1/* 2 Copyright (c) 2015-2024, 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/strncpy.c will be 33 used. */ 34#include <picolibc.h> 35#if !defined (__OPTIMIZE_SIZE__) && !defined (PREFER_SIZE_OVER_SPEED) \ 36 && !defined (__ARC_RF16__) 37 38#include "asm.h" 39 40/* If dst and src are 4 byte aligned, copy 8 bytes at a time. 41 If the src is 4, but not 8 byte aligned, we first read 4 bytes to get 42 it 8 byte aligned. Thus, we can do a little read-ahead, without 43 dereferencing a cache line that we should not touch. 44 Note that short and long instructions have been scheduled to avoid 45 branch stalls. 46 The beq_s to r3z could be made unaligned & long to avoid a stall 47 there, but the it is not likely to be taken often, and it 48 would also be likey to cost an unaligned mispredict at the next call. */ 49 50#if !defined (__ARC601__) && defined (__ARC_BARREL_SHIFTER__) 51 52#if defined (__ARC700___) || defined (__ARCEM__) || defined (__ARCHS__) 53#define BRand(a,b,l) tst a,b ` bne_l l 54#else 55#define BRand(a,b,l) and a,a,b ` brne_s a,0,l 56#endif 57 58ENTRY (strncpy) 59 cmp_s r2,8 60 or r12,r0,r1 61 bmsk.cc.f r12,r12,1 62 brne.d r12,0,.Lbytewise 63 mov_s r10,r0 64 ld_s r3,[r1,0] 65 mov r8,0x01010101 66 sub lp_count,r2,1 67 bbit0.d r1,2,.Loop_start 68 ror r11,r8 69 sub r12,r3,r8 70 bic_l r12,r12,r3 71 BRand (r12,r11,.Lr3z) 72 mov_s r4,r3 73 ld.a r3,[r1,4] 74 sub lp_count,lp_count,4 75 st.ab r4,[r10,4] 76 .balign 4 77.Loop_start: 78 lsr.f lp_count,lp_count,3 79 lpne .Loop_end 80 ld.a r4,[r1,4] 81 sub r12,r3,r8 82 bic_s r12,r12,r3 83 BRand (r12,r11,.Lr3z) 84 st.ab r3,[r10,4] 85 sub r12,r4,r8 86 bic r12,r12,r4 87 BRand (r12,r11,.Lr4z) 88 ld.a r3,[r1,4] 89 st.ab r4,[r10,4] 90.Loop_end: 91 bcc_s .Lastword 92 ld.a r4,[r1,4] 93 sub r12,r3,r8 94 bic_s r12,r12,r3 95 BRand (r12,r11,.Lr3z) 96 st.ab r3,[r10,4] 97 mov_s r3,r4 98.Lastword: 99 and.f lp_count,r2,3 100 mov.eq lp_count,4 101 lp .Last_byte_end 102#ifdef __LITTLE_ENDIAN__ 103 bmsk.f r1,r3,7 104 lsr.ne r3,r3,8 105#else 106 lsr.f r1,r3,24 107 asl.ne r3,r3,8 108#endif 109 stb.ab r1,[r10,1] 110.Last_byte_end: 111 j_s [blink] 112 113 .balign 4 114.Lr4z: 115 mov_l r3,r4 116.Lr3z: 117#if defined (__ARC700__) || defined (__ARCEM__) || defined (__ARCHS__) 118#ifdef __LITTLE_ENDIAN__ 119 bmsk.f r1,r3,7 120 lsr_s r3,r3,8 121#else 122 lsr.f r1,r3,24 123 asl_s r3,r3,8 124#endif 125 bne.d .Lr3z 126 stb.ab r1,[r10,1] 127#else /* ! __ARC700__ */ 128#ifdef __LITTLE_ENDIAN__ 129 bmsk.f r1,r3,7 130.Lr3z_loop: 131 lsr_s r3,r3,8 132 stb.ab r1,[r10,1] 133 bne.d .Lr3z_loop 134 bmsk.f r1,r3,7 135#else 136 lsr.f r1,r3,24 137.Lr3z_loop: 138 asl_s r3,r3,8 139 stb.ab r1,[r10,1] 140 bne.d .Lr3z_loop 141 lsr.f r1,r3,24 142#endif /* ENDIAN */ 143#endif /* ! __ARC700__ */ 144.Lzero_rest: 145 ; __strncpy_bzero requires: 146 ; return value in r0 147 ; zeroing length in r2 148 ; zeroing start address in r3 149 mov_s r3,r10 150 add_s r2,r2,r0 151 b.d __strncpy_bzero 152 sub_s r2,r2,r3 153 154 .balign 4 155.Lbytewise: 156 sub.f r2,r2,1 157 mov_l r3,r0 158 jcs [blink] 159.Lcharloop: 160 ldb.ab r12,[r1,1] 161 beq.d .Last_byte 162 sub.f r2,r2,1 163 brne.d r12,0,.Lcharloop 164 stb.ab r12,[r3,1] 165 b.d __strncpy_bzero 166 stb.ab r12,[r3,1] 167.Last_byte: 168 j_s.d [blink] 169 stb_l r12,[r3] 170ENDFUNC (strncpy) 171#endif /* !__ARC601__ && __ARC_BARREL_SHIFTER__ */ 172 173#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */ 174
