From c4563d2d668675c2d5083f6ad01c801d6ccbe013 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Wed, 28 Apr 1999 23:13:52 +0000 Subject: Update. 1999-04-28 Ulrich Drepper * argp/argp-ba.c (argp_program_bug_address): Don't initialize with 0. * argp/argp-parse.c (_argp_hang): Likewise. * argp/argp-pv.c (argp_program_version): Likewise. * argp/argp-pvh.c (argp_program_version_hook): Likewise. * inet/ether_hton.c (ether_hton, startp): Likewise. * inet/ether_ntoh.c (ether_ntoh, startp): Likewise. * inet/getnetgrent_r.c (setup, startp): Likewise. * intl/loadmsgcat.c (_nl_msg_cat_cntr): Likewise. * intl/localealias.c (string_space, string_space_act, string_space_max, nmap, maxmap): Likewise. * libio/iopopen.c (proc_file_chain): Likewise. * libio/oldiopopen.c (old_proc_file_chain): Likewise. * locale/lc-collate.c (__collate_table, __collate_extra, __collate_element_hash, __collate_element_strings, __collate_element_values): Likewise. * malloc/mcheck.c (mcheck_used): Likewise. * malloc/mtrace.c (added_atexit_handler): Likewise. * malloc/set-freeres.c (already_called): Likewise. * misc/getpass.c (getpass) [buf, bufsize]: Likewise. * misc/syslog.c (LogStat, LogTag): Likewise. * nss/XXX-lookup.c (DATABASE_NAME_SYMBOL): Likewise. * nss/getXXbyYY_r.c (startp): Likewise. * posix/getopt.c (optarg, __getopt_initialized): Likewise. * posix/regex.c (init_syntax_once) [done]: Likewise. (debug): Likewise. * string/strfry.c (init): Likewise. * sunrpc/svc_run.c (svc_top): Likewise. * posix/euidaccess.c (have_ids): Likewise. * sysdeps/unix/sysv/linux/poll.c (must_emulate): Likewise. * sysdeps/unix/sysv/linux/ttyname.c (__ttyname, namelen): Likewise. * time/getdate.c (getdate_err): Likewise. * time/tzfile.c (transitions, type_idxs, types, zone_names, leaps): Likewise. * time/tzset.c (old_tz, is_initialized): Likewise. * inet/getnameinfo.c (nrl_domainname): Rewrite to allow initialization of static data with zero. * signal/allocrtsig.c (init): Likewise. * string/Makefile (routines): Add strchrnul. * string/Versions [GLIBC_2.1.1]: Add strchrnul. * string/string.c: Add strchrnul prototype. * include/string.h: Add __strchrnul prototype. * sysdeps/generic/strchrnul.c: New file. * sysdeps/i386/strchrnul.S: New file. * sysdeps/i386/bits/string.c: Add strchrnul optimization. * sysdeps/i386/i486/bits/string.c: Likewise. * argp/argp-help.c (argp_args_usage): Use __strchrnul. * inet/ether_line.c (ether_line): Likewise. * nscd/nscd_conf.c (nscd_parse_file): Likewise. * nss/nsswitch.c (nss_parse_file): Likewise. * posix/execvp.c (execvp): Likewise. * posix/fnmatch.c (internal_fnmatch): Likewise. * resolv/res_hconf.c (_res_hconv_init): Likewise. * resolv/res_init.c (res_init): Likewise. * stdlib/fmtmsg.c (init): Likewise. * stdlib/getsubopt.c (getsubopt): Likewise. * catgets/catgets.c (catopen): Only allocate one memory block. (catclose): Only one free call necessary. * catgets/open_catalog.c (__open_catalog): Simplify handling of file descriptor. * ctype/ctype-extn.c: Make __toascii_l and __isascii_l alias instead of real functions. Simplify _tolower and _toupper. * grp/initgroups.c (compat_call): Remove unnecessary use of pointer variable. * iconv/gconv.h (struct gconv_info): Change data element from pointer to array of size 0. * iconv/gconv_open.c (__gconv_open): Allocate structures accordingly. * iconv/gconv_close.c (__gconv_close): Don't free data. * iconv/gconv_conf.c (add_alias): Avoid searching in tree twice to insert new alias. * iconv/gconv_db.c (add_derivation): More efficient copying. Check for error while inserting in tree. * include/time.h: Pretty print. * inet/ruserpass.c: Rewrite use of toktab to avoid string pointers in table and lots of relocations. * posix/regex.c (regerror): Rewrite use of re_error_msgid to avoid string pointers in table and lots of relocations. * intl/finddomain.c: Remove definition of strchr macro. * io/ftw.c (nftw_arr, ftw_arr): Make