1/******************************************************************************* 2 * 3 * Copyright (c) 1993 Intel Corporation 4 * 5 * Intel hereby grants you permission to copy, modify, and distribute this 6 * software and its documentation. Intel grants this permission provided 7 * that the above copyright notice appears in all copies and that both the 8 * copyright notice and this permission notice appear in supporting 9 * documentation. In addition, Intel grants this permission provided that 10 * you prominently mark as "not part of the original" any modifications 11 * made to this software or documentation, and that the name of Intel 12 * Corporation not be used in advertising or publicity pertaining to 13 * distribution of the software or the documentation without specific, 14 * written prior permission. 15 * 16 * Intel Corporation provides this AS IS, WITHOUT ANY WARRANTY, EXPRESS OR 17 * IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY 18 * OR FITNESS FOR A PARTICULAR PURPOSE. Intel makes no guarantee or 19 * representations regarding the use of, or the results of the use of, 20 * the software and documentation in terms of correctness, accuracy, 21 * reliability, currentness, or otherwise; and you rely on the software, 22 * documentation and results solely at your own risk. 23 * 24 * IN NO EVENT SHALL INTEL BE LIABLE FOR ANY LOSS OF USE, LOSS OF BUSINESS, 25 * LOSS OF PROFITS, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES 26 * OF ANY KIND. IN NO EVENT SHALL INTEL'S TOTAL LIABILITY EXCEED THE SUM 27 * PAID TO INTEL FOR THE PRODUCT LICENSED HEREUNDER. 28 * 29 ******************************************************************************/ 30 31 .file "mccpy_ca.s" 32#ifdef __PIC 33 .pic 34#endif 35#ifdef __PID 36 .pid 37#endif 38/* 39 * (c) copyright 1989,1993 Intel Corp., all rights reserved 40 */ 41 42/* 43 procedure memccpy (optimized assembler version for the 80960CA) 44 45 dest_addr = memccpy (dest_addr, src_addr, char, len) 46 47 copy len bytes pointed to by src_addr to the space pointed to by 48 dest_addr, stopping if char is copied. If char is copied, 49 return address of byte after char in dest string; else null. 50 51 Undefined behavior will occur if the end of the source array is in 52 the last two words of the program's allocated memory space. This 53 is so because the routine fetches ahead. Disallowing the fetch 54 ahead would impose a severe performance penalty. 55 56 Undefined behavior will also occur if the source and destination 57 strings overlap. 58 59 60 This program handles five cases: 61 62 1) both arguments start on a word boundary 63 2) neither are word aligned, but they are offset by the same amount 64 3) source is word aligned, destination is not 65 4) destination is word aligned, source is not 66 5) neither is word aligned, and they are offset by differing amounts 67 68 At the time of this writing, only g0 thru g7 and g13 are available 69 for use in this leafproc; other registers would have to be saved and 70 restored. These nine registers, plus tricky use of g14 are sufficient 71 to implement the routine. 72*/ 73 74#if __i960_BIG_ENDIAN__ 75#define MSW g6 76#define LSW g7 77#else 78#define LSW g6 79#define MSW g7 80#endif 81 82 .globl _memccpy 83 .leafproc _memccpy, __memccpy 84 .align 2 85_memccpy: 86#ifndef __PIC 87 lda Lrett,g14 88#else 89 lda Lrett-(.+8)(ip),g14 90#endif 91__memccpy: 92 notand g1,3,g5 # extract word addr of start of src 93 lda (g14),g13 # preserve return address 94 cmpibge.f 0,g3,Lexit_char_not_found # Lexit if # of bytes to move is <= 0 95 cmpo g5,g1 # check alignment of src 96 ld (g5),LSW # fetch word containing at least first byte 97 notand g0,3,g4 # extract word addr of start of dest 98 lda 4(g5),g5 # advance src word addr 99 shlo 24,g2,g2 # reduce char to single byte 100 bne.f Lcase_245 # branch if src is NOT word aligned 101 102Lcase_13: 103 cmpobe.t g0,g4,Lcase_1_setup # branch if dest word aligned 104 105Lcase_3: # src is word aligned; dest is not 106 mov LSW,MSW # make copy of first word of src 107 addo 4,g4,g1 # move dest word ptr to first word boundary 108 lda 32,g14 # initialize shift count to zero 109 110Lcase_25: 111Lcase_3_cloop_at_start: # character copying loop for start of dest str 112 cmpdeci 0,g3,g3 # is max_bytes exhausted? 