1*5d9d9091SRichard Lowe/* 2*5d9d9091SRichard Lowe * CDDL HEADER START 3*5d9d9091SRichard Lowe * 4*5d9d9091SRichard Lowe * The contents of this file are subject to the terms of the 5*5d9d9091SRichard Lowe * Common Development and Distribution License (the "License"). 6*5d9d9091SRichard Lowe * You may not use this file except in compliance with the License. 7*5d9d9091SRichard Lowe * 8*5d9d9091SRichard Lowe * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9*5d9d9091SRichard Lowe * or http://www.opensolaris.org/os/licensing. 10*5d9d9091SRichard Lowe * See the License for the specific language governing permissions 11*5d9d9091SRichard Lowe * and limitations under the License. 12*5d9d9091SRichard Lowe * 13*5d9d9091SRichard Lowe * When distributing Covered Code, include this CDDL HEADER in each 14*5d9d9091SRichard Lowe * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15*5d9d9091SRichard Lowe * If applicable, add the following below this CDDL HEADER, with the 16*5d9d9091SRichard Lowe * fields enclosed by brackets "[]" replaced with your own identifying 17*5d9d9091SRichard Lowe * information: Portions Copyright [yyyy] [name of copyright owner] 18*5d9d9091SRichard Lowe * 19*5d9d9091SRichard Lowe * CDDL HEADER END 20*5d9d9091SRichard Lowe */ 21*5d9d9091SRichard Lowe 22*5d9d9091SRichard Lowe/* 23*5d9d9091SRichard Lowe * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24*5d9d9091SRichard Lowe * Use is subject to license terms. 25*5d9d9091SRichard Lowe */ 26*5d9d9091SRichard Lowe 27*5d9d9091SRichard Lowe .file "memcmp.s" 28*5d9d9091SRichard Lowe 29*5d9d9091SRichard Lowe/* 30*5d9d9091SRichard Lowe * memcmp(s1, s2, len) 31*5d9d9091SRichard Lowe * 32*5d9d9091SRichard Lowe * Compare n bytes: s1>s2: >0 s1==s2: 0 s1<s2: <0 33*5d9d9091SRichard Lowe * 34*5d9d9091SRichard Lowe * Fast assembler language version of the following C-program for memcmp 35*5d9d9091SRichard Lowe * which represents the `standard' for the C-library. 36*5d9d9091SRichard Lowe * 37*5d9d9091SRichard Lowe * int 38*5d9d9091SRichard Lowe * memcmp(const void *s1, const void *s2, size_t n) 39*5d9d9091SRichard Lowe * { 40*5d9d9091SRichard Lowe * if (s1 != s2 && n != 0) { 41*5d9d9091SRichard Lowe * const char *ps1 = s1; 42*5d9d9091SRichard Lowe * const char *ps2 = s2; 43*5d9d9091SRichard Lowe * do { 44*5d9d9091SRichard Lowe * if (*ps1++ != *ps2++) 45*5d9d9091SRichard Lowe * return (ps1[-1] - ps2[-1]); 46*5d9d9091SRichard Lowe * } while (--n != 0); 47*5d9d9091SRichard Lowe * } 48*5d9d9091SRichard Lowe * return (NULL); 49*5d9d9091SRichard Lowe * } 50*5d9d9091SRichard Lowe */ 51*5d9d9091SRichard Lowe 52*5d9d9091SRichard Lowe#include <sys/asm_linkage.h> 53*5d9d9091SRichard Lowe 54*5d9d9091SRichard Lowe ANSI_PRAGMA_WEAK(memcmp,function) 55*5d9d9091SRichard Lowe 56*5d9d9091SRichard Lowe ENTRY(memcmp) 57*5d9d9091SRichard Lowe st %g2, [%sp + 68] ! g2 must be restored before retl 58*5d9d9091SRichard Lowe cmp %o0, %o1 ! s1 == s2? 