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/strlen.c will be 33 used. */ 34#if !defined (__OPTIMIZE_SIZE__) && !defined (PREFER_SIZE_OVER_SPEED) 35 36#include "asm.h" 37 38#if defined(__ARC601__) || !defined (__ARC_BARREL_SHIFTER__) 39/* This code is optimized for the ARC601 pipeline without barrel shifter. */ 40 41ENTRY (strlen) 42 or r3,r0,7 43 ld r2,[r3,-7] 44 ld.a r6,[r3,-3] 45 mov r4,0x01010101 46 ; uses long immediate 47#ifdef __LITTLE_ENDIAN__ 48 bmsk.f 0,r0,1 49 mov_s r1,31 50 add3_s r1,r1,r0 51 bmsk r7,r4,r1 52 xor.ne r7,r7,r4 53 btst_s r0,2 54 ror r5,r4 55 sub r1,r2,r7 56 bic_s r1,r1,r2 57 mov.eq r7,r4 58 sub r12,r6,r7 59 bic r12,r12,r6 60 or.eq r12,r12,r1 61 and r12,r12,r5 62 brne r12,0,.Learly_end 63#else /* BIG ENDIAN */ 64 add.f r1,r4,30 ; r1 mod 31 := -1; clear carry 65 ror r5,r4 66 sub3 r7,r1,r0 67 btst_s r0,2 68 sub r1,r2,r4 69 bic_s r1,r1,r2 70 bmsk r1,r1,r7 71 sub r12,r6,r4 72 bic r12,r12,r6 73 bmsk.ne r12,r12,r7 74 or.eq r12,r12,r1 75 and r12,r12,r5 76 brne r12,0,.Learly_end 77#endif /* ENDIAN */ 78 79.Loop: 80 ld_s r2,[r3,4] 81 ld.a r6,[r3,8] 82 ; stall for load result 83 sub r1,r2,r4 84 bic_s r1,r1,r2 85 sub r12,r6,r4 86 bic r12,r12,r6 87 or_s r12,r12,r1 88 and r12,r12,r5 89 breq_s r12,0,.Loop 90.Lend: 91 and.f r1,r1,r5 92 sub.ne r3,r3,4 93#ifdef __LITTLE_ENDIAN__ 94 mov.eq r1,r12 95 btst_s r1,7 96 sub r0,r3,r0 97 add.eq r0,r0,1 98 bmsk.f 0,r1,15 99 add.eq r0,r0,1 100 bmsk.f 0,r1,23 101 j_s.d [blink] 102 add.eq r0,r0,1 103#else /* BIG ENDIAN */ 104#ifdef __OPTIMIZE_SIZE__ 1051: ldb_s r1,[r3] 106 breq_s r1,0,0f 107 ldb.a r1,[r3,1] 108 breq_s r1,0,0f 109 ldb.a r1,[r3,1] 110 breq_s r1,0,0f 111 add_s r3,r3,1 1120: j_s.d [blink] 113 sub r0,r3,r0 114 115#define SPECIAL_EARLY_END 116.Learly_end: 117 mov_s r3,r0 118 b_s 1b 119#elif 0 /* Need more information about pipeline to assess if this is faster. */ 120 mov.eq r2,r6 121 and r2,r2,r5 122 sub1 r2,r4,r2 123 mov.eq r1,r12 124 bic.f r1,r1,r2 125 sub r0,r3,r0 126 add.pl r0,r0,1 127 btst.pl r1,23 128 add.eq r0,r0,1 129 btst.eq r1,15 130 j_s.d [blink] 131 add.eq r0,r0,1 132#else /* !__OPTIMIZE_SIZE__ */ 133 /* Need carry clear here. */ 134 mov.eq r2,r6 1351: bmsk r1,r2,23 136 breq r1,r2,0f 137 bmsk r2,r1,15 138 breq.d r1,r2,0f 139 add_s r3,r3,1 140 cmp r2,0x100 141 add_s r3,r3,2 1420: j_s.d [blink] 143 sbc r0,r3,r0 144 145#define SPECIAL_EARLY_END 146.Learly_end: 147 sub_s.ne r1,r1,r1 148 mov_s r12,0 149 bset r12,r12,r7 150 sub1 r2,r2,r12 151 b.d .Lend 152 sub1.ne r6,r6,r12 153#endif /* !__OPTIMIZE_SIZE__ */ 154#endif /* ENDIAN */ 155 156#ifndef SPECIAL_EARLY_END 157 .balign 4 158.Learly_end: 159 b.d .Lend 160 sub_s.ne r1,r1,r1 161#endif /* !SPECIAL_EARLY_END */ 162ENDFUNC (strlen) 163#endif /* __ARC601__ || !__ARC_BARREL_SHIFTER__*/ 164 165#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */ 166
