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author | Ulrich Drepper <drepper@redhat.com> | 1997-09-11 12:09:10 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 1997-09-11 12:09:10 +0000 |
commit | 9a0a462ceb4ab96c909b182f3052de2ef13fbe3a (patch) | |
tree | 59456497b6acefe69aab04fc28c38ea38852ccc7 /sysdeps/powerpc/strlen.S | |
parent | 26b4d7667169f8db26fd8194b3c498ec58e50f90 (diff) | |
download | glibc-9a0a462ceb4ab96c909b182f3052de2ef13fbe3a.tar.gz glibc-9a0a462ceb4ab96c909b182f3052de2ef13fbe3a.tar.xz glibc-9a0a462ceb4ab96c909b182f3052de2ef13fbe3a.zip |
Update.
1997-09-11 04:36 Ulrich Drepper <drepper@cygnus.com> * db2/db_int.h: Define __set_errno if not yet available. * db2/btree/bt_rec.c: Use __set_errno to set errno value. * db2/clib/getlong.c: Likewise. * db2/db185/db185.c: Likewise. * db2/db185/db185_int.h: Likewise. * db2/dbm/dbm.c: Likewise. * db2/lock/lock_deadlock.c: Likewise. * db2/log/log_archive.c: Likewise. * elf/dl-profile.c: Implement mcount function. * gmon/gmon.c: Use __profil not profil because of namespace pollution. * gmon/mcount.c: Remove BSD kernel code. Use compare&swap instruction if possible to change state variable. Optimize frompc folding. * gmon/sys/gmon.h (struct gmonparam): Change state field to long int. * sysdeps/i386/i486/atomicity.h: New file. * sysdeps/stub/atomicity.h: New file. * sysdeps/mach/hurd/profil.c: Define function as __profil and make profil weak alias. * sysdeps/posix/profil.c: Likewise. * string/bits/string2.h: New file. * include/bits/string2.h: New file. * string/Makefile (routines): Add mempcpy. (tests): Add inl-tester. Remove _D__NO_STRING_INLINES from CFLAGS-* variables. * sysdeps/generic/mempcpy.c: New file. * sysdeps/generic/memccpy.c: Undef function name to enable definition as macro. * sysdeps/generic/memchr.c: Likewise. * sysdeps/generic/memcmp.c: Likewise. * sysdeps/generic/memmem.c: Likewise. * sysdeps/generic/memmove.c: Likewise. * sysdeps/generic/strcat.c: Likewise. * sysdeps/generic/strchr.c: Likewise. * sysdeps/generic/strcmp.c: Likewise. * sysdeps/generic/strcpy.c: Likewise. * sysdeps/generic/strcspn.c: Likewise. * sysdeps/generic/strlen.c: Likewise. * sysdeps/generic/strncat.c: Likewise. * sysdeps/generic/strncmp.c: Likewise. * sysdeps/generic/strncpy.c: Likewise. * sysdeps/generic/strpbrk.c: Likewise. * sysdeps/generic/strrchr.c: Likewise. * sysdeps/generic/strsep.c: Likewise. * sysdeps/generic/strspn.c: Likewise. * sysdeps/generic/strstr.c: Likewise. * sysdeps/generic/strtok.c: Likewise. * sysdeps/generic/strtok_r.c: Likewise. * sysdeps/i386/memset.c: Likewise. * sysdeps/i386/bits/string.h: Correct a few types and constraints. * sysdeps/i386/i486/bits/string.h: Heavy rewrites and optimizations. * string/stratcliff.c: Undefine __USE_STRING_INLINES. * string/tst-strlen.c: Likewise. * string/string.h: Add prototype for mempcpy. Include bits/string2.h header always if optimizing. * intl/dcgettext.c: Don't unconditionally define stpcpy, only if not yet defined. * intl/l10nflist.c: Likewise. * string/tester.c: Add copyright and make little cleanups. * inet/test_ifindex.c: Change type of ni variable to unsigned int. * locale/programs/ld-ctype.c (struct locale_ctype_t): Change type of fields map_collection_max and map_collection_act to size_t. * nss/libnss_files.map: