From fd68d1c65622e09b2c8d8a81fe88d98cf386b48e Mon Sep 17 00:00:00 2001
From: Anthony Lloyd <anthony@lloydhq.com>
Date: Thu, 30 Nov 2023 22:02:55 +0000
Subject: [PATCH] doubles performance

---
 CsCheck/Check.cs            |  3 ++-
 Tests/FloatingPointTests.cs | 10 ++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/CsCheck/Check.cs b/CsCheck/Check.cs
index ad44f54..05a18db 100644
--- a/CsCheck/Check.cs
+++ b/CsCheck/Check.cs
@@ -3222,7 +3222,8 @@ public override string ToString()
             spinLock.Enter(ref lockTaken);
             if (!processing)
             {
-                var result = $"{Median.Median * 100.0:#0.00}%[{Median.Q1 * 100.0:#0.00}%..{Median.Q3 * 100.0:#0.00}%] {(Median.Median >= 0.0 ? "faster" : "slower")}";
+                var times = 1 / (1 - Math.Abs(Median.Median));
+                var result = $"{Median.Median * 100.0:#0.00}%[{Median.Q1 * 100.0:#0.00}%..{Median.Q3 * 100.0:#0.00}%] {times:#0.00}x {(Median.Median >= 0.0 ? "faster" : "slower")}";
                 if (double.IsNaN(Median.Median)) result = $"Time resolution too small try using repeat.\n{result}";
                 else if ((Median.Median >= 0.0) != (Faster > Slower)) result = $"Inconsistent result try using repeat or increasing sigma.\n{result}";
                 result = $"{result}, sigma={Math.Sqrt(SigmaSquared):#0.0} ({Faster:#,0} vs {Slower:#,0})";
diff --git a/Tests/FloatingPointTests.cs b/Tests/FloatingPointTests.cs
index dc20164..4ff4b46 100644
--- a/Tests/FloatingPointTests.cs
+++ b/Tests/FloatingPointTests.cs
@@ -30,6 +30,16 @@ public void DoubleSupportsRoundtripPrecisionTo15()
         }, writeLine: output.WriteLine);
     }
 
+    [Fact]
+    public void X()
+    {
+        var quantity = 1000;
+        var price = 99.99;
+        var fxRate = 1.2345;
+        var localValue = MathX.TwoMul(quantity, price, out double lo1);
+        var usdValue = MathX.TwoMul(localValue, fxRate, out double lo2);
+    }
+
     private static void DoubleSumPrecision(int significantFigures, int maxLength)
     {
         const double scaling = 0.01;