1  /* memcopy.h -- definitions for memory copy functions.  Motorola 68020 version.
       2     Copyright (C) 1991-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library.  If not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <sysdeps/generic/memcopy.h>
      20  
      21  #if	defined(__mc68020__) || defined(mc68020)
      22  
      23  /* WORD_COPY_FWD and WORD_COPY_BWD are not symmetric on the 68020,
      24     because of its weird instruction overlap characteristics.  */
      25  
      26  #undef	WORD_COPY_FWD
      27  #define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes)		      \
      28    do									      \
      29      {									      \
      30        size_t __nwords = (nbytes) / sizeof (op_t);			      \
      31        size_t __nblocks = __nwords / 8 + 1;				      \
      32        dst_bp -= (8 - __nwords % 8) * sizeof (op_t);			      \
      33        src_bp -= (8 - __nwords % 8) * sizeof (op_t);			      \
      34        switch (__nwords % 8)						      \
      35  	do								      \
      36  	  {								      \
      37  	    ((op_t *) dst_bp)[0] = ((op_t *) src_bp)[0];		      \
      38  	    /* Fall through.  */					      \
      39  	  case 7:							      \
      40  	    ((op_t *) dst_bp)[1] = ((op_t *) src_bp)[1];		      \
      41  	    /* Fall through.  */					      \
      42  	  case 6:							      \
      43  	    ((op_t *) dst_bp)[2] = ((op_t *) src_bp)[2];		      \
      44  	    /* Fall through.  */					      \
      45  	  case 5:							      \
      46  	    ((op_t *) dst_bp)[3] = ((op_t *) src_bp)[3];		      \
      47  	    /* Fall through.  */					      \
      48  	  case 4:							      \
      49  	    ((op_t *) dst_bp)[4] = ((op_t *) src_bp)[4];		      \
      50  	    /* Fall through.  */					      \
      51  	  case 3:							      \
      52  	    ((op_t *) dst_bp)[5] = ((op_t *) src_bp)[5];		      \
      53  	    /* Fall through.  */					      \
      54  	  case 2:							      \
      55  	    ((op_t *) dst_bp)[6] = ((op_t *) src_bp)[6];		      \
      56  	    /* Fall through.  */					      \
      57  	  case 1:							      \
      58  	    ((op_t *) dst_bp)[7] = ((op_t *) src_bp)[7];		      \
      59  	    /* Fall through.  */					      \
      60  	  case 0:							      \
      61  	    src_bp += 32;						      \
      62  	    dst_bp += 32;						      \
      63  	    __nblocks--;						      \
      64  	  }								      \
      65        while (__nblocks != 0);						      \
      66        (nbytes_left) = (nbytes) % sizeof (op_t);				      \
      67      } while (0)
      68  
      69  #undef	WORD_COPY_BWD
      70  #define WORD_COPY_BWD(dst_ep, src_ep, nbytes_left, nbytes)		      \
      71    do									      \
      72      {									      \
      73        size_t __nblocks = (nbytes) / 32 + 1;				      \
      74        op_t *__dst_ep = (op_t *) (dst_ep);				      \
      75        op_t *__src_ep = (op_t *) (src_ep);				      \
      76        switch ((nbytes) / sizeof (op_t) % 8)				      \
      77  	do								      \
      78  	  {								      \
      79  	    *--__dst_ep = *--__src_ep;					      \
      80  	    /* Fall through.  */					      \
      81  	  case 7:							      \
      82  	    *--__dst_ep = *--__src_ep;					      \
      83  	    /* Fall through.  */					      \
      84  	  case 6:							      \
      85  	    *--__dst_ep = *--__src_ep;					      \
      86  	    /* Fall through.  */					      \
      87  	  case 5:							      \
      88  	    *--__dst_ep = *--__src_ep;					      \
      89  	    /* Fall through.  */					      \
      90  	  case 4:							      \
      91  	    *--__dst_ep = *--__src_ep;					      \
      92  	    /* Fall through.  */					      \
      93  	  case 3:							      \
      94  	    *--__dst_ep = *--__src_ep;					      \
      95  	    /* Fall through.  */					      \
      96  	  case 2:							      \
      97  	    *--__dst_ep = *--__src_ep;					      \
      98  	    /* Fall through.  */					      \
      99  	  case 1:							      \
     100  	    *--__dst_ep = *--__src_ep;					      \
     101  	    /* Fall through.  */					      \
     102  	  case 0:							      \
     103  	    __nblocks--;						      \
     104  	  }								      \
     105        while (__nblocks != 0);						      \
     106        (nbytes_left) = (nbytes) % sizeof (op_t);				      \
     107        (dst_ep) = (unsigned long) __dst_ep;				      \
     108        (src_ep) = (unsigned long) __src_ep;				      \
     109      } while (0)
     110  
     111  #endif