1999-01-16  Ulrich Drepper  <drepper@cygnus.com>

	* elf/Makefile (tests): Add loadtest.
	Add rules to generate test modules.
	* Makeconfig (+link): Add $(LDFLAGS-$(@F)) to command line.
	* elf/loadtest.c: New file.
	* elf/testobj1.c: New file.
	* elf/testobj2.c: New file.
	* elf/testobj3.c: New file.

	* elf/dl-close.c: Correct removing module from global list.

	* elf/dl-open.c: Add debugging code.

	* include/string.h: Add __rawmemchr prototype.
	* string/Makefile (routines): Add rawmemchr.
	* string/Versions [GLIBC_2.1]: Add __rawmemchr and rawmemchr.
	* string/string.h: Add prototype for rawmemchr.
	* string/bits/string2.h: Optimize strchr with rawmemchr.
	* sysdeps/generic/rawmemchr.c: New file.
	* sysdeps/i386/rawmemchr.c: New file.
	* sysdeps/i386/i486/bits/string.h: Add rawmemchr inline code.
	Optimize strchr with rawmemchr.

	* sysdeps/unix/sysv/linux/bits/posix_opt.h: Define _LFS_LARGEFILE,
	_LFS64_LARGEFILE, and _LFS64_STDIO for Unix98.

1999-01-14  Andreas Jaeger  <aj@arthur.rhein-neckar.de>

	* nis/nis_error.c (nis_errlist): Fix capitilasation.
This commit is contained in:
Ulrich Drepper 1999-01-16 17:09:04 +00:00
parent 37a87f834a
commit 482eec0d11
22 changed files with 742 additions and 29 deletions

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@ -23,3 +23,4 @@ crypt
linuxthreads
libc.prj .libc.prcs_aux
libc.proj .snprj

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@ -1,3 +1,34 @@
1999-01-16 Ulrich Drepper <drepper@cygnus.com>
* elf/Makefile (tests): Add loadtest.
Add rules to generate test modules.
* Makeconfig (+link): Add $(LDFLAGS-$(@F)) to command line.
* elf/loadtest.c: New file.
* elf/testobj1.c: New file.
* elf/testobj2.c: New file.
* elf/testobj3.c: New file.
* elf/dl-close.c: Correct removing module from global list.
* elf/dl-open.c: Add debugging code.
* include/string.h: Add __rawmemchr prototype.
* string/Makefile (routines): Add rawmemchr.
* string/Versions [GLIBC_2.1]: Add __rawmemchr and rawmemchr.
* string/string.h: Add prototype for rawmemchr.
* string/bits/string2.h: Optimize strchr with rawmemchr.
* sysdeps/generic/rawmemchr.c: New file.
* sysdeps/i386/rawmemchr.c: New file.
* sysdeps/i386/i486/bits/string.h: Add rawmemchr inline code.
Optimize strchr with rawmemchr.
* sysdeps/unix/sysv/linux/bits/posix_opt.h: Define _LFS_LARGEFILE,
_LFS64_LARGEFILE, and _LFS64_STDIO for Unix98.
1999-01-14 Andreas Jaeger <aj@arthur.rhein-neckar.de>
* nis/nis_error.c (nis_errlist): Fix capitilasation.
1999-01-15 Ulrich Drepper <drepper@cygnus.com>
* posix/Makefile (tests): Add test-vfork.

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@ -1,4 +1,4 @@
# Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98 Free Software Foundation, Inc.
# Copyright (C) 1991,92,93,94,95,96,97,98,99 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
# The GNU C Library is free software; you can redistribute it and/or
@ -369,7 +369,7 @@ endif
# Command for linking programs with the C library.
ifndef +link
+link = $(CC) -nostdlib -nostartfiles -o $@ \
$(sysdep-LDFLAGS) $(config-LDFLAGS) $(LDFLAGS) \
$(sysdep-LDFLAGS) $(config-LDFLAGS) $(LDFLAGS) $(LDFLAGS-$(@F)) \
$(addprefix $(csu-objpfx),$(start-installed-name)) \
$(+preinit) $(+prector) \
$(filter-out $(addprefix $(csu-objpfx),start.o \

