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Diffstat (limited to 'gcc/doc/extend.texi')
| -rw-r--r-- | gcc/doc/extend.texi | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index eecb4ca5bf4..4a4c9a3a4a1 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -4240,10 +4240,16 @@ The @code{deprecated} attribute can also be used for functions and variables (@pxref{Function Attributes}, @pxref{Variable Attributes}.) @item may_alias -Accesses to objects with types with this attribute are not subjected to -type-based alias analysis, but are instead assumed to be able to alias -any other type of objects, just like the @code{char} type. See -@option{-fstrict-aliasing} for more information on aliasing issues. +Accesses through pointers to types with this attribute are not subject +to type-based alias analysis, but are instead assumed to be able to alias +any other type of objects. In the context of 6.5/7 an lvalue expression +dereferencing such a pointer is treated like having a character type. +See @option{-fstrict-aliasing} for more information on aliasing issues. +This extension exists to support some vector APIs, in which pointers to +one vector type are permitted to alias pointers to a different vector type. + +Note that an object of a type with this attribute does not have any +special semantics. Example of use: |