Group entries. * posix/unistd.h: Add prototype for __setpgid and __profil. * sysdeps/generic/crypt.h: Declare __crypt_r. * sysdeps/i386/bits/select.h: Fix fatal bugs, use correct casts now. * sysdeps/i386/fpu/bits/mathinline.h (isgreater, isgreaterequal, isless, islessequal, islessgreater, isunordered): Optimize a bit. * sysdeps/stub/ftruncate.c: Include missing header for prototype. * sysdeps/stub/getdents.c: Likewise. * sysdeps/stub/reboot.c: Likewise. * sysdeps/stub/swapon.c: Likewise. * sysdeps/stub/syscall.c: Likewise. * sysdeps/stub/ualarm.c: Likewise. * sysdeps/stub/usleep.c: Likewise. * sysdeps/unix/sysv/linux/if_index.c: Don't compile or use opensock if SIOGIFINDEX and SIOGIFNAME are not defined. * sysdeps/unix/sysv/linux/net/if.h: Add IFF_PORTSEL and IFF_AUTOMEDIA according to recent kernel changes. 1997-09-10 21:32 Klaus Espenlaub <kespenla@student.informatik.uni-ulm.de> * Makeconfig: Use $(have-initfini) instead of $(elf) to figure out the installed name of the startup code. (common-generated): Add version.mk. * Makefile (distclean-1): Add glibcbug. * Makerules: Replace -lgcc by $(gnulib). * catgets/Makefile (generated): Add xmalloc.o. * csu/Makefile (generated): Replace align.h and end.h by defs.h to match the generated file. * manual/Makefile (mostlyclean): Add stub-manual and stamp.o. (realclean): Changed to remove chapters-incl[12]. * po/Makefile (realclean): New rule to remove the generated .mo files. * time/Makefile: Only include zonefile dependencies if $(no_deps) is not true to avoid make clean failure when directory time doesn't exist yet. (generated): Add tzselect. * stdio/fgets.c (fgets): Add casts to reduce gcc warning noise. * stdio/internals.c (flushbuf): Likewise. * stdio/linewrap.c (lwupdate): Likewise. * stdio/memstream.c (enlarge_buffer): Likewise. * stdio-common/vfscanf.c (_IO_vfscanf): Likewise. * time/tzset.c (compute_change): Likewise. * misc/init-misc.c (__init_misc): Only declare static if HAVE_GNU_LD is defined. * sysdeps/posix/pipestream.c (FUNC): Change to generate ANSI C style functions. * sysdeps/stub/init-posix.c: Likewise. * sysdeps/stub/profil.c: Likewise. * munch-tmpl.c (__libc_init): Convert to ANSI C style declaration to reduce gcc warning noise. * stdio/glue.c (_filbuf, _flsbuf): Likewise. * stdio/obstream.c (grow, seek, input, init_obstream): Likewise. * stdio/vasprintf.c (enlarge_buffer): Likewise. * sysdeps/generic/sysd-stdio.c (__stdio_read, __stdio_write, __stdio_seek, __stdio_close, __stdio_fileno, __stdio_open, __stdio_reopen): Likewise. * sysdeps/posix/defs.c (_cleanup): Likewise. * time/offtime.c (__offtime): Add cast. * posix/getopt.c: Don't use text_set_element if not defined. * configure.in: Provide a check for underscores before user labels that works even when the compiler used for building doesn't work (like when there is no C library). Use the old way if the compiler works. 1997-09-10 05:08 David S. Miller <davem@caip.rutgers.edu> * sysdeps/unix/sysv/linux/sparc/bits/ioctls.h: The TC* ioctls use 'T' not 't' on SparcLinux. * sysdeps/unix/sysv/linux/sparc/bits/termios.h: tcflag_t is 32 bits. * sysdeps/unix/sysv/linux/sparc/sparc64/longjmp.S: Add aliases for _longjmp and siglongjmp. 1997-09-09 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * libio/stdio.h: Add format attributes to the extra printf and scanf like functions. * stdio/stdio.h: Likewise. 