From 6ceab9613fbd4c83565970836d8dfd7d539fcac3 Mon Sep 17 00:00:00 2001
From: Sergio Pedri <sergio0694@live.com>
Date: Wed, 24 Jun 2020 02:02:15 +0200
Subject: [PATCH] Added HasByteEqualTo APIs

---
 .../Helpers/BitHelper.cs                      | 31 +++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/Microsoft.Toolkit.HighPerformance/Helpers/BitHelper.cs b/Microsoft.Toolkit.HighPerformance/Helpers/BitHelper.cs
index 2e72020f..eabce3cb 100644
--- a/Microsoft.Toolkit.HighPerformance/Helpers/BitHelper.cs
+++ b/Microsoft.Toolkit.HighPerformance/Helpers/BitHelper.cs
@@ -134,6 +134,37 @@ namespace Microsoft.Toolkit.HighPerformance.Helpers
             return ((value - 0x0101_0101_0101_0101ul) & ~value & 0x8080_8080_8080_8080ul) != 0;
         }
 
+        /// <summary>
+        /// Checks whether a byte in the input <see cref="uint"/> value matches a target value.
+        /// </summary>
+        /// <param name="value">The input value to check.</param>
+        /// <param name="target">The target byte to look for.</param>
+        /// <returns>Whether <paramref name="value"/> has any bytes set to <paramref name="target"/>.</returns>
+        /// <remarks>
+        /// This method contains no branches.
+        /// For more info, see <see href="https://graphics.stanford.edu/~seander/bithacks.html"/>.
+        /// </remarks>
+        [Pure]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool HasByteEqualTo(uint value, byte target)
+        {
+            return HasZeroByte(value ^ (0x0101_0101u * target));
+        }
+
+        /// <summary>
+        /// Checks whether a byte in the input <see cref="uint"/> value matches a target value.
+        /// This method mirrors <see cref="HasByteEqualTo(uint,byte)"/>, but with <see cref="ulong"/> values.
+        /// </summary>
+        /// <param name="value">The input value to check.</param>
+        /// <param name="target">The target byte to look for.</param>
+        /// <returns>Whether <paramref name="value"/> has any bytes set to <paramref name="target"/>.</returns>
+        [Pure]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool HasByteEqualTo(ulong value, byte target)
+        {
+            return HasZeroByte(value ^ (0x0101_0101_0101_0101u * target));
+        }
+
         /// <summary>
         /// Sets a bit to a specified value.
         /// </summary>