From 3eb38795dbbbd8160012050de4dfef200a21f2bf Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ond=C5=99ej=20B=C3=ADlka?= Date: Fri, 19 Dec 2014 23:09:40 +0100 Subject: [PATCH] Simplify strncat. We rewrite strncat to use strnlen and malloc calls which simplifies code an is faster as these functions are better optimized than original code. --- ChangeLog | 4 ++++ string/strncat.c | 47 +++-------------------------------------------- 2 files changed, 7 insertions(+), 44 deletions(-) diff --git a/ChangeLog b/ChangeLog index 3cef094bc5..4c8bcb418f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,7 @@ +2014-12-19 Ondřej Bílka + + * string/strncat.c (STRNCAT): Simplify implementation. + 2014-12-19 David S. Miller * sysdeps/sparc/sparc32/soft-fp/q_neg.c (_Q_neg): Use a union to diff --git a/string/strncat.c b/string/strncat.c index 6d29114d38..0de9a01fde 100644 --- a/string/strncat.c +++ b/string/strncat.c @@ -17,10 +17,6 @@ #include -#ifdef _LIBC -# include -#endif - #ifndef STRNCAT # undef strncat # define STRNCAT strncat @@ -29,52 +25,15 @@ char * STRNCAT (char *s1, const char *s2, size_t n) { - char c; char *s = s1; /* Find the end of S1. */ s1 += strlen (s1); - /* Make S1 point before next character, so we can increment - it while memory is read (wins on pipelined cpus). */ - s1 -= 1; - - if (n >= 4) - { - size_t n4 = n >> 2; - do - { - c = *s2++; - *++s1 = c; - if (c == '\0') - return s; - c = *s2++; - *++s1 = c; - if (c == '\0') - return s; - c = *s2++; - *++s1 = c; - if (c == '\0') - return s; - c = *s2++; - *++s1 = c; - if (c == '\0') - return s; - } while (--n4 > 0); - n &= 3; - } - - while (n > 0) - { - c = *s2++; - *++s1 = c; - if (c == '\0') - return s; - n--; - } + size_t ss = __strnlen (s2, n); - if (c != '\0') - *++s1 = '\0'; + s1[ss] = '\0'; + memcpy (s1, s2, ss); return s; } -- 2.11.4.GIT