1 files changed, 39 insertions, 0 deletions

diff --git a/thirdparty/thekla_atlas/nvmath/KahanSum.h b/thirdparty/thekla_atlas/nvmath/KahanSum.h
new file mode 100644
index 0000000000..18d475e7cb
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+++ b/thirdparty/thekla_atlas/nvmath/KahanSum.h
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+// This code is in the public domain -- Ignacio Castaņo <castano@gmail.com>
+
+#pragma once
+#ifndef NV_MATH_KAHANSUM_H
+#define NV_MATH_KAHANSUM_H
+
+#include "nvmath.h"
+
+namespace nv
+{
+
+    class KahanSum
+    {
+    public:
+        KahanSum() : accum(0.0f), err(0) {};
+
+        void add(float f)
+        {
+            float compensated = f + err;
+            float tmp = accum + compensated;
+            err = accum - tmp;
+            err += compensated;
+            accum = tmp;
+        }
+
+        float sum() const
+        {
+            return accum;
+        }
+
+    private:
+        float accum;
+        float err;
+    };
+
+} // nv namespace
+
+
+#endif // NV_MATH_KAHANSUM_H