glibc/sysdeps/alpha/strlen.S
Roland McGrath 510ca033d6 Wed May 22 00:40:50 1996 David Mosberger-Tang <davidm@azstarnet.com>
* sysdeps/unix/sysv/linux/alpha/speed.c (speeds): Add entry for
 	460800 baud.

	* sysdeps/unix/sysv/linux/alpha/statbuf.h: New file.

	* sysdeps/unix/sysv/linux/Makefile (headers): Add
 	alpha/ptrace.h.
	* sysdeps/unix/sysv/linux/alpha/alpha/ptrace.h: New file.

	* sysdeps/libm-ieee754/s_scalbnf.c: Call __scalbnf instead of
 	scalbnf.

	* sysdeps/generic/sigset.h (__sigismember, __sigaddset,
 	__sigdelset): Add declaration to keep ANSI compilers quiet.

	* sysdeps/alpha/__math.h (cabs): Remove underscores from struct
 	__cabs_complex member names in call to __hypot().

	* sysdeps/alpha/copysign.S, sysdeps/alpha/fabs.S: New files.

	* sysdeps/alpha/divrem.h: Renamed from sysdeps/alpha/divrem.S to avoid
 	name collision with math library.

	* sysdeps/alpha/divl.S, sysdeps/alpha/divlu.S, sysdeps/alpha/divq.S,
	sysdeps/alpha/divqu.S, sysdeps/alpha/reml.S, sysdeps/alpha/remlu.S,
	sysdeps/alpha/remq.S, sysdeps/alpha/remqu.S: Include divrem.h instead
	of divrem.S.

	* sysdeps/unix/alpha/sysdep.h: Include regdef.h.  Define LEAF macro
	to simplify declaration of leaf functions.

	* sysdeps/alpha/_mcount.S, sysdeps/alpha/bb_init_func.S,
 	sysdeps/alpha/bsd-setjmp.S, sysdeps/alpha/ffs.S,
 	sysdeps/alpha/htonl.S, sysdeps/alpha/htons.S, sysdeps/alpha/memchr.S,
 	sysdeps/alpha/setjmp.S, sysdeps/alpha/strlen.S,
 	sysdeps/alpha/udiv_qrnnd.S, sysdeps/unix/sysv/linux/alpha/brk.S,
 	sysdeps/unix/sysv/linux/alpha/ieee_get_fp_control.S,
 	sysdeps/unix/sysv/linux/alpha/ieee_set_fp_control.S,
 	sysdeps/unix/sysv/linux/alpha/pipe.S,
 	sysdeps/unix/sysv/linux/sigsuspend.S,
 	sysdeps/unix/sysv/linux/alpha/syscall.S,
 	sysdeps/unix/sysv/linux/alpha/sysdep.S: Remove include of regdef.h.
  	sysdep.h includes it now. Replace ENTRY by LEAF with appropriate
 	framesize declaration.  Replace "lda pv,sym/jsr pv" by "jsr sym".

	* sysdeps/unix/sysv/linux/alpha/sysdep.h (NO_UNDERSCORES): Don't
	define.

	* sysdeps/unix/sysv/linux/alpha/syscalls.list: Added getsockopt,
	ptrace, and sysctl.

	* sysdeps/unix/sysv/linux/alpha/profil-counter.h: File removed.

	* sysdeps/unix/sysv/linux/alpha/ioperm.c: Modify to support
 	dynamic recognition of platform type.
	(_bus_base): New function.

	* sysdeps/unix/sysv/linux/alpha/llseek.S: New file.

	* sunrpc/rpc/rpc.h, sunrpc/rpc/svc.h: Avoid nested comments since
 	they produce ugly warnings by gcc.

	* posix/sys/types.h [__USE_MISC]: Add typedef for ulong.

Wed Mar 27 10:26:21 1996  David Mosberger-Tang  <davidm@azstarnet.com>

	* sysdeps/alpha/setjmp.S: Must establish global pointer before
 	address of __sigsetjmp_aux can be loaded.
1996-05-23 05:33:49 +00:00

71 lines
2.2 KiB
ArmAsm

/* Copyright (C) 1996 Free Software Foundation, Inc.
Contributed by David Mosberger (davidm@cs.arizona.edu).
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., 675 Mass Ave,
Cambridge, MA 02139, USA. */
/* Finds length of a 0-terminated string. Optimized for the Alpha
architecture:
- memory accessed as aligned quadwords only
- uses bcmpge to compare 8 bytes in parallel
- does binary search to find 0 byte in last
quadword (HAKMEM needed 12 instructions to
do this instead of the 9 instructions that
binary search needs). */
#include <sysdep.h>
.set noreorder
.set noat
ENTRY(strlen)
ldq_u t0, 0(a0) # load first quadword (a0 may be misaligned)
lda t1, -1(zero)
insqh t1, a0, t1
andnot a0, 7, v0
or t1, t0, t0
cmpbge zero, t0, t1 # t1 <- bitmask: bit i == 1 <==> i-th byte == 0
bne t1, found
loop: ldq t0, 8(v0)
addq v0, 8, v0 # addr += 8
nop # helps dual issue last two insns
cmpbge zero, t0, t1
beq t1, loop
found: blbs t1, done # make aligned case fast
negq t1, t2
and t1, t2, t1
and t1, 0x0f, t0
addq v0, 4, t2
cmoveq t0, t2, v0
and t1, 0x33, t0
addq v0, 2, t2
cmoveq t0, t2, v0
and t1, 0x55, t0
addq v0, 1, t2
cmoveq t0, t2, v0
done: subq v0, a0, v0
ret
.end strlen