OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

extend.texi (attribute aligned): Expand.

Browse Source 
gcc/ChangeLog:
	* doc/extend.texi (attribute aligned): Expand.

From-SVN: r266792
This commit is contained in:
Martin Sebor 2018-12-04 18:41:40 +00:00 committed by Martin Sebor
parent d012ab6057
commit de117207d7
2 changed files with 17 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
gcc/ChangeLog
View File

@ -1,3 +1,7 @@
2018-12-04 Martin Sebor <msebor@redhat.com>
* doc/extend.texi (attribute aligned): Expand.
2018-12-04 David Edelsohn <dje.gcc@gmail.com>
PR target/61976

22
gcc/doc/extend.texi
View File

@ -2442,16 +2442,20 @@ and may not be available on all targets.
@itemx aligned (@var{alignment})
@cindex @code{aligned} function attribute
The @code{aligned} attribute specifies a minimum alignment for
the function, measured in bytes. When specified, @var{alignment} must
be an integer constant power of 2. Specifying no @var{alignment} argument
implies the maximum alignment for the target, which is often, but by no
means always, 8 or 16 bytes.
the first instruction of the function, measured in bytes. When specified,
@var{alignment} must be an integer constant power of 2. Specifying no
@var{alignment} argument implies the ideal alignment for the target.
The @code{__alignof__} operator can be used to determine what that is
(@pxref{Alignment}). The attribute has no effect when a definition for
the function is not provided in the same translation unit.
You cannot use this attribute to decrease the alignment of a function,
only to increase it. However, when you explicitly specify a function
alignment this overrides the effect of the
@option{-falign-functions} (@pxref{Optimize Options}) option for this
function.
The attribute cannot be used to decrease the alignment of a function
previously declared with a more restrictive alignment; only to increase
it. Attempts to do otherwise are diagnosed. Some targets specify
a minimum default alignment for functions that is greater than 1. On
such targets, specifying a less restrictive alignment is silently ignored.
Using the attribute overrides the effect of the @option{-falign-functions}
(@pxref{Optimize Options}) option for this function.
Note that the effectiveness of @code{aligned} attributes may be
limited by inherent limitations in the system linker