Dan Sugalski <[EMAIL PROTECTED]> wrote:
> At 04:37 PM 8/1/00 -0400, John Tobey wrote:
> >Is foo() compiled any differently in
> >
> > inline i_foo() { BLA; BLA; BLA; }
> > foo() { i_foo(); }
> >
> >versus
> >
> > foo() { BLA; BLA; BLA; }
> >
> >?
>
> Probably. On many newer chips, the first form will probably get you a
> function called i_foo and foo will call it, rather than actually inlining
> the code. (Depends on how often i_foo is called) Function calls are
> reasonably cheap, and if you have one copy of the function instead of many,
> it may well be in the cache already, where it wouldn't be in the inlined case.
>
> Given that some of the faster machines take a 10x speed hit getting to main
> memory, that can make a *big* difference.
Well, I am going to assume you are wrong and the above two foo()
implementations will produce exactly the same code. I think GCC lets
you control whether i_foo becomes a bona fide symbol by letting you
declare it `extern inline'. In any case, I do *not* anticipate many
direct calls to i_foo() in any given translation unit.
> (FWIW, I was thinking of the difference between #define-ing a function and
> just declaring it--I'd forgotten about the inline keyword)
Please, let's assume `inline'.
--
John Tobey, late nite hacker <[EMAIL PROTECTED]>
\\\ ///
]]] With enough bugs, all eyes are shallow. [[[
/// \\\
