Daily update on 20230204 by nitload youmu, pow func added

源代码/.Net/StgSharp/Math/ASin.cs

@@ -1,4 +1,5 @@
-
+//
+// 
 // some of the code is rewritten from the AMD code:
 // https://github.com/amd/aocl-libm-ose/blob/a43e092b03213eb0e129a1cc129900e6e4475778/src/ref/asinf.c
 

源代码/.Net/StgSharp/Math/GetBits32.cs

@@ -4,7 +4,22 @@ using System.Text;
 
 namespace StgSharp
 {
+
+
     public static unsafe partial class Math
     {
+
+        /// <summary>
+        /// Get the bits of a float number
+        /// </summary>
+        /// <param name="x">The given float number</param>
+        /// <returns></returns>
+        public static uint GetBits32(float x)
+        {
+            Union4 union = new Union4();
+            union.f = x;
+            return union.i;
+        }
+
     }
 }

源代码/.Net/StgSharp/Math/Log.cs

@@ -24,10 +24,6 @@ namespace StgSharp
             0.53062825106217f,  0.536493370514568f, 0.542324290825362f, 0.548121408509688f, 0.553885113226438f, 0.559615787935423f, 0.56531380905006f,  0.570979546585738f, 0.576613364303994f, 0.582215619852664f,
             0.587786664902119f, 0.593326845277734f, 0.598836501088704f, 0.60431596685333f,  0.609765571620894f, 0.615185639090233f, 0.62057648772511f,  0.625938430866495f, 0.631271776841858f, 0.636576829071551f,
             0.641853886172395f, 0.647103242058538f, 0.65232518603969f,  0.657520002916794f, 0.662687973075237f, 0.667829372575655f, 0.672944473242426f, 0.678033542749897f, 0.683096844706444f, 0.688134638736401f,
-
-
-
-
         };
 
         /// <summary>
@@ -41,7 +37,7 @@ namespace StgSharp
         {
             if (x<0)
             {
-                throw new ArgumentException();
+                throw new ArgumentOutOfRangeException();
             }
             uint input = *(uint*)&x;
 

源代码/.Net/StgSharp/Math/Pow.cs

@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace StgSharp
+{ 
+    public static unsafe partial class Math
+    {
+        /// <summary>
+        /// calculate the value of x^y
+        /// </summary>
+        /// <param name="x"></param>
+        /// <param name="y"></param>
+        /// <returns>Returns the value of x^y</returns>
+        public static unsafe float Pow(float x, float y)
+        {
+            /* 
+             * x^y = E ^ ( log( x ) * y )
+             * Now define z = | log(x) * y | = m * n  
+             * and m is an integer, and 0.5 < |n| < 1
+             * then E ^ z = ( E ^ n ) ^ m
+             * 
+             * 
+             * As a float number can be expressed in (1+e)*(2^f)
+             * n = (1+e)/2
+             * m = 2 ^ (f + 1)
+             * 
+             */
+            float z, t;
+            if (x == 1 || y == 0)
+            {
+                return 1;
+            }
+            if (x==1&&y==0)
+            {
+                return 1.0f / 0;
+            }
+            z = StgSharp.Math.Log(x) * y;
+
+            bool sign = false;
+            if (z < 0)
+            {
+                sign = true;
+                z = -z;
+            }
+
+            if (z<0.5f)
+            {
+                t = 1.0f + z * (
+                    1.0f + z * (
+                    0.5f + z * (
+                    0.1666666667f + z * (
+                    0.0416666666667f + z *
+                    8.333333333e-3f))));
+            }
+            else
+            {
+                uint zBit = *(uint*)&z;
+                uint zBitAbs = zBit & 0b_0111_1111_1111_1111_1111_1111_1111_1111;
+                uint uintm = (zBitAbs >> 23);
+                int m = (*(int*)&uintm) - 126;
+
+
+                uint nBit = (zBitAbs & 0b_0000_0000_0111_1111_1111_1111_1111_1111)
+                    + 0b_0011_1111_0000_0000_0000_0000_0000_0000;
+                float n = *(float*)&nBit - 1;
+
+                t = 2.718281828f + n * (
+                    2.718281828f + n * (
+                    1.359140914f + n * (
+                    0.4530469714f + n * (
+                    0.1132617429f + n *
+                    0.02265234857f))));
+
+                for (int i = 0; i < m; i++)
+                {
+                    t = t * t;
+                }
+
+                
+            }
+            if (sign)
+            {
+                t = 1 / t;
+            }
+
+            return t;
+        }
+    }
+}

源代码/.Net/StgSharp/Math/Sqrt.cs

@@ -24,7 +24,16 @@ namespace StgSharp
              * 在进一步简化操作后，计算精度达到0.5%，速度约为.Net库函数的1.8倍
              */
 
-            /*
+
+            if (x < 0)
+            {
+                throw new ArgumentOutOfRangeException();
+            }
+            if (x == 0)
+            {
+                return 0;
+            }
+                /*
              * 提取指数位并减去指数位中的127
              * 由于平方根仅对正数有效
              * 故不考虑正负号