1/* 2 Copyright (c) 2015, Synopsys, Inc. All rights reserved. 3 4 Redistribution and use in source and binary forms, with or without 5 modification, are permitted provided that the following conditions are met: 6 7 1) Redistributions of source code must retain the above copyright notice, 8 this list of conditions and the following disclaimer. 9 10 2) Redistributions in binary form must reproduce the above copyright notice, 11 this list of conditions and the following disclaimer in the documentation 12 and/or other materials provided with the distribution. 13 14 3) Neither the name of the Synopsys, Inc., nor the names of its contributors 15 may be used to endorse or promote products derived from this software 16 without specific prior written permission. 17 18 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 POSSIBILITY OF SUCH DAMAGE. 29*/ 30 31/* This implementation is optimized for performance. For code size a generic 32 implementation of this function from newlib/libc/string/strchr.c will be 33 used. */ 34#if !defined (__OPTIMIZE_SIZE__) && !defined (PREFER_SIZE_OVER_SPEED) 35 36/* ARC700 has a relatively long pipeline and branch prediction, so we want 37 to avoid branches that are hard to predict. On the other hand, the 38 presence of the norm instruction makes it easier to operate on whole 39 words branch-free. */ 40#include "asm.h" 41 42#if (defined (__ARC700__) || defined (__ARCEM__) || defined (__ARCHS__)) \ 43 && defined (__ARC_NORM__) && defined (__ARC_BARREL_SHIFTER__) 44 45ENTRY (strchr) 46 extb_s r1,r1 47 asl r5,r1,8 48 bmsk r2,r0,1 49 or r5,r5,r1 50 mov_s r3,0x01010101 51 breq.d r2,r0,.Laligned 52 asl r4,r5,16 53 sub_s r0,r0,r2 54 asl r7,r2,3 55 ld_s r2,[r0] 56#ifdef __LITTLE_ENDIAN__ 57 asl r7,r3,r7 58#else 59 lsr r7,r3,r7 60#endif 61 or r5,r5,r4 62 ror r4,r3 63 sub r12,r2,r7 64 bic_s r12,r12,r2 65 and r12,r12,r4 66 brne.d r12,0,.Lfound0_ua 67 xor r6,r2,r5 68 ld.a r2,[r0,4] 69 sub r12,r6,r7 70 bic r12,r12,r6 71#ifdef __LITTLE_ENDIAN__ 72 and r7,r12,r4 73 breq r7,0,.Loop ; For speed, we want this branch to be unaligned. 74 b_l .Lfound_char ; Likewise this one. 75#else 76 and r12,r12,r4 77 breq_l r12,0,.Loop ; For speed, we want this branch to be unaligned. 78 lsr_s r12,r12,7 79 bic r2,r7,r6 80 b.d .Lfound_char_b 81 and_s r2,r2,r12 82#endif 83; /* We require this code address to be unaligned for speed... */ 84.Laligned: 85 ld_s r2,[r0] 86 or r5,r5,r4 87 ror r4,r3 88; /* ... so that this code address is aligned, for itself and ... */ 89.Loop: 90 sub r12,r2,r3 91 bic_s r12,r12,r2 92 and r12,r12,r4 93 brne.d r12,0,.Lfound0 94 xor r6,r2,r5 95 ld.a r2,[r0,4] 96 sub r12,r6,r3 97 bic r12,r12,r6 98 and r7,r12,r4 99 breq r7,0,.Loop /* ... so that this branch is unaligned. */ 100 ; Found searched-for character. r0 has already advanced to next word. 101#ifdef __LITTLE_ENDIAN__ 102/* We only need the information about the first matching byte 103 (i.e. the least significant matching byte) to be exact, 104 hence there is no problem with carry effects. */ 105.Lfound_char: 106 sub r3,r7,1 107 bic r3,r3,r7 108 norm r2,r3 109 sub_s r0,r0,1 110 asr_s r2,r2,3 111 j_l.d [blink] 112 sub_s r0,r0,r2 113 114 .balign 4 115.Lfound0_ua: 116 mov_l r3,r7 117.Lfound0: 118 sub r3,r6,r3 119 bic r3,r3,r6 120 and r2,r3,r4 121 or_s r12,r12,r2 122 sub_s r3,r12,1 123 bic_s r3,r3,r12 124 norm r3,r3 125 add_s r0,r0,3 126 asr_s r12,r3,3 127 asl.f 0,r2,r3 128 sub_s r0,r0,r12 129 j_s.d [blink] 130 mov.pl r0,0 131#else /* BIG ENDIAN */ 132.Lfound_char: 133 lsr r7,r7,7 134 135 bic r2,r7,r6 136.Lfound_char_b: 137 norm r2,r2 138 sub_s r0,r0,4 139 asr_s r2,r2,3 140 j_l.d [blink] 141 add_s r0,r0,r2 142 143.Lfound0_ua: 144 mov_s r3,r7 145.Lfound0: 146 asl_s r2,r2,7 147 or r7,r6,r4 148 bic_s r12,r12,r2 149 sub r2,r7,r3 150 or r2,r2,r6 151 bic r12,r2,r12 152 bic.f r3,r4,r12 153 norm r3,r3 154 155 add.pl r3,r3,1 156 asr_s r12,r3,3 157 asl.f 0,r2,r3 158 add_s r0,r0,r12 159 j_s.d [blink] 160 mov.mi r0,0 161#endif /* ENDIAN */ 162ENDFUNC (strchr) 163#endif /* (__ARC700__ || __ARCEM__ || __ARCHS__) && __ARC_NORM__ 164 && __ARC_BARREL_SHIFTER__ */ 165 166#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */ 167
