[Ffmpeg-devel] New inlining warnings in SVN

Rich Felker dalias
Mon Sep 4 18:07:17 CEST 2006


On Mon, Sep 04, 2006 at 03:18:15PM +0200, Guillaume POIRIER wrote:
> Note that AFAIK, this is the meaning of "inline" in the C standard,
> it's not a strange behaviour of some broken compilers.
> 
> This is what the norm has to say:
> 
> 1519 Making a function an inline function suggests that calls to the
> function be as fast as possible.118)
> 
> 1520 The extent to which such suggestions are effective is
> implementation-defined.119)
> 
> That's why there's the GNU extension __alway_inline__ (if it's not
> gnu, then it's not standard at least), and this extension does what it
> means: it forces to compiler to always inline the functions marked as
> such.
> 
> Also, the compiler is free to inline a function if it feels that it
> will be benefical, even if it's not been asked to.

Note that the opposite is of course also true. A compiler is free to
find common code in multiple places and move it to an anonymous
'function' and replace it with function calls. :)

Rich





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