[Xen-changelog] Make the fallback memset/memcpy/memmove have a concrete in-place

[BitKeeper Bot <riel@xxxxxxxxxxx>]

ChangeSet 1.1343, 2005/04/20 18:46:27+01:00, kaf24@xxxxxxxxxxxxxxxxxxxx

        Make the fallback memset/memcpy/memmove have a concrete in-place
        implementation, or we end up with a recursive dependency when building
        for x86/64.
        Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>



 string.c |   48 ++++++++++++++++++++++++++++++++++++++++++------
 1 files changed, 42 insertions(+), 6 deletions(-)


diff -Nru a/xen/arch/x86/string.c b/xen/arch/x86/string.c
--- a/xen/arch/x86/string.c     2005-04-20 14:03:59 -04:00
+++ b/xen/arch/x86/string.c     2005-04-20 14:03:59 -04:00
@@ -9,19 +9,55 @@
 #include <xen/lib.h>
 
 #undef memmove
-void *memmove(void *dest, const void *src, size_t count)
+void *memmove(void *dest, const void *src, size_t n)
 {
-    return __memmove(dest, src, count);
+    int d0, d1, d2;
+ 
+    if ( dest < src )
+        return memcpy(dest, src, n);
+
+    __asm__ __volatile__ (
+        "   std         ; "
+        "   rep ; movsb ; "
+        "   cld           "
+        : "=&c" (d0), "=&S" (d1), "=&D" (d2)
+        : "0" (n), "1" (n-1+(const char *)src), "2" (n-1+(char *)dest)
+        : "memory");
+
+    return dest;
 }
 
 #undef memcpy
-void *memcpy(void *dest, const void *src, size_t count)
+void *memcpy(void *dest, const void *src, size_t n)
 {
-    return __memcpy(dest, src, count);
+    int d0, d1, d2;
+
+    __asm__ __volatile__ (
+        "   rep ; movsl      ; "
+        "   testb $2,%b4     ; "
+        "   je 1f            ; "
+        "   movsw            ; "
+        "1: testb $1,%b4     ; "
+        "   je 2f            ; "
+        "   movsb            ; "
+        "2:                    "
+        : "=&c" (d0), "=&D" (d1), "=&S" (d2)
+        : "0" (n/4), "q" (n), "1" (dest), "2" (src)
+        : "memory");
+
+    return dest;
 }
 
 #undef memset
-void *memset(void *s, int c, size_t count)
+void *memset(void *s, int c, size_t n)
 {
-    return __memset(s, c, count);
+    int d0, d1;
+
+    __asm__ __volatile__ (
+        "rep ; stosb"
+        : "=&c" (d0), "=&D" (d1)
+        : "a" (c), "1" (s), "0" (n)
+        : "memory");
+
+    return s;
 }

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