View File

@ -1,4 +1,4 @@
# Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
# Copyright (C) 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
# The GNU C Library is free software; you can redistribute it and/or
@ -75,6 +75,8 @@ others += ldconfig
install-rootsbin += ldconfig
endif
tests = loadtest
include ../Rules
@ -200,6 +202,32 @@ else
$(objpfx)sprof: $(objpfx)libdl.a
endif
# This macro is similar to build-shlib but it does not define a soname
# and it does not depend on the destination name to start with `lib'.
define build-module
$(LINK.o) -shared -o $@ $(sysdep-LDFLAGS) $(config-LDFLAGS) \
-B$(csu-objpfx) $(load-map-file) \
$(LDFLAGS.so) $(LDFLAGS-$(@F:%.so=%).so) \
-L$(subst :, -L,$(rpath-link)) -Wl,-rpath-link=$(rpath-link) \
-Wl,--whole-archive -Wl,-soname,$(@F) \
$(filter-out $(map-file) $(+preinit) $(+postinit),$^) \
$(no-whole-archive) $(LDLIBS-$(@F:%.so=%).so)
endef
modules-names = testobj1 testobj2 testobj3
test-modules = $(addprefix $(objpfx),$(addsuffix .so,$(modules-names)))
$(objpfx)testobj2.so: $(objpfx)testobj1.so
LDLIBS-testobj2.so = $(objpfx)testobj1.so
$(test-modules): $(objpfx)%.so: %.c
$(build-module)
$(objpfx)loadtest: $(objpfx)libdl.so
LDFLAGS-loadtest = -rdynamic
$(objpfx)loadtest.out: $(test-modules)
# muwahaha
LDFLAGS-dl.so = -Wl,-dynamic-linker,$(slibdir)/$(rtld-installed-name)

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@ -1,5 +1,5 @@
/* Close a shared object opened by `_dl_open'.
Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -108,12 +108,11 @@ _dl_close (struct link_map *map)
do
--cnt;
while (_dl_main_searchlist->r_list[cnt] != imap);
while (cnt < _dl_main_searchlist->r_nlist)
{
_dl_main_searchlist->r_list[0]
= _dl_main_searchlist->r_list[1];
++cnt;
}
while (++cnt < _dl_main_searchlist->r_nlist)
_dl_main_searchlist->r_list[cnt - 1]
= _dl_main_searchlist->r_list[cnt];
--_dl_main_searchlist->r_nlist;
if (_dl_main_searchlist->r_nlist
== _dl_initial_searchlist.r_nlist)

View File

@ -1,5 +1,5 @@
/* Load a shared object at runtime, relocate it, and run its initializer.
Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -42,6 +42,11 @@ extern char **__libc_argv;
extern char **__environ;
/* Undefine the following for debugging. */
/* #define SCOPE_DEBUG 1 */
#ifdef SCOPE_DEBUG
static void show_scope (struct link_map *new);
#endif
/* During the program run we must not modify the global data of
loaded shared object simultanously in two threads. Therefore we
@ -86,6 +91,10 @@ dl_open_worker (void *a)
/* So far, so good. Now check the versions. */
(void) _dl_check_all_versions (new, 0);
#ifdef SCOPE_DEBUG
show_scope (new);
#endif
/* Relocate the objects loaded. We do this in reverse order so that copy
relocs of earlier objects overwrite the data written by later objects. */
@ -195,3 +204,34 @@ _dl_open (const char *file, int mode)
return args.map;
}
#ifdef SCOPE_DEBUG
#include <unistd.h>
static void
show_scope (struct link_map *new)
{
int scope_cnt;
for (scope_cnt = 0; new->l_scope[scope_cnt] != NULL; ++scope_cnt)
{
char numbuf[2];
unsigned int cnt;
numbuf[0] = '0' + scope_cnt;
numbuf[1] = '\0';
_dl_sysdep_message ("scope ", numbuf, ":", NULL);
for (cnt = 0; cnt < new->l_scope[scope_cnt]->r_nlist; ++cnt)
if (*new->l_scope[scope_cnt]->r_list[cnt]->l_name)
_dl_sysdep_message (" ",
new->l_scope[scope_cnt]->r_list[cnt]->l_name,
NULL);
else
_dl_sysdep_message (" <main>", NULL);
_dl_sysdep_message ("\n", NULL);
}
}
#endif

