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-rw-r--r--libc/string/Makefile2
-rw-r--r--libc/string/string.c33
2 files changed, 34 insertions, 1 deletions
diff --git a/libc/string/Makefile b/libc/string/Makefile
index 1c8c6283a..5a2aa3c04 100644
--- a/libc/string/Makefile
+++ b/libc/string/Makefile
@@ -27,7 +27,7 @@ LIBC=$(TOPDIR)libc.a
MSRC=string.c
MOBJ=strlen.o strcat.o strcpy.o strchr.o strcmp.o strncat.o strncpy.o \
strncmp.o strrchr.o strdup.o memcpy.o memccpy.o memset.o \
- memmove.o memcmp.o memchr.o
+ memmove.o memcmp.o memchr.o ffs.o
MSRC1=index.c
MOBJ1=index.o rindex.o
diff --git a/libc/string/string.c b/libc/string/string.c
index fdf848125..f77cf4c69 100644
--- a/libc/string/string.c
+++ b/libc/string/string.c
@@ -280,5 +280,38 @@ int memcmp(const void *s1, const void *s2, size_t len)
#endif
+/********************** Function memcmp ************************************/
+
+#ifdef L_ffs
+int ffs(int x)
+{
+ int r = 1;
+
+ if (!x)
+ return 0;
+ if (!(x & 0xffff)) {
+ x >>= 16;
+ r += 16;
+ }
+ if (!(x & 0xff)) {
+ x >>= 8;
+ r += 8;
+ }
+ if (!(x & 0xf)) {
+ x >>= 4;
+ r += 4;
+ }
+ if (!(x & 3)) {
+ x >>= 2;
+ r += 2;
+ }
+ if (!(x & 1)) {
+ x >>= 1;
+ r += 1;
+ }
+ return r;
+}
+#endif
+
/********************** THE END ********************************************/