113#if __i960_BIG_ENDIAN__ 114 lda -8(g14),g14 # augment the shift counter 115#else 116 lda 8(g14),g14 # augment the shift counter 117#endif 118 be.f Lexit_char_not_found # Lexit if max_bytes is exhausted 119#if __i960_BIG_ENDIAN__ 120 rotate 8,MSW,MSW # move next byte into position for extraction 121#endif 122 shlo 24,MSW,g4 123 stob MSW,(g0) # store the byte in dest 124 cmpo g4,g2 125 lda 1(g0),g0 # post-increment dest ptr 126#if ! __i960_BIG_ENDIAN__ 127 shro 8,MSW,MSW # move next byte into position for extraction 128#endif 129 be.f Lexit_char_found # Lexit if char found 130 cmpobne.t g1,g0,Lcase_3_cloop_at_start # branch if reached word boundary 131 132 ld (g5),MSW # fetch msw of operand for double shift 133 134Lcase_4: 135 shro 8,g2,g4 136 or g4,g2,g1 137 shro 16,g1,g4 138 or g4,g1,g4 139 140#if __i960_BIG_ENDIAN__ 141 cmpobne 0,g14,Lcase_3_wloop 142 143Lcase_3_wloop2: 144 cmpi g3,4 # less than four bytes to move? 145 lda 4(g5),g5 # post-increment src word addr 146 mov LSW,g1 # extract 4 bytes of src 147 bl.f Lcase_13_cloop_setup # branch if < four bytes left to move 148 scanbyte g4,g1 # branch if word has char in it 149 bo.f Lcase_13_cloop_setup 150 mov MSW,LSW # move msw to lsw 151 ld (g5),MSW # pre-fetch msw of operand for double shift 152 subi 4,g3,g3 # decrease max_byte count by the 4 bytes moved 153 st g1,(g0) # store 4 bytes to dest 154 addo 4,g0,g0 # post-increment dest ptr 155 b Lcase_3_wloop2 156#endif 157 158Lcase_3_wloop: 159 cmpi g3,4 # less than four bytes to move? 160 lda 4(g5),g5 # post-increment src word addr 161 eshro g14,g6,g1 # extract 4 bytes of src 162 bl.f Lcase_13_cloop_setup # branch if < four bytes left to move 163 scanbyte g4,g1 # branch if word has char in it 164 bo.f Lcase_13_cloop_setup 165 mov MSW,LSW # move msw to lsw 166 ld (g5),MSW # pre-fetch msw of operand for double shift 167 subi 4,g3,g3 # decrease max_byte count by the 4 bytes moved 168 st g1,(g0) # store 4 bytes to dest 169 addo 4,g0,g0 # post-increment dest ptr 170 b Lcase_3_wloop 171 172Lcase_1_setup: 173 subo 4,g0,g0 # store is pre-incrementing; back up dest addr 174 shro 8,g2,g4 175 or g4,g2,MSW 176 shro 16,MSW,g4 177 or g4,MSW,g4 178 b Lcase_1 179Lcase_1_wloop: # word copying loop 180 subi 4,g3,g3 # decrease max_byte count by the 4 bytes moved 181 ld (g5),LSW # pre-fetch next word of src 182 addo 4,g5,g5 # post-increment src addr 183 st g1,(g0) # store word in dest string 184Lcase_1: # src and dest are word aligned 185 cmpi g3,4 # check for fewer than four bytes to move 186 addo 4,g0,g0 # pre-increment dest addr 187 lda (LSW),g1 # keep a copy of the src word 188 bl.f Lcase_13_cloop_setup # branch if less than four bytes to copy 189 scanbyte LSW,g4 # branch if char is not in foursome 190 bno.t Lcase_1_wloop 191Lcase_13_cloop_setup: 192 cmpibe.f 0,g3,Lexit_char_not_found # Lexit if max_bytes is exhausted 193 194Lcase_1_cloop: 195#if __i960_BIG_ENDIAN__ 196 rotate 8,g1,g1 # move next byte into position for extraction 197#endif 198 shlo 24,g1,g4 199 stob g1,(g0) # store the byte in dest 200 cmpo g4,g2 201 lda 1(g0),g0 # post-increment dest byte addr 202 subi 1,g3,g3 203 be.f Lexit_char_found # Lexit if char reached 204 cmpi 0,g3 205#if ! __i960_BIG_ENDIAN__ 206 shro 8,g1,g1 # move next byte into position for extraction 207#endif 208 bne.t Lcase_1_cloop # continue if len not exhausted 209 210Lexit_char_not_found: 211 mov 0,g0 212Lexit_char_found: 213 lda 0,g14 214 bx (g13) # g0 = dest array address; g14 = 0 215Lrett: 216 ret 217 218 219Lcase_245: 220 cmpo g0,g4 # check alignment of dest 221 ld (g5),MSW # pre-fetch second half 222 and 3,g1,g1 # compute shift count 223 shlo 3,g1,g14 224#if __i960_BIG_ENDIAN__ 225 subo g14,0,g14 # adjust shift count for big endian 226#endif 227 be.t Lcase_4 # branch if dest is word aligned 228 or g4,g1,g1 # is src earlier in word, later, or sync w/ dst 229 cmpo g0,g1 # < indicates first word of dest has more bytes 230 /* than first word of source. */ 231 eshro g14,g6,g4 # extract four bytes 232 lda 4(g0),g1 # move dest word addr to first word boundary 233#if __i960_BIG_ENDIAN__ 234 bge.f 1f 235#else 236 bg.f 1f 237#endif 238 mov MSW,LSW 239 lda 4(g5),g5 # move src word addr to second word boundary 2401: 241 notand g1,3,g1 242 mov g4,MSW 243 b Lcase_25 244 245/* end of memccpy */ 246
