Re: std::pow implementation

[Richard Earnshaw <rearnsha at arm dot com>]

> Richard Earnshaw <rearnsha@arm.com> writes:
> 
> [...]
> 
> | > When I say "inline", I mean inline, regardless of other opinions 
> | > (including those of the compiler).
> | 
> | Really? And when you say "register" do you really mean that? 
> 
> It is tempting to make the analogy with "register", but you have to
> acknowledge the fact that inlining strategy is not at the same level
> of sophistication as register allocation.  Therefore, any answer you
> get for the question above is irrelevant to whether you should decide
> whether your programmed inliner always knows better than the
> programmer.   Until then, please listen to the programmer.  Don't
> transmute "inline".

I'm not arguing that the current implementation of inline is perfect (it's 
clearly not), just that the intent of the two keywords are conceptually 
similar -- it's an indication to the compiler of the programmer's intent.

If the original C specification had said that "register" meant "register" 
unconditionally, then the situation wouldn't have been any different -- 
the compiler would have to obey the user, even if the compiler could do 
better.  The same is also conceptually true with inline; if its meaning 
becomes "you, the compiler, have no choice in this decision" then it 
doesn't matter how smart the compiler can become it still has to obey the 
directive.  This, IMO, is clearly incompatible with the intent of inline, 
even as Stroustrup originally intended it.

R.