m68knommu: add optimize memmove() function
Greg Ungerer [Thu, 3 Feb 2011 11:58:39 +0000 (21:58 +1000)]
Add an m68k/coldfire optimized memmove() function for the m68knommu arch.
This is the same function as used by m68k. Simple speed tests show this
is faster once buffers are larger than 4 bytes, and significantly faster
on much larger buffers (4 times faster above about 100 bytes).

This also goes part of the way to fixing a regression caused by commit
ea61bc461d09e8d331a307916530aaae808c72a2 ("m68k/m68knommu: merge MMU and
non-MMU string.h"), which breaks non-coldfire non-mmu builds (which is
the 68x328 and 68360 families). They currently have no memmove() fucntion
defined, since there was none in the m68knommu/lib functions.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>

arch/m68k/include/asm/string.h
arch/m68knommu/lib/Makefile
arch/m68knommu/lib/memmove.c [new file with mode: 0644]

index ffc3c3f..3219845 100644 (file)
@@ -99,10 +99,10 @@ static inline int strcmp(const char *cs, const char *ct)
                : "+a" (cs), "+a" (ct), "=d" (res));
        return res;
 }
+#endif /* CONFIG_COLDFIRE */
 
 #define __HAVE_ARCH_MEMMOVE
 extern void *memmove(void *, const void *, __kernel_size_t);
-#endif /* CONFIG_COLDFIRE */
 
 #define memcmp(d, s, n) __builtin_memcmp(d, s, n)
 
index d94d709..32d852e 100644 (file)
@@ -4,4 +4,4 @@
 
 lib-y  := ashldi3.o ashrdi3.o lshrdi3.o \
           muldi3.o mulsi3.o divsi3.o udivsi3.o modsi3.o umodsi3.o \
-          checksum.o memcpy.o memset.o delay.o
+          checksum.o memcpy.o memmove.o memset.o delay.o
diff --git a/arch/m68knommu/lib/memmove.c b/arch/m68knommu/lib/memmove.c
new file mode 100644 (file)
index 0000000..b3dcfe9
--- /dev/null
@@ -0,0 +1,105 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#define __IN_STRING_C
+
+#include <linux/module.h>
+#include <linux/string.h>
+
+void *memmove(void *dest, const void *src, size_t n)
+{
+       void *xdest = dest;
+       size_t temp;
+
+       if (!n)
+               return xdest;
+
+       if (dest < src) {
+               if ((long)dest & 1) {
+                       char *cdest = dest;
+                       const char *csrc = src;
+                       *cdest++ = *csrc++;
+                       dest = cdest;
+                       src = csrc;
+                       n--;
+               }
+               if (n > 2 && (long)dest & 2) {
+                       short *sdest = dest;
+                       const short *ssrc = src;
+                       *sdest++ = *ssrc++;
+                       dest = sdest;
+                       src = ssrc;
+                       n -= 2;
+               }
+               temp = n >> 2;
+               if (temp) {
+                       long *ldest = dest;
+                       const long *lsrc = src;
+                       temp--;
+                       do
+                               *ldest++ = *lsrc++;
+                       while (temp--);
+                       dest = ldest;
+                       src = lsrc;
+               }
+               if (n & 2) {
+                       short *sdest = dest;
+                       const short *ssrc = src;
+                       *sdest++ = *ssrc++;
+                       dest = sdest;
+                       src = ssrc;
+               }
+               if (n & 1) {
+                       char *cdest = dest;
+                       const char *csrc = src;
+                       *cdest = *csrc;
+               }
+       } else {
+               dest = (char *)dest + n;
+               src = (const char *)src + n;
+               if ((long)dest & 1) {
+                       char *cdest = dest;
+                       const char *csrc = src;
+                       *--cdest = *--csrc;
+                       dest = cdest;
+                       src = csrc;
+                       n--;
+               }
+               if (n > 2 && (long)dest & 2) {
+                       short *sdest = dest;
+                       const short *ssrc = src;
+                       *--sdest = *--ssrc;
+                       dest = sdest;
+                       src = ssrc;
+                       n -= 2;
+               }
+               temp = n >> 2;
+               if (temp) {
+                       long *ldest = dest;
+                       const long *lsrc = src;
+                       temp--;
+                       do
+                               *--ldest = *--lsrc;
+                       while (temp--);
+                       dest = ldest;
+                       src = lsrc;
+               }
+               if (n & 2) {
+                       short *sdest = dest;
+                       const short *ssrc = src;
+                       *--sdest = *--ssrc;
+                       dest = sdest;
+                       src = ssrc;
+               }
+               if (n & 1) {
+                       char *cdest = dest;
+                       const char *csrc = src;
+                       *--cdest = *--csrc;
+               }
+       }
+       return xdest;
+}
+EXPORT_SYMBOL(memmove);