🚀 go-pugleaf

From article <3vnqah$1ev@news.cs.tu-berlin.de>, by mfx@cs.tu-berlin.de (Markus Freericks):
> Most hardware _has_ a clever trick for return values: registers. Most
> compilers use a register to pass the return value up, no?
> 
> On the topic of hidden costs: _current_ C has an "invisible overhead", as
> the return value is copied to some unnamed location by the returning
> function, and then read from that location when the calling function uses
> the value.  Introducing one or more explicit return parameters would remove
> this "hidden variable"!

Isn't this a question of implementation rather than a language
requirement?  I can imagine in theory a compiler passing a hidden
destination address parameter to a routine that had to return a large
struct, and then with careful alias analysis determining that the
address passed could be an actual assignment lhs rather than a
temporary.  Or is there some reason why this could not satisfy the
semantics of the standard?

Not that I have ever seen a C compiler actually doing this.

    Tony Bass

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