1997-09-09 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * nis/nss_nisplus/nisplus-network.c (_nss_nisplus_getnetbyaddr_r): Print tablename_val, not tablename_len. * nis/nss_nisplus/nisplus-ethers.c (_nss_nisplus_getntohost_r): Use sprintf instead of sprintf, the string always fits. * nis/nss_nisplus/nisplus-hosts.c (_nss_nisplus_gethostbyaddr_r): Likewise. * nis/nss_nisplus/nisplus-network.c (_nss_nisplus_getnetbyaddr_r): Likewise. * nis/nss_nisplus/nisplus-proto.c (_nss_nisplus_getprotobynumber_r): Likewise. * nis/nss_nisplus/nisplus-rpc.c (_nss_nisplus_getrpcbynumber_r): Likewise. * nis/nss_nisplus/nisplus-service.c (_nss_nisplus_getservbynumber_r): Likewise. * nis/nss_nisplus/nisplus-alias.c (_nss_create_tablename): Use __stpcpy, __stpncpy and __strdup instead of public names. * nis/nss_nisplus/nisplus-ethers.c (_nss_create_tablename): Likewise. * nis/nss_nisplus/nisplus-grp.c (_nss_create_tablename): Likewise. * nis/nss_nisplus/nisplus-hosts.c (_nss_create_tablename): Likewise. * nis/nss_nisplus/nisplus-netgrp.c (_nss_nisplus_parse_netgroup): Likewise. * nis/nss_nisplus/nisplus-network.c (_nss_nisplus_parse_netent): Likewise. (_nss_create_tablename): Likewise. * nis/nss_nisplus/nisplus-proto.c (_nss_nisplus_parse_protoent): Likewise. (_nss_create_tablename): Likewise. * nis/nss_nisplus/nisplus-pwd.c (_nss_create_tablename): Likewise. * nis/nss_nisplus/nisplus-rpc.c (_nss_nisplus_parse_rpcent): Likewise. (_nss_create_tablename): Likewise. * nis/nss_nisplus/nisplus-service.c (_nss_nisplus_parse_servent): Likewise. (_nss_create_tablename): Likewise. * nis/nss_nisplus/nisplus-spwd.c (_nss_create_tablename): Likewise. * libc.map: Export __stpcpy and __strdup. 1997-09-09 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * math/Makefile (CFLAGS-test-float.c, CFLAGS-test-double.c, CFLAGS-test-ldouble.c): Pass -ffloat-store to avoid excessive precision. 1997-09-09 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * include/rpc/auth_des.h: New file. 1997-09-09 Paul Eggert <eggert@twinsun.com> * time/mktime.c (__mktime_internal): Declare sec_requested even if !LEAP_SECONDS_POSSIBLE, since it's needed at the end when checking for time_t overflow. 1997-09-09 22:11 Ulrich Drepper <drepper@cygnus.com> * sysdeps/posix/getcwd.c: Correct test for too small buffer. Reported by Erik Troan <ewt@redhat.com>. * elf/dl-close.c: Include <bits/libc-lock.h>, not <libc-lock.h>. * elf/dl-open.c: Likewise. 1997-09-07 17:09 Richard Henderson <rth@cygnus.com> * sysdeps/alpha/Makefile: Kill setjmp_aux. * sysdeps/alpha/bits/setjmp.h: Rewrite in terms of an array. * sysdeps/alpha/__longjmp.c: Remove. * sysdeps/alpha/setjmp_aux.c: Remove. * sysdeps/alpha/__longjmp.S: New file. * sysdeps/alpha/bsd-_setjmp.S: Stub out. * sysdeps/alpha/bsd-setjmp.S: Likewise. * sysdeps/alpha/setjmp.S: Do the work; don't call __setjmp_aux. Move _setjmp and setjmp from bsd-*.S. 1997-09-06 20:20 Ulrich Drepper <drepper@cygnus.com> * include/rpc/auth.h: New file. * include/rpc/auth_unix.h: New file. 1997-09-06 Paul Eggert <eggert@twinsun.com> Fix gmtime so that it reports leap seconds when TZ indicates that leap seconds are desired. * time/gmtime.c (<stddef.h>): Remove unnecessary