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/memcmp.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_NORM__) \ 39 || !defined (__ARC_BARREL_SHIFTER__) 40 41/* Addresses are unsigned, and at 0 is the vector table, so it's OK to assume 42 that we can subtract 8 from a source end address without underflow. */ 43 44ENTRY (memcmp) 45 or r12,r0,r1 46 tst r12,3 47 breq r2,0,.Lnil 48 add_s r3,r0,r2 49 50/* This algorithm for big endian targets sometimes works incorrectly 51 when sources are aligned. To be precise the last step is omitted. 52 Just use a simple bytewise variant until the algorithm is reviewed 53 and fixed. */ 54 55#ifdef __LITTLE_ENDIAN__ 56 bne_s .Lbytewise 57#else /* BIG ENDIAN */ 58 b_s .Lbytewise 59#endif /* ENDIAN */ 60 sub r6,r3,8 61 ld r4,[r0,0] 62 ld r5,[r1,0] 632: 64 brhs r0,r6,.Loop_end 65 ld_s r3,[r0,4] 66 ld_s r12,[r1,4] 67 brne r4,r5,.Leven 68 ld.a r4,[r0,8] 69 breq.d r3,r12,2b 70 ld.a r5,[r1,8] 71#ifdef __LITTLE_ENDIAN__ 72 mov_s r4,r3 73 b.d .Lodd 74 mov_s r5,r12 75#else /* BIG ENDIAN */ 76 cmp_s r3,r12 77 j_s.d [blink] 78 rrc r0,2 79#endif /* ENDIAN */ 80 81 .balign 4 82.Loop_end: 83 sub r3,r0,r6 84 brhs r3,4,.Last_cmp 85 brne r4,r5,.Leven 86 ld r4,[r0,4] 87 ld r5,[r1,4] 88#ifdef __LITTLE_ENDIAN__ 89 .balign 4 90.Last_cmp: 91 mov_l r0,24 92 add3 r2,r0,r2 93 xor r0,r4,r5 94 b.d .Leven_cmp 95 bset r0,r0,r2 96.Lodd: 97.Leven: 98 xor r0,r4,r5 99.Leven_cmp: 100 mov_s r1,0x80808080 101 ; uses long immediate 102 sub_s r12,r0,1 103 bic_s r0,r0,r12 104 sub r0,r1,r0 105 xor_s r0,r0,r1 106 and r1,r5,r0 107 and r0,r4,r0 108#else /* BIG ENDIAN */ 109.Last_cmp: 110 mov_s r3,0 111 sub3 r2,r3,r2 112 sub_s r3,r3,1 113 bclr r3,r3,r2 114 add_l r3,r3,1 115 and r0,r4,r3 116 and r1,r5,r3 117.Leven: 118#endif /* ENDIAN */ 119 xor.f 0,r0,r1 120 sub_s r0,r0,r1 121 j_s.d [blink] 122 mov.mi r0,r1 123 .balign 4 124.Lbytewise: 125 ldb r4,[r0,0] 126 ldb r5,[r1,0] 127 sub r6,r3,2 1283: 129 brhs r0,r6,.Lbyte_end 130 ldb_s r3,[r0,1] 131 ldb_s r12,[r1,1] 132 brne r4,r5,.Lbyte_even 133 ldb.a r4,[r0,2] 134 breq.d r3,r12,3b 135 ldb.a r5,[r1,2] 136.Lbyte_odd: 137 j_s.d [blink] 138 sub r0,r3,r12 139 .balign 4 140.Lbyte_end: 141 bbit1 r2,0,.Lbyte_even 142 brne r4,r5,.Lbyte_even 143 ldb r4,[r0,1] 144 ldb r5,[r1,1] 145.Lbyte_even: 146 j_s.d [blink] 147 sub r0,r4,r5 148.Lnil: 149 j_s.d [blink] 150 mov_s r0,0 151ENDFUNC (memcmp) 152#endif /* __ARC601__ || !__ARC_NORM__ || !__ARC_BARREL_SHIFTER__ */ 153 154#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */ 155
