glibc/sysdeps/generic/pagecopy.h

38 lines
1.4 KiB
C

/* Macros for copying by pages; used in memcpy, memmove.
Copyright (C) 1995-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* The macro PAGE_COPY_FWD_MAYBE defined in memcopy.h is used in memmove if the
PAGE_COPY_THRESHOLD macro is set to a non-zero value. The default is 0,
that is copying by pages is not implemented.
System-specific pagecopy.h files that want to support page copying should
define these macros:
PAGE_COPY_THRESHOLD
-- A non-zero minimum size for which virtual copying by pages is worthwhile.
PAGE_SIZE
-- Size of a page.
PAGE_COPY_FWD (dstp, srcp, nbytes_left, nbytes)
-- Macro to perform the virtual copy operation.
The pointers will be aligned to PAGE_SIZE bytes.
*/
#define PAGE_COPY_THRESHOLD 0