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-rw-r--r--contrib/syslinux-4.02/gpxe/src/arch/x86/core/x86_string.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/arch/x86/core/x86_string.c b/contrib/syslinux-4.02/gpxe/src/arch/x86/core/x86_string.c
new file mode 100644
index 0000000..5838eba
--- /dev/null
+++ b/contrib/syslinux-4.02/gpxe/src/arch/x86/core/x86_string.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/** @file
+ *
+ * Optimised string operations
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <string.h>
+
+/**
+ * Copy memory area
+ *
+ * @v dest Destination address
+ * @v src Source address
+ * @v len Length
+ * @ret dest Destination address
+ */
+void * __memcpy ( void *dest, const void *src, size_t len ) {
+ void *edi = dest;
+ const void *esi = src;
+ int discard_ecx;
+
+ /* We often do large dword-aligned and dword-length block
+ * moves. Using movsl rather than movsb speeds these up by
+ * around 32%.
+ */
+ if ( len >> 2 ) {
+ __asm__ __volatile__ ( "rep movsl"
+ : "=&D" ( edi ), "=&S" ( esi ),
+ "=&c" ( discard_ecx )
+ : "0" ( edi ), "1" ( esi ),
+ "2" ( len >> 2 )
+ : "memory" );
+ }
+ if ( len & 0x02 ) {
+ __asm__ __volatile__ ( "movsw" : "=&D" ( edi ), "=&S" ( esi )
+ : "0" ( edi ), "1" ( esi ) : "memory" );
+ }
+ if ( len & 0x01 ) {
+ __asm__ __volatile__ ( "movsb" : "=&D" ( edi ), "=&S" ( esi )
+ : "0" ( edi ), "1" ( esi ) : "memory" );
+ }
+ return dest;
+}