extend.texi: Document behavior of __attribute__((aligned)) on typedefs.

* doc/extend.texi: Document behavior of __attribute__((aligned))
	on typedefs.

From-SVN: r125747
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Matthew Wilcox 2007-06-16 00:33:01 +07:00 committed by Mark Mitchell
parent c3a1ef9da9
commit e9f9692b8e
2 changed files with 10 additions and 2 deletions

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@ -1,3 +1,8 @@
2007-06-15 Matthew Wilcox <matthew@wil.cx>
* doc/extend.texi: Document behavior of __attribute__((aligned))
on typedefs.
2007-06-15 Mark Mitchell <mark@codesourcery.com>
* rtlanal.c (note_stores): Improve documentation.

View file

@ -3153,8 +3153,11 @@ copy operations more efficient, because the compiler can use whatever
instructions copy the biggest chunks of memory when performing copies to
or from the variables or fields that you have aligned this way.
The @code{aligned} attribute can only increase the alignment; but you
can decrease it by specifying @code{packed} as well. See below.
When used on a struct, or struct member, the @code{aligned} attribute can
only increase the alignment; in order to decrease it, the @code{packed}
attribute must be specified as well. When used as part of a typedef, the
@code{aligned} attribute can both increase and decrease alignment, and
specifying the @code{packed} attribute will generate a warning.
Note that the effectiveness of @code{aligned} attributes may be limited
by inherent limitations in your linker. On many systems, the linker is