xref: /onnv-gate/usr/src/lib/libc/sparcv9/gen/strcpy.s (revision 7298:b69e27387f74)
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	"strcpy.s"
280Sstevel@tonic-gate
290Sstevel@tonic-gate/*
300Sstevel@tonic-gate * strcpy(s1, s2)
310Sstevel@tonic-gate *
320Sstevel@tonic-gate * Copy string s2 to s1.  s1 must be large enough. Return s1.
330Sstevel@tonic-gate *
340Sstevel@tonic-gate * Fast assembler language version of the following C-program strcpy
350Sstevel@tonic-gate * which represents the `standard' for the C-library.
360Sstevel@tonic-gate *
370Sstevel@tonic-gate *	char *
380Sstevel@tonic-gate *	strcpy(s1, s2)
390Sstevel@tonic-gate *	register char *s1;
400Sstevel@tonic-gate *	register const char *s2;
410Sstevel@tonic-gate *	{
420Sstevel@tonic-gate *		char *os1 = s1;
430Sstevel@tonic-gate *
440Sstevel@tonic-gate *		while(*s1++ = *s2++)
450Sstevel@tonic-gate *			;
460Sstevel@tonic-gate *		return(os1);
470Sstevel@tonic-gate *	}
480Sstevel@tonic-gate *
490Sstevel@tonic-gate */
500Sstevel@tonic-gate
510Sstevel@tonic-gate#include <sys/asm_linkage.h>
520Sstevel@tonic-gate
530Sstevel@tonic-gate	! This implementation of strcpy works by first checking the
540Sstevel@tonic-gate	! source alignment and copying byte, half byte, or word
550Sstevel@tonic-gate	! quantities until the source ptr is aligned at an extended
560Sstevel@tonic-gate	! word boundary.  Once this has occurred, the string is copied,
570Sstevel@tonic-gate	! checking for zero bytes, depending upon its dst ptr alignment.
580Sstevel@tonic-gate	! (methods for xword, word, half-word, and byte copies are present)
590Sstevel@tonic-gate
600Sstevel@tonic-gate	ENTRY(strcpy)
610Sstevel@tonic-gate
620Sstevel@tonic-gate	.align 32
630Sstevel@tonic-gate
640Sstevel@tonic-gate	sub	%o1, %o0, %o3		! src - dst
650Sstevel@tonic-gate	andcc	%o1, 7, %o4		! dword aligned ?
660Sstevel@tonic-gate	bz,pn	%ncc, .srcaligned	! yup
670Sstevel@tonic-gate	mov	%o0, %o2		! save dst
680Sstevel@tonic-gate
690Sstevel@tonic-gate.chkbyte:
700Sstevel@tonic-gate	andcc	%o1, 1, %g0		! need to copy byte ?
710Sstevel@tonic-gate	bz,pn	%ncc, .chkhalfword	! nope, maybe halfword
720Sstevel@tonic-gate	sub	%g0, %o1, %g1		! %g1<2:0> = # of unaligned bytes
730Sstevel@tonic-gate	ldub	[%o2 + %o3], %o5	! src[0]
740Sstevel@tonic-gate	tst	%o5			! src[0] == 0 ?
750Sstevel@tonic-gate	stb	%o5, [%o2]		! dst[0] = src[0]
760Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
770Sstevel@tonic-gate	inc	%o2			! src++, dst++
780Sstevel@tonic-gate
790Sstevel@tonic-gate.chkhalfword:
800Sstevel@tonic-gate	andcc	%g1, 2, %g0		! need to copy half-word ?
810Sstevel@tonic-gate	bz,pn	%ncc, .chkword		! nope, maybe word
820Sstevel@tonic-gate	nop				!
830Sstevel@tonic-gate	lduh	[%o2 + %o3], %o5	! load src halfword
840Sstevel@tonic-gate	srl	%o5, 8, %o4		! extract first byte
850Sstevel@tonic-gate	tst	%o4			! first byte == 0 ?
860Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
870Sstevel@tonic-gate	stb	%o4, [%o2]		! store first byte
880Sstevel@tonic-gate	andcc	%o5, 0xff, %g0		! extract second byte
890Sstevel@tonic-gate	stb 	%o5, [%o2 + 1]		! store second byte
900Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, 2nd byte zero, done
910Sstevel@tonic-gate	add	%o2, 2, %o2		! src += 2
920Sstevel@tonic-gate
930Sstevel@tonic-gate.chkword:
940Sstevel@tonic-gate	andcc	%g1, 4, %g0		! need to copy word ?
950Sstevel@tonic-gate	bz,pn	%ncc, .srcaligned	! nope
960Sstevel@tonic-gate	nop				!
