[thirdparty/glibc.git] / sysdeps / alpha / alphaev67 / strrchr.S

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

/* Return the address of the last occurrence 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(strrchr)
#ifdef PROF
	ldgp	gp, 0(pv)
	lda	AT, _mcount
	jsr	AT, (AT), _mcount
	.prologue 1
#else
	.prologue 0
#endif

	and	a1, 0xff, t2	# E : 00000000000000ch
	insbl	a1, 1, t4	# U : 000000000000ch00
	insbl	a1, 2, t5	# U : 0000000000ch0000
	ldq_u   t0, 0(a0)	# L : load first quadword Latency=3

	mov	zero, t6	# E : t6 is last match aligned addr
	or	t2, t4, a1	# E : 000000000000chch
	sll	t5, 8, t3	# U : 00000000ch000000
	mov	zero, t8	# E : t8 is last match byte compare mask

	andnot  a0, 7, v0	# E : align source addr
	or	t5, t3, t3	# E : 00000000chch0000
	sll	a1, 32, t2	# U : 0000chch00000000
	sll	a1, 48, t4	# U : chch000000000000

	or	t4, a1, a1	# E : chch00000000chch
	or	t2, t3, t2	# E : 0000chchchch0000
	or	a1, t2, a1	# E : chchchchchchchch
	lda	t5, -1		# E : build garbage mask

	cmpbge  zero, t0, t1	# E : bits set iff byte == zero
	mskqh	t5, a0, t4	# E : Complete garbage mask
	xor	t0, a1, t2	# E : make bytes == c zero
	cmpbge	zero, t4, t4	# E : bits set iff byte is garbage

	cmpbge  zero, t2, t3	# E : bits set iff byte == c
	andnot	t1, t4, t1	# E : clear garbage from null test
	andnot	t3, t4, t3	# E : clear garbage from char test
	bne	t1, $eos	# U : did we already hit the terminator?

	/* Character search main loop */
$loop:
	ldq	t0, 8(v0)	# L : load next quadword
	cmovne	t3, v0, t6	# E : save previous comparisons match
	nop			#   : Latency=2, extra map slot (keep nop with cmov)
	nop

	cmovne	t3, t3, t8	# E : Latency=2, extra map slot
	nop			#   : keep with cmovne
	addq	v0, 8, v0	# E :
	xor	t0, a1, t2	# E :

	cmpbge	zero, t0, t1	# E : bits set iff byte == zero
	cmpbge	zero, t2, t3	# E : bits set iff byte == c
	beq	t1, $loop	# U : if we havnt seen a null, loop
	nop

	/* Mask out character matches after terminator */
$eos:
	negq	t1, t4		# E : isolate first null byte match
	and	t1, t4, t4	# E :
	subq	t4, 1, t5	# E : build a mask of the bytes upto...
	or	t4, t5, t4	# E : ... and including the null

	and	t3, t4, t3	# E : mask out char matches after null
	cmovne	t3, t3, t8	# E : save it, if match found Latency=2, extra map slot
	nop			#   : Keep with cmovne
	nop

	cmovne	t3, v0, t6	# E :
	nop			#   : Keep with cmovne
	/* Locate the address of the last matched character */
	ctlz	t8, t2		# U0 : Latency=3 (0x40 for t8=0)
	nop

	cmoveq	t8, 0x3f, t2	# E : Compensate for case when no match is seen
	nop			# E : hide the cmov latency (2) behind ctlz latency
	lda	t5, 0x3f($31)	# E :
	subq	t5, t2, t5	# E : Normalize leading zero count

	addq	t6, t5, v0	# E : and add to quadword address
	ret			# L0 : Latency=3
	nop
	nop

