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 45#if defined (__ARC601__) || !defined (__ARC_BARREL_SHIFTER__) 46 47#define BRand(a,b,l) and a,a,b ` brne_s a,0,l 48 49ENTRY (strncpy) 50 cmp_s r2,8 51 or r12,r0,r1 52 bmsk.cc.f r12,r12,1 53 brne.d r12,0,.Lbytewise 54 mov_s r10,r0 55 ld_s r3,[r1,0] 56 mov r8,0x01010101 57 add r6,r0,r2 58 sub r6,r6,8 59 bbit0.d r1,2,.Loop_start 60 ror r11,r8 61 sub r12,r3,r8 62 bic_l r12,r12,r3 63 BRand (r12,r11,.Lr3z) 64 mov_s r4,r3 65 ld.a r3,[r1,4] 66 st.ab r4,[r10,4] 67 .balign 4 68.Loop_start: 69 brhs r10,r6,.Loop_end 701: 71 ld.a r4,[r1,4] 72 sub r12,r3,r8 73 bic_s r12,r12,r3 74 BRand (r12,r11,.Lr3z2) 75 st.ab r3,[r10,8] 76 sub r12,r4,r8 77 bic r12,r12,r4 78 BRand (r12,r11,.Lr4z) 79 ld.a r3,[r1,4] 80 brlo.d r10,r6,1b 81 st r4,[r10,-4] 82.Loop_end: 83 add r6,r6,4 84 brhs r10,r6,.Lastword 85 sub r12,r3,r8 86 bic_s r12,r12,r3 87 BRand (r12,r11,.Lr3z) 88 add_s r1,r1,4 89 st.ab r3,[r10,4] 90.Lastword: 91 sub_s r2,r2,1 92 b.d .Lstart_charloop 93 bmsk.f r2,r2,1 94 95 .balign 4 96 nop_s 97.Lr3z2: sub_s r1,r1,4 98.Lr4z: 99.Lr3z: 100 .balign 4 101.Lr3z_loop: 102 ldb.ab r3,[r1,1] 103 brne.d r3,0,.Lr3z_loop 104 stb.ab r3,[r10,1] 105 106.Lzero_rest: 107 ; __strncpy_bzero requires: 108 ; return value in r0 109 ; zeroing length in r2 110 ; zeroing start address in r3 111 mov_s r3,r10 112 add_s r2,r2,r0 113 b.d __strncpy_bzero 114 sub_s r2,r2,r3 115 116 .balign 4 117.Lbytewise: 118 sub.f r2,r2,1 119 jcs [blink] 120.Lstart_charloop: 121 mov_s r3,r10 122.Lcharloop: 123 ldb.ab r12,[r1,1] 124 beq.d .Last_byte 125 sub.f r2,r2,1 126 brne.d r12,0,.Lcharloop 127 stb.ab r12,[r3,1] 128 b.d __strncpy_bzero 129 stb.ab r12,[r3,1] 130.Last_byte: 131 j_s.d [blink] 132 stb_s r12,[r3] 133ENDFUNC (strncpy) 134#endif /* __ARC601__ || !__ARC_BARREL_SHIFTER__ */ 135 136#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */ 137
