1  /* Macros for copying by pages; used in memcpy, memmove.  Mach version.
       2     Copyright (C) 1995-2023 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 <mach.h>
      20  
      21  /* Threshold at which vm_copy is more efficient than well-optimized copying
      22     by words.  */
      23  #define PAGE_COPY_THRESHOLD		(16384)
      24  
      25  #define PAGE_SIZE		__vm_page_size
      26  #define PAGE_COPY_FWD(dstp, srcp, nbytes_left, nbytes)			      \
      27    ((nbytes_left) = ((nbytes)						      \
      28  		    - (__vm_copy (__mach_task_self (),			      \
      29  				  (vm_address_t) srcp, trunc_page (nbytes),   \
      30  				  (vm_address_t) dstp) == KERN_SUCCESS	      \
      31  		       ? trunc_page (nbytes)				      \
      32  		       : 0)))