1/* 2 * (c) Copyright 1986 HEWLETT-PACKARD COMPANY 3 * 4 * To anyone who acknowledges that this file is provided "AS IS" 5 * without any express or implied warranty: 6 * permission to use, copy, modify, and distribute this file 7 * for any purpose is hereby granted without fee, provided that 8 * the above copyright notice and this notice appears in all 9 * copies, and that the name of Hewlett-Packard Company not be 10 * used in advertising or publicity pertaining to distribution 11 * of the software without specific, written prior permission. 12 * Hewlett-Packard Company makes no representations about the 13 * suitability of this software for any purpose. 14 */ 15 16/* strcmp(s1, s2) */ 17/* returns integer: < 0 iff s1 lexicographically less than s2 */ 18/* > 0 iff s1 lexicographically greater than s2 */ 19/* = 0 iff s1 lexicographically equal to s2 */ 20/* = 0 iff s1 lexicographically equal to s2 */ 21/* quit after n charachters */ 22#include "DEFS.h" 23 24#define s1 26 25#define s2 25 26#define tmp1 19 27#define s2word 20 28#define tmp3 21 29#define tmp7 22 30#define s1word 29 31#define save 1 32#define tmp6 23 33#define tmp5 28 34#define count 24 35 36ENTRY(strncmp) 37 combt,<,n r0,count,search /* N <= 0 yields equality */ 38 bv r0(rp) /* */ 39 copy 0,ret0 /* return 0 (DELAY SLOT) */ 40search: combf,=,n s1,s2,findout /* s1 != s2? */ 41 bv r0(rp) /* */ 42 copy 0,ret0 /* return 0 (delay slot) */ 43findout: 44 comibf,=,n 0,s1,checks1 /* s1 == NULL? */ 45 ldbs 0(0,s2),ret0 /* */ 46 bv r0(rp) /* */ 47 subi 0,ret0,ret0 /* ret0 <- -*s2 */ 48checks1: 49 comibf,=,n 0,s2,checkitout /* s2 == NULL? */ 50 bv r0(rp) /* */ 51 ldbs 0(0,s1),28 /* return *s1 */ 52 53checkitout: 54 extru s2,31,2,tmp1 /* Extract the low two bits of the s2. */ 55 extru s1,31,2,tmp5 /* Extract the low two bits of the s1 */ 56 sub,= tmp5,tmp1,tmp3 /* Are s1 & s2 aligned with each other? */ 57 b not_aligned /* It's more complicated (not_aligned) */ 58 dep 0,31,2,s1 /* Compute word address of s1 (DELAY SLOT) */ 59 dep 0,31,2,s2 /* Compute word address of s2 */ 60 ldwm 4(0,s1),s1word /* get next s1 word s1+=4 */ 61 combt,= tmp5,r0,skipmask /* skip masking, if we can */ 62 ldwm 4(0,s2),s2word /* get next s2 word s2+=4 (DELAY SLOT) */ 63 add tmp5,count,count /* bump count by the number of bytes */ 64 /* we are going to mask */ 65 sh3add tmp5,r0,save /* save now has number of bits to mask */ 66 mtctl save,11 67 zvdepi -2,32,save /* load save with proper mask */ 68 or save,s1word,s1word /* mask s1word (s1) */ 69 or save,s2word,s2word /* mask s2word (s2) */ 70 71 72skipmask: 73 combt,=,n s1word,s2word,chknulls /* are these words equal? */ 74 75checkbyte: 76 extru s1word,7,8,tmp3 /* get first byte (character) */ 77ckbyte2: extru s2word,7,8,tmp7 /* get first byte (character) */ 78 combf,= tmp3,tmp7,done /* quit if first byte is not equal */ 79 sub tmp3,tmp7,ret0 /* return difference (delay slot) */ 80 comibt,=,n 0,tmp3,done /* have we reached the end of string */ 81 /* if so done ret0 already has zero */ 82 addibt,<=,n -1,count,done /* have we checked N chars? ret0 == 0 */ 83 extru s1word,15,8,tmp3 /* get second byte (character) */ 84 extru s2word,15,8,tmp7 /* get second byte (character) */ 85 combf,= tmp3,tmp7,done /* quit if second byte is not equal */ 86 sub tmp3,tmp7,ret0 /* return difference (delay slot) */ 87 comibt,=,n 0,tmp3,done /* have we reached the end of string */ 88 /* if so done ret0 already has zero */ 89 addibt,<=,n -1,count,done /* have we checked N chars? */ 90 extru s1word,23,8,tmp3 /* get third byte (character) */ 91 extru s2word,23,8,tmp7 /* get third byte (character) */ 92 combf,= tmp3,tmp7,done /* done if third byte is not equal */ 93 sub tmp3,tmp7,ret0 /* return difference (delay slot) */ 94 comibt,=,n 0,tmp3,done /* have we reached the end of