const. * locale/loadlocale.c (_nl_load_locale): Optimize string copying. * locale/localeinfo.h (_nl_category_names): Change into an array with fixed width char string elements. * locale/setlocale.c (_nl_category_names): Likewise. (_nl_current): Make global. * locale/nl_langinfo.c (nldata): Removed. Use _nl_current now. * malloc/Makefile (distribute): Add stackinfo.h. * sysdeps/generic/stackinfo.h: New file. * sysdeps/i386/stackinfo.h: New file. * posix/execl.c: Use stackinfo.h in optimizing alloca use. * posix/execle.c: Likewise. * posix/execlp.c: Likewise. * nis/nis_table.c (__create_ib_request): Always use realloc. * posix/execvp.c (execute): Rename to script_execute and keep only code to execute using shell. (execvp): Call execv directly and only fall back on script_execute. * resolv/inet_net_pton.c (inet_net_pton_ipv4): Remove digits define and always use xdigits instead. * resolv/res_init.c (res_init): Use rawmemchr instead of strchr where appropriate. * stdlib/fpioconst.h (__tens): New declaration. (struct mp_power): Remove array, add arrayoff element. * stdlib/fpioconst.c: Replace definitions of _ten_p* arrays by one __tens array and add in _fpioconst_pow10 offsets into __tens. * stdio-common/printf_fp.c: Rewrite to use new __tens array. * stdlib/strtod.c: Likewise. * stdlib/a64l.c (a64l_table): Avoid unnecessary elements. * stdlib/exit.c: Rewrite to use __exit_funcs being as sign for end of the list. * stdlib/atexit.c (__exit_funcs): Don't initialize. * stdlib/fmtmsg.c (keywords): Make name element fixed width array. * sunrpc/clnt_perr.c: Rewrite clnt_sperrno and auth_errmsg to use a single and an array with offsets. * sunrpc/des_soft.c (partab): Make it const. * sunrpc/key_call.c (trytimeout, tottimeout): Make const. (__key_encryptsession_pk_LOCAL): Don't initialize with 0. (__key_decryptsession_pk_LOCAL): Likewise. (__key_gendes_LOCAL): Likewise. (MESSENGER): Mark const. (key_call_private_main): Don't initialize with 0. (use_keyenvoy): Don't initialize with 0. (key_call): Rewrite to reverse logic of use_doors variable. * sunrpc/netname.c (OPSYS): Define as array, not pointer. (startp): Don't initialize with zero. * sunrpc/openchild.c (_openchild): Make first argument const. * sunrpc/pmap_rmt.c (timeout): Mark const. * sunrpc/xcrypt.c (hex): Likewise. * sysdeps/unix/sysv/linux/getcwd.c: Rewrite to allow omitting initialization of global variables. * sysdeps/unix/sysv/linux/getpt.c: Likewise. * sysdeps/unix/sysv/linux/if_index.c: Likewise. * termios/tcgetsid.c: Likewise. * sysdeps/unix/sysv/linux/i386/dl-procinfo.h (x86_cap_flags): Change fxsr to osfxsr. * time/tzfile.c (__tzfile_read): Rewrite to allocate only one memory block. Add function to free memory if wanted. * time/tzset.c (tzset_internal): Pass extra argument to __tzfile_read. * wcsmbs/wcsmbsload.c (to_wc, to_mb): Correct initializers. * wcsmbs/wmemset.c: Little code optimization. --- sysdeps/generic/strchrnul.c | 166 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 166 insertions(+) create mode 100644 sysdeps/generic/strchrnul.c (limited to 'sysdeps/generic/strchrnul.c') diff --git a/sysdeps/generic/strchrnul.c b/sysdeps/generic/strchrnul.c new file mode 100644 index 0000000000..1d6ece5332 --- /dev/null +++ b/sysdeps/generic/strchrnul.c @@ -0,0 +1,166 @@ +/* Copyright (C) 1991, 93, 94, 95, 96, 97, 99 Free Software Foundation, Inc. + Based on strlen implementation by Torbjorn Granlund (tege@sics.se), + with help from Dan Sahlin (dan@sics.se) and + bug fix and commentary by Jim Blandy (jimb@ai.mit.edu); + adaptation to strchr suggested by Dick Karpinski (dick@cca.ucsf.edu), + and implemented by Roland McGrath (roland@ai.mit.edu). + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include + +#undef __strchrnul +#undef strchrnul + +/* Find the first occurrence of C in S or the final NUL byte. */ +char * +__strchrnul (s, c) + const char *s; + int