/* * 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. */ #pragma ident "%Z%%M% %I% %E% SMI" .file "%M%" #include ANSI_PRAGMA_WEAK(memmove,function) /* * memmove(s1, s2, len) * Copy s2 to s1, always copy n bytes. * For overlapped copies it does the right thing. */ ENTRY(memmove) save %sp, -SA(MINFRAME), %sp ! not a leaf routine any more mov %i0, %l6 ! Save pointer to destination cmp %i1, %i0 ! if from address is >= to use forward copy bgeu,a 2f ! else use backward if ... cmp %i2, 17 ! delay slot, for small counts copy bytes sub %i0, %i1, %i4 ! get difference of two addresses cmp %i2, %i4 ! compare size and difference of addresses bgu ovbc ! if size is bigger, have do overlapped copy cmp %i2, 17 ! delay slot, for small counts copy bytes ! ! normal, copy forwards ! 2: ble dbytecp andcc %i1, 3, %i5 ! is src word aligned bz aldst cmp %i5, 2 ! is src half-word aligned be s2algn cmp %i5, 3 ! src is byte aligned s1algn: ldub [%i1], %i3 ! move 1 or 3 bytes to align it inc 1, %i1 stb %i3, [%i0] ! move a byte to align src inc 1, %i0 bne s2algn dec %i2 b ald ! now go align dest andcc %i0, 3, %i5 s2algn: lduh [%i1], %i3 ! know src is 2 byte alinged inc 2, %i1 srl %i3, 8, %i4 stb %i4, [%i0] ! have to do bytes, stb %i3, [%i0 + 1] ! don't know dst alingment inc 2, %i0 dec 2, %i2 aldst: andcc %i0, 3, %i5 ! align the destination address ald: bz w4cp cmp %i5, 2 bz w2cp cmp %i5, 3 w3cp: ld [%i1], %i4 inc 4, %i1 srl %i4, 24, %i5 stb %i5, [%i0] bne w1cp inc %i0 dec 1, %i2 andn %i2, 3, %i3 ! i3 is aligned word count dec 4, %i3 ! avoid reading beyond tail of src sub %i1, %i0, %i1 ! i1 gets the difference 1: sll %i4, 8, %g1 ! save residual bytes ld [%i1+%i0], %i4 deccc 4, %i3 srl %i4, 24, %i5 ! merge with residual or %i5, %g1, %g1 st %g1, [%i0] bnz 1b inc 4, %i0 sub %i1, 3, %i1 ! used one byte of last word read and %i2, 3, %i2 b 7f inc 4, %i2 w1cp: srl %i4, 8, %i5 sth %i5, [%i0] inc 2, %i0 dec 3, %i2 andn %i2, 3, %i3 dec 4, %i3 ! avoid reading beyond tail of src sub %i1, %i0, %i1 ! i1 gets the difference 2: sll %i4, 24, %g1 ! save residual bytes ld [%i1+%i0], %i4 deccc 4, %i3 srl %i4, 8, %i5 ! merge with residual or %i5, %g1, %g1 st %g1, [%i0] bnz 2b inc 4, %i0 sub %i1, 1, %i1 ! used three bytes of last word read and %i2, 3, %i2 b 7f inc 4, %i2 w2cp: ld [%i1], %i4 inc 4, %i1 srl %i4, 16, %i5 sth %i5, [%i0] inc 2, %i0 dec 2, %i2 andn %i2, 3, %i3 ! i3 is aligned word count dec 4, %i3 ! avoid reading beyond tail of src sub %i1, %i0, %i1 ! i1 gets the difference 3: sll %i4, 16, %g1 ! save residual bytes ld [%i1+%i0], %i4 deccc 4, %i3 srl %i4, 16, %i5 ! merge with residual or %i5, %g1, %g1 st %g1, [%i0] bnz 3b inc 4, %i0 sub %i1, 2, %i1 ! used two bytes of last word read and %i2, 3, %i2 b 7f inc 4, %i2 w4cp: andn %i2, 3, %i3 ! i3 is aligned word count sub %i1, %i0, %i1 ! i1 gets the difference 1: ld [%i1+%i0], %i4 ! read from address deccc 4, %i3 ! decrement count st %i4, [%i0] ! write at destination address bg 1b inc 4, %i0 ! increment to address b 7f and %i2, 3, %i2 ! number of leftover bytes, if any ! ! differenced byte copy, works with any alignment ! dbytecp: b 7f sub %i1, %i0, %i1 ! i1 gets the difference 4: stb %i4, [%i0] ! write to address inc %i0 ! inc to address 7: deccc %i2 ! decrement count bge,a 4b ! loop till done ldub [%i1+%i0], %i4 ! read from address ret restore %l6, %g0, %o0 ! return pointer to destination ! ! an overlapped copy that must be done "backwards" ! ovbc: add %i1, %i2, %i1 ! get to end of source space add %i0, %i2, %i0 ! get to end of destination space sub %i1, %i0, %i1 ! i1 gets the difference 5: dec %i0 ! decrement to address ldub [%i1+%i0], %i3 ! read a byte deccc %i2 ! decrement count bg 5b ! loop until done stb %i3, [%i0] ! write byte ret restore %l6, %g0, %o0 ! return pointer to destination SET_SIZE(memmove)