about summary refs log tree commit diff
path: root/sysdeps/s390/multiarch/strncmp-vx.S
blob: ee35d2debf39fe4d052928b31014273cabb170d8 (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
/* Vector optimized 32/64 bit S/390 version of strncmp.
   Copyright (C) 2015-2017 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 strncmp (const char *s1, const char *s2, size_t n)
   Compare at most n characters of two strings.

   Register usage:
   -r0=tmp
   -r1=tmp
   -r2=s1
   -r3=s2
   -r4=n
   -r5=current_len
   -v16=part of s1
   -v17=part of s2
   -v18=index of unequal
*/
ENTRY(__strncmp_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,  */
	lghi	%r5,0		/* current_len = 0.  */

.Lloop:
	vlbb	%v16,0(%r5,%r2),6 /* Load s1 to block boundary.  */
	vlbb	%v17,0(%r5,%r3),6 /* Load s2 to block boundary.  */
	lcbb	%r0,0(%r5,%r2),6 /* Get loaded byte count of s1.  */
	jo	.Llt16_1	/* Jump away if vr is not fully loaded.  */
	lcbb	%r1,0(%r5,%r3),6 /* Get loaded byte count of s2.  */
	jo	.Llt16_2	/* Jump away if vr is not fully loaded.  */
	aghi	%r5,16		/* Both vrs are fully loaded.  */
	clgrjhe	%r5,%r4,.Llastcmp /* If current_len >= n ->last compare.  */
	vfenezbs %v18,%v16,%v17	/* Compare not equal with zero search.  */
	jno	.Lfound

	vlbb	%v16,0(%r5,%r2),6
	vlbb	%v17,0(%r5,%r3),6
	lcbb	%r0,0(%r5,%r2),6
	jo	.Llt16_1
	lcbb	%r1,0(%r5,%r3),6
	jo	.Llt16_2
	aghi	%r5,16
	clgrjhe	%r5,%r4,.Llastcmp
	vfenezbs %v18,%v16,%v17
	jno	.Lfound

	vlbb	%v16,0(%r5,%r2),6
	vlbb	%v17,0(%r5,%r3),6
	lcbb	%r0,0(%r5,%r2),6
	jo	.Llt16_1
	lcbb	%r1,0(%r5,%r3),6
	jo	.Llt16_2
	aghi	%r5,16
	clgrjhe	%r5,%r4,.Llastcmp
	vfenezbs %v18,%v16,%v17
	jno	.Lfound

	vlbb	%v16,0(%r5,%r2),6
	vlbb	%v17,0(%r5,%r3),6
	lcbb	%r0,0(%r5,%r2),6
	jo	.Llt16_1
	lcbb	%r1,0(%r5,%r3),6
	jo	.Llt16_2
	aghi	%r5,16
	clgrjhe	%r5,%r4,.Llastcmp
	vfenezbs %v18,%v16,%v17
	jno	.Lfound
	j	.Lloop

.Llt16_1:
	lcbb	%r1,0(%r5,%r3),6 /* Get loaded byte count ofs2.  */
.Llt16_2:
	clr	%r0,%r1		/* Compare logical.  */
	locrh	%r0,%r1		/* Compute minimum of bytes loaded.  */
	algfr	%r5,%r0		/* Add smallest loaded bytes to current_len.  */
	clgrj	%r5,%r4,10,.Llastcmp /* If current_len >= n ->last compare.  */
	vfenezbs %v18,%v16,%v17	/* Compare not equal with zero search.  */
	vlgvb	%r1,%v18,7	/* Get not equal index or 16 if all equal.  */
	clrjl	%r1,%r0,.Lfound /* Jump away if miscompare is within
				    loaded bytes (index < loaded-bytes) */
	j	.Lloop

.Llastcmp:
	/* Use comparision result only if located within first n characters.
	   %r0: loaded byte count in vreg;
	   %r5: current_len;
	   %r4: n;
	   (current_len - n): [0...16[
	   First ignored match index: loaded bytes - (current_len-n): ]0...16]
	*/
	slgr	%r5,%r4		/* %r5 = current_len - n.  */
	slr	%r0,%r5		/* %r0 = first ignored match index.  */
	vfenezbs %v18,%v16,%v17	/* Compare not equal with zero search.  */
	vlgvb	%r1,%v18,7	/* Get not equal index or 16 if all equal.  */
	clrjl	%r1,%r0,.Lfound /* Jump away if miscompare is within
				    loaded bytes and below n bytes.  */
	j	.Lend_equal	/* Miscompare after n-bytes -> end equal.  */

.Lfound:
	/* Difference or end of string.  */
	je	.Lend_equal
	lghi	%r2,1
	lghi	%r1,-1
	locgrl	%r2,%r1
	br	%r14
.Lend_equal:
	lghi	%r2,0
	br	%r14
END(__strncmp_vx)
#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */