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Thu Oct 17 01:55:34 1996 Ulrich Drepper <drepper@cygnus.com> * sunrpc/Makefile ($(objpfx)rpcsvc/%.h, $(objpfx)x%.c): Write output to $@T and move to $@ later since the new rpcgen will not overwrite existing files. * po/Makefile (libc.pot): Fix typo. Sun Oct 13 20:52:07 1996 Thorsten Kukuk <kukuk@weber.uni-paderborn.de> Update rpcgen program to TI-rpc code. * sunrpc/Makefile (rpcgen-objs): Add rpc_tblout.o and rpc_sample.o. (distribute): Add proto.h. * sunrpc/proto.h: New file. Prototypes for all the RPC functions. * sunrpc/rpc_clntout.c: Change to allow generation of ISO C code. * sunrpc/rpc_cout.c: Likewise. * sunrpc/rpc_hout.c: Likewise. * sunrpc/rpc_main.c: Likewise. * sunrpc/rpc_parse.c: Likewise. * sunrpc/rpc_parse.h: Likewise. * sunrpc/rpc_scan.c: Likewise. * sunrpc/rpc_scan.h: Likewise. * sunrpc/rpc_svcout.c: Likewise. * sunrpc/rpc_util.c: Likewise. * sunrpc/rpc_util.h: Likewise. * sunrpc/rpc_tblout.c: New file. * sunrpc/rpc_sample.c: Likewise. Thu Oct 17 00:26:20 1996 NIIBE Yutaka <gniibe@mri.co.jp> * sysdeps/unix/opendir.c: Add semicolon for consistency. Wed Oct 16 12:26:53 1996 Sven Verdoolaege <skimo@breughel.ufsia.ac.be> * locale/progams/localedef.c (main): Test with -1 to find out whether read failed. Wed Oct 16 14:54:59 1996 Ulrich Drepper <drepper@cygnus.com> * sysdeps/unix/sysv/linux/i386/clone.S: Use JUMPTARGET and PSEUDO_END macro. Tue Oct 15 21:27:42 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/unix/sysv/linux/m68k/sigcontext.h: Removed. Tue Oct 15 15:52:29 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/unix/sysv/linux/m68k/clone.S: Add CALL_MCOUNT. * sysdeps/unix/sysv/linux/m68k/mmap.S: Likewise. * sysdeps/unix/sysv/linux/m68k/sigreturn.S: Likewise. * sysdeps/unix/sysv/linux/m68k/socket.S: Likewise. * sysdeps/unix/sysv/linux/m68k/sysdep.S (__errno_location): Likewise. * sysdeps/unix/sysv/linux/m68k/syscall.S: Likewise. Correct generation of system call. Tue Oct 15 15:13:16 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * Makerules (sysd-Makefile): Fix command so that it works in the subdirectories. (BUILD_CFLAGS): Change back using $(..) instead of $(common-objpfx), the latter fails in the toplevel directory when $(objdir) is relative. (common-objdir-compile): Run compiler in $(objdir). * sysdeps/posix/Makefile (mk-stdiolim): Likewise. Tue Oct 15 23:39:48 1996 Ulrich Drepper <drepper@cygnus.com> * string/string.h [__USE_SVID]: Add prototype for swab. * time/sys/time.h [__USE_BSD]: Add prototype for ualarm. Reported by Andreas Jaeger. The available nlist implementation is not generally usable. Especially on the currently supported ELF systems the nlist function comes with the libelf. * misc/Makefile (headers): Remove nlist.h. (routines): Remove nlist. * Makefile ($(objpfx)version-info.h): Include information about system the libc is built on in version-info.h file. * po/Makefile (distribute): Add header.pot. Tue Oct 15 16:34:15 1996 Andreas Jaeger <aj@arthur.pfalz.de> * sysdeps/unix/sysv/linux/sleep.c: Include file with prototype. * sysdeps/unix/sysv/linux/reboot.c: Likewise. * misc/error.c: Likewise. Tue Oct 15 22:41:27 1996 Ulrich Drepper <drepper@cygnus.com> * sysdeps/unix/sysv/linux/syscalls.list: Add {get,set}resuid. Tue Oct 15 08:06:02 1996 Andreas Jaeger <aj@arthur.pfalz.de> * crypt/Makefiel (rpath-link): Extend search path to current directory. Fri Oct 11 09:18:06 1996 Sven Verdoolaege <skimo@breughel.ufsia.ac.be> * sysdeps/i386/i586/strlen.S: Correct handling of prolog for aligning pointer. Tue Oct 15 02:13:21 1996 Ulrich Drepper <drepper@cygnus.com> * stdio-common/vfprintf.c: Don't declare __flockfile as weak. * crypt/md5-crypt.c (md5_crypt_r): Add cast to prevent warning. Sun Oct 13 19:16:10 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/unix/sysv/linux/m68k/sysdep.h (POUND): Macro removed, replaced by `&'. (PSEUDO_END): Provide definition to use .size directive. (PSEUDO): Don't interpret negative return values less than -128 as syscall error. * sysdeps/unix/sysv/linux/m68k/syscall.S (syscall): Likewise. * sysdeps/m68k/bsd-_setjmp.S: Use PSEUDO_END macro to provide .size directive. * sysdeps/m68k/bsd-setjmp.S: Likewise. * sysdeps/unix/sysv/linux/m68k/clone.S: Likewise. * sysdeps/unix/sysv/linux/m68k/mmap.S: Likewise. * sysdeps/unix/sysv/linux/m68k/sigreturn.S: Likewise. * sysdeps/unix/sysv/linux/m68k/socket.S: Likewise. * sysdeps/unix/sysv/linux/m68k/syscall.S: Likewise. * sysdeps/unix/sysv/linux/m68k/sysdep.S: Use PSEUDO_END instead of explicit .size directive. * libio/iogets.c: Warn when gets is used. cd * time/strptime.c: Recognize %s, %u, %g, and %G format.
