Author: brane
Date: Fri Feb 28 16:46:45 2025
New Revision: 1924100
URL: http://svn.apache.org/viewvc?rev=1924100&view=rev
Log:
Summary: Deprecate and disable the SVN_UNALIGNED_ACCESS_IS_OK macro.
Compiler optimizations that generate vector instructions will cause crashes
at least on x86 and probably other architectures if memory access is not
properly aligned. Compiler-generated vectorized code will be faster than
the manually coded optimizations anyway.
* notes/knobs (SVN_UNALIGNED_ACCESS_IS_OK): Note that the macro is deprecated.
* subversion/include/svn_types (SVN_UNALIGNED_ACCESS_IS_OK): Always set the
value of this macro to 0. We can't remove it because it's part of the
public API.
Reported by: Sam James <sam at gentoo dot org>
Modified:
subversion/trunk/notes/knobs
subversion/trunk/subversion/include/svn_types.h
Modified: subversion/trunk/notes/knobs
URL:
http://svn.apache.org/viewvc/subversion/trunk/notes/knobs?rev=1924100&r1=1924099&r2=1924100&view=diff
==============================================================================
--- subversion/trunk/notes/knobs (original)
+++ subversion/trunk/notes/knobs Fri Feb 28 16:46:45 2025
@@ -38,7 +38,7 @@ SUFFIX_LINES_TO_KEEP
SVN_FS_FS_DEFAULT_MAX_FILES_PER_DIR
SVN_FS_FS_MAX_LINEAR_DELTIFICATION
SVN_FS_FS_MAX_DELTIFICATION_WALK
-SVN_UNALIGNED_ACCESS_IS_OK
+SVN_UNALIGNED_ACCESS_IS_OK (deprecated)
2.2 Features
@@ -164,12 +164,14 @@ SVN_I_LIKE_LATENCY_SO_IGNORE_HTTPV2
3.8 SVN_UNALIGNED_ACCESS_IS_OK
+ DEPRECATED, unused. The rest of this entry is historical.
+
Scope: (global)
Purpose: enable data accesss optimizations.
If your target CPU supports unaligned memory access without
significant performance penalties, you should enable this
optimization as it allows for processing 4 or 8 bytes at
- once instead of just one byte at a time.
+ once instead of just one byte at a time.
Range: 0 1
Default: platform dependant (see svn_types.h)
Suggested: 0
Modified: subversion/trunk/subversion/include/svn_types.h
URL:
http://svn.apache.org/viewvc/subversion/trunk/subversion/include/svn_types.h?rev=1924100&r1=1924099&r2=1924100&view=diff
==============================================================================
--- subversion/trunk/subversion/include/svn_types.h (original)
+++ subversion/trunk/subversion/include/svn_types.h Fri Feb 28 16:46:45 2025
@@ -124,16 +124,12 @@ extern "C" {
* if unaligned access is supported for integers.
*
* @since New in 1.7.
+ * @deprecated Provided for backward compatibility with the 1.14 API.
*/
-#ifndef SVN_UNALIGNED_ACCESS_IS_OK
-# if defined(_M_IX86) || defined(i386) \
- || defined(_M_X64) || defined(__x86_64) \
- || defined(__powerpc__) || defined(__ppc__)
-# define SVN_UNALIGNED_ACCESS_IS_OK 1
-# else
-# define SVN_UNALIGNED_ACCESS_IS_OK 0
-# endif
+#ifdef SVN_UNALIGNED_ACCESS_IS_OK
+# undef SVN_UNALIGNED_ACCESS_IS_OK
#endif
+#define SVN_UNALIGNED_ACCESS_IS_OK 0