c; +{ + const unsigned char *char_ptr; + const unsigned long int *longword_ptr; + unsigned long int longword, magic_bits, charmask; + + c = (unsigned char) c; + + /* 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; ((unsigned long int) char_ptr + & (sizeof (longword) - 1)) != 0; + ++char_ptr) + if (*char_ptr == c || *char_ptr == '\0') + return (void *) char_ptr; + + /* All these elucidatory comments refer to 4-byte longwords, + but the theory applies equally well to 8-byte longwords. */ + + longword_ptr = (unsigned long int *) char_ptr; + + /* 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 + + The 1-bits make sure that carries propagate to the next 0-bit. + The 0-bits provide holes for carries to fall into. */ + switch (sizeof (longword)) + { + case 4: magic_bits = 0x7efefeffL; break; + case 8: magic_bits = ((0x7efefefeL << 16) << 16) | 0xfefefeffL; break; + default: + abort (); + } + + /* Set up a longword, each of whose bytes is C. */ + charmask = c | (c << 8); + charmask |= charmask << 16; + if (sizeof (longword) > 4) + /* Do the shift in two steps to avoid a warning if long has 32 bits. */ + charmask |= (charmask << 16) << 16; + if (sizeof (longword) > 8) + abort (); + + /* Instead of the traditional loop which tests each character, + we will test a longword at a time. The tricky part is testing + if *any of the four* bytes in the longword in question are zero. */ + for (;;) + { + /* We tentatively exit the loop if adding MAGIC_BITS to + LONGWORD fails to change any of the hole bits of LONGWORD. + + 1) Is this safe? Will it catch all the zero bytes? + Suppose there is a byte with all zeros. Any carry bits + propagating from its left will fall into the hole at its + least significant bit and stop. Since there will be no + carry from its most significant bit, the LSB of the + byte to the left will be unchanged, and the zero will be + detected. + + 2) Is this worthwhile? Will it ignore everything except + zero bytes? Suppose every byte of LONGWORD has a bit set + somewhere. There will be a carry into bit 8. If bit 8 + is set, this will carry into bit 16. If bit 8 is clear, + one of bits 9-15 must be set, so there will be a carry + into bit 16. Similarly, there will be a carry into bit + 24. If one of bits 24-30 is set, there will be a carry + into bit 31, so all of the hole bits will be changed. + + The one misfire occurs when bits 24-30 are clear and bit + 31 is set; in this case, the hole at bit 31 is not + changed. If we had access to the processor carry flag, + we could close this loophole by putting the fourth hole + at bit 32! + + So it ignores everything except 128's, when they're aligned + properly. + + 3) But wait! Aren't we looking for C as well as zero? + Good point. So what we do is XOR LONGWORD with a longword, + each of whose bytes is C. This turns each byte that is C + into a zero. */ + + longword = *longword_ptr++; + + /* 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. */ + & ~magic_bits) != 0 || + + /* That caught zeroes. Now test for C. */ + ((((longword ^ charmask) + magic_bits) ^ ~(longword ^ charmask)) + & ~magic_bits) != 0) + { + /* Which of the bytes was C or zero? + If none of them were, it was a misfire; continue the search. */ + + const unsigned char *cp = (const unsigned char *) (longword_ptr - 1); + + if (*cp == c || *cp == '\0') + return (char *) cp; + if (*++cp == c || *cp == '\0') + return (char *) cp; + if (*++cp == c || *cp == '\0') + return (char *) cp; + if (*++cp == c || *cp == '\0') + return (char *) cp; + if (sizeof (longword) > 4) + { + if (*++cp == c || *cp == '\0') + return (char *) cp; + if (*++cp == c || *cp == '\0') + return (char *) cp; + if (*++cp == c || *cp == '\0') + return (char *) cp; + if (*++cp == c || *cp == '\0') + return (char *) cp; + } + } + } + + /* This should never happen. */ + return NULL; +} + +weak_alias (__strchrnul, strchrnul) -- cgit v1.2.3