summaryrefslogtreecommitdiff
path: root/sysdeps
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@redhat.com>1999-01-16 17:09:04 +0000
committerUlrich Drepper <drepper@redhat.com>1999-01-16 17:09:04 +0000
commit482eec0d1188823ad93247f79bf965886e8bd4f7 (patch)
tree5a3157c41a1310f5440de77f841753a32bb1444d /sysdeps
parent37a87f834a459f6136ff44c7887b013d1ae0f6be (diff)
Update.
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.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/generic/rawmemchr.c182
-rw-r--r--sysdeps/i386/i486/bits/string.h30
-rw-r--r--sysdeps/i386/rawmemchr.S218
-rw-r--r--sysdeps/unix/sysv/linux/bits/posix_opt.h7
4 files changed, 434 insertions, 3 deletions
diff --git a/sysdeps/generic/rawmemchr.c b/sysdeps/generic/rawmemchr.c
new file mode 100644
index 0000000000..c205968668
--- /dev/null
+++ b/sysdeps/generic/rawmemchr.c
@@ -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)
diff --git a/sysdeps/i386/i486/bits/string.h b/sysdeps/i386/i486/bits/string.h
index f810de06ea..e20f037ab7 100644
--- a/sysdeps/i386/i486/bits/string.h
+++ b/sysdeps/i386/i486/bits/string.h
@@ -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);
diff --git a/sysdeps/i386/rawmemchr.S b/sysdeps/i386/rawmemchr.S
new file mode 100644
index 0000000000..83626e0473
--- /dev/null
+++ b/sysdeps/i386/rawmemchr.S
@@ -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)
diff --git a/sysdeps/unix/sysv/linux/bits/posix_opt.h b/sysdeps/unix/sysv/linux/bits/posix_opt.h
index 5ef6d0563d..2a53420578 100644
--- a/sysdeps/unix/sysv/linux/bits/posix_opt.h
+++ b/sysdeps/unix/sysv/linux/bits/posix_opt.h
@@ -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 */