From 9eb01d1c576320aae04ad46c3b3831774dd2fe91 Mon Sep 17 00:00:00 2001
From: Ben Adams <thundercat@illyriad.co.uk>
Date: Wed, 5 Oct 2016 16:23:58 +0100
Subject: [PATCH] Reduce Vector register pressure by not overlapping

---
 .../Internal/Infrastructure/MemoryPoolIterator.cs   | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Infrastructure/MemoryPoolIterator.cs b/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Infrastructure/MemoryPoolIterator.cs
index 0ab1bf01ad..34f8b44608 100644
--- a/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Infrastructure/MemoryPoolIterator.cs
+++ b/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Infrastructure/MemoryPoolIterator.cs
@@ -509,13 +509,14 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure
                         if (following >= _vectorSpan)
                         {
                             var data = new Vector<byte>(array, index);
-                            var byte0Equals = Vector.Equals(data, byte0Vector);
-                            var byte1Equals = Vector.Equals(data, byte1Vector);
 
+                            var byte0Equals = Vector.Equals(data, byte0Vector);
                             if (!byte0Equals.Equals(Vector<byte>.Zero))
                             {
                                 byte0Index = LocateFirstFoundByte(ref byte0Equals);
                             }
+
+                            var byte1Equals = Vector.Equals(data, byte1Vector);
                             if (!byte1Equals.Equals(Vector<byte>.Zero))
                             {
                                 byte1Index = LocateFirstFoundByte(ref byte1Equals);
@@ -652,18 +653,20 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure
                         if (following >= _vectorSpan)
                         {
                             var data = new Vector<byte>(array, index);
-                            var byte0Equals = Vector.Equals(data, byte0Vector);
-                            var byte1Equals = Vector.Equals(data, byte1Vector);
-                            var byte2Equals = Vector.Equals(data, byte2Vector);
 
+                            var byte0Equals = Vector.Equals(data, byte0Vector);
                             if (!byte0Equals.Equals(Vector<byte>.Zero))
                             {
                                 byte0Index = LocateFirstFoundByte(ref byte0Equals);
                             }
+
+                            var byte1Equals = Vector.Equals(data, byte1Vector);
                             if (!byte1Equals.Equals(Vector<byte>.Zero))
                             {
                                 byte1Index = LocateFirstFoundByte(ref byte1Equals);
                             }
+
+                            var byte2Equals = Vector.Equals(data, byte2Vector);
                             if (!byte2Equals.Equals(Vector<byte>.Zero))
                             {
                                 byte2Index = LocateFirstFoundByte(ref byte2Equals);