114
elf/loadtest.c Normal file
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@ -0,0 +1,114 @@
#include <assert.h>
#include <dlfcn.h>
#include <errno.h>
#include <error.h>
#include <stdio.h>
#include <stdlib.h>
/* How many load/unload operations do we do. */
#define TEST_ROUNDS 100
static struct
{
/* Name of the module. */
const char *name;
/* The handle. */
void *handle;
} testobjs[] =
{
{ "testobj1.so", NULL },
{ "testobj2.so", NULL },
{ "testobj3.so", NULL },
};
#define NOBJS (sizeof (testobjs) / sizeof (testobjs[0]))
static const struct
{
/* Name of a function to call. */
const char *fname;
/* Index in status and handle array. */
int index;
/* Options while loading the module. */
int options;
} tests[] =
{
{ "obj1func2", 0, RTLD_LAZY },
{ "obj1func1", 0, RTLD_LAZY | RTLD_GLOBAL },
{ "obj1func1", 0, RTLD_NOW, },
{ "obj1func2", 0, RTLD_NOW | RTLD_GLOBAL },
{ "obj2func2", 1, RTLD_LAZY },
{ "obj2func1", 1, RTLD_LAZY | RTLD_GLOBAL, },
{ "obj2func1", 1, RTLD_NOW, },
{ "obj2func2", 1, RTLD_NOW | RTLD_GLOBAL },
{ "obj3func2", 2, RTLD_LAZY },
{ "obj3func1", 2, RTLD_LAZY | RTLD_GLOBAL },
{ "obj3func1", 2, RTLD_NOW },
{ "obj3func2", 2, RTLD_NOW | RTLD_GLOBAL },
};
#define NTESTS (sizeof (tests) / sizeof (tests[0]))
int
main (void)
{
int count = TEST_ROUNDS;
/* Just a seed. */
srandom (TEST_ROUNDS);
while (count--)
{
int nr = random () % NTESTS;
int index = tests[nr].index;
printf ("%4d: %4d: ", count + 1, nr);
fflush (stdout);
if (testobjs[index].handle == NULL)
{
int (*fct) (int);
/* Load the object. */
testobjs[index].handle = dlopen (testobjs[index].name,
tests[nr].options);
if (testobjs[index].handle == NULL)
error (EXIT_FAILURE, 0, "cannot load `%s': %s",
testobjs[index].name, dlerror ());
/* Test the function call. */
fct = dlsym (testobjs[index].handle, tests[nr].fname);
if (fct == NULL)
error (EXIT_FAILURE, 0,
"cannot get function `%s' from shared object `%s': %s",
tests[nr].fname, testobjs[index].name, dlerror ());
fct (10);
printf ("successfully loaded `%s'\n", testobjs[index].name);
}
else
{
dlclose (testobjs[index].handle);
testobjs[index].handle = NULL;
printf ("successfully unloaded `%s'\n", testobjs[index].name);
}
}
/* Unload all loaded modules. */
for (count = 0; count < NOBJS; ++count)
if (testobjs[count].handle != NULL)
dlclose (testobjs[count].handle);
return 0;
}
int
foo (int a)
{
return a - 1;
}

11
elf/testobj1.c Normal file
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@ -0,0 +1,11 @@
int
obj1func1 (int a __attribute__ ((unused)))
{
return 42;
}
int
obj1func2 (int a)
{
return foo (a) + 10;
}

11
elf/testobj2.c Normal file
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@ -0,0 +1,11 @@
int
obj2func1 (int a __attribute__ ((unused)))
{
return 43;
}
int
obj2func2 (int a)
{
return obj1func1 (a) + 10;
}

11
elf/testobj3.c Normal file
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@ -0,0 +1,11 @@
int
obj3func1 (int a __attribute__ ((unused)))
{
return 44;
}
int
obj3func2 (int a)
{
return foo (a) + 42;
}

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@ -16,4 +16,6 @@ extern int __strncasecmp __P ((__const char *__s1, __const char *__s2,
extern char *__strndup __P ((__const char *__string, size_t __n));
extern __ptr_t __rawmemchr __P ((__const __ptr_t __s, int __c));
#endif

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@ -1,3 +1,8 @@
1999-01-16 Ulrich Drepper <drepper@cygnus.com>
* sysdeps/unix/sysv/linux/bits/posix_opt.h: Add _LFS_ASYNCHRONOUS_IO,
_LFS_LARGEFILE, _LFS64_LARGEFILE, and _LFS64_STDIO from Unix98.
1999-01-07 Xavier Leroy <Xavier.Leroy@inria.fr>
* pthread.c: Use a third signal __pthread_sig_debug distinct

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@ -1,5 +1,5 @@
/* Define POSIX options for Linux.
Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -96,5 +96,15 @@
/* We support asynchronous I/O. */
#define _POSIX_ASYNCHRONOUS_IO 1
/* Alternative name for Unix98. */
#define _LFS_ASYNCHRONOUS_IO 1
/* The LFS support in asynchronous I/O is also available. */
#define _LFS64_ASYNCHRONOUS_IO 1
/* The rest of the LFS is also available. */
#define _LFS_LARGEFILE 1
#define _LFS64_LARGEFILE 1
#define _LFS64_STDIO 1
#endif /* posix_opt.h */