59*5d9d9091SRichard Lowe be .cmpeq 60*5d9d9091SRichard Lowe cmp %o2, 17 61*5d9d9091SRichard Lowe bleu,a .cmpbyt ! for small counts go do bytes 62*5d9d9091SRichard Lowe sub %o1, %o0, %o1 63*5d9d9091SRichard Lowe 64*5d9d9091SRichard Lowe andcc %o0, 3, %o3 ! is s1 aligned? 65*5d9d9091SRichard Lowe bz,a .iss2 ! if so go check s2 66*5d9d9091SRichard Lowe andcc %o1, 3, %o4 ! is s2 aligned? 67*5d9d9091SRichard Lowe cmp %o3, 2 68*5d9d9091SRichard Lowe be .algn2 69*5d9d9091SRichard Lowe cmp %o3, 3 70*5d9d9091SRichard Lowe 71*5d9d9091SRichard Lowe.algn1: ldub [%o0], %o4 ! cmp one byte 72*5d9d9091SRichard Lowe inc %o0 73*5d9d9091SRichard Lowe ldub [%o1], %o5 74*5d9d9091SRichard Lowe inc %o1 75*5d9d9091SRichard Lowe dec %o2 76*5d9d9091SRichard Lowe be .algn3 77*5d9d9091SRichard Lowe cmp %o4, %o5 78*5d9d9091SRichard Lowe be .algn2 79*5d9d9091SRichard Lowe nop 80*5d9d9091SRichard Lowe b,a .noteq 81*5d9d9091SRichard Lowe 82*5d9d9091SRichard Lowe.algn2: lduh [%o0], %o4 83*5d9d9091SRichard Lowe inc 2, %o0 84*5d9d9091SRichard Lowe ldub [%o1], %o5 85*5d9d9091SRichard Lowe inc 1, %o1 86*5d9d9091SRichard Lowe srl %o4, 8, %o3 87*5d9d9091SRichard Lowe cmp %o3, %o5 88*5d9d9091SRichard Lowe be,a 1f 89*5d9d9091SRichard Lowe ldub [%o1], %o5 ! delay slot, get next byte from s2 90*5d9d9091SRichard Lowe b .noteq 91*5d9d9091SRichard Lowe mov %o3, %o4 ! delay slot, move *s1 to %o4 92*5d9d9091SRichard Lowe1: inc %o1 93*5d9d9091SRichard Lowe dec 2, %o2 94*5d9d9091SRichard Lowe and %o4, 0xff, %o4 95*5d9d9091SRichard Lowe cmp %o4, %o5 96*5d9d9091SRichard Lowe.algn3: be,a .iss2 97*5d9d9091SRichard Lowe andcc %o1, 3, %o4 ! delay slot, is s2 aligned? 98*5d9d9091SRichard Lowe b,a .noteq 99*5d9d9091SRichard Lowe 100*5d9d9091SRichard Lowe.cmpbyt:b .bytcmp 101*5d9d9091SRichard Lowe deccc %o2 102*5d9d9091SRichard Lowe1: ldub [%o0 + %o1], %o5 ! byte compare loop 103*5d9d9091SRichard Lowe inc %o0 104*5d9d9091SRichard Lowe cmp %o4, %o5 105*5d9d9091SRichard Lowe be,a .bytcmp 106*5d9d9091SRichard Lowe deccc %o2 ! delay slot, compare count (len) 107*5d9d9091SRichard Lowe b,a .noteq 108*5d9d9091SRichard Lowe.bytcmp:bgeu,a 1b 109*5d9d9091SRichard Lowe ldub [%o0], %o4 110*5d9d9091SRichard Lowe.cmpeq: ld [%sp + 68], %g2 111*5d9d9091SRichard Lowe retl ! strings compare equal 112*5d9d9091SRichard Lowe clr %o0 113*5d9d9091SRichard Lowe 114*5d9d9091SRichard Lowe.noteq_word: ! words aren't