END(strrchr)

weak_alias (strrchr, rindex)
Commit	Line	Data
5f5831be UD	1	/* Copyright (C) 2000 Free Software Foundation, Inc.
	2	EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.com>.
	3
	4	This file is part of the GNU C Library.
	5
	6	The GNU C Library is free software; you can redistribute it and/or
	7	modify it under the terms of the GNU Library General Public License as
	8	published by the Free Software Foundation; either version 2 of the
	9	License, or (at your option) any later version.
	10
	11	The GNU C Library is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	Library General Public License for more details.
	15
	16	You should have received a copy of the GNU Library General Public
	17	License along with the GNU C Library; see the file COPYING.LIB. If not,
	18	write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	19	Boston, MA 02111-1307, USA. */
	20
	21	/* Return the address of the last occurrence of a given character
	22	within a null-terminated string, or null if it is not found. */
	23
	24	#include <sysdep.h>
	25
	26	.arch ev6
	27	.set noreorder
	28	.set noat
	29
	30	ENTRY(strrchr)
	31	#ifdef PROF
	32	ldgp gp, 0(pv)
	33	lda AT, _mcount
	34	jsr AT, (AT), _mcount
	35	.prologue 1
	36	#else
	37	.prologue 0
	38	#endif
	39
	40	and a1, 0xff, t2 # E : 00000000000000ch
	41	insbl a1, 1, t4 # U : 000000000000ch00
	42	insbl a1, 2, t5 # U : 0000000000ch0000
	43	ldq_u t0, 0(a0) # L : load first quadword Latency=3
	44
	45	mov zero, t6 # E : t6 is last match aligned addr
	46	or t2, t4, a1 # E : 000000000000chch
	47	sll t5, 8, t3 # U : 00000000ch000000
	48	mov zero, t8 # E : t8 is last match byte compare mask
	49
	50	andnot a0, 7, v0 # E : align source addr
	51	or t5, t3, t3 # E : 00000000chch0000
	52	sll a1, 32, t2 # U : 0000chch00000000
	53	sll a1, 48, t4 # U : chch000000000000
	54
	55	or t4, a1, a1 # E : chch00000000chch
	56	or t2, t3, t2 # E : 0000chchchch0000
	57	or a1, t2, a1 # E : chchchchchchchch
	58	lda t5, -1 # E : build garbage mask
	59
	60	cmpbge zero, t0, t1 # E : bits set iff byte == zero
	61	mskqh t5, a0, t4 # E : Complete garbage mask
	62	xor t0, a1, t2 # E : make bytes == c zero
	63	cmpbge zero, t4, t4 # E : bits set iff byte is garbage
	64
65	cmpbge zero, t2, t3 # E : bits set iff byte == c
66	andnot t1, t4, t1 # E : clear garbage from null test
67	andnot t3, t4, t3 # E : clear garbage from char test
68	bne t1, $eos # U : did we already hit the terminator?
69
70	/* Character search main loop */
71	$loop:
72	ldq t0, 8(v0) # L : load next quadword
73	cmovne t3, v0, t6 # E : save previous comparisons match
74	nop # : Latency=2, extra map slot (keep nop with cmov)
75	nop
76
77	cmovne t3, t3, t8 # E : Latency=2, extra map slot
78	nop # : keep with cmovne
79	addq v0, 8, v0 # E :
80	xor t0, a1, t2 # E :
81
82	cmpbge zero, t0, t1 # E : bits set iff byte == zero
83	cmpbge zero, t2, t3 # E : bits set iff byte == c
84	beq t1, $loop # U : if we havnt seen a null, loop
85	nop
86
87	/* Mask out character matches after terminator */
88	$eos:
89	negq t1, t4 # E : isolate first null byte match
90	and t1, t4, t4 # E :
91	subq t4, 1, t5 # E : build a mask of the bytes upto...
92	or t4, t5, t4 # E : ... and including the null
93
94	and t3, t4, t3 # E : mask out char matches after null
95	cmovne t3, t3, t8 # E : save it, if match found Latency=2, extra map slot
96	nop # : Keep with cmovne
97	nop
98
99	cmovne t3, v0, t6 # E :
100	nop # : Keep with cmovne
101	/* Locate the address of the last matched character */
102	ctlz t8, t2 # U0 : Latency=3 (0x40 for t8=0)
103	nop
104
105	cmoveq t8, 0x3f, t2 # E : Compensate for case when no match is seen
106	nop # E : hide the cmov latency (2) behind ctlz latency
107	lda t5, 0x3f($31) # E :
108	subq t5, t2, t5 # E : Normalize leading zero count
109
110	addq t6, t5, v0 # E : and add to quadword address
111	ret # L0 : Latency=3
112	nop
113	nop
114
115	END(strrchr)
116
117	weak_alias (strrchr, rindex)