string */ 95 /* if so done ret0 already has zero */ 96 addibt,<=,n -1,count,done /* have we checked N chars? */ 97 extru s1word,31,8,tmp3 /* get last byte (character) */ 98 extru s2word,31,8,tmp7 /* get last byte (character) */ 99 bv r0(rp) /* */ 100 sub tmp3,tmp7,ret0 /* the last characters in the word is */ 101 /* where the difference is, so return */ 102 /* the difference and we're outta here */ 103 104 105chknulls: 106 addibt,<=,n -4,count,zero /* have we checked N chars? */ 107 uxor,nbz s1word,0,0 /* don't have to check s2 Just quit */ 108 bv r0(rp) /* */ 109 copy 0,28 /* return 0 */ 110 ldwm 4(0,s2),s2word /* get next s2 word s2+=4 */ 111 b skipmask /* keep checking */ 112 ldwm 4(0,s1),s1word /* get next s1 word s1+=4 */ 113 114 115not_aligned: 116 dep r0,31,2,s2 /* Compute word address of s2 */ 117 combt,<,n r0,tmp3,shifts1 /* Do we shift s1 or s2 */ 118 sh3add tmp3,r0,tmp3 /* eight bits per byte so mul by 8 */ 119 ldwm 4(0,s1),s1word /* get first word of s1 */ 120 ldwm 4(0,s2),s2word /* get first word or s2 */ 121 combt,=,n r0,tmp5,masks2 /* Do we need to mask beginning of s1 */ 122 add tmp5,count,count /* bump count by the number of bytes */ 123 /* we are going to mask */ 124 sh3add tmp5,r0,save /* save now has number of bits to mask */ 125 mtctl save,11 126 zvdepi -2,32,save /* load save with proper mask */ 127 or save,s1word,s1word /* */ 128masks2: sh3add tmp1,r0,save /* save now has number of bits to mask */ 129 mtctl save,11 130 zvdepi -2,32,save /* load save with proper mask */ 131 or save,s2word,s2word /* */ 132 mtctl tmp3,11 /* Move shift amount to CR11 */ 133more: uxor,nbz s2word,r0,r0 /* Is there a null in first word */ 134 b,n chunk1 /* */ 135 ldwm 4(0,s2),tmp7 /* load second word to enable us to shift */ 136 vshd s2word,tmp7,s2word /* */ 137 combf,=,n s1word,s2word,ckbyte2 /* */ 138 extru s1word,7,8,tmp3 /* get first byte (DELAY SLOT) */ 139 addibt,<=,n -4,count,zero /* have we checked N chars? */ 140 uxor,nbz s1word,0,0 /* even though they're equal we could be done */ 141 b,n zero 142 copy tmp7,s2word /* */ 143 b more /* keep checking */ 144 ldwm 4(0,s1),s1word /* get next s1 (DELAY SLOT) */ 145 146chunk1: 147 vshd s2word,r0,s2word /* */ 148 b ckbyte2 /* */ 149 extru s1word,7,8,tmp3 /* */ 150 151 152shifts1: 153 sh3add tmp3,r0,tmp3 /* eight bits per byte so mul by 4 */ 154 sub r0,tmp3,tmp3 /* Get negative value for left shift */ 155 ldwm 4(0,s2),s2word /* get first word of s2 */ 156 ldwm 4(0,s1),s1word /* get first word or s1 */ 157 combt,=,n r0,tmp1,masks1 /* Do we need to mask beginning of s2 */ 158 add tmp1,count,count /* bump count by the number of bytes */ 159 /* we are going to mask */ 160 sh3add tmp1,r0,save /* save now has number of bits to mask */ 161 mtctl save,11 162 zvdepi -2,32,save /* load save with proper mask */ 163 or save,s2word,s2word /* */ 164masks1: sh3add tmp5,r0,save /* save now has number of bits to mask */ 165 mtctl save,11 166 zvdepi -2,32,save /* load save with proper mask */ 167 or save,s1word,s1word /* */ 168 mtctl tmp3,11 /* Move shift amount to CR11 */ 169more1: uxor,nbz s1word,r0,r0 /* Is there a null in first byte */ 170 b,n chunk2 /* */ 171 ldwm 4(0,s1),tmp7 /* load second word to enable us to shift */ 172 vshd s1word,tmp7,s1word /* */ 173 combf,=,n s2word,s1word,ckbyte2 /* */ 174 extru s1word,7,8,tmp3 /* get first byte (DELAY SLOT) */ 175 addibt,<=,n -4,count,zero /* have we checked N chars? */ 176 uxor,nbz s2word,0,0 /* even though they're equal we could be done */ 177 b,n zero /* zero ret0 and quit */ 178 copy tmp7,s1word /* */ 179 b more1 /* keep checking */ 180 ldwm 4(0,s2),s2word /* get next s2 (DELAY SLOT) */ 181 182chunk2: 183 vshd s1word,r0,s1word /* */ 184 b ckbyte2 /* */ 185 extru s1word,7,8,tmp3 /* */ 186 187zero: copy r0,ret0 188done: 189EXIT(strncmp) 190
