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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/i386/strchrnul.S
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/i386/strchrnul.S')
-rw-r--r--sysdeps/i386/strchrnul.S275
1 files changed, 275 insertions, 0 deletions
diff --git a/sysdeps/i386/strchrnul.S b/sysdeps/i386/strchrnul.S
new file mode 100644
index 0000000000..45950c3564
--- /dev/null
+++ b/sysdeps/i386/strchrnul.S
@@ -0,0 +1,275 @@
+/* strchrnul (str, ch) -- Return pointer to first occurrence of CH in STR
+   or the final NUL byte.
+   For Intel 80x86, x>=3.
+   Copyright (C) 1994, 1995, 1996, 1997, 1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@gnu.org>
+   Some optimisations by Alan Modra <Alan@SPRI.Levels.UniSA.Edu.Au>
+
+   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 <sysdep.h>
+#include "asm-syntax.h"
+
+/*
+   INPUT PARAMETERS:
+   str		(sp + 4)
+   ch		(sp + 8)
+*/
+
+	.text
+ENTRY (__strchrnul)
+	pushl %edi		/* Save callee-safe registers used here.  */
+
+	movl 8(%esp), %eax	/* get string pointer */
+	movl 12(%esp), %edx	/* get character we are looking for */
+
+	/* At the moment %edx contains C.  What we need for the
+	   algorithm is C in all bytes of the dword.  Avoid
+	   operations on 16 bit words because these require an
+	   prefix byte (and one more cycle).  */
+	movb %dl, %dh		/* now it is 0|0|c|c */
+	movl %edx, %ecx
+	shll $16, %edx		/* now it is c|c|0|0 */
+	movw %cx, %dx		/* and finally c|c|c|c */
+
+	/* Before we start with the main loop we process single bytes
+	   until the source pointer is aligned.  This has two reasons:
+	   1. aligned 32-bit memory access is faster
+	   and (more important)
+	   2. we process in the main loop 32 bit in one step although
+	      we don't know the end of the string.  But accessing at
+	      4-byte alignment guarantees that we never access illegal
+	      memory if this would not also be done by the trivial
+	      implementation (this is because all processor inherent
+	      boundaries are multiples of 4.  */
+
+	testb $3, %eax		/* correctly aligned ? */
+	jz L(11)		/* yes => begin loop */
+	movb (%eax), %cl	/* load byte in question (we need it twice) */
+	cmpb %cl, %dl		/* compare byte */
+	je L(6)			/* target found => return */
+	testb %cl, %cl		/* is NUL? */
+	jz L(6)			/* yes => return NULL */
+	incl %eax		/* increment pointer */
+
+	testb $3, %eax		/* correctly aligned ? */
+	jz L(11)		/* yes => begin loop */
+	movb (%eax), %cl	/* load byte in question (we need it twice) */
+	cmpb %cl, %dl		/* compare byte */
+	je L(6)			/* target found => return */
+	testb %cl, %cl		/* is NUL? */
+	jz L(6)			/* yes => return NULL */
+	incl %eax		/* increment pointer */
+
+	testb $3, %eax		/* correctly aligned ? */
+	jz L(11)		/* yes => begin loop */
+	movb (%eax), %cl	/* load byte in question (we need it twice) */
+	cmpb %cl, %dl		/* compare byte */
+	je L(6)			/* target found => return */
+	testb %cl, %cl		/* is NUL? */
+	jz L(6)			/* yes => return NULL */
+	incl %eax		/* increment pointer */
+
+	/* No we have reached alignment.  */
+	jmp L(11)		/* begin loop */
+
+      /* We 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 24-31 is set, there will be a carry
+	 into bit 32 (=carry flag), so all of the hole bits will
+	 be changed.
