10Sstevel@tonic-gate/* 20Sstevel@tonic-gate * CDDL HEADER START 30Sstevel@tonic-gate * 40Sstevel@tonic-gate * The contents of this file are subject to the terms of the 56812Sraf * Common Development and Distribution License (the "License"). 66812Sraf * You may not use this file except in compliance with the License. 70Sstevel@tonic-gate * 80Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 90Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 100Sstevel@tonic-gate * See the License for the specific language governing permissions 110Sstevel@tonic-gate * and limitations under the License. 120Sstevel@tonic-gate * 130Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 140Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 150Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 160Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 170Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 180Sstevel@tonic-gate * 190Sstevel@tonic-gate * CDDL HEADER END 200Sstevel@tonic-gate */ 216812Sraf 220Sstevel@tonic-gate/* 236812Sraf * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 240Sstevel@tonic-gate * Use is subject to license terms. 250Sstevel@tonic-gate */ 260Sstevel@tonic-gate 27*7298SMark.J.Nelson@Sun.COM .file "strcmp.s" 280Sstevel@tonic-gate 290Sstevel@tonic-gate/* strcmp(s1, s2) 300Sstevel@tonic-gate * 310Sstevel@tonic-gate * Compare strings: s1>s2: >0 s1==s2: 0 s1<s2: <0 320Sstevel@tonic-gate * 330Sstevel@tonic-gate * Fast assembler language version of the following C-program for strcmp 340Sstevel@tonic-gate * which represents the `standard' for the C-library. 350Sstevel@tonic-gate * 360Sstevel@tonic-gate * int 370Sstevel@tonic-gate * strcmp(s1, s2) 380Sstevel@tonic-gate * register const char *s1; 390Sstevel@tonic-gate * register const char *s2; 400Sstevel@tonic-gate * { 410Sstevel@tonic-gate * 420Sstevel@tonic-gate * if(s1 == s2) 430Sstevel@tonic-gate * return(0); 440Sstevel@tonic-gate * while(*s1 == *s2++) 450Sstevel@tonic-gate * if(*s1++ == '\0') 460Sstevel@tonic-gate * return(0); 470Sstevel@tonic-gate * return(*s1 - s2[-1]); 480Sstevel@tonic-gate * } 490Sstevel@tonic-gate */ 500Sstevel@tonic-gate 510Sstevel@tonic-gate#include <sys/asm_linkage.h> 520Sstevel@tonic-gate 530Sstevel@tonic-gate ! This strcmp implementation first determines whether s1 is aligned. 540Sstevel@tonic-gate ! If it is not, it attempts to align it and then checks the 550Sstevel@tonic-gate ! alignment of the destination string. If it is possible to 560Sstevel@tonic-gate ! align s2, this also happens and then the compare begins. Otherwise, 570Sstevel@tonic-gate ! a different compare for non-aligned strings is used. 580Sstevel@tonic-gate 590Sstevel@tonic-gate ENTRY(strcmp) 600Sstevel@tonic-gate 610Sstevel@tonic-gate .align 32 620Sstevel@tonic-gate 630Sstevel@tonic-gate subcc %o0, %o1, %o2 ! s1 == s2 ? 640Sstevel@tonic-gate bz,pn %xcc, .stringsequal ! yup, same string, done 650Sstevel@tonic-gate sethi %hi(0x01010101), %o5 ! magic2<31:13> 660Sstevel@tonic-gate andcc %o0, 7, %o3 ! s1 sword-aligned ? 670Sstevel@tonic-gate or %o5, %lo(0x01010101),%o5! magic2<31:0> 680Sstevel@tonic-gate bz,pn %xcc, .s1aligned ! yup 690Sstevel@tonic-gate sllx %o5, 32, %o4 ! magic2<63:32> 700Sstevel@tonic-gate sub %o3, 8, %o3 ! number of bytes till s1 aligned 710Sstevel@tonic-gate 720Sstevel@tonic-gate.aligns1: 730Sstevel@tonic-gate ldub [%o1 + %o2], %o0 ! s1[] 740Sstevel@tonic-gate ldub [%o1], %g1 ! s2[] 750Sstevel@tonic-gate subcc %o0, %g1, %o0 ! s1[] != s2[] ? 760Sstevel@tonic-gate bne,pn %xcc, .done ! yup, done 770Sstevel@tonic-gate addcc %o0, %g1, %g0 ! s1[] == 0 ? 780Sstevel@tonic-gate bz,pn %xcc, .done ! yup, done 790Sstevel@tonic-gate inccc %o3 ! s1 aligned yet? 800Sstevel@tonic-gate bnz,pt %xcc, .aligns1 ! nope, compare another pair of bytes 810Sstevel@tonic-gate inc %o1 ! s1++, s2++ 820Sstevel@tonic-gate 830Sstevel@tonic-gate.s1aligned: 840Sstevel@tonic-gate andcc %o1, 7, %o3 ! s2 dword aligned ? 850Sstevel@tonic-gate or %o5, %o4, %o5 ! magic2<63:0> 860Sstevel@tonic-gate bz,pn %xcc, .s2aligned ! yup 870Sstevel@tonic-gate sllx %o5, 7, %o4 ! magic1 880Sstevel@tonic-gate sllx %o3, 3, %g5 ! leftshift = 8*ofs 890Sstevel@tonic-gate orn %g0, %g0, %g1 ! all ones 900Sstevel@tonic-gate and %o1, -8, %o1 ! round s1 down to next aligned dword 910Sstevel@tonic-gate srlx %g1, %g5, %g1 ! mask for fixing up bytes 920Sstevel@tonic-gate ldx [%o1], %o0 ! new lower dword in s2 930Sstevel@tonic-gate orn %o0, %g1, %o0 ! force start bytes to non-zero 940Sstevel@tonic-gate sub %g0, %g5, %g4 ! rightshift = -(8*ofs) mod 64 950Sstevel@tonic-gate sllx %o0, %g5, %g1 ! partial unaligned word from s2 960Sstevel@tonic-gate add %o2, %o3, %o2 ! adjust pointers 970Sstevel@tonic-gate nop ! align loop to 16-byte boundary 980Sstevel@tonic-gate nop ! align loop to 16-byte boundary 990Sstevel@tonic-gate 1000Sstevel@tonic-gate.cmp: 1010Sstevel@tonic-gate andn %o4, %o0, %o3 ! ~word & 0x80808080 1020Sstevel@tonic-gate sub %o0, %o5, %o0 ! word - 0x01010101 1030Sstevel@tonic-gate andcc %o0, %o3, %g0 ! (word - 0x01010101) & ~word & 0x80808080 1040Sstevel@tonic-gate bz,a,pt %xcc, .doload ! no null byte in previous word from s2 1050Sstevel@tonic-gate ldx [%o1+8], %o0 ! next aligned word in s2 1060Sstevel@tonic-gate.doload: 1070Sstevel@tonic-gate srlx %o0, %g4, %o3 ! bytes from aligned word from s2 1080Sstevel@tonic-gate or %g1, %o3, %g1 ! merge to get unaligned word from s2 1090Sstevel@tonic-gate ldx [%o1 + %o2], %o3 ! word from s1 1100Sstevel@tonic-gate cmp %o3, %g1 ! *s1 != *s2 ? 1110Sstevel@tonic-gate bne,pn %xcc, .wordsdiffer ! yup, find the byte that is different 1120Sstevel@tonic-gate add %o1, 8, %o1 ! s1+=8, s2+=8 1130Sstevel@tonic-gate andn %o4, %o3, %g1 ! ~word & 0x80808080 1140Sstevel@tonic-gate sub %o3, %o5, %o3 ! word - 0x01010101 1150Sstevel@tonic-gate andcc %o3, %g1, %g0 ! (word - 0x01010101) & ~word & 0x80808080 1160Sstevel@tonic-gate bz,pt %xcc, .cmp ! no null-byte in s1 yet 1170Sstevel@tonic-gate sllx %o0, %g5, %g1 ! partial unaligned word from s2 1180Sstevel@tonic-gate 1190Sstevel@tonic-gate ! words are equal but the end of s1 has been reached 1200Sstevel@tonic-gate ! this means the strings must be equal 1210Sstevel@tonic-gate.strequal: 1220Sstevel@tonic-gate retl ! return from leaf function 1230Sstevel@tonic-gate mov %g0, %o0 ! return 0, i.e. strings are equal 1240Sstevel@tonic-gate nop 1250Sstevel@tonic-gate 1260Sstevel@tonic-gate.s2aligned: 1270Sstevel@tonic-gate ldx [%o1 + %o2], %o3 ! load word from s1 1280Sstevel@tonic-gate 1290Sstevel@tonic-gate.cmpaligned: 1300Sstevel@tonic-gate ldx [%o1], %g1 ! load word from s2 1310Sstevel@tonic-gate cmp %o3, %g1 ! *scr1 == *src2 ? 1320Sstevel@tonic-gate bne,pn %xcc, .wordsdiffer ! nope, find mismatching character 1330Sstevel@tonic-gate add %o1, 8, %o1 ! src1 += 8, src2 += 8 1340Sstevel@tonic-gate andn %o4, %o3, %o0 ! ~word & 0x80808080 1350Sstevel@tonic-gate sub %o3, %o5, %o3 ! word - 0x01010101 1360Sstevel@tonic-gate andcc %o3, %o0, %g0 ! (word - 0x01010101) & ~word & 0x80808080 1370Sstevel@tonic-gate bz,a,pt %xcc, .cmpaligned ! no null-byte in s1 yet 1380Sstevel@tonic-gate ldx [%o1 + %o2], %o3 ! load word from s1 1390Sstevel@tonic-gate 1400Sstevel@tonic-gate ! words are equal but the end of s1 has been reached 1410Sstevel@tonic-gate ! this means the strings must be equal 1420Sstevel@tonic-gate 1430Sstevel@tonic-gate.stringsequal: 1440Sstevel@tonic-gate retl ! return from leaf function 1450Sstevel@tonic-gate mov %g0, %o0 ! return 0, i.e. strings are equal 1460Sstevel@tonic-gate nop ! align loop on 16-byte boundary 1470Sstevel@tonic-gate nop ! align loop on 16-byte boundary 1480Sstevel@tonic-gate nop ! align loop on 16-byte boundary 1490Sstevel@tonic-gate 1500Sstevel@tonic-gate.wordsdiffer: 1510Sstevel@tonic-gate mov 56, %o4 ! initial shift count 1520Sstevel@tonic-gate srlx %g1, %o4, %o2 ! first byte of mismatching word in s2 1530Sstevel@tonic-gate.cmpbytes: 1540Sstevel@tonic-gate srlx %o3, %o4, %o1 ! first byte of mismatching word in s1 1550Sstevel@tonic-gate subcc %o1, %o2, %o0 ! *s1-*s2 1560Sstevel@tonic-gate bnz,pn %xcc, .done ! bytes differ, return difference 1570Sstevel@tonic-gate nop 1580Sstevel@tonic-gate andcc %o1, 0xff, %o0 ! *s1 == 0 ? 1590Sstevel@tonic-gate bz,pn %xcc, .done ! yup, strings match 1600Sstevel@tonic-gate subcc %o4, 8, %o4 ! shift_count -= 8 1610Sstevel@tonic-gate bpos,pt %xcc, .cmpbytes ! until all bytes processed 1620Sstevel@tonic-gate srlx %g1, %o4, %o2 ! first byte of mismatching word in s2 1630Sstevel@tonic-gate 1640Sstevel@tonic-gate.done: 1650Sstevel@tonic-gate retl ! return from leaf routine 1660Sstevel@tonic-gate nop ! padding 1670Sstevel@tonic-gate 1680Sstevel@tonic-gate SET_SIZE(strcmp) 169