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 43#if defined (__ARC601__) || !defined (__ARC_BARREL_SHIFTER__) 44 45#define BRand(a,b,l) and a,a,b ` brne_s a,0,l 46 47ENTRY (strncpy) 48 cmp_s r2,8 49 or r12,r0,r1 50 bmsk.cc.f r12,r12,1 51 brne.d r12,0,.Lbytewise 52 mov_s r10,r0 53 ld_s r3,[r1,0] 54 mov r8,0x01010101 55 add r6,r0,r2 56 sub r6,r6,8 57 bbit0.d r1,2,.Loop_start 58 ror r11,r8 59 sub r12,r3,r8 60 bic_l r12,r12,r3 61 BRand (r12,r11,.Lr3z) 62 mov_s r4,r3 63 ld.a r3,[r1,4] 64 st.ab r4,[r10,4] 65 .balign 4 66.Loop_start: 67 brhs r10,r6,.Loop_end 681: 69 ld.a r4,[r1,4] 70 sub r12,r3,r8 71 bic_s r12,r12,r3 72 BRand (r12,r11,.Lr3z2) 73 st.ab r3,[r10,8] 74 sub r12,r4,r8 75 bic r12,r12,r4 76 BRand (r12,r11,.Lr4z) 77 ld.a r3,[r1,4] 78 brlo.d r10,r6,1b 79 st r4,[r10,-4] 80.Loop_end: 81 add r6,r6,4 82 brhs r10,r6,.Lastword 83 sub r12,r3,r8 84 bic_s r12,r12,r3 85 BRand (r12,r11,.Lr3z) 86 add_s r1,r1,4 87 st.ab r3,[r10,4] 88.Lastword: 89 sub_s r2,r2,1 90 b.d .Lstart_charloop 91 bmsk.f r2,r2,1 92 93 .balign 4 94 nop_s 95.Lr3z2: sub_s r1,r1,4 96.Lr4z: 97.Lr3z: 98 .balign 4 99.Lr3z_loop: 100 ldb.ab r3,[r1,1] 101 brne.d r3,0,.Lr3z_loop 102 stb.ab r3,[r10,1] 103 104.Lzero_rest: 105 ; __strncpy_bzero requires: 106 ; return value in r0 107 ; zeroing length in r2 108 ; zeroing start address in r3 109 mov_s r3,r10 110 add_s r2,r2,r0 111 b.d __strncpy_bzero 112 sub_s r2,r2,r3 113 114 .balign 4 115.Lbytewise: 116 sub.f r2,r2,1 117 jcs [blink] 118.Lstart_charloop: 119 mov_s r3,r10 120.Lcharloop: 121 ldb.ab r12,[r1,1] 122 beq.d .Last_byte 123 sub.f r2,r2,1 124 brne.d r12,0,.Lcharloop 125 stb.ab r12,[r3,1] 126 b.d __strncpy_bzero 127 stb.ab r12,[r3,1] 128.Last_byte: 129 j_s.d [blink] 130 stb_s r12,[r3] 131ENDFUNC (strncpy) 132#endif /* __ARC601__ || !__ARC_BARREL_SHIFTER__ */ 133 134#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */ 135