equal. find unequal byte 115*5d9d9091SRichard Lowe srl %o4, 24, %o1 ! first byte 116*5d9d9091SRichard Lowe srl %o5, 24, %o2 117*5d9d9091SRichard Lowe cmp %o1, %o2 118*5d9d9091SRichard Lowe bne 1f 119*5d9d9091SRichard Lowe sll %o4, 8, %o4 120*5d9d9091SRichard Lowe sll %o5, 8, %o5 121*5d9d9091SRichard Lowe srl %o4, 24, %o1 122*5d9d9091SRichard Lowe srl %o5, 24, %o2 123*5d9d9091SRichard Lowe cmp %o1, %o2 124*5d9d9091SRichard Lowe bne 1f 125*5d9d9091SRichard Lowe sll %o4, 8, %o4 126*5d9d9091SRichard Lowe sll %o5, 8, %o5 127*5d9d9091SRichard Lowe srl %o4, 24, %o1 128*5d9d9091SRichard Lowe srl %o5, 24, %o2 129*5d9d9091SRichard Lowe cmp %o1, %o2 130*5d9d9091SRichard Lowe bne 1f 131*5d9d9091SRichard Lowe sll %o4, 8, %o4 132*5d9d9091SRichard Lowe sll %o5, 8, %o5 133*5d9d9091SRichard Lowe srl %o4, 24, %o1 134*5d9d9091SRichard Lowe srl %o5, 24, %o2 135*5d9d9091SRichard Lowe1: 136*5d9d9091SRichard Lowe ld [%sp + 68], %g2 137*5d9d9091SRichard Lowe retl 138*5d9d9091SRichard Lowe sub %o1, %o2, %o0 ! delay slot 139*5d9d9091SRichard Lowe 140*5d9d9091SRichard Lowe.noteq: 141*5d9d9091SRichard Lowe ld [%sp + 68], %g2 142*5d9d9091SRichard Lowe retl ! strings aren't equal 143*5d9d9091SRichard Lowe sub %o4, %o5, %o0 ! delay slot, return(*s1 - *s2) 144*5d9d9091SRichard Lowe 145*5d9d9091SRichard Lowe.iss2: andn %o2, 3, %o3 ! count of aligned bytes 146*5d9d9091SRichard Lowe and %o2, 3, %o2 ! remaining bytes 147*5d9d9091SRichard Lowe bz .w4cmp ! if s2 word aligned, compare words 148*5d9d9091SRichard Lowe cmp %o4, 2 149*5d9d9091SRichard Lowe be .w2cmp ! s2 half aligned 150*5d9d9091SRichard Lowe cmp %o4, 1 151*5d9d9091SRichard Lowe 152*5d9d9091SRichard Lowe.w3cmp: 153*5d9d9091SRichard Lowe dec 4, %o3 ! avoid reading beyond the last byte 154*5d9d9091SRichard Lowe inc 4, %o2 155*5d9d9091SRichard Lowe ldub [%o1], %g1 ! read a byte to align for word reads 156*5d9d9091SRichard Lowe inc 1, %o1 157*5d9d9091SRichard Lowe be .w1cmp ! aligned to 1 or 3 bytes 158*5d9d9091SRichard Lowe sll %g1, 24, %o5 159*5d9d9091SRichard Lowe 160*5d9d9091SRichard Lowe sub %o1, %o0, %o1 161*5d9d9091SRichard Lowe2: ld [%o0 + %o1], %g1 162*5d9d9091SRichard Lowe ld [%o0], %o4 163*5d9d9091SRichard Lowe inc 4, %o0 164*5d9d9091SRichard Lowe srl %g1, 8, %g2 ! merge with the other half 165*5d9d9091SRichard Lowe or %g2, %o5, %o5 166*5d9d9091SRichard Lowe cmp %o4, %o5 167*5d9d9091SRichard Lowe bne .noteq_word 168*5d9d9091SRichard Lowe deccc 4, %o3 169*5d9d9091SRichard Lowe bnz 2b 170*5d9d9091SRichard Lowe sll %g1, 24, %o5 171*5d9d9091SRichard Lowe sub %o1, 1, %o1 ! used 3 bytes of the last word read 172*5d9d9091SRichard Lowe b .bytcmp 173*5d9d9091SRichard Lowe deccc %o2 174*5d9d9091SRichard Lowe 175*5d9d9091SRichard Lowe.w1cmp: 176*5d9d9091SRichard Lowe dec 4, %o3 ! avoid reading beyond the last byte 177*5d9d9091SRichard Lowe inc 4, %o2 178*5d9d9091SRichard Lowe lduh [%o1], %g1 ! read 3 bytes to word align 179*5d9d9091SRichard Lowe inc 2, %o1 180*5d9d9091SRichard Lowe sll %g1, 8, %g2 181*5d9d9091SRichard Lowe or %o5, %g2, %o5 182*5d9d9091SRichard Lowe 183*5d9d9091SRichard Lowe sub %o1, %o0, %o1 184*5d9d9091SRichard Lowe3: ld [%o0 + %o1], %g1 185*5d9d9091SRichard Lowe ld [%o0], %o4 186*5d9d9091SRichard Lowe inc 4, %o0 187*5d9d9091SRichard Lowe srl %g1, 24, %g2 ! merge with the other half 188*5d9d9091SRichard Lowe or %g2, %o5, %o5 189*5d9d9091SRichard Lowe cmp %o4, %o5 190*5d9d9091SRichard Lowe bne .noteq_word 191*5d9d9091SRichard Lowe deccc 4, %o3 192*5d9d9091SRichard Lowe bnz 3b 193*5d9d9091SRichard Lowe sll %g1, 8, %o5 194*5d9d9091SRichard Lowe sub %o1, 3, %o1 ! used 1 byte of the last word read 195*5d9d9091SRichard Lowe b .bytcmp 196*5d9d9091SRichard Lowe deccc %o2 197*5d9d9091SRichard Lowe 198*5d9d9091SRichard Lowe.w2cmp: 199*5d9d9091SRichard Lowe dec 4, %o3 ! avoid reading beyond the last byte 200*5d9d9091SRichard Lowe inc 4, %o2 201*5d9d9091SRichard Lowe lduh [%o1], %g1 ! read a halfword to align s2 202*5d9d9091SRichard Lowe inc 2, %o1 203*5d9d9091SRichard Lowe sll %g1, 16, %o5 204*5d9d9091SRichard Lowe 205*5d9d9091SRichard Lowe sub %o1, %o0, %o1 206*5d9d9091SRichard Lowe4: ld [%o0 + %o1], %g1 ! read a word from s2 207*5d9d9091SRichard Lowe ld [%o0], %o4 ! read a word from s1 208*5d9d9091SRichard Lowe inc 4, %o0 209*5d9d9091SRichard Lowe srl %g1, 16, %g2 ! merge with the other half 210*5d9d9091SRichard Lowe or %g2, %o5, %o5 211*5d9d9091SRichard Lowe cmp %o4, %o5 212*5d9d9091SRichard Lowe bne .noteq_word 213*5d9d9091SRichard Lowe deccc 4, %o3 214*5d9d9091SRichard Lowe bnz 4b 215*5d9d9091SRichard Lowe sll %g1, 16, %o5 216*5d9d9091SRichard Lowe sub %o1, 2, %o1 ! only used half of the last read word 217*5d9d9091SRichard Lowe b .bytcmp 218*5d9d9091SRichard Lowe deccc %o2 219*5d9d9091SRichard Lowe 220*5d9d9091SRichard Lowe.w4cmp: 221*5d9d9091SRichard Lowe sub %o1, %o0, %o1 222*5d9d9091SRichard Lowe ld [%o0 + %o1], %o5 223*5d9d9091SRichard Lowe5: ld [%o0], %o4 224*5d9d9091SRichard Lowe inc 4, %o0 225*5d9d9091SRichard Lowe cmp %o4, %o5 226*5d9d9091SRichard Lowe bne .noteq_word 227*5d9d9091SRichard Lowe deccc 4, %o3 228*5d9d9091SRichard Lowe bnz,a 5b 229*5d9d9091SRichard Lowe ld [%o0 + %o1], %o5 230*5d9d9091SRichard Lowe b .bytcmp ! compare remaining bytes, if any 231*5d9d9091SRichard Lowe deccc %o2 232*5d9d9091SRichard Lowe 233*5d9d9091SRichard Lowe SET_SIZE(memcmp) 234