184 lines
5.5 KiB
ArmAsm
184 lines
5.5 KiB
ArmAsm
/* strlen -- Compute length og NUL terminated string.
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Highly optimized version for ix86, x>=5.
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Copyright (C) 1995, 1996 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <sysdep.h>
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/* This version is especially optimized for the i586 (and following?)
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processors. This is mainly done by using the two pipelines. The
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version optimized for i486 is weak in this aspect because to get
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as much parallelism we have to executs some *more* instructions.
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The code below is structured to reflect the pairing of the instructions
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as *I think* it is. I have no processor data book to verify this.
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If you find something you think is incorrect let me know. */
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/* The magic value which is used throughout in the whole code. */
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#define magic 0xfefefeff
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/*
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INPUT PARAMETERS:
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str (sp + 4)
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*/
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.text
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ENTRY(strlen)
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movl 4(%esp), %eax /* get string pointer */
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movl $3, %edx /* load mask (= 3) */
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andl %eax, %edx /* separate last two bits of address */
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jz L1 /* aligned => start loop */
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jp L0 /* exactly two bits set */
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cmpb %dh, (%eax) /* is byte NUL? */
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je L2 /* yes => return */
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incl %eax /* increment pointer */
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cmpb %dh, (%eax) /* is byte NUL? */
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je L2 /* yes => return */
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incl %eax /* increment pointer */
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xorl $2, %edx
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jz L1
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L0: cmpb %dh, (%eax) /* is byte NUL? */
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je L2 /* yes => return */
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incl %eax /* increment pointer */
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xorl %edx, %edx /* We need %edx == 0 for later */
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/* We exit the loop if adding MAGIC_BITS to LONGWORD fails to
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change any of the hole bits of LONGWORD.
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1) Is this safe? Will it catch all the zero bytes?
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Suppose there is a byte with all zeros. Any carry bits
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propagating from its left will fall into the hole at its
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least significant bit and stop. Since there will be no
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carry from its most significant bit, the LSB of the
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byte to the left will be unchanged, and the zero will be
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detected.
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2) Is this worthwhile? Will it ignore everything except
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zero bytes? Suppose every byte of LONGWORD has a bit set
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somewhere. There will be a carry into bit 8. If bit 8
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is set, this will carry into bit 16. If bit 8 is clear,
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one of bits 9-15 must be set, so there will be a carry
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into bit 16. Similarly, there will be a carry into bit
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24. If one of bits 24-31 is set, there will be a carry
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into bit 32 (=carry flag), so all of the hole bits will
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be changed.
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Note: %edx == 0 in any case here. */
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L1:
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movl (%eax), %ecx /* get word (= 4 bytes) in question */
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addl $4, %eax /* adjust pointer for *next* word */
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subl %ecx, %edx /* first step to negate word */
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addl $magic, %ecx /* add magic word */
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decl %edx /* complete negation of word */
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jnc L3 /* previous addl caused overflow? */
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xorl %ecx, %edx /* (word+magic)^word */
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andl $~magic, %edx /* any of the carry flags set? */
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jne L3 /* yes => determine byte */
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movl (%eax), %ecx /* get word (= 4 bytes) in question */
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addl $4, %eax /* adjust pointer for *next* word */
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subl %ecx, %edx /* first step to negate word */
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addl $magic, %ecx /* add magic word */
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decl %edx /* complete negation of word */
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jnc L3 /* previous addl caused overflow? */
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xorl %ecx, %edx /* (word+magic)^word */
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andl $~magic, %edx /* any of the carry flags set? */
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jne L3 /* yes => determine byte */
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movl (%eax), %ecx /* get word (= 4 bytes) in question */
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addl $4, %eax /* adjust pointer for *next* word */
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subl %ecx, %edx /* first step to negate word */
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addl $magic, %ecx /* add magic word */
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decl %edx /* complete negation of word */
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jnc L3 /* previous addl caused overflow? */
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xorl %ecx, %edx /* (word+magic)^word */
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andl $~magic, %edx /* any of the carry flags set? */
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jne L3 /* yes => determine byte */
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movl (%eax), %ecx /* get word (= 4 bytes) in question */
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addl $4, %eax /* adjust pointer for *next* word */
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subl %ecx, %edx /* first step to negate word */
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addl $magic, %ecx /* add magic word */
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decl %edx /* complete negation of word */
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jnc L3 /* previous addl caused overflow? */
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xorl %ecx, %edx /* (word+magic)^word */
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andl $~magic, %edx /* any of the carry flags set? */
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je L1 /* no => start loop again */
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L3: subl $4, %eax /* correct too early pointer increment */
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subl $magic, %ecx
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cmpb $0, %cl /* lowest byte NUL? */
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jz L2 /* yes => return */
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inc %eax /* increment pointer */
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testb %ch, %ch /* second byte NUL? */
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jz L2 /* yes => return */
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shrl $16, %ecx /* make upper bytes accessible */
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incl %eax /* increment pointer */
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cmpb $0, %cl /* is third byte NUL? */
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jz L2 /* yes => return */
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incl %eax /* increment pointer */
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L2: subl 4(%esp), %eax /* now compute the length as difference
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between start and terminating NUL
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character */
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ret
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PSEUDO_END (strlen)
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