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authorRich Felker <dalias@aerifal.cx>2012-10-22 15:17:09 -0400
committerRich Felker <dalias@aerifal.cx>2012-10-22 15:17:09 -0400
commit838951c97edc05cb2a25948ee542415b55b8f605 (patch)
tree3b9daebb7f47597258b5478960751a326f0bc316 /src/string/stpcpy.c
parent4eb4844b31906e1f8d4a1a1ff7a5c94e1083661f (diff)
downloadmusl-838951c97edc05cb2a25948ee542415b55b8f605.tar.gz
simplify logic in stpcpy; avoid copying first aligned byte twice
gcc seems to be generating identical or near-identical code for both versions, but the newer code is more expressive of what it's doing.
Diffstat (limited to 'src/string/stpcpy.c')
-rw-r--r--src/string/stpcpy.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/src/string/stpcpy.c b/src/string/stpcpy.c
index da96f215..feb9eb81 100644
--- a/src/string/stpcpy.c
+++ b/src/string/stpcpy.c
@@ -4,7 +4,7 @@
#include <limits.h>
#include "libc.h"
-#define ALIGN (sizeof(size_t)-1)
+#define ALIGN (sizeof(size_t))
#define ONES ((size_t)-1/UCHAR_MAX)
#define HIGHS (ONES * (UCHAR_MAX/2+1))
#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
@@ -14,9 +14,9 @@ char *__stpcpy(char *restrict d, const char *restrict s)
size_t *wd;
const size_t *ws;
- if (((uintptr_t)s & ALIGN) == ((uintptr_t)d & ALIGN)) {
- for (; (*d=*s) && ((uintptr_t)s & ALIGN); s++, d++);
- if (!*s) return d;
+ if ((uintptr_t)s % ALIGN == (uintptr_t)d % ALIGN) {
+ for (; (uintptr_t)s % ALIGN; s++, d++)
+ if (!(*d=*s)) return d;
wd=(void *)d; ws=(const void *)s;
for (; !HASZERO(*ws); *wd++ = *ws++);
d=(void *)wd; s=(const void *)ws;