyright 2014 Alex Dyachenko
+
+This file is part of the MPIR Library.
+
+The MPIR Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published
+by the Free Software Foundation; either version 3 of the License, or (at
+your option) any later version.
+
+The MPIR Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the MPIR Library.  If not, see http://www.gnu.org/licenses/.  
+*/
+
+using System;
+using System.IO;
+using System.Text;
+using System.Linq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace MPIR.Tests.HugeIntTests
+{
+    [TestClass]
+    public class NumberTheoretic
+    {
+        [TestMethod]
+        public void IsProbablePrime()
+        {
+            using (var a = new HugeInt("622288097498926496141095869268883999563096063592498055290461"))
+            using (var random = MpirRandom.Default())
+            {
+                Assert.IsTrue(a.IsProbablePrime(random, 10, 0));
+                a.Value = a * 2;
+                Assert.IsFalse(a.IsProbablePrime(random, 10, 0));
+            }
+        }
+
+        [TestMethod]
+        public void IsLikelyPrime()
+        {
+            using (var a = new HugeInt("622288097498926496141095869268883999563096063592498055290461"))
+            using (var random = MpirRandom.Default())
+            {
+                Assert.IsTrue(a.IsLikelyPrime(random, 0));
+                a.Value = a * 2;
+                Assert.IsFalse(a.IsLikelyPrime(random, 0));
+            }
+        }
+    }
+}

mpir.net/mpir.net/HugeInt.cpp

@@ -18,6 +18,7 @@ along with the MPIR Library.  If not, see http://www.gnu.org/licenses/.
 */
 
 #include "Stdafx.h"
+#include "Random.h"
 
 using namespace System::Runtime::InteropServices;
 using namespace System::Text;
@@ -642,4 +643,18 @@ namespace MPIR
     }
 
     #pragma endregion
+
+    #pragma region number-theoretic
+
+    bool HugeInt::IsProbablePrime(MpirRandom^ random, int probability, mpir_ui pretested)
+    {
+        return mpz_probable_prime_p(_value, random->_value, probability, pretested) != 0;
+    }
+            
+    bool HugeInt::IsLikelyPrime(MpirRandom^ random, mpir_ui pretested)
+    {
+        return mpz_likely_prime_p(_value, random->_value, pretested) != 0;
+    }
+
+    #pragma endregion
 };

mpir.net/mpir.net/HugeInt.h

@@ -263,6 +263,7 @@ private ref class Mpir##name##Expression : base
 
 namespace MPIR
 {
+    ref class MpirRandom;
     ref class HugeInt;
     ref class MpirDivideExpression;
     ref class MpirDivideUiExpression;
@@ -1993,6 +1994,38 @@ namespace MPIR
             size_t GetLimb(mp_size_t index) { return mpz_getlimbn(_value, index); }
 
             #pragma endregion
+    
+            #pragma region number-theoretic
+
+            /// <summary>
+            /// Determines whether the number is a probable prime with the chance of error being at most 1 in 2^<paramref name="probability"/>.
+            /// <para>This function does some trial divisions to speed up the average case, then some probabilistic
+            /// primality tests to achieve the desired level of error.
+            /// </para>This function interface is preliminary and may change in the future.
+            /// </summary>
+            /// <param name="random">Random number generator to use for probabilistic primality tests</param>
+            /// <param name="probability">Defines the maximum allowed probability of a false positive.
+            /// <para>The odds of a composite number being reported as a probable prime are at most 1 in 2^probability</para></param>
+            /// <param name="pretested">Used to inform the function that trial division up to div has already been performed,
+            /// and so the number is known to have NO divisors &lt;= pretested.
+            /// <para>Use 0 to inform the function that no trial division has been done.</para></param>
+            /// <returns>true if the number is probably prime, or false if it is definitely composite.</returns>
+            bool IsProbablePrime(MpirRandom^ random, int probability, mpir_ui pretested);
+
+            /// <summary>
+            /// Determine whether the number is likely a prime, i.e. you can consider it a prime for practical purposes.
+            /// <para>This function does some trial divisions to speed up the average case, then some probabilistic primality tests.
+            /// </para>The term "likely" refers to the fact that the number will not have small factors.
+            /// <para>This function interface is preliminary and may change in the future.
+            /// </para></summary>
+            /// <param name="random">Random number generator to use for probabilistic primality tests</param>
+            /// <param name="pretested">Used to inform the function that trial division up to div has already been performed,
+            /// and so the number is known to have NO divisors &lt;= pretested.
+            /// <para>Use 0 to inform the function that no trial division has been done.</para></param>
+            /// <returns>true if the number is likely prime, or false if it is definitely composite.</returns>
+            bool IsLikelyPrime(MpirRandom^ random, mpir_ui pretested);
+
+            #pragma endregion
     };
 
     #pragma endregion