Re: [PATCH]: Add more altivec builtins

[Aldy Hernandez <aldyh at redhat dot com>]

On Wed, 2001-12-05 at 11:39, Joseph S. Myers wrote:
> On 5 Dec 2001, Aldy Hernandez wrote:
> 
> > > Also the point that the companion built-in function __builtin_choose_expr
> > 
> > why do we need this companion function?  is it absolutely necessary? 
> > can't we achieve the same functionality with stmt expressions?
> 
> Statement expressions are irrelevant; their type is just the type of the
> expression of the expression statement that is the last statement in them.
> Your problem is to arrange for the return value to be of the correct type,
> and to call the right function when calling the wrong function would be an
> error (for example, if passing vector float arguments to a function
> expecting vector int ones is an error, such a call cannot be present
> anywhere in the expression, even in a conditioned out (if (0)) part,
> without special treatment to ignore such errors).

ahh, i see.

> > i'm not planning on doing a c++ version of it,  rth suggested this
> > wasn't necessary because c++ already has real overloading and templates,
> > so we don't need it for c++.  i will be provididng a c++ variant of
> > altivec.h
> 
> The diagnostic machinery is still relevant to ignoring errors in half of
> the expression in C.

ok, i see.  it would be nice, not absolutely necessary.

-- 
Aldy Hernandez			E-mail: aldyh@redhat.com
Professional Gypsy
Red Hat, Inc.