Re: [PATCH for 3.12] mutex: Avoid gcc version dependent__builtin_constant_p() usage.

[Tetsuo Handa]

Peter Zijlstra wrote:
> On Thu, Oct 17, 2013 at 12:54:21PM +0200, