projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 798f5b4b | 1 | /* Vector optimized 32/64 bit S/390 version of memrchr. |
| f7a9f785 | 2 | Copyright (C) 2015-2016 Free Software Foundation, Inc. |
| 798f5b4b SL |
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 | <http://www.gnu.org/licenses/>. */ | |
| 18 | ||
| 19 | #if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) | |
| 20 | ||
| 21 | # include "sysdep.h" | |
| 22 | # include "asm-syntax.h" | |
| 23 | ||
| 24 | .text | |
| 25 | ||
| 26 | /* void *memrchr (const void *s, int c, size_t n) | |
| 27 | Scans memory for character c backwards | |
| 28 | and returns pointer to first c. | |
| 29 | ||
| 30 | Register usage: | |
| 31 | -r0=tmp | |
| 32 | -r1=tmp | |
| 33 | -r2=s | |
| 34 | -r3=c | |
| 35 | -r4=n | |
| 36 | -r5=s in loop | |
| 37 | ||
| 38 | -v16=part of s | |
| 39 | -v17=index of found c | |
| 40 | -v18=c replicated | |
| 41 | -v20=permute pattern | |
| 42 | */ | |
| 43 | ENTRY(__memrchr_vx) | |
| 44 | .machine "z13" | |
| 45 | .machinemode "zarch_nohighgprs" | |
| 46 | ||
| 47 | # if !defined __s390x__ | |
| 48 | llgfr %r4,%r4 | |
| 49 | # endif /* !defined __s390x__ */ | |
| 50 | clgije %r4,0,.Lnot_found | |
| 51 | ||
| 52 | vlvgb %v18,%r3,0 /* Generate vector which elements are all c. | |
| 53 | If c > 255, c will be truncated. */ | |
| 54 | vrepb %v18,%v18,0 | |
| 55 | ||
| 56 | llcr %r3,%r3 /* char c_char = (char) c. */ | |
| 57 | ||
| 58 | /* check byte n - 1. */ | |
| 59 | llc %r0,-1(%r4,%r2) | |
| 60 | slgfi %r4,1 | |
| 61 | clrje %r0,%r3,.Lfound_end | |
| 62 | jh .Lnot_found /* Return NULL if n is now 0. */ | |
| 63 | ||
| 64 | larl %r1,.Lpermute_mask /* Load permute mask. */ | |
| 65 | vl %v20,0(%r1) | |
| 66 | ||
| 67 | /* check byte n - 2. */ | |
| 68 | llc %r0,-1(%r4,%r2) | |
| 69 | slgfi %r4,1 | |
| 70 | clrje %r0,%r3,.Lfound_end | |
| 71 | jh .Lnot_found /* Return NULL if n is now 0. */ | |
| 72 | ||
| 73 | clgijhe %r4,64,.Lloop64 /* If n >= 64 -> loop64. */ | |
| 74 | ||
| 75 | .Llt64: | |
| 76 | /* Process n < 64 bytes. */ | |
| 77 | clgijl %r4,16,.Llt16 /* Jump away if n < 16. */ | |
| 78 | aghi %r4,-16 | |
| 79 | vl %v16,0(%r4,%r2) | |
| 80 | vfeebs %v17,%v16,%v18 | |
| 81 | jno .Lfound0 | |
| 82 | clgijl %r4,16,.Llt16 | |
| 83 | aghi %r4,-16 | |
| 84 | vl %v16,0(%r4,%r2) | |
| 85 | vfeebs %v17,%v16,%v18 | |
| 86 | jno .Lfound0 | |
| 87 | clgijl %r4,16,.Llt16 | |
| 88 | aghi %r4,-16 | |
| 89 | vl %v16,0(%r4,%r2) | |
| 90 | vfeebs %v17,%v16,%v18 | |
| 91 | jno .Lfound0 | |
| 92 | .Llt16: | |
| 93 | clgfi %r4,0 /* if remaining bytes == 0, return NULL. */ | |
