/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ .file "strcpy.s" /* * strcpy(s1, s2) * * Copy string s2 to s1. s1 must be large enough. Return s1. * * Fast assembler language version of the following C-program strcpy * which represents the `standard' for the C-library. * * char * * strcpy(s1, s2) * register char *s1; * register const char *s2; * { * char *os1 = s1; * * while(*s1++ = *s2++) * ; * return(os1); * } * */ #include ! This implementation of strcpy works by first checking the ! source alignment and copying byte, half byte, or word ! quantities until the source ptr is aligned at an extended ! word boundary. Once this has occurred, the string is copied, ! checking for zero bytes, depending upon its dst ptr alignment. ! (methods for xword, word, half-word, and byte copies are present) ENTRY(strcpy) .align 32 sub %o1, %o0, %o3 ! src - dst andcc %o1, 7, %o4 ! dword aligned ? bz,pn %ncc, .srcaligned ! yup mov %o0, %o2 ! save dst .chkbyte: andcc %o1, 1, %g0 ! need to copy byte ? bz,pn %ncc, .chkhalfword ! nope, maybe halfword sub %g0, %o1, %g1 ! %g1<2:0> = # of unaligned bytes ldub [%o2 + %o3], %o5 ! src[0] tst %o5 ! src[0] == 0 ? stb %o5, [%o2] ! dst[0] = src[0] bz,pn %ncc, .done ! yup, done inc %o2 ! src++, dst++ .chkhalfword: andcc %g1, 2, %g0 ! need to copy half-word ? bz,pn %ncc, .chkword ! nope, maybe word nop ! lduh [%o2 + %o3], %o5 ! load src halfword srl %o5, 8, %o4 ! extract first byte tst %o4 ! first byte == 0 ? bz,pn %ncc, .done ! yup, done stb %o4, [%o2] ! store first byte andcc %o5, 0xff, %g0 ! extract second byte stb %o5, [%o2 + 1] ! store second byte bz,pn %ncc, .done ! yup, 2nd byte zero, done add %o2, 2, %o2 ! src += 2 .chkword: andcc %g1, 4, %g0 ! need to copy word ? bz,pn %ncc, .srcaligned ! nope nop ! lduw [%o2 + %o3], %o5 ! load src word srl %o5, 24, %o4 ! extract first byte tst %o4 ! is first byte zero ? bz,pn %ncc, .done ! yup, done stb %o4, [%o2] ! store first byte srl %o5, 16, %o4 ! extract second byte andcc %o4, 0xff, %g0 ! is second byte zero ? bz,pn %ncc, .done ! yup, done stb %o4, [%o2 + 1] ! store second byte srl %o5, 8, %o4 ! extract third byte andcc %o4, 0xff, %g0 ! third byte zero ? bz,pn %ncc, .done ! yup, done stb %o4, [%o2 + 2] ! store third byte andcc %o5, 0xff, %g0 ! fourth byte zero ? stb %o5, [%o2 + 3] ! store fourth byte bz,pn %ncc, .done ! yup, fourth byte zero, done add %o2, 4, %o2 ! src += 2 .srcaligned: sethi %hi(0x01010101), %o4 ! Alan Mycroft's magic1 or %o4, %lo(0x01010101),%o4! finish loading magic1 sllx %o4, 32, %o1 ! spread magic1 and %o2, 3, %g4 ! dst<1:0> to examine offset or %o4, %o1, %o4 ! to all 64 bits cmp %g4, 1 ! dst offset of 1 or 5 sllx %o4, 7, %o5 ! Alan Mycroft's magic2 be,pn %ncc, .storebyte1241 ! store 1, 2, 4, 1 bytes cmp %g4, 3 ! dst offset of 3 or 7 be,pn %ncc, .storebyte1421 ! store 1, 4, 2, 1 bytes cmp %g4, 2 ! dst halfword aligned ? be,pn %ncc, .storehalfword ! yup, store half-word wise andcc %o2, 7, %g0 ! dst word aligned ? bnz,pn %ncc, .storeword2 ! yup, store word wise .empty .storedword: ldx [%o2 + %o3], %o1 ! src dword add %o2, 8, %o2 ! src += 8, dst += 8 andn %o5, %o1, %g1 ! ~dword & 0x8080808080808080 sub %o1, %o4, %g4 ! dword - 0x0101010101010101 andcc %g4, %g1, %g0 ! ((dword - 0x0101010101010101) & ~dword & 0x8080808080808080) bz,a,pt %ncc, .storedword ! no zero byte if magic expression == 0 stx %o1, [%o2 - 8] ! store word to dst (address pre-incremented) .zerobyte: orn %o4, %g0, %o4 ! 0xffffffffffffffff sllx %o4, 56, %o4 ! 0xff00000000000000 srlx %o1, 56, %o3 ! %o3<7:0> = first byte andcc %o1, %o4, %g0 ! first byte zero? bz,pn %ncc, .done ! yup, done stb %o3, [%o2 - 8] ! store first byte srlx %o4, 8, %o4 ! 0x00ff000000000000 srlx %o1, 48, %o3 ! %o3<7:0> = second byte andcc %o1, %o4, %g0 ! second byte zero? bz,pn %ncc, .done ! yup, done stb %o3, [%o2 - 7] ! store second byte srlx %o4, 8, %o4 ! 