From 55207c949e92c91d0f6c83514d34ffe314f0c263 Mon Sep 17 00:00:00 2001
From: David Crocker <dcrocker@eschertech.com>
Date: Mon, 14 Feb 2022 14:05:32 +0000
Subject: [PATCH] Correct to memmoveu32 for when forward copying is needed

---
 src/CoreIO.cpp | 43 +++++++++++++++++++++++++------------------
 1 file changed, 25 insertions(+), 18 deletions(-)

diff --git a/src/CoreIO.cpp b/src/CoreIO.cpp
index 16b8ae7b..282b84b3 100644
--- a/src/CoreIO.cpp
+++ b/src/CoreIO.cpp
@@ -427,34 +427,41 @@ void __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns"))) memcp
 
 	if ((numWords & 1) != 0)
 	{
-		*dst++ = *src++;
+		*dst = *src;
 	}
 }
 
 // Optimised version of memmove for when we know that the source and destination are 32-bit aligned and a whole number of 32-bit words are to be copied
 void __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns"))) memmoveu32(uint32_t *_ecv_array dst, const uint32_t *_ecv_array src, size_t numWords) noexcept
 {
-	dst += numWords;
-	src += numWords;
-
-	while (numWords >= 4)
+	if (dst <= src)
 	{
-		*--dst = *--src;
-		*--dst = *--src;
-		*--dst = *--src;
-		*--dst = *--src;
-		numWords -= 4;
+		memcpyu32(dst, src, numWords);
 	}
-
-	if ((numWords & 2) != 0)
+	else
 	{
-		*--dst = *--src;
-		*--dst = *--src;
-	}
+		dst += numWords;
+		src += numWords;
 
-	if ((numWords & 1) != 0)
-	{
-		*--dst = *--src;
+		while (numWords >= 4)
+		{
+			*--dst = *--src;
+			*--dst = *--src;
+			*--dst = *--src;
+			*--dst = *--src;
+			numWords -= 4;
+		}
+
+		if ((numWords & 2) != 0)
+		{
+			*--dst = *--src;
+			*--dst = *--src;
+		}
+
+		if ((numWords & 1) != 0)
+		{
+			*--dst = *--src;
+		}
 	}
 }