X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=Novacoin%2Fuint256.cs;h=c9134010ed604c09ce69335237065ff097fc5c8f;hb=198c3037b62f2c6007dee4c0a8b0fa41e9225c24;hp=dfaebea6de1dc67b9ee2b41a02bf3c9ab2e5c4b8;hpb=8ad3c74259a603dc5f175c34ebe5a740c09ff6ae;p=NovacoinLibrary.git

diff --git a/Novacoin/uint256.cs b/Novacoin/uint256.cs
index dfaebea..c913401 100644
--- a/Novacoin/uint256.cs
+++ b/Novacoin/uint256.cs
@@ -18,6 +18,7 @@
 
 using System;
 using System.Diagnostics.Contracts;
+using System.Linq;
 
 namespace Novacoin
 {
@@ -251,7 +252,7 @@ namespace Novacoin
             return a - new uint256(b);
         }
 
-        public static uint256 operator /(uint256 a, uint divisor)
+        public static uint256 operator /(uint256 a, uint b)
         {
             var result = new uint256();
 
@@ -262,14 +263,14 @@ namespace Novacoin
             {
                 r <<= 32;
                 r |= a.pn[i];
-                result.pn[i] = (uint)(r / divisor);
-                r %= divisor;
+                result.pn[i] = (uint)(r / b);
+                r %= b;
             }
 
             return result;
         }
 
-        public static uint256 operator *(uint256 a, uint multiplier)
+        public static uint256 operator *(uint256 a, ulong b)
         {
             var result = new uint256();
 
@@ -278,7 +279,7 @@ namespace Novacoin
 
             do
             {
-                c += a.pn[i] * (ulong)multiplier;
+                c += a.pn[i] * b;
                 result.pn[i] = (uint)c;
                 c >>= 32;
             } while (++i < result.nWidth);
@@ -286,7 +287,67 @@ namespace Novacoin
             return result;
         }
 
-        public static uint operator %(uint256 a, uint divisor)
+        public static uint256 operator *(uint256 a, uint256 b)
+        {
+            if (!a || !b)
+            {
+                // Multiplication by zero results with zero.
+                return 0;
+            }
+            else if (b.bits <= 32)
+            {
+                if (b.pn[0] == 1)
+                {
+                    // If right is 1 then return left operand value
+                    return a;
+                }
+
+                return a * b.pn[0];
+            }
+            else if (a.bits <= 32)
+            {
+                if (a.pn[0] == 1)
+                {
+                    // If left is 1 then return right operand value
+                    return b;
+                }
+
+                return a * b.pn[0];
+            }
+
+            int m = a.bits / 32 + (a.bits % 32 != 0 ? 1 : 0);
+            int n = b.bits / 32 + (b.bits % 32 != 0 ? 1 : 0);
+
+            uint256 result = new uint256();
+
+            uint[] left = a.pn.Take(m).ToArray();
+            uint[] right = b.pn.Take(n).ToArray();
+
+            for (int i = 0; i < m; ++i)
+            {
+                uint ai = left[i];
+                int k = i;
+
+                ulong temp = 0;
+                for (int j = 0; j < n; ++j)
+                {
+                    temp = temp + ((ulong)ai) * right[j] + result.pn[k];
+                    result.pn[k++] = (uint)temp;
+                    temp >>= 32;
+                }
+
+                while (temp != 0)
+                {
+                    temp += result.pn[k];
+                    result.pn[k++] = (uint)temp;
+                    temp >>= 32;
+                }
+            }
+
+            return result;
+        }
+
+        public static uint operator %(uint256 a, uint b)
         {
             ulong r = 0;
             int i = a.nWidth;
@@ -295,43 +356,57 @@ namespace Novacoin
             {
                 r <<= 32;
                 r |= a.pn[i];
-                r %= divisor;
+                r %= b;
             }
 
             return (uint)r;
         }
 
-        public static uint256 operator /(uint256 a, uint256 divisor)
+        public static uint256 operator /(uint256 a, uint256 b)
         {
-            if (divisor.bits <= 32)
+            if (b.bits <= 32)
             {
-                return a / divisor.Low32;
+                return a / b.Low32;
             }
 
-            return Divide(a, divisor)[0];
+            uint256 result = new uint256();
+
+            uint[] quotient;
+            uint[] remainder_value;
+
+            int m = a.bits / 32 + (a.bits % 32 != 0 ? 1 : 0);
+            int n = b.bits / 32 + (b.bits % 32 != 0 ? 1 : 0);
+
+            BignumHelper.DivModUnsigned(a.pn.Take(m).ToArray(), b.pn.Take(n).ToArray(), out quotient, out remainder_value);
+
+            quotient.CopyTo(result.pn, 0);
+
+            return result;
         }
 
-        public static uint256 operator %(uint256 a, uint256 divisor)
+        public static uint256 operator %(uint256 a, uint256 b)
         {
-            if (divisor.bits <= 32)
+            if (b.bits <= 32)
             {
-                return a % divisor.Low32;
+                return a % b.Low32;
             }
 
-            return Divide(a, divisor)[1];
-        }
-        #endregion
+            uint256 result = new uint256();
 
-        public static uint256[] Divide(uint256 bi1, uint256 bi2)
-        {
-            // STUB!
+            uint[] quotient;
+            uint[] remainder_value;
 
-            uint256[] ret = new uint256[2] { 0, 0 };
+            int m = a.bits / 32 + (a.bits % 32 != 0 ? 1 : 0);
+            int n = b.bits / 32 + (b.bits % 32 != 0 ? 1 : 0);
 
-            return ret;
-        }
+            BignumHelper.DivModUnsigned(a.pn.Take(m).ToArray(), b.pn.Take(n).ToArray(), out quotient, out remainder_value);
+
+            remainder_value.CopyTo(result.pn, 0);
 
+            return result;
 
+        }
+        #endregion
 
         #region Shift
         public static uint256 operator <<(uint256 a, int shift)