This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / sh64 / lib / memcpy.c

diff --git a/arch/sh64/lib/memcpy.c b/arch/sh64/lib/memcpy.c
new file mode 100644 (file)
index 0000000..c785d0a
--- /dev/null
+++ b/arch/sh64/lib/memcpy.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2002 Mark Debbage (Mark.Debbage@superh.com)
+ *
+ * May be copied or modified under the terms of the GNU General Public
+ * License.  See linux/COPYING for more information.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <asm/string.h>
+
+// This is a simplistic optimization of memcpy to increase the
+// granularity of access beyond one byte using aligned
+// loads and stores. This is not an optimal implementation
+// for SH-5 (especially with regard to prefetching and the cache),
+// and a better version should be provided later ...
+
+void *memcpy(void *dest, const void *src, size_t count)
+{
+       char *d = (char *) dest, *s = (char *) src;
+
+       if (count >= 32) {
+               int i = 8 - (((unsigned long) d) & 0x7);
+
+               if (i != 8)
+                       while (i-- && count--) {
+                               *d++ = *s++;
+                       }
+
+               if (((((unsigned long) d) & 0x7) == 0) &&
+                   ((((unsigned long) s) & 0x7) == 0)) {
+                       while (count >= 32) {
+                               unsigned long long t1, t2, t3, t4;
+                               t1 = *(unsigned long long *) (s);
+                               t2 = *(unsigned long long *) (s + 8);
+                               t3 = *(unsigned long long *) (s + 16);
+                               t4 = *(unsigned long long *) (s + 24);
+                               *(unsigned long long *) (d) = t1;
+                               *(unsigned long long *) (d + 8) = t2;
+                               *(unsigned long long *) (d + 16) = t3;
+                               *(unsigned long long *) (d + 24) = t4;
+                               d += 32;
+                               s += 32;
+                               count -= 32;
+                       }
+                       while (count >= 8) {
+                               *(unsigned long long *) d =
+                                   *(unsigned long long *) s;
+                               d += 8;
+                               s += 8;
+                               count -= 8;
+                       }
+               }
+
+               if (((((unsigned long) d) & 0x3) == 0) &&
+                   ((((unsigned long) s) & 0x3) == 0)) {
+                       while (count >= 4) {
+                               *(unsigned long *) d = *(unsigned long *) s;
+                               d += 4;
+                               s += 4;
+                               count -= 4;
+                       }
+               }
+
+               if (((((unsigned long) d) & 0x1) == 0) &&
+                   ((((unsigned long) s) & 0x1) == 0)) {
+                       while (count >= 2) {
+                               *(unsigned short *) d = *(unsigned short *) s;
+                               d += 2;
+                               s += 2;
+                               count -= 2;
+                       }
+               }
+       }
+
+       while (count--) {
+               *d++ = *s++;
+       }
+
+       return d;
+}