0x0000ff0000000000 srlx %o1, 40, %o3 ! %o3<7:0> = third byte andcc %o1, %o4, %g0 ! third byte zero? bz,pn %ncc, .done ! yup, done stb %o3, [%o2 - 6] ! store third byte srlx %o4, 8, %o4 ! 0x000000ff00000000 srlx %o1, 32, %o3 ! %o3<7:0> = fourth byte andcc %o1, %o4, %g0 ! fourth byte zero? bz,pn %ncc, .done ! yup, done stb %o3, [%o2 - 5] ! store fourth byte srlx %o4, 8, %o4 ! 0x00000000ff000000 srlx %o1, 24, %o3 ! %o3<7:0> = fifth byte andcc %o1, %o4, %g0 ! fifth byte zero? bz,pn %ncc, .done ! yup, done stb %o3, [%o2 - 4] ! store fifth byte srlx %o4, 8, %o4 ! 0x0000000000ff0000 srlx %o1, 16, %o3 ! %o3<7:0> = sixth byte andcc %o1, %o4, %g0 ! sixth byte zero? bz,pn %ncc, .done ! yup, done stb %o3, [%o2 - 3] ! store sixth byte srlx %o4, 8, %o4 ! 0x000000000000ff00 andcc %o1, %o4, %g0 ! seventh byte zero? srlx %o1, 8, %o3 ! %o3<7:0> = seventh byte bz,pn %ncc, .done ! yup, done stb %o3, [%o2 - 2] ! store seventh byte stb %o1, [%o2 - 1] ! store eigth byte .done: retl ! done with leaf function nop ! ensure following loop 16-byte aligned .storebyte1421: ldx [%o2 + %o3], %o1 ! x = src[] add %o2, 8, %o2 ! src += 8, dst += 8 andn %o5, %o1, %g1 ! ~x & 0x8080808080808080 sub %o1, %o4, %g4 ! x - 0x0101010101010101 andcc %g4, %g1, %g0 ! ((x - 0x0101010101010101) & ~x & 0x8080808080808080) bnz,pn %ncc, .zerobyte ! x has zero byte, handle end cases srlx %o1, 56, %g1 ! %g1<7:0> = first byte; word aligned now stb %g1, [%o2 - 8] ! store first byte srlx %o1, 24, %g1 ! %g1<31:0> = bytes 2, 3, 4, 5 stw %g1, [%o2 - 7] ! store bytes 2, 3, 4, 5 srlx %o1, 8, %g1 ! %g1<15:0> = bytes 6, 7 sth %g1, [%o2 - 3] ! store bytes 6, 7 ba .storebyte1421 ! next dword stb %o1, [%o2 - 1] ! store eigth byte nop ! ensure following loop 16-byte aligned nop ! ensure following loop 16-byte aligned .storebyte1241: ldx [%o2 + %o3], %o1 ! x = src[] add %o2, 8, %o2 ! src += 8, dst += 8 andn %o5, %o1, %g1 ! ~x & 0x8080808080808080 sub %o1, %o4, %g4 ! x - 0x0101010101010101 andcc %g4, %g1, %g0 ! ((x - 0x0101010101010101) & ~x & 0x8080808080808080) bnz,pn %ncc, .zerobyte ! x has zero byte, handle end cases srlx %o1, 56, %g1 ! %g1<7:0> = first byte; word aligned now stb %g1, [%o2 - 8] ! store first byte srlx %o1, 40, %g1 ! %g1<15:0> = bytes 2, 3 sth %g1, [%o2 - 7] ! store bytes 2, 3 srlx %o1, 8, %g1 ! %g1<31:0> = bytes 4, 5, 6, 7 stw %g1, [%o2 - 5] ! store bytes 4, 5, 6, 7 ba .storebyte1241 ! next dword stb %o1, [%o2 - 1] ! store eigth byte nop ! ensure following loop 16-byte aligned nop ! ensure following loop 16-byte aligned .storehalfword: ldx [%o2 + %o3], %o1 ! x = src[] add %o2, 8, %o2 ! src += 8, dst += 8 andn %o5, %o1, %g1 ! ~x & 0x8080808080808080 sub %o1, %o4, %g4 ! x - 0x0101010101010101 andcc %g4, %g1, %g0 ! ((x - 0x0101010101010101) & ~x & 0x8080808080808080) bnz,pn %ncc, .zerobyte ! x has zero byte, handle end cases srlx %o1, 48, %g1 ! get first and second byte sth %g1, [%o2 - 8] ! store first and second byte; word aligned now srlx %o1, 16, %g1 ! %g1<31:0> = bytes 3, 4, 5, 6 stw %g1, [%o2 - 6] ! store bytes 3, 4, 5, 6 ba .storehalfword ! next word sth %o1, [%o2 - 2] ! store seventh and eigth byte .storeword: ldx [%o2 + %o3], %o1 ! x = src[] .storeword2: add %o2, 8, %o2 ! src += 8, dst += 8 andn %o5, %o1, %g1 ! ~x & 0x0x8080808080808080 sub %o1, %o4, %g4 ! x - 0x0101010101010101 andcc %g4, %g1, %g0 ! ((x - 0x0101010101010101) & ~x & 0x8080808080808080) bnz,pn %ncc, .zerobyte ! x has zero byte, handle end cases srlx %o1, 32, %g1 ! get bytes 1,2,3,4 stw %g1, [%o2 - 8] ! store bytes 1,2,3,4 (address is pre-incremented) ba .storeword ! no zero byte if magic expression == 0 stw %o1, [%o2 - 4] ! store bytes 5,6,7,8 nop ! padding, do not remove!!! nop ! padding, do not remove!!! SET_SIZE(strcpy)