aboutsummaryrefslogtreecommitdiff
path: root/arch/tile/lib/memmove_32.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/tile/lib/memmove_32.c')
-rw-r--r--arch/tile/lib/memmove_32.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/tile/lib/memmove_32.c b/arch/tile/lib/memmove_32.c
new file mode 100644
index 00000000000..fd615ae6ade
--- /dev/null
+++ b/arch/tile/lib/memmove_32.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * 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, version 2.
+ *
+ * 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, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+void *memmove(void *dest, const void *src, size_t n)
+{
+ if ((const char *)src >= (char *)dest + n
+ || (char *)dest >= (const char *)src + n) {
+ /* We found no overlap, so let memcpy do all the heavy
+ * lifting (prefetching, etc.)
+ */
+ return memcpy(dest, src, n);
+ }
+
+ if (n != 0) {
+ const uint8_t *in;
+ uint8_t x;
+ uint8_t *out;
+ int stride;
+
+ if (src < dest) {
+ /* copy backwards */
+ in = (const uint8_t *)src + n - 1;
+ out = (uint8_t *)dest + n - 1;
+ stride = -1;
+ } else {
+ /* copy forwards */
+ in = (const uint8_t *)src;
+ out = (uint8_t *)dest;
+ stride = 1;
+ }
+
+ /* Manually software-pipeline this loop. */
+ x = *in;
+ in += stride;
+
+ while (--n != 0) {
+ *out = x;
+ out += stride;
+ x = *in;
+ in += stride;
+ }
+
+ *out = x;
+ }
+
+ return dest;
+}
+EXPORT_SYMBOL(memmove);