From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: PJ Reiniger <pj.reiniger@gmail.com>
Date: Tue, 3 May 2022 22:50:24 -0400
Subject: [PATCH 15/36] Add lerp and sgn

---
 llvm/include/llvm/Support/MathExtras.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/llvm/include/llvm/Support/MathExtras.h b/llvm/include/llvm/Support/MathExtras.h
index 60b3b9012a32dda5e7c3ba1dc5923ffa68df8215..daa79d99578e934ca001d1de5d2772ff961b8fc3 100644
--- a/llvm/include/llvm/Support/MathExtras.h
+++ b/llvm/include/llvm/Support/MathExtras.h
@@ -617,6 +617,26 @@ std::enable_if_t<std::is_signed_v<T>, T> MulOverflow(T X, T Y, T &Result) {
     return UX > (static_cast<U>((std::numeric_limits<T>::max)())) / UY;
 }
 
+// Typesafe implementation of the signum function.
+// Returns -1 if negative, 1 if positive, 0 if 0.
+template <typename T>
+constexpr int sgn(T val) {
+  return (T(0) < val) - (val < T(0));
+}
+
+/**
+ * Linearly interpolates between two values.
+ *
+ * @param startValue The start value.
+ * @param endValue The end value.
+ * @param t The fraction for interpolation.
+ *
+ * @return The interpolated value.
+ */
+template <typename T>
+constexpr T Lerp(const T& startValue, const T& endValue, double t) {
+  return startValue + (endValue - startValue) * t;
+}
 } // End llvm namespace
 
 #endif