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Date:   Wed, 10 Oct 2018 10:35:54 +0200 (CEST)
From:   Richard Biener <rguenther@suse.de>
To:     Borislav Petkov <bp@alien8.de>
cc:     Segher Boessenkool <segher@kernel.crashing.org>,
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Subject: Re: PROPOSAL: Extend inline asm syntax with size spec
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On Wed, 10 Oct 2018, Borislav Petkov wrote:

> On Wed, Oct 10, 2018 at 03:03:25AM -0500, Segher Boessenkool wrote:
> > The code immediately after this makes it size 1, even for things like
> > asm(""), I suppose this works better for the inliner.  But that's a detail
> > (and it might change); the description says "consider this asm as minimum
> > length and cost for inlining decisions", which works for either 0 or 1.
> 
> Thanks for implementing this, much appreciated. If you need people to
> test stuff, lemme know.
> 
> > You can think of it as meaning "we want this asm inlined always", and then
> > whether that actually happens depends on if the function around it is
> > inlined or not.
> 
> My only concern is how we would catch the other extremity where the
> inline asm grows too big and we end up inlining it everywhere and thus
> getting fat. The 0day bot already builds tinyconfigs but we should be
> looking at vmlinux size growth too.

Well, it's like always-inline functions, you have to be careful
and _not_ put it everywhere...  It's also somewhat different to
always-inline functions as those lose their special-ness once
inlined (the inlined body is properly accounted for size).

Richard.