include. (gmtime): Put after gmtime_r, to help the compiler inline. (__tz_convert): New decl. (gmtime_r): Use __tz_convert instead of __offtime, so that leap seconds are handled correctly. * time/localtime.c (<errno.h>, <libc-lock.h>): Remove includes that are now unnecessary. (__tzset_internal, __tz_compute, __tzfile_compute, __use_tzfile, __tzset_lock): Remove extern decls that are now unnecessary. (localtime_internal): Moved to __tz_convert in tzset.c. so that localtime and gmtime can both use it easily. (localtime): Put after localtime_r, to help the compiler inline. (localtime_r): Use __tz_convert instead of localtime_internal. * time/strftime.c (__tz_compute): Remove unused (and now incorrect) decl. * time/tzfile.c (__tzfile_compute): New arg USE_LOCALTIME. * time/tzset.c (<errno.h>): Include. (_tmbuf): New decl. (__tzfile_compute): New function. (tz_compute): Renamed from __tz_compute. No longer extern. Remove redundant call to tzset_internal. (tzset_internal): Renamed from __tzset_internal. No longer extern. (tzset_lock): Renamed from __tzset_lock. No longer extern. (__tz_convert): New function, containing functionality of old localtime_internal function, plus locking and optional UTC. 1997-09-06 Paul Eggert <eggert@twinsun.com> * time/tzfile.c (__tzfile_read): Don't read a file if TZ is the empty string, just use UTC without leap seconds. This is for compatibility with the Olson code. 1997-09-06 Paul Eggert <eggert@twinsun.com> * time/tzset.c (__tzname_max): Lock tz data structures before invoking tzset_internal. * time/tzfile.c: Define compute_tzname_max statically. 1997-09-07 10:57 Thorsten Kukuk <kukuk@vt.uni-paderborn.de> * nis/nis_call.c: Remove not longer necessary HAVE_SECURE_RPC ifdefs. * nis/nis_intern.h: Likewise. * nis/nss_nis/nis-publickey.c: Likewise. * nis/nss_nisplus/nisplus-publickey.c: Likewise. * nis/ypclnt.c: Likewise. * sunrpc/auth_des.c: Don't dereference NULL pointer, initialize ad->ad_timediff. * sunrpc/auth_none.c: Don't define our own prototypes, use the one from the header files. * sunrpc/auth_unix.c: Likewise. * sunrpc/clnt_raw.c: Likewise. * sunrpc/clnt_tcp.c: Likewise. * sunrpc/rpc_cmsg.c: Likewise. * sunrpc/key_call.c: Fix signal handling. * sunrpc/openchild.c: Don't use /bin/sh to start /usr/etc/keyenvoy, or we will get a deadlock with NIS+. * sunrpc/rpc/auth.h: Add prototype for xdr_opaque_auth, don't define HAVE_SECURE_RPC. 1997-09-07 15:51 Ulrich Drepper <drepper@cygnus.com> * sysdeps/i386/bits/select.h [__GNUC__] (__FD_ZERO, __FD_SET, __FD_CLR, __FD_ISSET): Use correct casts to address array correctly. Reported by urbanw@cs.umu.se. 1997-09-07 05:07 Ulrich Drepper <drepper@cygnus.com> * elf/dl-close.c: Include <bits/libc-lock.h>, not <libc-lock.h>. * elf/dl-open.c: Likewise. * sysdeps/i386/memset.c: Undefine memset in case the header with the optimized functions is included. Patches by NIIBE Yutaka <gniibe@mri.co.jp>. * sysdeps/i386/bits/string.h [__PIC__] (strcspn, strspn, strpbrk, strsep): Use register for second parameter. * sysdeps/i386/i486/bits/string.h: Likewise. Reported by NIIBE Yutaka <gniibe@mri.co.jp>. 