View File

@ -34,25 +34,25 @@ static const char *nis_errlist[] =
N_("Unknown object"),
N_("Server busy, try again"),
N_("Generic system error"),
N_("First/Next chain broken"),
N_("First/next chain broken"),
N_("Permission denied"),
N_("Not owner"),
N_("Name not served by this server"),
N_("Server out of memory"),
N_("Object with same name exists"),
N_("Not master server for this domain"),
N_("Invalid Object for operation"),
N_("Malformed Name, or illegal name"),
N_("Invalid object for operation"),
N_("Malformed name, or illegal name"),
N_("Unable to create callback"),
N_("Results sent to callback proc"),
N_("Not Found, no such name"),
N_("Not found, no such name"),
N_("Name/entry isn't unique"),
N_("Modification failed"),
N_("Database for table does not exist"),
N_("Entry/Table type mismatch"),
N_("Link Points to illegal name"),
N_("Partial Success"),
N_("Too many Attributes"),
N_("Entry/table type mismatch"),
N_("Link points to illegal name"),
N_("Partial success"),
N_("Too many attributes"),
N_("Error in RPC subsystem"),
N_("Missing or malformed attribute"),
N_("Named object is not searchable"),

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@ -1,4 +1,4 @@
# Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98 Free Software Foundation, Inc.
# Copyright (C) 1991,92,93,94,95,96,97,98,99 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
# The GNU C Library is free software; you can redistribute it and/or
@ -34,7 +34,7 @@ routines := strcat strchr strcmp strcoll strcpy strcspn \
mempcpy bcopy bzero ffs ffsll stpcpy stpncpy \
strcasecmp strncase strcasecmp_l strncase_l \
memccpy memcpy wordcopy strsep strcasestr \
swab strfry memfrob memmem \
swab strfry memfrob memmem rawmemchr \
$(addprefix argz-,append count create ctsep next \
delete extract insert stringify \
addsep replace) \

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@ -41,8 +41,8 @@ libc {
strsignal; strspn; strstr; strtok; strtok_r; strxfrm; swab;
}
GLIBC_2.1 {
# functions used in other libraries
__strcasestr;
# functions used in macros and other libraries
__rawmemchr; __strcasestr;
# f*
ffsl; ffsll;
@ -50,6 +50,9 @@ libc {
# m*
mempcpy;
# r*
rawmemchr;
# s*
strcasestr; strverscmp;
}

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@ -1,5 +1,5 @@
/* Machine-independant string function optimizations.
Copyright (C) 1997, 1998 Free Software Foundation, Inc.
Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
@ -252,6 +252,16 @@ __mempcpy_small (void *__dest1, char __src1,
#endif
/* Return pointer to C in S. */
#ifndef _HAVE_STRING_ARCH_strchr
extern __ptr_t __rawmemchr (const __ptr_t __s, int __c);
# define strchr(s, c) \
(__extension__ (__builtin_constant_p (c) && (c) == '\0' \
? (char *) __rawmemchr (s, c) \
: strchr (s, c)))
#endif
/* Copy SRC to DEST. */
#ifndef _HAVE_STRING_ARCH_strcpy
# define strcpy(dest, src) \

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@ -1,4 +1,4 @@
/* Copyright (C) 1991, 92, 93, 95, 96, 97, 98 Free Software Foundation, Inc.
/* Copyright (C) 1991,92,93,95,96,97,98,99 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -60,6 +60,12 @@ extern int memcmp __P ((__const __ptr_t __s1, __const __ptr_t __s2,
/* Search N bytes of S for C. */
extern __ptr_t memchr __P ((__const __ptr_t __s, int __c, size_t __n));
#ifdef __USE_GNU
/* Search in S for C. This is similar to `memchr' but there is no
length limit. */
extern __ptr_t rawmemchr __P ((__const __ptr_t __s, int __c));
#endif
/* Copy SRC to DEST. */
extern char *strcpy __P ((char *__restrict __dest,

