about summary refs log tree commit diff
path: root/sysdeps/s390/multiarch/wmemcmp-vx.S
blob: e2fc21e4192b0dd81a55ebc0e3f122223926c616 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/* Vector Optimized 32/64 bit S/390 version of wmemcmp.
   Copyright (C) 2015-2018 Free Software Foundation, Inc.
   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/>.  */

#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)

# include "sysdep.h"
# include "asm-syntax.h"

	.text

/* int wmemcmp (const wchar_t *s1, const wchar_t *s2, size_t n)
   Compare at most n characters of two wchar_t-arrays.

   Register usage:
   -r0=tmp
   -r1=number of blocks
   -r2=s1
   -r3=s2
   -r4=n
   -r5=current_len
   -v16=part of s1
   -v17=part of s2
   -v18=index of unequal
*/
ENTRY(__wmemcmp_vx)
	.machine "z13"
	.machinemode "zarch_nohighgprs"

# if !defined __s390x__
	llgfr	%r4,%r4
# endif /* !defined __s390x__ */
	clgije	%r4,0,.Lend_equal /* Nothing to do if n == 0.  */

	/* Check range of maxlen and convert to byte-count.  */
# ifdef __s390x__
	tmhh	%r4,49152	/* Test bit 0 or 1 of maxlen.  */
	lghi	%r1,-4		/* Max byte-count is 18446744073709551612.  */
# else
	tmlh	%r4,49152	/* Test bit 0 or 1 of maxlen.  */
	llilf	%r1,4294967292	/* Max byte-count is 4294967292.  */
# endif /* !__s390x__ */
	sllg	%r4,%r4,2	/* Convert character-count to byte-count.  */
	locgrne	%r4,%r1		/* Use max byte-count, if bit 0/1 was one.  */

	lghi	%r5,0		/* current_len = 0.  */

	clgijh	%r4,16,.Lgt16

.Lremaining:
	aghi	%r4,-1		/* vstl needs highest index.  */
	vll	%v16,%r4,0(%r2)
	vll	%v17,%r4,0(%r3)
	vfenef	%v18,%v16,%v17	/* Compare not equal.  */
	vlgvb	%r1,%v18,7	/* Load unequal index or 16 if not found.  */
	clrj	%r1,%r4,12,.Lfound2 /* r1 <= r4 -> unequal within loaded
					bytes.  */

.Lend_equal:
	lghi	%r2,0
	br	%r14

.Lfound:
	/* vfenezf found an unequal element or zero.
	   This instruction compares unsigned words, but wchar_t is signed.
	   Thus we have to compare the found element again.  */
	vlgvb	%r1,%v18,7	/* Extract not equal byte-index.  */
.Lfound2:
	srl	%r1,2		/* And convert it to character-index.  */
	vlgvf	%r0,%v16,0(%r1)	/* Load character-values.  */
	vlgvf	%r1,%v17,0(%r1)
	cr	%r0,%r1
	je	.Lend_equal
	lghi	%r2,1
	lghi	%r1,-1
	locgrl	%r2,%r1
	br	%r14

.Lgt16:
	clgijh	%r4,64,.Lpreloop64

.Lpreloop16:
	srlg	%r1,%r4,4	/* Split into 16byte blocks */
.Lloop16:
	vl	%v16,0(%r5,%r2)
	vl	%v17,0(%r5,%r3)
	aghi	%r5,16
	vfenefs	%v18,%v16,%v17	/* Compare not equal.  */
	jno	.Lfound
	brctg	%r1,.Lloop16	/* Loop until all blocks are processed.  */

	llgfr	%r4,%r4
	nilf	%r4,15		/* Get remaining bytes */
	locgre	%r2,%r4
	ber	%r14
	la	%r2,0(%r5,%r2)
	la	%r3,0(%r5,%r3)
	j	.Lremaining

.Lpreloop64:
	srlg	%r1,%r4,6	/* Split into 64byte blocks */
.Lloop64:
	vl	%v16,0(%r5,%r2)
	vl	%v17,0(%r5,%r3)
	vfenefs	%v18,%v16,%v17	/* Compare not equal.  */
	jno	.Lfound

	vl	%v16,16(%r5,%r2)
	vl	%v17,16(%r5,%r3)
	vfenefs	%v18,%v16,%v17
	jno	.Lfound

	vl	%v16,32(%r5,%r2)
	vl	%v17,32(%r5,%r3)
	vfenefs	%v18,%v16,%v17
	jno	.Lfound

	vl	%v16,48(%r5,%r2)
	vl	%v17,48(%r5,%r3)
	aghi	%r5,64
	vfenefs	%v18,%v16,%v17
	jno	.Lfound

	brctg	%r1,.Lloop64	/* Loop until all blocks are processed.  */

	llgfr	%r4,%r4
	nilf	%r4,63		/* Get remaining bytes */
	locgre	%r2,%r4
	ber	%r14
	clgijh	%r4,16,.Lpreloop16
	la	%r2,0(%r5,%r2)
	la	%r3,0(%r5,%r3)
	j	.Lremaining
END(__wmemcmp_vx)
#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */