[BZ #315]

2004-08-09  Paul Eggert  <eggert@cs.ucla.edu>
	[BZ #315]
	* manual/memory.texi (Obstacks Data Alignment): The default
	alignment is not 4: it is enough to hold any type of data.
	Problem reported by Benno in
	<http://sources.redhat.com/ml/libc-alpha/2004-08/msg00055.html>.

diff --git a/ChangeLog b/ChangeLog
index bf5d464..97670e8 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,14 @@
        * sysdeps/unix/sysv/linux/x86_64/sys/epoll.h: Update comment, remove
        __THROW from epoll_wait, to match .../linux/sys/epoll.h file.
 
+2004-08-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+       [BZ #315]
+       * manual/memory.texi (Obstacks Data Alignment): The default
+       alignment is not 4: it is enough to hold any type of data.
+       Problem reported by Benno in
+       <http://sources.redhat.com/ml/libc-alpha/2004-08/msg00055.html>.
+
 2005-11-15  Robert Millan  <robertmh@gnu.org>
 
        [BZ #2161]

diff --git a/manual/memory.texi b/manual/memory.texi
index 0f28806..91b9d84 100644 (file)
--- a/manual/memory.texi
+++ b/manual/memory.texi
@@ -1968,7 +1968,8 @@ obstack_next_free (@var{obstack-ptr}) - obstack_base (@var{obstack-ptr})
 
 Each obstack has an @dfn{alignment boundary}; each object allocated in
 the obstack automatically starts on an address that is a multiple of the
-specified boundary.  By default, this boundary is 4 bytes.
+specified boundary.  By default, this boundary is aligned so that
+the object can hold any type of data.
 
 To access an obstack's alignment boundary, use the macro
 @code{obstack_alignment_mask}, whose function prototype looks like
@@ -1980,7 +1981,9 @@ this:
 The value is a bit mask; a bit that is 1 indicates that the corresponding
 bit in the address of an object should be 0.  The mask value should be one
 less than a power of 2; the effect is that all object addresses are
-multiples of that power of 2.  The default value of the mask is 3, so that
+multiples of that power of 2.  The default value of the mask is a value
+that allows aligned objects to hold any type of data: for example, if
+its value is 3, any type of data can be stored at locations whose
 addresses are multiples of 4.  A mask value of 0 means an object can start
 on any multiple of 1 (that is, no alignment is required).