182
sysdeps/generic/rawmemchr.c Normal file
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@ -0,0 +1,182 @@
/* Copyright (C) 1991, 1993, 1996, 1997, 1999 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),
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. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#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. */
#if defined (_LIBC)
# include <string.h>
#endif
#if defined (HAVE_LIMITS_H) || defined (_LIBC)
# include <limits.h>
#endif
#define LONG_MAX_32_BITS 2147483647
#ifndef LONG_MAX
#define LONG_MAX LONG_MAX_32_BITS
#endif
#include <sys/types.h>
#undef memchr
/* Search no more than N bytes of S for C. */
__ptr_t
__rawmemchr (s, c)
const __ptr_t 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 = (const unsigned char *) s;
((unsigned long int) char_ptr & (sizeof (longword) - 1)) != 0;
++char_ptr)
if (*char_ptr == c)
return (__ptr_t) 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. */
if (sizeof (longword) != 4 && sizeof (longword) != 8)
abort ();
#if LONG_MAX <= LONG_MAX_32_BITS
magic_bits = 0x7efefeff;
#else
magic_bits = ((unsigned long int) 0x7efefefe << 32) | 0xfefefeff;
#endif
/* Set up a longword, each of whose bytes is C. */
charmask = c | (c << 8);
charmask |= charmask << 16;
#if LONG_MAX > LONG_MAX_32_BITS
charmask |= charmask << 32;
#endif
/* 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. */
while (1)
{
/* 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, 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. */
longword = *longword_ptr++ ^ charmask;
/* 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)
{
/* Which of the bytes was C? If none of them were, it was
a misfire; continue the search. */
const unsigned char *cp = (const unsigned char *) (longword_ptr - 1);
if (cp[0] == c)
return (__ptr_t) cp;
if (cp[1] == c)
return (__ptr_t) &cp[1];
if (cp[2] == c)
return (__ptr_t) &cp[2];
if (cp[3] == c)
return (__ptr_t) &cp[3];
#if LONG_MAX > 2147483647
if (cp[4] == c)
return (__ptr_t) &cp[4];
if (cp[5] == c)
return (__ptr_t) &cp[5];
if (cp[6] == c)
return (__ptr_t) &cp[6];
if (cp[7] == c)
return (__ptr_t) &cp[7];
#endif
}
}
}
weak_alias (__rawmemchr, rawmemchr)

View File

@ -1,5 +1,5 @@
/* Optimized, inlined string functions. i486 version.
Copyright (C) 1997, 1998 Free Software Foundation, Inc.
Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -377,6 +377,30 @@ memchr (__const void *__s, int __c, size_t __n)
}
/* Return pointer to C in S. */
#define _HAVE_STRING_ARCH_rawmemchr 1
__STRING_INLINE void *
__rawmemchr (const void *__s, int __c)
{
register unsigned long int __d0;
register unsigned char *__res;
__asm__ __volatile__
("cld\n\t"
"repne; scasb\n\t"
: "=D" (__res), "=&c" (__d0)
: "a" (__c), "0" (__s), "1" (0xffffffff)
: "cc");
return __res - 1;
}
#ifdef __USE_GNU
__STRING_INLINE void *
rawmemchr (const void *__s, int __c)
{
return __rawmemchr (__s, __c);
}
#endif /* use GNU */
/* Return the length of S. */
#define _HAVE_STRING_ARCH_strlen 1
#define strlen(str) \
@ -1049,7 +1073,9 @@ __strncmp_g (__const char *__s1, __const char *__s2, size_t __n)
#define _HAVE_STRING_ARCH_strchr 1
#define strchr(s, c) \
(__extension__ (__builtin_constant_p (c) \
? __strchr_c (s, ((c) & 0xff) << 8) \
? ((c) == '\0' \
? (char *) __rawmemchr (s, c) \
: __strchr_c (s, ((c) & 0xff) << 8)) \
: __strchr_g (s, c)))
__STRING_INLINE char *__strchr_c (__const char *__s, int __c);