1997-09-03 09:48 Geoff Keating <geoffk@ozemail.com.au> * math/libm-test.c: Change various tolerances to match what the tested routines can actually provide. * math/Makefile: Add new tests. * math/atest-sincos.c: New file. * math/atest-exp.c: New file. * csu/Makefile: Give initfini.s and initfiniS.s their own CFLAGS-* macros so they can be overridden. * sysdeps/powerpc/Makefile [subdir=csu]: Override flags for initfiniS.s to use -fpic instead of -fPIC, because the sed script breaks otherwise. * sysdeps/powerpc/Makefile [build-shared]: Use -fpic not -fPIC for efficiency. * sysdeps/powerpc/dl-machine.h (ELF_MACHINE_RUNTIME_TRAMPOLINE): Don't use register 0, to let _mcount be in a shared object. * sysdeps/powerpc/dl-machine.h: Use full sentences in comments. Generally clean up. Suppress some code we don't need when relocating ld.so. * sysdeps/powerpc/test-arith.c: Change loop indices to size_t when appropriate to suppress gcc warning. * resolv/res_send.c: Suppress warning. * sunrpc/xdr_sizeof.c: Suppress warning. * FAQ: Add ppc-linux. * manual/maint.texi: Add ppc-linux. Explain that gcc can't build it yet. * sysdeps/unix/sysv/linux/powerpc/profil-counter.h: Correct for current kernels. 1997-08-15 07:45 Geoff Keating <geoffk@ozemail.com.au> * stdlib/fmtmsg.c: Use two parameters for __libc_once_define. * sysdeps/i386/machine-gmon.h: Correct typo. * sysdeps/unix/sysv/linux/powerpc/bits/mman.h: Change to match kernel. * sysdeps/generic/dl-sysdep.c: Add hook for bizzare PPC argument hack. * sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c: Rewrite to use sysdeps/linux/dl-sysdep.c. * sysdeps/powerpc/Makefile [subdir=gmon]: Compile ppc-mcount. * sysdeps/powerpc/machine-gmon.h: Use ppc-mcount. * sysdeps/powerpc/ppc-mcount: New file. The following are mostly changes to allow profiling: * sysdeps/powerpc/add_n.S: Added. * sysdeps/powerpc/add_n.s: Removed. * sysdeps/powerpc/addmul_1.S: Added. * sysdeps/powerpc/addmul_1.s: Removed. * sysdeps/powerpc/bsd-_setjmp.S: Use JUMPTARGET macro. * sysdeps/powerpc/bsd-setjmp.S: Use JUMPTARGET macro. * sysdeps/powerpc/lshift.S: Added. * sysdeps/powerpc/lshift.s: Removed. * sysdeps/powerpc/memset.S: Added. * sysdeps/powerpc/memset.s: Removed. * sysdeps/powerpc/mul_1.S: Added. * sysdeps/powerpc/mul_1.s: Removed. * sysdeps/powerpc/rshift.S: Added. * sysdeps/powerpc/rshift.s: Removed. * sysdeps/powerpc/s_copysign.S: Use ENTRY, END, weak_alias macros. * sysdeps/powerpc/s_fabs.S: Use ENTRY, END, weak_alias macros. * sysdeps/powerpc/setjmp.S: Use JUMPTARGET macro. * sysdeps/powerpc/strchr.S: Added. * sysdeps/powerpc/strchr.s: Removed. * sysdeps/powerpc/strcmp.S: Added. * sysdeps/powerpc/strcmp.s: Removed. * sysdeps/powerpc/strlen.S: Added. * sysdeps/powerpc/strlen.s: Removed. * sysdeps/powerpc/sub_n.S: Added. * sysdeps/powerpc/sub_n.s: Removed. * sysdeps/powerpc/submul_1.S: Added. * sysdeps/powerpc/submul_1.s: Removed. * sysdeps/unix/sysv/linux/powerpc/_exit.S: Removed. * sysdeps/unix/sysv/linux/powerpc/brk.S: Added. * sysdeps/unix/sysv/linux/powerpc/brk.c: Removed. * sysdeps/unix/sysv/linux/powerpc/clone.S: Use new macros. Fix various bugs. Document that it isn't tested. * sysdeps/unix/sysv/linux/powerpc/sigreturn.S: Make look like sysdeps/unix/_exit.S. * sysdeps/unix/sysv/linux/powerpc/socket.S: Use new macros. * sysdeps/unix/sysv/linux/powerpc/syscall.S: Use new macros. * sysdeps/unix/sysv/linux/powerpc/sysdep.h: Define some new macros to make assembler (possibly) more portable, allow profiling, etc.