| 94 | locghie %r2,0 | |
| 95 | ber %r14 | |
| 96 | ||
| 97 | aghi %r4,-1 /* vll needs highest index. */ | |
| 98 | vll %v16,%r4,0(%r2) /* Load remaining bytes. */ | |
| 99 | ||
| 100 | /* Right-shift of v16 to mask bytes after highest index. */ | |
| 101 | lhi %r0,15 | |
| 102 | slr %r0,%r4 /* Compute byte count for vector shift right. */ | |
| 103 | sll %r0,3 /* Convert to bit count. */ | |
| 104 | vlvgb %v17,%r0,7 | |
| 105 | vsrlb %v16,%v16,%v17 /* Vector shift right by byte by number of bytes | |
| 106 | specified in bits 1-4 of byte 7 in v17. */ | |
| 107 | j .Lfound_permute | |
| 108 | ||
| 109 | .Lfound48: | |
| 110 | aghi %r4,16 | |
| 111 | .Lfound32: | |
| 112 | aghi %r4,16 | |
| 113 | .Lfound16: | |
| 114 | aghi %r4,16 | |
| 115 | .Lfound0: | |
| 116 | la %r2,0(%r4,%r2) /* Set pointer to start of v16. */ | |
| 117 | lghi %r4,15 /* Set highest index in v16 to last index. */ | |
| 118 | .Lfound_permute: | |
| 119 | /* Search for a c in v16 in reversed byte order. v16 contains %r4 + 1 | |
| 120 | bytes. If v16 was not fully loaded, the bytes are already | |
| 121 | right shifted, so that the bytes in v16 can simply be reversed. */ | |
| 122 | vperm %v16,%v16,%v16,%v20 /* Permute v16 to reversed order. */ | |
| 123 | vfeeb %v16,%v16,%v18 /* Find c in reversed v16. */ | |
| 124 | vlgvb %r1,%v16,7 /* Index of c or 16 if not found. */ | |
| 125 | ||
| 126 | /* Return NULL if there is no c in loaded bytes. */ | |
| 127 | clrjh %r1,%r4,.Lnot_found | |
| 128 | ||
| 129 | slgr %r4,%r1 | |
| 130 | .Lfound_end: | |
| 131 | la %r2,0(%r4,%r2) /* Return pointer to c. */ | |
| 132 | br %r14 | |
| 133 | ||
| 134 | .Lnot_found: | |
| 135 | lghi %r2,0 | |
| 136 | br %r14 | |
| 137 | ||
| 138 | .Lpermute_mask: | |
| 139 | .byte 0x0F,0x0E,0x0D,0x0C,0x0B,0x0A,0x09,0x08 | |
| 140 | .byte 0x07,0x06,0x05,0x04,0x03,0x02,0x01,0x00 | |
| 141 | ||
| 142 | .Lloop64: | |
| 143 | aghi %r4,-64 | |
| 144 | vl %v16,48(%r4,%r2) /* Load 16bytes of memory area. */ | |
| 145 | vfeebs %v17,%v16,%v18 /* Find c. */ | |
| 146 | jno .Lfound48 /* Jump away if c was found. */ | |
| 147 | vl %v16,32(%r4,%r2) | |
| 148 | vfeebs %v17,%v16,%v18 | |
| 149 | jno .Lfound32 | |
| 150 | vl %v16,16(%r4,%r2) | |
| 151 | vfeebs %v17,%v16,%v18 | |
| 152 | jno .Lfound16 | |
| 153 | vl %v16,0(%r4,%r2) | |
| 154 | vfeebs %v17,%v16,%v18 | |
| 155 | jno .Lfound0 | |
| 156 | ||
| 157 | clgijhe %r4,64,.Lloop64 /* If n >= 64 -> loop64. */ | |
| 158 | j .Llt64 | |
| 159 | END(__memrchr_vx) | |
| 160 | #endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */ |