17c478bd9Sstevel@tonic-gate/* 27c478bd9Sstevel@tonic-gate * CDDL HEADER START 37c478bd9Sstevel@tonic-gate * 47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 57257d1b4Sraf * Common Development and Distribution License (the "License"). 67257d1b4Sraf * You may not use this file except in compliance with the License. 77c478bd9Sstevel@tonic-gate * 87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 117c478bd9Sstevel@tonic-gate * and limitations under the License. 127c478bd9Sstevel@tonic-gate * 137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 187c478bd9Sstevel@tonic-gate * 197c478bd9Sstevel@tonic-gate * CDDL HEADER END 207c478bd9Sstevel@tonic-gate */ 217257d1b4Sraf 227c478bd9Sstevel@tonic-gate/* 237257d1b4Sraf * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 247c478bd9Sstevel@tonic-gate * Use is subject to license terms. 257c478bd9Sstevel@tonic-gate */ 267c478bd9Sstevel@tonic-gate 27*9a70fc3bSMark J. Nelson .file "strchr.s" 287c478bd9Sstevel@tonic-gate 297c478bd9Sstevel@tonic-gate/* 307c478bd9Sstevel@tonic-gate * The strchr() function returns a pointer to the first occurrence of c 317c478bd9Sstevel@tonic-gate * (converted to a char) in string s, or a null pointer if c does not occur 327c478bd9Sstevel@tonic-gate * in the string. 337c478bd9Sstevel@tonic-gate */ 347c478bd9Sstevel@tonic-gate 357c478bd9Sstevel@tonic-gate#include <sys/asm_linkage.h> 367c478bd9Sstevel@tonic-gate 377c478bd9Sstevel@tonic-gate ! Here, we start by checking to see if we're searching the dest 387c478bd9Sstevel@tonic-gate ! string for a null byte. We have fast code for this, so it's 397c478bd9Sstevel@tonic-gate ! an important special case. Otherwise, if the string is not 407c478bd9Sstevel@tonic-gate ! word aligned, we check a for the search char a byte at a time 417c478bd9Sstevel@tonic-gate ! until we've reached a word boundary. Once this has happened 427c478bd9Sstevel@tonic-gate ! some zero-byte finding values are initialized and the string 437c478bd9Sstevel@tonic-gate ! is checked a word at a time 447c478bd9Sstevel@tonic-gate 457c478bd9Sstevel@tonic-gate ENTRY(strchr) 467c478bd9Sstevel@tonic-gate 477c478bd9Sstevel@tonic-gate .align 32 487c478bd9Sstevel@tonic-gate 497c478bd9Sstevel@tonic-gate andcc %o1, 0xff, %o1 ! search only for this one byte 507c478bd9Sstevel@tonic-gate bz .searchnullbyte ! faster code for searching null 517c478bd9Sstevel@tonic-gate andcc %o0, 3, %o4 ! str word aligned ? 527c478bd9Sstevel@tonic-gate bz,a .prepword2 ! yup, prepare for word-wise search 537c478bd9Sstevel@tonic-gate sll %o1, 8, %g1 ! start spreading findchar across word 547c478bd9Sstevel@tonic-gate 557c478bd9Sstevel@tonic-gate ldub [%o0], %o2 ! str[0] 567c478bd9Sstevel@tonic-gate cmp %o2, %o1 ! str[0] == findchar ? 577c478bd9Sstevel@tonic-gate be .done ! yup, done 587c478bd9Sstevel@tonic-gate tst %o2 ! str[0] == 0 ? 597c478bd9Sstevel@tonic-gate bz .notfound ! yup, return null pointer 607c478bd9Sstevel@tonic-gate cmp %o4, 3 ! only one byte needed to align? 617c478bd9Sstevel@tonic-gate bz .prepword ! yup, prepare for word-wise search 627c478bd9Sstevel@tonic-gate inc %o0 ! str++ 637c478bd9Sstevel@tonic-gate ldub [%o0], %o2 ! str[1] 647c478bd9Sstevel@tonic-gate cmp %o2, %o1 ! str[1] == findchar ? 657c478bd9Sstevel@tonic-gate be .done ! yup, done 667c478bd9Sstevel@tonic-gate tst %o2 ! str[1] == 0 ? 677c478bd9Sstevel@tonic-gate bz .notfound ! yup, return null pointer 687c478bd9Sstevel@tonic-gate cmp %o4, 2 ! only two bytes needed to align? 697c478bd9Sstevel@tonic-gate bz .prepword ! yup, prepare for word-wise search 707c478bd9Sstevel@tonic-gate inc %o0 ! str++ 717c478bd9Sstevel@tonic-gate ldub [%o0], %o2 ! str[2] 727c478bd9Sstevel@tonic-gate cmp %o2, %o1 ! str[2] == findchar ? 737c478bd9Sstevel@tonic-gate be .done ! yup, done 747c478bd9Sstevel@tonic-gate tst %o2 ! str[2] == 0 ? 757c478bd9Sstevel@tonic-gate bz .notfound ! yup, return null pointer 767c478bd9Sstevel@tonic-gate inc %o0 ! str++ 777c478bd9Sstevel@tonic-gate 787c478bd9Sstevel@tonic-gate.prepword: 797c478bd9Sstevel@tonic-gate sll %o1, 8, %g1 ! spread findchar ------+ 807c478bd9Sstevel@tonic-gate.prepword2: ! 817c478bd9Sstevel@tonic-gate sethi %hi(0x01010101), %o4 ! Alan Mycroft's magic1 ! 827c478bd9Sstevel@tonic-gate or %o1, %g1, %o1 ! across all <---------+ 837c478bd9Sstevel@tonic-gate sethi %hi(0x80808080), %o5 ! Alan Mycroft's magic2 ! 847c478bd9Sstevel@tonic-gate sll %o1, 16, %g1 ! four bytes <--------+ 857c478bd9Sstevel@tonic-gate or %o4, %lo(0x01010101), %o4 ! 867c478bd9Sstevel@tonic-gate or %o1, %g1, %o1 ! of a word <--------+ 877c478bd9Sstevel@tonic-gate or %o5, %lo(0x80808080), %o5 887c478bd9Sstevel@tonic-gate 897c478bd9Sstevel@tonic-gate.searchchar: 907c478bd9Sstevel@tonic-gate lduw [%o0], %o2 ! src word 917c478bd9Sstevel@tonic-gate andn %o5, %o2, %o3 ! ~word & 0x80808080 927c478bd9Sstevel@tonic-gate sub %o2, %o4, %g1 ! word = (word - 0x01010101) 937c478bd9Sstevel@tonic-gate andcc %o3, %g1, %g0 ! ((word - 0x01010101) & ~word & 0x80808080) 947c478bd9Sstevel@tonic-gate bnz .haszerobyte ! zero byte if magic expression != 0 957c478bd9Sstevel@tonic-gate xor %o2, %o1, %g1 ! tword = word ^ findchar 967c478bd9Sstevel@tonic-gate andn %o5, %g1, %o3 ! ~tword & 0x80808080 977c478bd9Sstevel@tonic-gate sub %g1, %o4, %o2 ! (tword - 0x01010101) 987c478bd9Sstevel@tonic-gate andcc %o3, %o2, %g0 ! ((tword - 0x01010101) & ~tword & 0x80808080) 997c478bd9Sstevel@tonic-gate bz,a .searchchar ! no findchar if magic expression == 0 1007c478bd9Sstevel@tonic-gate add %o0, 4, %o0 ! str += 4 1017c478bd9Sstevel@tonic-gate 1027c478bd9Sstevel@tonic-gate ! here we know "word" contains the searched character, but no null 1037c478bd9Sstevel@tonic-gate ! byte. if there was a null byte, we would have gone to .haszerobyte 1047c478bd9Sstevel@tonic-gate ! "tword" has null bytes where "word" had findchar. Examine "tword" 1057c478bd9Sstevel@tonic-gate 1067c478bd9Sstevel@tonic-gate.foundchar: 1077c478bd9Sstevel@tonic-gate set 0xff000000, %o4 ! mask for 1st byte 1087c478bd9Sstevel@tonic-gate andcc %g1, %o4, %g0 ! first byte zero (= found search char) ? 1097c478bd9Sstevel@tonic-gate bz .done ! yup, done 1107c478bd9Sstevel@tonic-gate set 0x00ff0000, %o5 ! mask for 2nd byte 1117c478bd9Sstevel@tonic-gate inc %o0 ! str++ 1127c478bd9Sstevel@tonic-gate andcc %g1, %o5, %g0 ! second byte zero (= found search char) ? 1137c478bd9Sstevel@tonic-gate bz .done ! yup, done 1147c478bd9Sstevel@tonic-gate srl %o4, 16, %o4 ! 0x0000ff00 = mask for 3rd byte 1157c478bd9Sstevel@tonic-gate inc %o0 ! str++ 1167c478bd9Sstevel@tonic-gate andcc %g1, %o4, %g0 ! third byte zero (= found search char) ? 1177c478bd9Sstevel@tonic-gate bnz,a .done ! nope, increment in delay slot 1187c478bd9Sstevel@tonic-gate inc %o0 ! str++ 1197c478bd9Sstevel@tonic-gate 1207c478bd9Sstevel@tonic-gate.done: 1217c478bd9Sstevel@tonic-gate retl ! done with leaf function 1227c478bd9Sstevel@tonic-gate nop ! padding 1237c478bd9Sstevel@tonic-gate 1247c478bd9Sstevel@tonic-gate ! Here we know that "word" contains a null byte indicating the 1257c478bd9Sstevel@tonic-gate ! end of the string. However, "word" might also contain findchar 1267c478bd9Sstevel@tonic-gate ! "tword" (in %g1) has null bytes where "word" had findchar. So 1277c478bd9Sstevel@tonic-gate ! check both "tword" and "word" 1287c478bd9Sstevel@tonic-gate 1297c478bd9Sstevel@tonic-gate.haszerobyte: 1307c478bd9Sstevel@tonic-gate set 0xff000000, %o4 ! mask for 1st byte 1317c478bd9Sstevel@tonic-gate andcc %g1, %o4, %g0 ! first byte == findchar ? 1327c478bd9Sstevel@tonic-gate bz .done ! yup, done 1337c478bd9Sstevel@tonic-gate andcc %o2, %o4, %g0 ! first byte == 0 ? 1347c478bd9Sstevel@tonic-gate bz .notfound ! yup, return null pointer 1357c478bd9Sstevel@tonic-gate set 0x00ff0000, %o4 ! mask for 2nd byte 1367c478bd9Sstevel@tonic-gate inc %o0 ! str++ 1377c478bd9Sstevel@tonic-gate andcc %g1, %o4, %g0 ! second byte == findchar ? 1387c478bd9Sstevel@tonic-gate bz .done ! yup, done 1397c478bd9Sstevel@tonic-gate andcc %o2, %o4, %g0 ! second byte == 0 ? 1407c478bd9Sstevel@tonic-gate bz .notfound ! yup, return null pointer 1417c478bd9Sstevel@tonic-gate srl %o4, 8, %o4 ! mask for 3rd byte = 0x0000ff00 1427c478bd9Sstevel@tonic-gate inc %o0 ! str++ 1437c478bd9Sstevel@tonic-gate andcc %g1, %o4, %g0 ! third byte == findchar ? 1447c478bd9Sstevel@tonic-gate bz .done ! yup, done 1457c478bd9Sstevel@tonic-gate andcc %o2, %o4, %g0 ! third byte == 0 ? 1467c478bd9Sstevel@tonic-gate bz .notfound ! yup, return null pointer 1477c478bd9Sstevel@tonic-gate andcc %g1, 0xff, %g0 ! fourth byte == findchar ? 1487c478bd9Sstevel@tonic-gate bz .done ! yup, done 1497c478bd9Sstevel@tonic-gate inc %o0 ! str++ 1507c478bd9Sstevel@tonic-gate 1517c478bd9Sstevel@tonic-gate.notfound: 1527c478bd9Sstevel@tonic-gate retl ! done with leaf function 1537c478bd9Sstevel@tonic-gate xor %o0, %o0, %o0 ! return null pointer 1547c478bd9Sstevel@tonic-gate 1557c478bd9Sstevel@tonic-gate ! since findchar == 0, we only have to do one test per item 1567c478bd9Sstevel@tonic-gate ! instead of two. This makes the search much faster. 1577c478bd9Sstevel@tonic-gate 1587c478bd9Sstevel@tonic-gate.searchnullbyte: 1597c478bd9Sstevel@tonic-gate bz .straligned ! str is word aligned 1607c478bd9Sstevel@tonic-gate nop ! padding 1617c478bd9Sstevel@tonic-gate 1627c478bd9Sstevel@tonic-gate cmp %o4, 2 ! str halfword aligned ? 