X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fmemchr.c;h=ae232ae3439e64233406579a621e5e91e6e9d81a;hb=6e9405a068eabd607da1b526b68e4373ae43da71;hp=57f99735f337ae9c412d77b6d838c1ba3b934dd2;hpb=ff9e18a3c9c9b659fee0f2c65269a38a2d133bde;p=gnulib.git diff --git a/lib/memchr.c b/lib/memchr.c index 57f99735f..ae232ae34 100644 --- a/lib/memchr.c +++ b/lib/memchr.c @@ -1,5 +1,7 @@ -/* Copyright (C) 1991, 1993 Free Software Foundation, Inc. - Based on strlen implemention by Torbjorn Granlund (tege@sics.se), +/* Copyright (C) 1991, 1993, 1996, 1997, 1999, 2000, 2003 Free + Software Foundation, Inc. + + Based on strlen implementation by Torbjorn Granlund (tege@sics.se), with help from Dan Sahlin (dan@sics.se) and commentary by Jim Blandy (jimb@ai.mit.edu); adaptation to memchr suggested by Dick Karpinski (dick@cca.ucsf.edu), @@ -20,57 +22,55 @@ GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software -Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ +Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, +USA. */ #ifdef HAVE_CONFIG_H -#include +# include #endif -#undef __ptr_t -#if defined (__cplusplus) || (defined (__STDC__) && __STDC__) -# define __ptr_t void * -#else /* Not C++ or ANSI C. */ -# define __ptr_t char * -#endif /* C++ or ANSI C. */ +#include -#if defined (HAVE_STRING_H) || defined (_LIBC) -# include +#if defined _LIBC +# include +#else +# define reg_char char #endif -#if defined (HAVE_LIMIT_H) || defined (_LIBC) -# include -#endif +#include +#include #define LONG_MAX_32_BITS 2147483647 -#ifndef LONG_MAX -#define LONG_MAX LONG_MAX_32_BITS -#endif - #include +#if HAVE_BP_SYM_H || defined _LIBC +# include +#else +# define BP_SYM(sym) sym +#endif +#undef memchr +#undef __memchr /* Search no more than N bytes of S for C. */ - -__ptr_t -memchr (s, c, n) - const __ptr_t s; - int c; - size_t n; +void * +__memchr (void const *s, int c_in, size_t n) { const unsigned char *char_ptr; const unsigned long int *longword_ptr; unsigned long int longword, magic_bits, charmask; + unsigned reg_char c; - c = (unsigned char) c; + c = (unsigned char) c_in; /* Handle the first few characters by reading one character at a time. Do this until CHAR_PTR is aligned on a longword boundary. */ - for (char_ptr = s; n > 0 && ((unsigned long int) char_ptr - & (sizeof (longword) - 1)) != 0; + for (char_ptr = (const unsigned char *) s; + n > 0 && ((unsigned long int) char_ptr + & (sizeof (longword) - 1)) != 0; --n, ++char_ptr) if (*char_ptr == c) - return (__ptr_t) char_ptr; + return (void *) char_ptr; /* All these elucidatory comments refer to 4-byte longwords, but the theory applies equally well to 8-byte longwords. */ @@ -80,9 +80,9 @@ memchr (s, c, n) /* Bits 31, 24, 16, and 8 of this number are zero. Call these bits the "holes." Note that there is a hole just to the left of each byte, with an extra at the end: - + bits: 01111110 11111110 11111110 11111111 - bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD + bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD The 1-bits make sure that carries propagate to the next 0-bit. The 0-bits provide holes for carries to fall into. */ @@ -146,10 +146,10 @@ memchr (s, c, n) /* Add MAGIC_BITS to LONGWORD. */ if ((((longword + magic_bits) - + /* Set those bits that were unchanged by the addition. */ ^ ~longword) - + /* Look at only the hole bits. If any of the hole bits are unchanged, most likely one of the bytes was a zero. */ @@ -161,22 +161,22 @@ memchr (s, c, n) const unsigned char *cp = (const unsigned char *) (longword_ptr - 1); if (cp[0] == c) - return (__ptr_t) cp; + return (void *) cp; if (cp[1] == c) - return (__ptr_t) &cp[1]; + return (void *) &cp[1]; if (cp[2] == c) - return (__ptr_t) &cp[2]; + return (void *) &cp[2]; if (cp[3] == c) - return (__ptr_t) &cp[3]; + return (void *) &cp[3]; #if LONG_MAX > 2147483647 if (cp[4] == c) - return (__ptr_t) &cp[4]; + return (void *) &cp[4]; if (cp[5] == c) - return (__ptr_t) &cp[5]; + return (void *) &cp[5]; if (cp[6] == c) - return (__ptr_t) &cp[6]; + return (void *) &cp[6]; if (cp[7] == c) - return (__ptr_t) &cp[7]; + return (void *) &cp[7]; #endif } @@ -188,10 +188,13 @@ memchr (s, c, n) while (n-- > 0) { if (*char_ptr == c) - return (__ptr_t) char_ptr; + return (void *) char_ptr; else ++char_ptr; } return 0; } +#ifdef weak_alias +weak_alias (__memchr, BP_SYM (memchr)) +#endif