Added memset16() for filling memory regions with 16 bit values, needed for upcoming 16 bit LCD driver opts. ASM optimised for coldfire.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8773 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 79 insertions, 0 deletions

diff --git a/firmware/common/memset16.c b/firmware/common/memset16.c
new file mode 100755
index 0000000000..0aee97a169
--- /dev/null
+++ b/firmware/common/memset16.c
@@ -0,0 +1,79 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2006 by Jens Arnold
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include <string.h>
+#define LBLOCKSIZE (sizeof(long)/2)
+#define UNALIGNED(X)   ((long)X & (LBLOCKSIZE - 1))
+#define TOO_SMALL(LEN) ((LEN) < LBLOCKSIZE)
+
+void *memset16(void *dst, int val, size_t len)
+{
+#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
+    unsigned short *p = (unsigned short *)dst;
+
+    while (len--)
+        *p++ = val;
+
+    return dst;
+#else
+    unsigned short *p = (unsigned short *)dst;
+    unsigned int i;
+    unsigned long buffer;
+    unsigned long *aligned_addr;
+
+    if (!TOO_SMALL(len) && !UNALIGNED(dst))
+    {
+        aligned_addr = (unsigned long *)dst;
+
+        val &= 0xffff;
+        if (LBLOCKSIZE == 2)
+        {
+            buffer = (val << 16) | val;
+        }
+        else
+        {
+            buffer = 0;
+            for (i = 0; i < LBLOCKSIZE; i++)
+	        buffer = (buffer << 16) | val;
+        }
+
+        while (len >= LBLOCKSIZE*4)
+        {
+            *aligned_addr++ = buffer;
+            *aligned_addr++ = buffer;
+            *aligned_addr++ = buffer;
+            *aligned_addr++ = buffer;
+            len -= 4*LBLOCKSIZE;
+        }
+
+        while (len >= LBLOCKSIZE)
+        {
+            *aligned_addr++ = buffer;
+            len -= LBLOCKSIZE;
+        }
+
+        p = (unsigned short *)aligned_addr;
+    }
+
+    while (len--)
+        *p++ = val;
+
+    return dst;
+#endif /* not PREFER_SIZE_OVER_SPEED */
+}