[thirdparty/glibc.git] / sysdeps / alpha / strchr.S

/* Copyright (C) 1996, 2003 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Richard Henderson (rth@tamu.edu)

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

/* Return the address of a given character within a null-terminated
   string, or null if it is not found.

   This is generally scheduled for the EV5 (got to look out for my own
   interests :-), but with EV4 needs in mind.  There *should* be no more
   stalls for the EV4 than there are for the EV5.
*/

#include <sysdep.h>

	.set noreorder
	.set noat

ENTRY(strchr)
#ifdef PROF
	ldgp	gp, 0(pv)
	lda	AT, _mcount
	jsr	AT, (AT), _mcount
	.prologue 1
#else
	.prologue 0
#endif

	zapnot	a1, 1, a1	# e0    : zero extend the search character
	ldq_u   t0, 0(a0)	# .. e1 : load first quadword
	sll	a1, 8, t5	# e0    : replicate the search character
	andnot  a0, 7, v0	# .. e1 : align our loop pointer
	or	t5, a1, a1	# e0    :
	lda	t4, -1		# .. e1 : build garbage mask
	sll	a1, 16, t5	# e0    :
	cmpbge  zero, t0, t2	# .. e1 : bits set iff byte == zero
	mskqh	t4, a0, t4	# e0    :
	or	t5, a1, a1	# .. e1 :
	sll	a1, 32, t5	# e0    :
	cmpbge	zero, t4, t4	# .. e1 : bits set iff byte is garbage
	or	t5, a1, a1	# e0    :
	xor	t0, a1, t1	# .. e1 : make bytes == c zero
	cmpbge  zero, t1, t3	# e0    : bits set iff byte == c
	or	t2, t3, t0	# e1    : bits set iff char match or zero match
	andnot	t0, t4, t0	# e0    : clear garbage bits
	bne	t0, $found	# .. e1 (zdb)

$loop:	ldq	t0, 8(v0)	# e0    :
	addq	v0, 8, v0	# .. e1 :
	nop			# e0    :
	xor	t0, a1, t1	# .. e1 (ev5 data stall)
	cmpbge	zero, t0, t2	# e0    : bits set iff byte == 0
	cmpbge	zero, t1, t3	# .. e1 : bits set iff byte == c
	or	t2, t3, t0	# e0    :
	beq	t0, $loop	# .. e1 (zdb)

$found:	negq    t0, t1		# e0    : clear all but least set bit
	and     t0, t1, t0	# e1 (stall)

	and	t0, t3, t1	# e0    : bit set iff byte was the char
	beq	t1, $retnull	# .. e1 (zdb)

	and     t0, 0xf0, t2	# e0    : binary search for that set bit
	and	t0, 0xcc, t3	# .. e1 :
	and	t0, 0xaa, t4	# e0    :
	cmovne	t2, 4, t2	# .. e1 :
	cmovne	t3, 2, t3	# e0    :
	cmovne	t4, 1, t4	# .. e1 :
	addq	t2, t3, t2	# e0    :
	addq	v0, t4, v0	# .. e1 :
	addq	v0, t2, v0	# e0    :
	ret			# .. e1 :

$retnull:
	mov	zero, v0	# e0    :
	ret			# .. e1 :

	END(strchr)

weak_alias (strchr, index)
libc_hidden_builtin_def (strchr)
Commit	Line	Data
85dd1003	1	/* Copyright (C) 1996, 2003 Free Software Foundation, Inc.
2c6fe0bd	2	This file is part of the GNU C Library.
cccda09f UD	3	Contributed by Richard Henderson (rth@tamu.edu)
cccda09f UD	4
2c6fe0bd	5	The GNU C Library is free software; you can redistribute it and/or
41bdb6e2 AJ	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
cccda09f	9
2c6fe0bd UD	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41bdb6e2	13	Lesser General Public License for more details.
cccda09f	14
41bdb6e2 AJ	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, write to the Free
	17	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	18	02111-1307 USA. */
cccda09f UD	19
cccda09f UD	20	/* Return the address of a given character within a null-terminated
2c6fe0bd	21	string, or null if it is not found.
cccda09f UD	22
	23	This is generally scheduled for the EV5 (got to look out for my own
	24	interests :-), but with EV4 needs in mind. There should be no more
	25	stalls for the EV4 than there are for the EV5.
	26	*/
	27
	28	#include <sysdep.h>
	29
	30	.set noreorder
	31	.set noat
	32
	33	ENTRY(strchr)
2c6fe0bd UD	34	#ifdef PROF
	35	ldgp gp, 0(pv)
	36	lda AT, _mcount
	37	jsr AT, (AT), _mcount
	38	.prologue 1
	39	#else
cccda09f	40	.prologue 0
2c6fe0bd	41	#endif
cccda09f UD	42
	43	zapnot a1, 1, a1 # e0 : zero extend the search character
	44	ldq_u t0, 0(a0) # .. e1 : load first quadword
	45	sll a1, 8, t5 # e0 : replicate the search character
	46	andnot a0, 7, v0 # .. e1 : align our loop pointer
	47	or t5, a1, a1 # e0 :
	48	lda t4, -1 # .. e1 : build garbage mask
	49	sll a1, 16, t5 # e0 :
	50	cmpbge zero, t0, t2 # .. e1 : bits set iff byte == zero
	51	mskqh t4, a0, t4 # e0 :
	52	or t5, a1, a1 # .. e1 :
	53	sll a1, 32, t5 # e0 :
	54	cmpbge zero, t4, t4 # .. e1 : bits set iff byte is garbage
	55	or t5, a1, a1 # e0 :
	56	xor t0, a1, t1 # .. e1 : make bytes == c zero
	57	cmpbge zero, t1, t3 # e0 : bits set iff byte == c
	58	or t2, t3, t0 # e1 : bits set iff char match or zero match
	59	andnot t0, t4, t0 # e0 : clear garbage bits
	60	bne t0, $found # .. e1 (zdb)
	61
	62	$loop: ldq t0, 8(v0) # e0 :
	63	addq v0, 8, v0 # .. e1 :
	64	nop # e0 :
	65	xor t0, a1, t1 # .. e1 (ev5 data stall)
	66	cmpbge zero, t0, t2 # e0 : bits set iff byte == 0
	67	cmpbge zero, t1, t3 # .. e1 : bits set iff byte == c
	68	or t2, t3, t0 # e0 :
	69	beq t0, $loop # .. e1 (zdb)
	70
	71	$found: negq t0, t1 # e0 : clear all but least set bit
	72	and t0, t1, t0 # e1 (stall)
	73
	74	and t0, t3, t1 # e0 : bit set iff byte was the char
	75	beq t1, $retnull # .. e1 (zdb)
	76
	77	and t0, 0xf0, t2 # e0 : binary search for that set bit
	78	and t0, 0xcc, t3 # .. e1 :
	79	and t0, 0xaa, t4 # e0 :
	80	cmovne t2, 4, t2 # .. e1 :
	81	cmovne t3, 2, t3 # e0 :
	82	cmovne t4, 1, t4 # .. e1 :
	83	addq t2, t3, t2 # e0 :
	84	addq v0, t4, v0 # .. e1 :
	85	addq v0, t2, v0 # e0 :
	86	ret # .. e1 :
	87
	88	$retnull:
	89	mov zero, v0 # e0 :
	90	ret # .. e1 :
	91
	92	END(strchr)
	93
	94	weak_alias (strchr, index)
85dd1003	95	libc_hidden_builtin_def (strchr)