970Sstevel@tonic-gate	lduw	[%o2 + %o3], %o5	! load src word
980Sstevel@tonic-gate	srl	%o5, 24, %o4		! extract first byte
990Sstevel@tonic-gate	tst	%o4			! is first byte zero ?
1000Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1010Sstevel@tonic-gate	stb	%o4, [%o2]		! store first byte
1020Sstevel@tonic-gate	srl	%o5, 16, %o4		! extract second byte
1030Sstevel@tonic-gate	andcc	%o4, 0xff, %g0		! is second byte zero ?
1040Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1050Sstevel@tonic-gate	stb	%o4, [%o2 + 1]		! store second byte
1060Sstevel@tonic-gate	srl	%o5, 8, %o4		! extract third byte
1070Sstevel@tonic-gate	andcc	%o4, 0xff, %g0		! third byte zero ?
1080Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1090Sstevel@tonic-gate	stb	%o4, [%o2 + 2]		! store third byte
1100Sstevel@tonic-gate	andcc	%o5, 0xff, %g0		! fourth byte zero ?
1110Sstevel@tonic-gate	stb 	%o5, [%o2 + 3]		! store fourth byte
1120Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, fourth byte zero, done
1130Sstevel@tonic-gate	add	%o2, 4, %o2		! src += 2
1140Sstevel@tonic-gate
1150Sstevel@tonic-gate.srcaligned:
1160Sstevel@tonic-gate	sethi	%hi(0x01010101), %o4	! Alan Mycroft's magic1
1170Sstevel@tonic-gate	or	%o4, %lo(0x01010101),%o4!  finish loading magic1
1180Sstevel@tonic-gate	sllx	%o4, 32, %o1		! spread magic1
1190Sstevel@tonic-gate	and	%o2, 3, %g4		! dst<1:0> to examine offset
1200Sstevel@tonic-gate	or	%o4, %o1, %o4		!   to all 64 bits
1210Sstevel@tonic-gate	cmp	%g4, 1			! dst offset of 1 or 5
1220Sstevel@tonic-gate	sllx	%o4, 7, %o5		!  Alan Mycroft's magic2
1230Sstevel@tonic-gate	be,pn	%ncc, .storebyte1241	! store 1, 2, 4, 1 bytes
1240Sstevel@tonic-gate	cmp	%g4, 3			! dst offset of 3 or 7
1250Sstevel@tonic-gate	be,pn	%ncc, .storebyte1421	! store 1, 4, 2, 1 bytes
1260Sstevel@tonic-gate	cmp	%g4, 2			! dst halfword aligned ?
1270Sstevel@tonic-gate	be,pn	%ncc, .storehalfword	! yup, store half-word wise
1280Sstevel@tonic-gate	andcc	%o2, 7, %g0		! dst word aligned ?
1290Sstevel@tonic-gate	bnz,pn	%ncc, .storeword2	! yup, store word wise
1300Sstevel@tonic-gate	.empty
1310Sstevel@tonic-gate
1320Sstevel@tonic-gate.storedword:
1330Sstevel@tonic-gate	ldx	[%o2 + %o3], %o1	! src dword
1340Sstevel@tonic-gate	add	%o2, 8, %o2		! src += 8, dst += 8
1350Sstevel@tonic-gate	andn	%o5, %o1, %g1		! ~dword & 0x8080808080808080
1360Sstevel@tonic-gate	sub	%o1, %o4, %g4		! dword - 0x0101010101010101
1370Sstevel@tonic-gate	andcc	%g4, %g1, %g0		! ((dword - 0x0101010101010101) & ~dword & 0x8080808080808080)
1380Sstevel@tonic-gate	bz,a,pt	%ncc, .storedword	! no zero byte if magic expression == 0
1390Sstevel@tonic-gate	stx	%o1, [%o2 - 8]		! store word to dst (address pre-incremented)
1400Sstevel@tonic-gate
1410Sstevel@tonic-gate.zerobyte:
1420Sstevel@tonic-gate	orn	%o4, %g0, %o4		! 0xffffffffffffffff
1430Sstevel@tonic-gate	sllx	%o4, 56, %o4		! 0xff00000000000000
1440Sstevel@tonic-gate	srlx	%o1, 56, %o3		! %o3<7:0> = first byte
1450Sstevel@tonic-gate	andcc	%o1, %o4, %g0		! first byte zero?
1460Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1470Sstevel@tonic-gate	stb	%o3, [%o2 - 8]		! store first byte
1480Sstevel@tonic-gate	srlx	%o4, 8, %o4		! 0x00ff000000000000
1490Sstevel@tonic-gate	srlx	%o1, 48, %o3		! %o3<7:0> = second byte
1500Sstevel@tonic-gate	andcc	%o1, %o4, %g0		! second byte zero?
