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