1/* Vector optimized 32/64 bit S/390 version of stpcpy.
2 Copyright (C) 2015-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
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.
9
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
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <ifunc-stpcpy.h>
20
21#if HAVE_STPCPY_Z13
22
23# include "sysdep.h"
24# include "asm-syntax.h"
25
26 .text
27
28/* char * stpcpy (const char *dest, const char *src)
29 Copy string src to dest returning a pointer to its end.
30
31 Register usage:
32 -r1=tmp
33 -r2=dest and return value
34 -r3=src
35 -r4=tmp
36 -r5=current_len
37 -v16=part of src
38 -v17=index of zero
39 -v18=part of src
40*/
41ENTRY(STPCPY_Z13)
42 .machine "z13"
43 .machinemode "zarch_nohighgprs"
44
45 vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */
46 lcbb %r1,0(%r3),6 /* Get bytes to 4k-byte boundary or 16. */
47
48 vfenezb %v17,%v16,%v16 /* Find element not equal with zero search. */
49 vlgvb %r5,%v17,7 /* Load zero index or 16 if not found. */
50 clrjl %r5,%r1,.Lfound_align /* If found zero within loaded bytes,
51 copy bytes before and return. */
52
53 /* Align s to 16 byte. */
54 risbgn %r4,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */
55 lghi %r5,15 /* current_len = 15. */
56 slr %r5,%r4 /* Compute highest index to 16byte boundary. */
57
58 vstl %v16,%r5,0(%r2) /* Copy loaded characters - no zero. */
59 ahi %r5,1 /* Start loop at next character. */
60
61 /* Find zero in 16byte aligned loop. */
62.Lloop:
63 vl %v16,0(%r5,%r3) /* Load s. */
64 vfenezbs %v17,%v16,%v16 /* Find element not equal with zero search. */
65 je .Lfound_v16_0 /* Jump away if zero was found. */
66 vl %v18,16(%r5,%r3) /* Load next part of s. */
67 vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */
68 vfenezbs %v17,%v18,%v18
69 je .Lfound_v18_16
70 vl %v16,32(%r5,%r3)
71 vst %v18,16(%r5,%r2)
72 vfenezbs %v17,%v16,%v16
73 je .Lfound_v16_32
74 vl %v18,48(%r5,%r3)
75 vst %v16,32(%r5,%r2)
76 vfenezbs %v17,%v18,%v18
77 je .Lfound_v18_48
78 vst %v18,48(%r5,%r2)
79
80 aghi %r5,64
81 j .Lloop /* No zero found -> loop. */
82
83.Lfound_v16_32:
84 aghi %r5,32
85.Lfound_v16_0:
86 la %r3,0(%r5,%r2)
87 vlgvb %r1,%v17,7 /* Load byte index of zero. */
88 vstl %v16,%r1,0(%r3) /* Copy characters including zero. */
89 la %r2,0(%r1,%r3) /* Return pointer to zero. */
90 br %r14
91
92.Lfound_v18_48:
93 aghi %r5,32
94.Lfound_v18_16:
95 la %r3,16(%r5,%r2)
96 vlgvb %r1,%v17,7 /* Load byte index of zero. */
97 vstl %v18,%r1,0(%r3) /* Copy characters including zero. */
98 la %r2,0(%r1,%r3) /* Return pointer to zero. */
99 br %r14
100
101.Lfound_align:
102 vstl %v16,%r5,0(%r2) /* Copy characters including zero. */
103 la %r2,0(%r5,%r2) /* Return pointer to zero. */
104 br %r14
105END(STPCPY_Z13)
106
107# if ! HAVE_STPCPY_IFUNC
108strong_alias (STPCPY_Z13, __stpcpy)
109weak_alias (__stpcpy, stpcpy)
110# endif
111
112# if ! HAVE_STPCPY_C && defined SHARED && IS_IN (libc)
113strong_alias (STPCPY_Z13, __GI_stpcpy)
114strong_alias (STPCPY_Z13, __GI___stpcpy)
115# endif
116#endif
117

source code of glibc/sysdeps/s390/stpcpy-vx.S