+
+	 3) But wait!  Aren't we looking for C, not 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.  */
+
+	/* Each round the main loop processes 16 bytes.  */
+
+	ALIGN(4)
+
+L(1):	addl $16, %eax		/* adjust pointer for whole round */
+
+L(11):	movl (%eax), %ecx	/* get word (= 4 bytes) in question */
+	xorl %edx, %ecx		/* XOR with word c|c|c|c => bytes of str == c
+				   are now 0 */
+	movl $0xfefefeff, %edi	/* magic value */
+	addl %ecx, %edi		/* add the magic value to the word.  We get
+				   carry bits reported for each byte which
+				   is *not* C */
+
+	/* According to the algorithm we had to reverse the effect of the
+	   XOR first and then test the overflow bits.  But because the
+	   following XOR would destroy the carry flag and it would (in a
+	   representation with more than 32 bits) not alter then last
+	   overflow, we can now test this condition.  If no carry is signaled
+	   no overflow must have occurred in the last byte => it was 0.	*/
+	jnc L(7)
+
+	/* We are only interested in carry bits that change due to the
+	   previous add, so remove original bits */
+	xorl %ecx, %edi		/* ((word^charmask)+magic)^(word^charmask) */
+
+	/* Now test for the other three overflow bits.  */
+	orl $0xfefefeff, %edi	/* set all non-carry bits */
+	incl %edi		/* add 1: if one carry bit was *not* set
+				   the addition will not result in 0.  */
+
+	/* If at least one byte of the word is C we don't get 0 in %edi.  */
+	jnz L(7)		/* found it => return pointer */
+
+	/* Now we made sure the dword does not contain the character we are
+	   looking for.  But because we deal with strings we have to check
+	   for the end of string before testing the next dword.  */
+
+	xorl %edx, %ecx		/* restore original dword without reload */
+	movl $0xfefefeff, %edi	/* magic value */
+	addl %ecx, %edi		/* add the magic value to the word.  We get
+				   carry bits reported for each byte which
+				   is *not* 0 */
+	jnc L(71)		/* highest byte is NUL => return NULL */
+	xorl %ecx, %edi		/* (word+magic)^word */
+	orl $0xfefefeff, %edi	/* set all non-carry bits */
+	incl %edi		/* add 1: if one carry bit was *not* set
+				   the addition will not result in 0.  */
+	jnz L(71)		/* found NUL => return NULL */
+
+	movl 4(%eax), %ecx	/* get word (= 4 bytes) in question */
+	xorl %edx, %ecx		/* XOR with word c|c|c|c => bytes of str == c
+				   are now 0 */
+	movl $0xfefefeff, %edi	/* magic value */
+	addl %ecx, %edi		/* add the magic value to the word.  We get
+				   carry bits reported for each byte which
+				   is *not* C */
+	jnc L(71)		/* highest byte is C => return pointer */
+	xorl %ecx, %edi		/* ((word^charmask)+magic)^(word^charmask) */
+	orl $0xfefefeff, %edi	/* set all non-carry bits */
+	incl %edi		/* add 1: if one carry bit was *not* set
+				   the addition will not result in 0.  */
+	jnz L(71)		/* found it => return pointer */
+	xorl %edx, %ecx		/* restore original dword without reload */
+	movl $0xfefefeff, %edi	/* magic value */
+	addl %ecx, %edi		/* add the magic value to the word.  We get
+				   carry bits reported for each byte which
+				   is *not* 0 */
+	jnc L(71)		/* highest byte is NUL => return NULL */
+	xorl %ecx, %edi		/* (word+magic)^word */
+	orl $0xfefefeff, %edi	/* set all non-carry bits */
+	incl %edi		/* add 1: if one carry bit was *not* set
+				   the addition will not result in 0.  */
+	jnz L(71)		/* found NUL => return NULL */
+