1510Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1520Sstevel@tonic-gate	stb	%o3, [%o2 - 7]		! store second byte
1530Sstevel@tonic-gate	srlx	%o4, 8, %o4		! 0x0000ff0000000000
1540Sstevel@tonic-gate	srlx	%o1, 40, %o3		! %o3<7:0> = third byte
1550Sstevel@tonic-gate	andcc	%o1, %o4, %g0		! third byte zero?
1560Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1570Sstevel@tonic-gate	stb	%o3, [%o2 - 6]		! store third byte
1580Sstevel@tonic-gate	srlx	%o4, 8, %o4		! 0x000000ff00000000
1590Sstevel@tonic-gate	srlx	%o1, 32, %o3		! %o3<7:0> = fourth byte
1600Sstevel@tonic-gate	andcc	%o1, %o4, %g0		! fourth byte zero?
1610Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1620Sstevel@tonic-gate	stb	%o3, [%o2 - 5]		! store fourth byte
1630Sstevel@tonic-gate	srlx	%o4, 8, %o4		! 0x00000000ff000000
1640Sstevel@tonic-gate	srlx	%o1, 24, %o3		! %o3<7:0> = fifth byte
1650Sstevel@tonic-gate	andcc	%o1, %o4, %g0		! fifth byte zero?
1660Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1670Sstevel@tonic-gate	stb	%o3, [%o2 - 4]		! store fifth byte
1680Sstevel@tonic-gate	srlx	%o4, 8, %o4		! 0x0000000000ff0000
1690Sstevel@tonic-gate	srlx	%o1, 16, %o3		! %o3<7:0> = sixth byte
1700Sstevel@tonic-gate	andcc	%o1, %o4, %g0		! sixth byte zero?
1710Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1720Sstevel@tonic-gate	stb	%o3, [%o2 - 3]		! store sixth byte
1730Sstevel@tonic-gate	srlx	%o4, 8, %o4		! 0x000000000000ff00
1740Sstevel@tonic-gate	andcc	%o1, %o4, %g0		! seventh byte zero?
1750Sstevel@tonic-gate	srlx	%o1, 8, %o3		! %o3<7:0> = seventh byte
1760Sstevel@tonic-gate	bz,pn	%ncc, .done		! yup, done
1770Sstevel@tonic-gate	stb	%o3, [%o2 - 2]		! store seventh byte
1780Sstevel@tonic-gate	stb	%o1, [%o2 - 1]		! store eigth byte
1790Sstevel@tonic-gate.done:
1800Sstevel@tonic-gate	retl				! done with leaf function
1810Sstevel@tonic-gate
1820Sstevel@tonic-gate	nop				! ensure following loop 16-byte aligned
1830Sstevel@tonic-gate
1840Sstevel@tonic-gate.storebyte1421:
1850Sstevel@tonic-gate	ldx	[%o2 + %o3], %o1	! x = src[]
1860Sstevel@tonic-gate	add	%o2, 8, %o2		! src += 8, dst += 8
1870Sstevel@tonic-gate	andn	%o5, %o1, %g1		! ~x & 0x8080808080808080
1880Sstevel@tonic-gate	sub	%o1, %o4, %g4		! x - 0x0101010101010101
1890Sstevel@tonic-gate	andcc	%g4, %g1, %g0		! ((x - 0x0101010101010101) & ~x & 0x8080808080808080)
1900Sstevel@tonic-gate	bnz,pn	%ncc, .zerobyte		! x has zero byte, handle end cases
1910Sstevel@tonic-gate	srlx	%o1, 56, %g1		! %g1<7:0> = first byte; word aligned now
1920Sstevel@tonic-gate	stb	%g1, [%o2 - 8]		! store first byte
1930Sstevel@tonic-gate	srlx	%o1, 24, %g1		! %g1<31:0> = bytes 2, 3, 4, 5
1940Sstevel@tonic-gate	stw	%g1, [%o2 - 7]		! store bytes 2, 3, 4, 5
1950Sstevel@tonic-gate	srlx	%o1, 8, %g1		! %g1<15:0> = bytes 6, 7
1960Sstevel@tonic-gate	sth	%g1, [%o2 - 3]		! store bytes 6, 7
1970Sstevel@tonic-gate	ba	.storebyte1421		! next dword
1980Sstevel@tonic-gate	stb	%o1, [%o2 - 1]		! store eigth byte
1990Sstevel@tonic-gate
2000Sstevel@tonic-gate	nop				! ensure following loop 16-byte aligned
2010Sstevel@tonic-gate	nop				! ensure following loop 16-byte aligned
2020Sstevel@tonic-gate
