/* $NetBSD: memmove.S,v 1.1 2014/09/03 19:34:25 matt Exp $ */ /* stropt/memmove.S, pl_string_common, pl_linux 10/11/04 11:45:37 * ========================================================================== * Optimized memmove implementation for IBM PowerPC 405/440. * * Copyright (c) 2003, IBM Corporation * All rights reserved. * * Redistribution and use in source and binary forms, with or * without modification, are permitted provided that the following * conditions are met: * * * Redistributions of source code must retain the above * copyright notice, this list of conditions and the following * disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials * provided with the distribution. * * Neither the name of IBM nor the names of its contributors * may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * ========================================================================== * * Function: Move memory area (handles overlapping regions) * * void *memmove(void * dest, const void * src, int n) * * Input: r3 - destination address * r4 - source address * r5 - byte count * Output: r11 - destination address * * ========================================================================== */ #include <machine/asm.h> #ifdef _BCOPY /* bcopy = memcpy/memmove with arguments reversed. */ /* LINTSTUB: Func: void bcopy(void *, void *, size_t) */ ENTRY(bcopy) l.or r6, r3, r0 /* swap src/dst */ l.or r3, r4, r0 l.or r4, r6, r0 #else /* LINTSTUB: Func: void *memmove(void *, const void *, size_t) */ ENTRY(memmove) #endif l.or r11, r3, r0 /* Save dst (return value) */ l.sfges r4, r3 /* Branch to reverse if */ l.bnf .Lreverse /* src < dest. Don't want to */ /* overwrite end of src with */ /* start of dest */ l.addi r4, r4, -4 /* Back up src and dst pointers */ l.addi r3, r3, -4 /* due to auto-update of 'load' */ l.srli r13, r5, 2 /* How many words in total cnt */ l.sfeqi r13, 0 l.bf .Llast1 /* Handle byte by byte if < 4 */ /* bytes total */ l.lwz r7, 4(r4) /* Preload first word */ l.addi r4, r4, 4 l.j .Lg1 l.nop .Lg0: /* Main loop */ l.lwz r7, 4(r4) /* Load a new word */ l.sw 4(r3), r6 /* Store previous word */ l.addi r4, r4, 4 /* advance */ l.addi r3, r3, 4 /* advance */ .Lg1: l.addi r13, r13, -1 l.sfeqi r13, 0 l.bf .Llast /* Dec cnt, and branch if just */ l.nop /* one word to store */ l.lwz r6, 4(r4) /* Load another word */ l.sw 4(r3), r7 /* Store previous word */ l.addi r4, r4, 4 /* advance to next word */ l.addi r3, r3, 4 /* advance to next word */ l.addi r13, r13, -1 /* Decrement count */ l.sfeqi r13, 0 /* last word? */ l.bnf .Lg0 /* no, loop, more words */ l.nop l.or r7, r6, r0 /* If word count -> 0, then... */ .Llast: l.sw 4(r3), r7 /* ... store last word */ l.addi r3, r3, 4 .Llast1: /* Byte-by-byte copy */ l.andi r5, r5, 3 /* get remaining byte count */ l.sfeqi r5, 0 /* is it 0? */ l.bf .Ldone /* yes, we're done */ l.nop /* -- delay slot -- */ l.lbz r6, 4(r4) /* 1st byte: update addr by 4 */ l.sb 4(r3), r6 /* since we pre-adjusted by 4 */ l.addi r4, r4, 4 /* advance to next word */ l.addi r3, r3, 4 /* advance to next word */ l.addi r5, r5, -1 /* decrement count */ l.sfeqi r5, 0 /* is it 0? */ l.bf .Ldone /* yes, we're done */ l.nop /* -- delay slot -- */ .Llast2: l.lbz r6, 1(r4) /* But handle the rest by */ l.sb 1(r3), r6 /* updating addr by 1 */ l.addi r4, r4, 1 /* advance to next word */ l.addi r3, r3, 1 /* advance to next word */ l.addi r5, r5, -1 /* decrement count */ l.sfeqi r5, 0 /* is it 0? */ l.bnf .Llast2 /* yes, we're done */ l.nop /* -- delay slot -- */ .Ldone: l.jr lr /* return */ l.nop /* -- delay slot -- */ /* We're here since src < dest. Don't want to overwrite end of */ /* src with start of dest */ .Lreverse: l.add r4, r4, r5 /* Work from end to beginning */ l.add r3, r3, r5 /* so add count to string ptrs */ l.srli r13, r5, 2 /* Words in total count */ l.sfeqi r13, 0 l.bf .Lrlast1 /* Handle byte by byte if < 4 */ /* bytes total */ l.nop l.lwz r7, -4(r4) /* Preload first word */ l.addi r4, r4, -4 /* update pointer */ l.j .Lrg1 .Lrg0: /* Main loop */ l.lwz r7, -4(r4) /* Load a new word */ l.sw -4(r3), r6 /* Store previous word */ l.addi r4, r4, -4 l.addi r3, r3, -4 .Lrg1: l.addi r13, r13, -1 /* decrement count */ l.sfeqi r13, 0 /* just one pending word left? */ l.bf .Lrlast /* yes, deal with it */ l.lwz r6, -4(r4) /* Load another word */ l.sw -4(r3), r7 /* Store previous word */ l.addi r4, r4, -4 l.addi r3, r3, -4 l.addi r13, r13, -1 /* decrement count */ l.sfeqi r13, 0 /* just one pending word left? */ l.bnf .Lrg0 /* no, loop again more words */ l.nop l.or r7, r6, r0 /* If word count -> 0, then... */ .Lrlast: l.sw -4(r3), r7 /* ... store last word */ l.addi r3, r3, -4 /* update pointer */ .Lrlast1: /* Byte-by-byte copy */ l.andi r5, r5, 3 l.sfeqi r5, 0 l.bf .Lrdone .Lrlast2: l.lbz r6, -1(r4) /* Handle the rest, byte by */ l.sb -1(r3), r6 /* byte */ l.addi r4, r4, -1 l.addi r3, r3, -1 l.addi r5, r5, -1 /* decrement count */ l.sfeqi r5, 0 /* is it 0? */ l.bnf .Lrlast2 /* no, loop again */ l.nop .Lrdone: l.jr lr l.nop #ifdef _BCOPY END(bcopy) #else END(memmove) #endif
