/* Copyright (C) 2000-2018 Free Software Foundation, Inc.

   Contributed by Richard Henderson <rth@tamu.edu>, 1996.

   EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.com>.

   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 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, see

   <http://www.gnu.org/licenses/>.  */

/* Return the address of a given character within a null-terminated

   string, or null if it is not found.  */

#include <sysdep.h>

	.arch ev6

	.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

	ldq_u   t0, 0(a0)	# L : load first quadword Latency=3

	and	a1, 0xff, t3	# E : 00000000000000ch

	insbl	a1, 1, t5	# U : 000000000000ch00

	insbl	a1, 7, a2	# U : ch00000000000000

	insbl	t3, 6, a3	# U : 00ch000000000000

	or	t5, t3, a1	# E : 000000000000chch

	andnot  a0, 7, v0	# E : align our loop pointer

	lda	t4, -1		# E : build garbage mask

	mskqh	t4, a0, t4	# U : only want relevant part of first quad

	or	a2, a3, a2	# E : chch000000000000

	inswl	a1, 2, t5	# E : 00000000chch0000

	inswl	a1, 4, a3	# E : 0000chch00000000

	or	a1, a2, a1	# E : chch00000000chch

	or	a3, t5, t5	# E : 0000chchchch0000

	cmpbge  zero, t0, t2	# E : bits set iff byte == zero

	cmpbge	zero, t4, t4	# E : bits set iff byte is garbage

	/* This quad is _very_ serialized.  Lots of stalling happens */

	or	t5, a1, a1	# E : chchchchchchchch

	xor	t0, a1, t1	# E : make bytes == c zero

	cmpbge  zero, t1, t3	# E : bits set iff byte == c

	or	t2, t3, t0	# E : bits set iff char match or zero match

	andnot	t0, t4, t0	# E : clear garbage bits

	cttz	t0, a2		# U0 : speculative (in case we get a match)

	nop			# E :

	bne	t0, $found	# U :

	/*

	 * Yuk.  This loop is going to stall like crazy waiting for the

	 * data to be loaded.  Not much can be done about it unless it's

	 * unrolled multiple times, which is generally unsafe.

	 */

$loop:

	ldq	t0, 8(v0)	# L : Latency=3

	addq	v0, 8, v0	# E :

	xor	t0, a1, t1	# E :

	cmpbge	zero, t0, t2	# E : bits set iff byte == 0

	cmpbge	zero, t1, t3	# E : bits set iff byte == c

	or	t2, t3, t0	# E :

	cttz	t3, a2		# U0 : speculative (in case we get a match)

	beq	t0, $loop	# U :

$found:

	negq    t0, t1		# E : clear all but least set bit

	and     t0, t1, t0	# E :

	and	t0, t3, t1	# E : bit set iff byte was the char

	addq	v0, a2, v0	# E : Add in the bit number from above

	cmoveq	t1, $31, v0	# E : Two mapping slots, latency = 2

	nop

	nop

	ret			# L0 :

	END(strchr)

weak_alias (strchr, index)

libc_hidden_builtin_def (strchr)