Diffstat (limited to 'sysdeps/powerpc/strlen.S')
-rw-r--r-- | sysdeps/powerpc/strlen.S | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/sysdeps/powerpc/strlen.S b/sysdeps/powerpc/strlen.S new file mode 100644 index 0000000000..dc6660b8fc --- /dev/null +++ b/sysdeps/powerpc/strlen.S @@ -0,0 +1,144 @@ +/* Optimized strlen implementation for PowerPC. + Copyright (C) 1997 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 + 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> + +/* The algorithm here uses the following techniques: + + 1) Given a word 'x', we can test to see if it contains any 0 bytes + by subtracting 0x01010101, and seeing if any of the high bits of each + byte changed from 0 to 1. This works because the least significant + 0 byte must have had no incoming carry (otherwise it's not the least + significant), so it is 0x00 - 0x01 == 0xff. For all other + byte values, either they have the high bit set initially, or when + 1 is subtracted you get a value in the range 0x00-0x7f, none of which + have their high bit set. The expression here is + (x + 0xfefefeff) & ~(x | 0x7f7f7f7f), which gives 0x00000000 when + there were no 0x00 bytes in the word. + + 2) Given a word 'x', we can test to see _which_ byte was zero by + calculating ~(((x & 0x7f7f7f7f) + 0x7f7f7f7f) | x | 0x7f7f7f7f). + This produces 0x80 in each byte that was zero, and 0x00 in all + the other bytes. The '| 0x7f7f7f7f' clears the low 7 bits in each + byte, and the '| x' part ensures that bytes with the high bit set + produce 0x00. The addition will carry into the high bit of each byte + iff that byte had one of its low 7 bits set. We can then just see + which was the most significant bit set and divide by 8 to find how + many to add to the index. + This is from the book 'The PowerPC Compiler Writer's Guide', + by Steve Hoxey, Faraydon Karim, Bill Hay and Hank Warren. + + We deal with strings not aligned to a word boundary by taking the + first word and ensuring that bytes not part of the string + are treated as nonzero. To allow for memory latency, we unroll the + loop a few times, being careful to ensure that we do not read ahead + across cache line boundaries. + + Questions to answer: + 1) How long are strings passed to strlen? If they're often really long, + we should probably use cache management instructions and/or unroll the + loop more. If they're often quite short, it might be better to use + fact (2) in the inner loop than have to recalculate it. + 2) How popular are bytes with the high bit set? If they are very rare, + on some processors it might be useful to use the simpler expression + ~((x - 0x01010101) | 0x7f7f7f7f) (that is, on processors with only one + ALU), but this fails when any character has its high bit set. */ + +/* Some notes on register usage: Under the SVR4 ABI, we can use registers + 0 and 3 through 12 (so long as we don't call any procedures) without + saving them. We can also use registers 14 through 31 if we save them. + We can't use r1 (it's the stack pointer), r2 nor r13 because the user + program may expect them to hold their usual value if we get sent + a signal. Integer parameters are passed in r3 through r10. + We can use condition registers cr0, cr1, cr5, cr6, and cr7 without saving + them, the others we must save. */ + +ENTRY(strlen) +/* On entry, r3 points to the string, and it's left that way. + We use r6 to store 0xfefefeff, and r7 to store 0x7f7f7f7f. + r4 is used to keep the current index into the string; r5 holds + the number of padding bits we prepend to the string to make it + start at a word boundary. r8 holds the 'current' word. + r9-12 are temporaries. r0 is used as a temporary and for discarded + results. */ + clrrwi %r4,%r3,2 + lis %r7,0x7f7f + rlwinm %r5,%r3,3,27,28 + lwz %r8,0(%r4) + li %r9,-1 + addi %r7,%r7,0x7f7f +/* That's the setup done, now do the first pair of words. + We make an exception and use method (2) on the first two words, to reduce + overhead. */ + srw %r9,%r9,%r5 + and %r0,%r7,%r8 + or %r10,%r7,%r8 + add %r0,%r0,%r7 + nor %r0,%r10,%r0 + and. %r8,%r0,%r9 + mtcrf 0x01,%r3 + bne L(done0) + lis %r6,0xfeff + addi %r6,%r6,-0x101 +/* Are we now aligned to a doubleword boundary? */ + bt 29,L(loop) + +/* Handle second word of pair. */ + lwzu %r8,4(%r4) + and %r0,%r7,%r8 + or %r10,%r7,%r8 + add %r0,%r0,%r7 + nor. %r8,%r10,%r0 + bne L(done0) + +/* The loop. */ + +L(loop): + lwz %r8,4(%r4) + lwzu %r9,8(%r4) + add %r0,%r6,%r8 + nor %r10,%r7,%r8 + and. %r0,%r0,%r10 + add %r11,%r6,%r9 + nor %r12,%r7,%r9 + bne L(done1) + and. %r0,%r11,%r12 + beq L(loop) + + and %r0,%r7,%r9 + add %r0,%r0,%r7 + andc %r8,%r12,%r0 + b L(done0) + +L(done1): + and %r0,%r7,%r8 + subi %r4,%r4,4 + add %r0,%r0,%r7 + andc %r8,%r10,%r0 + +/* When we get to here, r4 points to the first word in the string that + contains a zero byte, and the most significant set bit in r8 is in that + byte. */ +L(done0): + cntlzw %r11,%r8 + subf %r0,%r3,%r4 + srwi %r11,%r11,3 + add %r3,%r0,%r11 + blr +END(strlen) |