2030Sstevel@tonic-gate.storebyte1241:
2040Sstevel@tonic-gate	ldx	[%o2 + %o3], %o1	! x = src[]
2050Sstevel@tonic-gate	add	%o2, 8, %o2		! src += 8, dst += 8
2060Sstevel@tonic-gate	andn	%o5, %o1, %g1		! ~x & 0x8080808080808080
2070Sstevel@tonic-gate	sub	%o1, %o4, %g4		! x - 0x0101010101010101
2080Sstevel@tonic-gate	andcc	%g4, %g1, %g0		! ((x - 0x0101010101010101) & ~x & 0x8080808080808080)
2090Sstevel@tonic-gate	bnz,pn	%ncc, .zerobyte		! x has zero byte, handle end cases
2100Sstevel@tonic-gate	srlx	%o1, 56, %g1		! %g1<7:0> = first byte; word aligned now
2110Sstevel@tonic-gate	stb	%g1, [%o2 - 8]		! store first byte
2120Sstevel@tonic-gate	srlx	%o1, 40, %g1		! %g1<15:0> = bytes 2, 3
2130Sstevel@tonic-gate	sth	%g1, [%o2 - 7]		! store bytes 2, 3
2140Sstevel@tonic-gate	srlx	%o1, 8, %g1		! %g1<31:0> = bytes 4, 5, 6, 7
2150Sstevel@tonic-gate	stw	%g1, [%o2 - 5]		! store bytes 4, 5, 6, 7
2160Sstevel@tonic-gate	ba	.storebyte1241		! next dword
2170Sstevel@tonic-gate	stb	%o1, [%o2 - 1]		! store eigth byte
2180Sstevel@tonic-gate
2190Sstevel@tonic-gate	nop				! ensure following loop 16-byte aligned
2200Sstevel@tonic-gate	nop				! ensure following loop 16-byte aligned
2210Sstevel@tonic-gate
2220Sstevel@tonic-gate.storehalfword:
2230Sstevel@tonic-gate	ldx	[%o2 + %o3], %o1	! x = src[]
2240Sstevel@tonic-gate	add	%o2, 8, %o2		! src += 8, dst += 8
2250Sstevel@tonic-gate	andn	%o5, %o1, %g1		! ~x & 0x8080808080808080
2260Sstevel@tonic-gate	sub	%o1, %o4, %g4		! x - 0x0101010101010101
2270Sstevel@tonic-gate	andcc	%g4, %g1, %g0		! ((x - 0x0101010101010101) & ~x & 0x8080808080808080)
2280Sstevel@tonic-gate	bnz,pn	%ncc, .zerobyte		! x has zero byte, handle end cases
2290Sstevel@tonic-gate	srlx	%o1, 48, %g1		! get first and second byte
2300Sstevel@tonic-gate	sth	%g1, [%o2 - 8]		! store first and second byte; word aligned now
2310Sstevel@tonic-gate	srlx	%o1, 16, %g1		! %g1<31:0> = bytes 3, 4, 5, 6
2320Sstevel@tonic-gate	stw	%g1, [%o2 - 6]		! store bytes 3, 4, 5, 6
2330Sstevel@tonic-gate	ba	.storehalfword		! next word
2340Sstevel@tonic-gate	sth	%o1, [%o2 - 2]		! store seventh and eigth byte
2350Sstevel@tonic-gate
2360Sstevel@tonic-gate.storeword:
2370Sstevel@tonic-gate	ldx	[%o2 + %o3], %o1	! x = src[]
2380Sstevel@tonic-gate.storeword2:
2390Sstevel@tonic-gate	add	%o2, 8, %o2		! src += 8, dst += 8
2400Sstevel@tonic-gate	andn	%o5, %o1, %g1		! ~x & 0x0x8080808080808080
2410Sstevel@tonic-gate	sub	%o1, %o4, %g4		! x - 0x0101010101010101
2420Sstevel@tonic-gate	andcc	%g4, %g1, %g0		! ((x - 0x0101010101010101) & ~x & 0x8080808080808080)
2430Sstevel@tonic-gate	bnz,pn	%ncc, .zerobyte		! x has zero byte, handle end cases
2440Sstevel@tonic-gate	srlx	%o1, 32, %g1		! get bytes 1,2,3,4
2450Sstevel@tonic-gate	stw	%g1, [%o2 - 8]		! store bytes 1,2,3,4 (address is pre-incremented)
2460Sstevel@tonic-gate	ba	.storeword		! no zero byte if magic expression == 0
2470Sstevel@tonic-gate	stw	%o1, [%o2 - 4]		! store bytes 5,6,7,8
2480Sstevel@tonic-gate
2490Sstevel@tonic-gate	nop				! padding, do not remove!!!
2500Sstevel@tonic-gate	nop				! padding, do not remove!!!
2510Sstevel@tonic-gate	SET_SIZE(strcpy)
2520Sstevel@tonic-gate
253