218
sysdeps/i386/rawmemchr.S Normal file
View File

@ -0,0 +1,218 @@
/* rawmemchr (str, ch) -- Return pointer to first occurrence of CH in STR.
For Intel 80x86, x>=3.
Copyright (C) 1994, 95, 96, 97, 98, 99 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>
Optimised a little by Alan Modra <Alan@SPRI.Levels.UniSA.Edu.Au>
This version is developed using the same algorithm as the fast C
version which carries the following introduction:
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),
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 <sysdep.h>
#include "asm-syntax.h"
/*
INPUT PARAMETERS:
str (sp + 4)
c (sp + 8)
*/
.text
ENTRY (__rawmemchr)
/* Save callee-safe register used in this function. */
pushl %edi
/* Load parameters into registers. */
movl 8(%esp), %eax /* str: pointer to memory block. */
movl 12(%esp), %edx /* c: byte 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 c|c|0|0 */
movw %cx, %dx /* And finally c|c|c|c */
/* Better performance can be achieved if the word (32
bit) memory access is aligned on a four-byte-boundary.
So process first bytes one by one until boundary is
reached. Don't use a loop for better performance. */
testb $3, %al /* correctly aligned ? */
je L(1) /* yes => begin loop */
cmpb %dl, (%eax) /* compare byte */
je L(9) /* target found => return */
incl %eax /* increment source pointer */
testb $3, %al /* correctly aligned ? */
je L(1) /* yes => begin loop */
cmpb %dl, (%eax) /* compare byte */
je L(9) /* target found => return */
incl %eax /* increment source pointer */
testb $3, %al /* correctly aligned ? */
je L(1) /* yes => begin loop */
cmpb %dl, (%eax) /* compare byte */
je L(9) /* target found => return */
incl %eax /* increment source pointer */
/* 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): movl (%eax), %ecx /* get word (= 4 bytes) in question */
movl $0xfefefeff, %edi /* magic value */
xorl %edx, %ecx /* XOR with word c|c|c|c => bytes of str == c
are now 0 */
addl %ecx, %edi /* add the magic value to the word. We get
carry bits reported for each byte which
is *not* 0 */
/* 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(8)
/* 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(8) /* found it => return pointer */
/* This process is unfolded four times for better performance.
we don't increment the source pointer each time. Instead we
use offsets and increment by 16 in each run of the loop. But
before probing for the matching byte we need some extra code
(following LL(13) below). Even the len can be compared with
constants instead of decrementing each time. */
movl 4(%eax), %ecx /* get word (= 4 bytes) in question */
movl $0xfefefeff, %edi /* magic value */
xorl %edx, %ecx /* XOR with word c|c|c|c => bytes of str == c
are now 0 */
addl %ecx, %edi /* add the magic value to the word. We get
carry bits reported for each byte which
is *not* 0 */
jnc L(7) /* 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(7) /* found it => return pointer */
movl 8(%eax), %ecx /* get word (= 4 bytes) in question */
movl $0xfefefeff, %edi /* magic value */
xorl %edx, %ecx /* XOR with word c|c|c|c => bytes of str == c
are now 0 */
addl %ecx, %edi /* add the magic value to the word. We get
carry bits reported for each byte which
is *not* 0 */
jnc L(6) /* 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(6) /* found it => return pointer */
movl 12(%eax), %ecx /* get word (= 4 bytes) in question */
movl $0xfefefeff, %edi /* magic value */
xorl %edx, %ecx /* XOR with word c|c|c|c => bytes of str == c
are now 0 */
addl %ecx, %edi /* add the magic value to the word. We get
carry bits reported for each byte which
is *not* 0 */
jnc L(5) /* 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(5) /* found it => return pointer */
/* Adjust both counters for a full round, i.e. 16 bytes. */
addl $16, %eax
jmp L(1)
/* add missing source pointer increments */
L(5): addl $4, %eax
L(6): addl $4, %eax
L(7): addl $4, %eax
/* Test for the matching byte in the word. %ecx contains a NUL
char in the byte which originally was the byte we are looking
at. */
L(8): testb %cl, %cl /* test first byte in dword */
jz L(9) /* if zero => return pointer */
incl %eax /* increment source pointer */
testb %ch, %ch /* test second byte in dword */
jz L(9) /* if zero => return pointer */
incl %eax /* increment source pointer */
testl $0xff0000, %ecx /* test third byte in dword */
jz L(9) /* if zero => return pointer */
incl %eax /* increment source pointer */
/* No further test needed we we know it is one of the four bytes. */
L(9): popl %edi /* pop saved register */
ret
END (__rawmemchr)
weak_alias (__rawmemchr, rawmemchr)

View File

@ -1,5 +1,5 @@
/* Define POSIX options for Linux.
Copyright (C) 1996, 1997 Free Software Foundation, Inc.
Copyright (C) 1996, 1997, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -76,4 +76,9 @@
/* Real-time signals are supported. */
#define _POSIX_REALTIME_SIGNALS 1
/* The LFS interface is available, except for the asynchronous I/O. */
#define _LFS_LARGEFILE 1
#define _LFS64_LARGEFILE 1
#define _LFS64_STDIO 1
#endif /* bits/posix_opt.h */