added root functions

2026-09-16 20:24:08 +04:00
parent 24d2aef892
commit 7084fae174
11 changed files with 1912 additions and 94 deletions
@@ -0,0 +1,27 @@
+using Shouldly;
+using Xunit;
+
+namespace Just.PreciseMath.Tests;
+
+public class DoubleDoubleRootFunctionsTests
+{
+    [Fact]
+    public void ExistingRootsAreAvailableOnTheTypeAndMatchFacadeBits()
+    {
+        DoubleDouble[] values = [DoubleDouble.Zero, DoubleDouble.NegativeZero,
+            DoubleDouble.NaN, DoubleDouble.PositiveInfinity, DoubleDouble.NegativeInfinity,
+            new(-1.0), new(double.Epsilon), new(2.0), new(double.MaxValue),
+            DoubleDouble.FromComponents(1.0, Math.ScaleB(1.0, -1000))];
+        foreach (DoubleDouble value in values)
+        {
+            AssertBits(DDMath.Sqrt(value), DoubleDouble.Sqrt(value));
+            AssertBits(DDMath.InvSqrt(value), DoubleDouble.InvSqrt(value));
+        }
+    }
+
+    private static void AssertBits(DoubleDouble expected, DoubleDouble actual)
+    {
+        BitConverter.DoubleToInt64Bits(actual.High).ShouldBe(BitConverter.DoubleToInt64Bits(expected.High));
+        BitConverter.DoubleToInt64Bits(actual.Low).ShouldBe(BitConverter.DoubleToInt64Bits(expected.Low));
+    }
+}