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 <picolibc.h> 23 24#include "DEFS.h" 25 26#define s1 26 27#define s2 25 28#define tmp1 19 29#define s2word 20 30#define tmp3 21 31#define tmp7 22 32#define s1word 29 33#define save 1 34#define tmp6 23 35#define tmp5 28 36#define count 24 37 38ENTRY(strncmp) 39 combt,<,n r0,count,search /* N <= 0 yields equality */ 40 bv r0(rp) /* */ 41 copy 0,ret0 /* return 0 (DELAY SLOT) */ 42search: combf,=,n s1,s2,findout /* s1 != s2? */ 43 bv r0(rp) /* */ 44 copy 0,ret0 /* return 0 (delay slot) */ 45findout: 46 comibf,=,n 0,s1,checks1 /* s1 == NULL? */ 47 ldbs 0(0,s2),ret0 /* */ 48 bv r0(rp) /* */ 49 subi 0,ret0,ret0 /* ret0 <- -*s2 */ 50checks1: 51 comibf,=,n 0,s2,checkitout /* s2 == NULL? */ 52 bv r0(rp) /* */ 53 ldbs 0(0,s1),28 /* return *s1 */ 54 55checkitout: 56 extru s2,31,2,tmp1 /* Extract the low two bits of the s2. */ 57 extru s1,31,2,tmp5 /* Extract the low two bits of the s1 */ 58 sub,= tmp5,tmp1,tmp3 /* Are s1 & s2 aligned with each other? */ 59 b not_aligned /* It's more complicated (not_aligned) */ 60 dep 0,31,2,s1 /* Compute word address of s1 (DELAY SLOT) */ 61 dep 0,31,2,s2 /* Compute word address of s2 */ 62 ldwm 4(0,s1),s1word /* get next s1 word s1+=4 */ 63 combt,= tmp5,r0,skipmask /* skip masking, if we can */ 64 ldwm 4(0,s2),s2word /* get next s2 word s2+=4 (DELAY SLOT) */ 65 add tmp5,count,count /* bump count by the number of bytes */ 66 /* we are going to mask */ 67 sh3add tmp5,r0,save /* save now has number of bits to mask */ 68 mtctl save,11 69 zvdepi -2,32,save /* load save with proper mask */ 70 or save,s1word,s1word /* mask s1word (s1) */ 71 or save,s2word,s2word /* mask s2word (s2) */ 72 73 74skipmask: 75 combt,=,n s1word,s2word,chknulls /* are these words equal? */ 76 77checkbyte: 78 extru s1word,7,8,tmp3 /* get first byte (character) */ 79ckbyte2: extru s2word,7,8,tmp7 /* get first byte (character) */ 80 combf,= tmp3,tmp7,done /* quit if first byte is not equal */ 81 sub tmp3,tmp7,ret0 /* return difference (delay slot) */ 82 comibt,=,n 0,tmp3,done /* have we reached the end of string */ 83 /* if so done ret0 already has zero */ 84 addibt,<=,n -1,count,done /* have we checked N chars? ret0 == 0 */ 85 extru s1word,15,8,tmp3 /* get second byte (character) */ 86 extru s2word,15,8,tmp7 /* get second byte (character) */ 87 combf,= tmp3,tmp7,done /* quit if second byte is not equal */ 88 sub tmp3,tmp7,ret0 /* return difference (delay slot) */ 89 comibt,=,n 0,tmp3,done /* have we reached the end of string */ 90 /* if so done ret0 already has zero */ 91 addibt,<=,n -1,count,done /* have we checked N chars? */ 92 extru s1word,23,8,tmp3 /* get third byte (character) */ 93 extru s2word,23,8,tmp7 /* get third byte (character) */ 94 combf,= tmp3,tmp7,done /* done if third byte is not equal */ 95 sub tmp3,tmp7,ret0 /* return difference (delay slot) */ 96 comibt,=,n 0,tmp3,done /* have we reached the end of string */ 97 /* if so done ret0 already has zero */ 98 addibt,<=,n -1,count,done /* have we checked N chars? */ 99 extru s1word,31,8,tmp3 /* get last byte (character) */ 100 extru s2word,31,8,tmp7 /* get last byte (character) */ 101 bv r0(rp) /* */ 102 sub tmp3,tmp7,ret0 /* the last characters in the word is */ 103 /* where the difference is, so return */ 104 /* the difference and we're outta here */ 105 106 107chknulls: 108 addibt,<=,n -4,count,zero /* have we checked N chars? */ 109 uxor,nbz s1word,0,0 /* don't have to check s2 Just quit */ 110 bv r0(rp) /* */ 111 copy 0,28 /* return 0 */ 112 ldwm 4(0,s2),s2word /* get next s2 word s2+=4 */ 113 b skipmask /* keep checking */ 114 ldwm 4(0,s1),s1word /* get next s1 word s1+=4 */ 115 116 117not_aligned: 118 dep r0,31,2,s2 /* Compute word address of s2 */ 119 combt,<,n r0,tmp3,shifts1 /* Do we shift s1 or s2 */ 120 sh3add tmp3,r0,tmp3 /* eight bits per byte so mul by 8 */ 121 ldwm 4(0,s1),s1word /* get first word of s1 */ 122 ldwm 4(0,s2),s2word /* get first word or s2 */ 123 combt,=,n r0,tmp5,masks2 /* Do we need to mask beginning of s1 */ 124 add tmp5,count,count /* bump count by the number of bytes */ 125 /* we are going to mask */ 126 sh3add tmp5,r0,save /* save now has number of bits to mask */ 127 mtctl save,11 128 zvdepi -2,32,save /* load save with proper mask */ 129 or save,s1word,s1word /* */ 130masks2: sh3add tmp1,r0,save /* save now has number of bits to mask */ 131 mtctl save,11 132 zvdepi -2,32,save /* load save with proper mask */ 133 or save,s2word,s2word /* */ 134 mtctl tmp3,11 /* Move shift amount to CR11 */ 135more: uxor,nbz s2word,r0,r0 /* Is there a null in first word */ 136 b,n chunk1 /* */ 137 ldwm 4(0,s2),tmp7 /* load second word to enable us to shift */ 138 vshd s2word,tmp7,s2word /* */ 139 combf,=,n s1word,s2word,ckbyte2 /* */ 140 extru s1word,7,8,tmp3 /* get first byte (DELAY SLOT) */ 141 addibt,<=,n -4,count,zero /* have we checked N chars? */ 142 uxor,nbz s1word,0,0 /* even though they're equal we could be done */ 143 b,n zero 144 copy tmp7,s2word /* */ 145 b more /* keep checking */ 146 ldwm 4(0,s1),s1word /* get next s1 (DELAY SLOT) */ 147 148chunk1: 149 vshd s2word,r0,s2word /* */ 150 b ckbyte2 /* */ 151 extru s1word,7,8,tmp3 /* */ 152 153 154shifts1: 155 sh3add tmp3,r0,tmp3 /* eight bits per byte so mul by 4 */ 156 sub r0,tmp3,tmp3 /* Get negative value for left shift */ 157 ldwm 4(0,s2),s2word /* get first word of s2 */ 158 ldwm 4(0,s1),s1word /* get first word or s1 */ 159 combt,=,n r0,tmp1,masks1 /* Do we need to mask beginning of s2 */ 160 add tmp1,count,count /* bump count by the number of bytes */ 161 /* we are going to mask */ 162 sh3add tmp1,r0,save /* save now has number of bits to mask */ 163 mtctl save,11 164 zvdepi -2,32,save /* load save with proper mask */ 165 or save,s2word,s2word /* */ 166masks1: sh3add tmp5,r0,save /* save now has number of bits to mask */ 167 mtctl save,11 168 zvdepi -2,32,save /* load save with proper mask */ 169 or save,s1word,s1word /* */ 170 mtctl tmp3,11 /* Move shift amount to CR11 */ 171more1: uxor,nbz s1word,r0,r0 /* Is there a null in first byte */ 172 b,n chunk2 /* */ 173 ldwm 4(0,s1),tmp7 /* load second word to enable us to shift */ 174 vshd s1word,tmp7,s1word /* */ 175 combf,=,n s2word,s1word,ckbyte2 /* */ 176 extru s1word,7,8,tmp3 /* get first byte (DELAY SLOT) */ 177 addibt,<=,n -4,count,zero /* have we checked N chars? */ 178 uxor,nbz s2word,0,0 /* even though they're equal we could be done */ 179 b,n zero /* zero ret0 and quit */ 180 copy tmp7,s1word /* */ 181 b more1 /* keep checking */ 182 ldwm 4(0,s2),s2word /* get next s2 (DELAY SLOT) */ 183 184chunk2: 185 vshd s1word,r0,s1word /* */ 186 b ckbyte2 /* */ 187 extru s1word,7,8,tmp3 /* */ 188 189zero: copy r0,ret0 190done: 191EXIT(strncmp) 192
