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authorSiddhesh Poyarekar <siddhesh@redhat.com>2014-07-03 01:28:45 +0530
committerSiddhesh Poyarekar <siddhesh@redhat.com>2014-07-03 01:49:43 +0530
commit99f8dc922033821edcc13f9f8360e9fda40dfcff (patch)
tree50c567b703247e62945dbe084c754c149f38ba9e /sysdeps/generic
parentbc8ea38590070604006399e42469087e943fc8ec (diff)
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Fix -Wundef warning on PAGE_COPY_THRESHOLD
The PAGE_COPY_THRESHOLD macro is meant to be overridden by architecture-specific pagecopy.h, but it is currently done only by mach; all other architectures use the default. Check to see if the macro is defined in addition to whether it is set to a non-zero value.
Diffstat (limited to 'sysdeps/generic')
-rw-r--r--sysdeps/generic/memcopy.h42
-rw-r--r--sysdeps/generic/pagecopy.h53
2 files changed, 50 insertions, 45 deletions
diff --git a/sysdeps/generic/memcopy.h b/sysdeps/generic/memcopy.h
index b39a960..45c5fcb 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 2c35b71..3c81de1 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