+	movl 8(%eax), %ecx	/* get word (= 4 bytes) in question */
+	xorl %edx, %ecx		/* XOR with word c|c|c|c => bytes of str == c
+				   are now 0 */
+	movl $0xfefefeff, %edi	/* magic value */
+	addl %ecx, %edi		/* add the magic value to the word.  We get
+				   carry bits reported for each byte which
+				   is *not* C */
+	jnc L(72)		/* highest byte is C => return pointer */
+	xorl %ecx, %edi		/* ((word^charmask)+magic)^(word^charmask) */
+	orl $0xfefefeff, %edi	/* set all non-carry bits */
+	incl %edi		/* add 1: if one carry bit was *not* set
+				   the addition will not result in 0.  */
+	jnz L(72)		/* found it => return pointer */
+	xorl %edx, %ecx		/* restore original dword without reload */
+	movl $0xfefefeff, %edi	/* magic value */
+	addl %ecx, %edi		/* add the magic value to the word.  We get
+				   carry bits reported for each byte which
+				   is *not* 0 */
+	jnc L(72)		/* highest byte is NUL => return NULL */
+	xorl %ecx, %edi		/* (word+magic)^word */
+	orl $0xfefefeff, %edi	/* set all non-carry bits */
+	incl %edi		/* add 1: if one carry bit was *not* set
+				   the addition will not result in 0.  */
+	jnz L(72)		/* found NUL => return NULL */
+
+	movl 12(%eax), %ecx	/* get word (= 4 bytes) in question */
+	xorl %edx, %ecx		/* XOR with word c|c|c|c => bytes of str == c
+				   are now 0 */
+	movl $0xfefefeff, %edi	/* magic value */
+	addl %ecx, %edi		/* add the magic value to the word.  We get
+				   carry bits reported for each byte which
+				   is *not* C */
+	jnc L(73)		/* highest byte is C => return pointer */
+	xorl %ecx, %edi		/* ((word^charmask)+magic)^(word^charmask) */
+	orl $0xfefefeff, %edi	/* set all non-carry bits */
+	incl %edi		/* add 1: if one carry bit was *not* set
+				   the addition will not result in 0.  */
+	jnz L(73)		/* found it => return pointer */
+	xorl %edx, %ecx		/* restore original dword without reload */
+	movl $0xfefefeff, %edi	/* magic value */
+	addl %ecx, %edi		/* add the magic value to the word.  We get
+				   carry bits reported for each byte which
+				   is *not* 0 */
+	jnc L(73)		/* highest byte is NUL => return NULL */
+	xorl %ecx, %edi		/* (word+magic)^word */
+	orl $0xfefefeff, %edi	/* set all non-carry bits */
+	incl %edi		/* add 1: if one carry bit was *not* set
+				   the addition will not result in 0.  */
+	jz L(1)			/* no NUL found => restart loop */
+
+L(73):	addl $4, %eax		/* adjust pointer */
+L(72):	addl $4, %eax
+L(71):	addl $4, %eax
+
+	/* We now scan for the byte in which the character was matched.
+	   But we have to take care of the case that a NUL char is
+	   found before this in the dword.  */
+
+L(7):	testb %cl, %cl		/* is first byte C? */
+	jz L(6)			/* yes => return pointer */
+	cmpb %dl, %cl		/* is first byte NUL? */
+	je L(6)			/* yes => return NULL */
+	incl %eax		/* it's not in the first byte */
+
+	testb %ch, %ch		/* is second byte C? */
+	jz L(6)			/* yes => return pointer */
+	cmpb %dl, %ch		/* is second byte NUL? */
+	je L(6)			/* yes => return NULL? */
+	incl %eax		/* it's not in the second byte */
+
+	shrl $16, %ecx		/* make upper byte accessible */
+	testb %cl, %cl		/* is third byte C? */
+	jz L(6)			/* yes => return pointer */
+	cmpb %dl, %cl		/* is third byte NUL? */
+	je L(6)			/* yes => return NULL */
+
+	/* It must be in the fourth byte and it cannot be NUL.  */
+	incl %eax
+
+L(6):	popl %edi		/* restore saved register content */
+
+	ret
+END (__strchrnul)
+
+weak_alias (__strchrnul, strchrnul)