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   1 /*-------------------------------------------------------------------------
   2   _memmove.c - part of string library functions
   3
   4              Adapted By -  Erik Petrich  . epetrich@users.sourceforge.net
   5              from _memcpy.c which was originally
   6              Written By -  Sandeep Dutta . sandeep.dutta@usa.net (1999)
   7
   8    This library is free software; you can redistribute it and/or modify it
   9    under the terms of the GNU Library General Public License as published by the
  10    Free Software Foundation; either version 2, or (at your option) any
  11    later version.
  12
  13    This library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU Library General Public License for more details.
  17
  18    You should have received a copy of the GNU Library General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21
  22    In other words, you are welcome to use, share and improve this program.
  23    You are forbidden to forbid anyone else to use, share and improve
  24    what you give them.   Help stamp out software-hoarding!
  25 -------------------------------------------------------------------------*/
  26 #include "string.h"
  27 #include <sdcc-lib.h>
  28
  29 #ifndef _SDCC_PORT_PROVIDES_MEMMOVE
  30 #define _SDCC_PORT_PROVIDES_MEMMOVE 0
  31 #endif
  32
  33 #if !_SDCC_PORT_PROVIDES_MEMMOVE
  34
  35 void * memmove (
  36         void * dst,
  37         void * src,
  38         size_t acount
  39         )
  40 {
  41 #if _SDCC_Z80_STYLE_LIB_OPT
  42
  43 #pragma noinduction
  44
  45         char * d;
  46         char * s;
  47         /* PENDING: Divide first to get around sign problems */
  48         int count = -(acount >> 2);
  49
  50         if (((int)src < (int)dst) && ((((int)src)+acount) > (int)dst)) {
  51                 /*
  52                  * copy from higher addresses to lower addresses
  53                  */
  54                 d = ((char *)dst)+acount-1;
  55                 s = ((char *)src)+acount-1;
  56                 while (count) {
  57                         *d-- = *s--;
  58                         *d-- = *s--;
  59                         *d-- = *s--;
  60                         *d-- = *s--;
  61                         count++;
  62                 }
  63
  64                 if (acount & 2) {
  65                         *d-- = *s--;
  66                         *d-- = *s--;
  67                 }
  68                 if (acount & 1) {
  69                         *d-- = *s--;
  70                 }
  71         }
  72         else {
  73                 /*
  74                  * copy from lower addresses to higher addresses
  75                  */
  76                 d = dst;
  77                 s = src;
  78                 while (count) {
  79                         *d++ = *s++;
  80                         *d++ = *s++;
  81                         *d++ = *s++;
  82                         *d++ = *s++;
  83                         count++;
  84                 }
  85
  86                 if (acount & 2) {
  87                         *d++ = *s++;
  88                         *d++ = *s++;
  89                 }
  90                 if (acount & 1) {
  91                         *d++ = *s++;
  92                 }
  93         }
  94         return dst;
  95 #else
  96         void * ret = dst;
  97         char * d;
  98         char * s;
  99
 100         if (((int)src < (int)dst) && ((((int)src)+acount) > (int)dst)) {
 101                 /*
 102                  * copy from higher addresses to lower addresses
 103                  */
 104                 d = ((char *)dst)+acount-1;
 105                 s = ((char *)src)+acount-1;
 106                 while (acount--) {
 107                         *d-- = *s--;
 108                 }
 109         }
 110         else {
 111                 /*
 112                  * copy from lower addresses to higher addresses
 113                  */
 114                 d = dst;
 115                 s = src;
 116                 while (acount--) {
 117                         *d++ = *s++;
 118                 }
 119         }
 120
 121         return(ret);
 122 #endif
 123 }
 124 #endif