glibc/sysdeps/alpha/ffs.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

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1.8 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 the first bit set in an integer. Optimized for the Alpha
architecture. */
#include <sysdep.h>
.set noreorder
.set noat
ENTRY(ffs)
.prologue 0
ldq_u zero, 0(sp) # on the 21064, this helps dual-issuing
addl a0, zero, a0 # the last insn and reduces the stall
negq a0, t0 # due to the srl instruction
and a0, t0, t0
clr v0
beq a0, done
# now do binary search for first non-zero bit
zapnot t0, 0x03, t2
addq v0, 16, t3
cmoveq t2, t3, v0
zapnot t0, 0x05, t2
addq v0, 8, t3
cmoveq t2, t3, v0
srl t0, v0, t0
addq v0, 1, v0
and t0, 0x0f, t2
addq v0, 4, t3
cmoveq t2, t3, v0
and t0, 0x33, t2
addq v0, 2, t3
cmoveq t2, t3, v0
and t0, 0x55, t2
addq v0, 1, t3
cmoveq t2, t3, v0
done: ret
.end ffs