1637c478bd9Sstevel@tonic-gate be .s2aligned ! yup 1647c478bd9Sstevel@tonic-gate ldub [%o0], %o1 ! str[0] 1657c478bd9Sstevel@tonic-gate tst %o1 ! byte zero? 1667c478bd9Sstevel@tonic-gate bz .done2 ! yup, done 1677c478bd9Sstevel@tonic-gate cmp %o4, 3 ! only one byte needed to align? 1687c478bd9Sstevel@tonic-gate bz .straligned ! yup 1697c478bd9Sstevel@tonic-gate inc %o0 ! str++ 1707c478bd9Sstevel@tonic-gate 1717c478bd9Sstevel@tonic-gate ! check to see if we're half word aligned, which it better than 1727c478bd9Sstevel@tonic-gate ! not being aligned at all. Search the first half of the word 1737c478bd9Sstevel@tonic-gate ! if we are, and then search by whole word. 1747c478bd9Sstevel@tonic-gate 1757c478bd9Sstevel@tonic-gate.s2aligned: 1767c478bd9Sstevel@tonic-gate lduh [%o0], %o1 ! str[] 1777c478bd9Sstevel@tonic-gate srl %o1, 8, %o4 ! %o4<7:0> = first byte 1787c478bd9Sstevel@tonic-gate tst %o4 ! first byte zero ? 1797c478bd9Sstevel@tonic-gate bz .done2 ! yup, done 1807c478bd9Sstevel@tonic-gate andcc %o1, 0xff, %g0 ! second byte zero ? 1817c478bd9Sstevel@tonic-gate bz,a .done2 ! yup, done 1827c478bd9Sstevel@tonic-gate inc %o0 ! str++ 1837c478bd9Sstevel@tonic-gate add %o0, 2, %o0 ! str+=2 1847c478bd9Sstevel@tonic-gate 1857c478bd9Sstevel@tonic-gate.straligned: 1867c478bd9Sstevel@tonic-gate sethi %hi(0x01010101), %o4 ! Alan Mycroft's magic1 1877c478bd9Sstevel@tonic-gate sethi %hi(0x80808080), %o5 ! Alan Mycroft's magic2 1887c478bd9Sstevel@tonic-gate or %o4, %lo(0x01010101), %o4 1897c478bd9Sstevel@tonic-gate or %o5, %lo(0x80808080), %o5 1907c478bd9Sstevel@tonic-gate 1917c478bd9Sstevel@tonic-gate.searchword: 1927c478bd9Sstevel@tonic-gate lduw [%o0], %o1 ! src word 1937c478bd9Sstevel@tonic-gate andn %o5, %o1, %o3 ! ~word & 0x80808080 1947c478bd9Sstevel@tonic-gate sub %o1, %o4, %g1 ! word = (word - 0x01010101) 1957c478bd9Sstevel@tonic-gate andcc %o3, %g1, %g0 ! ((word - 0x01010101) & ~word & 0x80808080) 1967c478bd9Sstevel@tonic-gate bz,a .searchword ! no zero byte if magic expression == 0 1977c478bd9Sstevel@tonic-gate add %o0, 4, %o0 ! str += 4 1987c478bd9Sstevel@tonic-gate 1997c478bd9Sstevel@tonic-gate.zerobyte: 2007c478bd9Sstevel@tonic-gate set 0xff000000, %o4 ! mask for 1st byte 2017c478bd9Sstevel@tonic-gate andcc %o1, %o4, %g0 ! first byte zero? 2027c478bd9Sstevel@tonic-gate bz .done2 ! yup, done 2037c478bd9Sstevel@tonic-gate set 0x00ff0000, %o5 ! mask for 2nd byte 2047c478bd9Sstevel@tonic-gate inc %o0 ! str++ 2057c478bd9Sstevel@tonic-gate andcc %o1, %o5, %g0 ! second byte zero? 2067c478bd9Sstevel@tonic-gate bz .done2 ! yup, done 2077c478bd9Sstevel@tonic-gate srl %o4, 16, %o4 ! 0x0000ff00 = mask for 3rd byte 2087c478bd9Sstevel@tonic-gate inc %o0 ! str++ 2097c478bd9Sstevel@tonic-gate andcc %o1, %o4, %g0 ! third byte zero? 2107c478bd9Sstevel@tonic-gate bnz,a .done2 ! nope, increment in delay slot 2117c478bd9Sstevel@tonic-gate inc %o0 ! str++ 2127c478bd9Sstevel@tonic-gate.done2: 2137c478bd9Sstevel@tonic-gate retl ! return from leaf function 2147c478bd9Sstevel@tonic-gate nop ! padding 2157c478bd9Sstevel@tonic-gate 2167c478bd9Sstevel@tonic-gate SET_SIZE(strchr) 217