Re: Vector types and type conversions

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

Mark Mitchell <mark@codesourcery.com> writes:

| Gabriel Dos Reis wrote:
| 
| > I agree with everything you have said.  I suppose I'm a bit unclear
| > about this:
| > 
| >    already defined.  __value_cast<T> would just be an alias for
| >    static_cast<T> for non-vector types, but for vector types it would do a
| >    value-preserving conversion, even if C-style and static casts are
| >                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
| >    bit-preserving, for backwards compatibility.
| >    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| > 
| > in particular the last sentence.
| 
| The point is that the existing Altivec and SPE cast syntax requires that
|   a C-style cast from one vector type to another be bit-preserving.  So,
| we can't change that (or static_casts, which are the kind of C++ cast
| that are using to implement this kind of C-style cast) without breaking
| backwards compatibility.

Thanks for the clarification!  

-- Gaby