patch-2.4.22 linux-2.4.22/arch/sh64/lib/memcpy.c
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- Lines: 83
- Date:
2003-08-25 04:44:40.000000000 -0700
- Orig file:
linux-2.4.21/arch/sh64/lib/memcpy.c
- Orig date:
1969-12-31 16:00:00.000000000 -0800
diff -urN linux-2.4.21/arch/sh64/lib/memcpy.c linux-2.4.22/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;
+}
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