diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/generic/memcopy.h | 42 | ||||
| -rw-r--r-- | sysdeps/generic/pagecopy.h | 53 | ||||
| -rw-r--r-- | sysdeps/mach/pagecopy.h | 3 | ||||
| -rw-r--r-- | sysdeps/powerpc/memmove.c | 1 |
4 files changed, 50 insertions, 49 deletions
diff --git a/sysdeps/generic/memcopy.h b/sysdeps/generic/memcopy.h index b39a9608b8..45c5fcb479 100644 --- a/sysdeps/generic/memcopy.h +++ b/sysdeps/generic/memcopy.h @@ -40,6 +40,7 @@ #include <sys/cdefs.h> #include <endian.h> +#include <pagecopy.h> /* The macros defined in this file are: @@ -144,6 +145,47 @@ extern void _wordcopy_bwd_dest_aligned (long int, long int, size_t) __THROW; (nbytes_left) = (nbytes) % OPSIZ; \ } while (0) +/* The macro PAGE_COPY_FWD_MAYBE (dstp, srcp, nbytes_left, nbytes) is invoked + like WORD_COPY_FWD et al. The pointers should be at least word aligned. + This will check if virtual copying by pages can and should be done and do it + if so. The pointers will be aligned to PAGE_SIZE bytes. The macro requires + that pagecopy.h defines at least PAGE_COPY_THRESHOLD to 0. If + PAGE_COPY_THRESHOLD is non-zero, the header must also define PAGE_COPY_FWD + and PAGE_SIZE. +*/ +#if PAGE_COPY_THRESHOLD + +# include <assert.h> + +# define PAGE_COPY_FWD_MAYBE(dstp, srcp, nbytes_left, nbytes) \ + do \ + { \ + if ((nbytes) >= PAGE_COPY_THRESHOLD && \ + PAGE_OFFSET ((dstp) - (srcp)) == 0) \ + { \ + /* The amount to copy is past the threshold for copying \ + pages virtually with kernel VM operations, and the \ + source and destination addresses have the same alignment. */ \ + size_t nbytes_before = PAGE_OFFSET (-(dstp)); \ + if (nbytes_before != 0) \ + { \ + /* First copy the words before the first page boundary. */ \ + WORD_COPY_FWD (dstp, srcp, nbytes_left, nbytes_before); \ + assert (nbytes_left == 0); \ + nbytes -= nbytes_before; \ + } \ + PAGE_COPY_FWD (dstp, srcp, nbytes_left, nbytes); \ + } \ + } while (0) + +/* The page size is always a power of two, so we can avoid modulo division. */ +# define PAGE_OFFSET(n) ((n) & (PAGE_SIZE - 1)) + +#else + +# define PAGE_COPY_FWD_MAYBE(dstp, srcp, nbytes_left, nbytes) /* nada */ + +#endif /* Threshold value for when to enter the unrolled loops. */ #define OP_T_THRES 16 diff --git a/sysdeps/generic/pagecopy.h b/sysdeps/generic/pagecopy.h index 2c35b71b87..3c81de1b23 100644 --- a/sysdeps/generic/pagecopy.h +++ b/sysdeps/generic/pagecopy.h @@ -1,4 +1,4 @@ -/* Macros for copying by pages; used in memcpy, memmove. Generic macros. +/* Macros for copying by pages; used in memcpy, memmove. Copyright (C) 1995-2014 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -16,19 +16,15 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ -/* This file defines the macro: +/* 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. - PAGE_COPY_FWD_MAYBE (dstp, srcp, nbytes_left, nbytes) - - which is invoked like WORD_COPY_FWD et al. The pointers should be at - least word aligned. This will check if virtual copying by pages can and - should be done and do it if so. - - System-specific pagecopy.h files should define these macros and then - #include this file: + System-specific pagecopy.h files that want to support page copying should + define these macros: PAGE_COPY_THRESHOLD - -- Minimum size for which virtual copying by pages is worthwhile. + -- A non-zero minimum size for which virtual copying by pages is worthwhile. PAGE_SIZE -- Size of a page. @@ -38,37 +34,4 @@ The pointers will be aligned to PAGE_SIZE bytes. */ - -#if PAGE_COPY_THRESHOLD - -#include <assert.h> - -#define PAGE_COPY_FWD_MAYBE(dstp, srcp, nbytes_left, nbytes) \ - do \ - { \ - if ((nbytes) >= PAGE_COPY_THRESHOLD && \ - PAGE_OFFSET ((dstp) - (srcp)) == 0) \ - { \ - /* The amount to copy is past the threshold for copying \ - pages virtually with kernel VM operations, and the \ - source and destination addresses have the same alignment. */ \ - size_t nbytes_before = PAGE_OFFSET (-(dstp)); \ - if (nbytes_before != 0) \ - { \ - /* First copy the words before the first page boundary. */ \ - WORD_COPY_FWD (dstp, srcp, nbytes_left, nbytes_before); \ - assert (nbytes_left == 0); \ - nbytes -= nbytes_before; \ - } \ - PAGE_COPY_FWD (dstp, srcp, nbytes_left, nbytes); \ - } \ - } while (0) - -/* The page size is always a power of two, so we can avoid modulo division. */ -#define PAGE_OFFSET(n) ((n) & (PAGE_SIZE - 1)) - -#else - -#define PAGE_COPY_FWD_MAYBE(dstp, srcp, nbytes_left, nbytes) /* nada */ - -#endif +#define PAGE_COPY_THRESHOLD 0 diff --git a/sysdeps/mach/pagecopy.h b/sysdeps/mach/pagecopy.h index 36c3697605..8db2147a7c 100644 --- a/sysdeps/mach/pagecopy.h +++ b/sysdeps/mach/pagecopy.h @@ -30,6 +30,3 @@ (vm_address_t) dstp) == KERN_SUCCESS \ ? trunc_page (nbytes) \ : 0))) - -/* Get the generic macro. */ -#include <sysdeps/generic/pagecopy.h> diff --git a/sysdeps/powerpc/memmove.c b/sysdeps/powerpc/memmove.c index 3859da8615..98ffb14794 100644 --- a/sysdeps/powerpc/memmove.c +++ b/sysdeps/powerpc/memmove.c @@ -20,7 +20,6 @@ #include <string.h> #include <memcopy.h> -#include <pagecopy.h> /* All this is so that bcopy.c can #include this file after defining some things. */ |