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authorUlrich Drepper <drepper@redhat.com>1999-04-28 23:13:52 +0000
committerUlrich Drepper <drepper@redhat.com>1999-04-28 23:13:52 +0000
commitc4563d2d668675c2d5083f6ad01c801d6ccbe013 (patch)
tree1e6af86f8c33743c81080dffb17a8e8209825c06 /sysdeps/generic/strchrnul.c
parent89afc233db58d3de7669332d141113ec2ca4991d (diff)
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Update.
1999-04-28 Ulrich Drepper <drepper@cygnus.com> * 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.
Diffstat (limited to 'sysdeps/generic/strchrnul.c')
-rw-r--r--sysdeps/generic/strchrnul.c166
1 files changed, 166 insertions, 0 deletions
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 <string.h>
+
+#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)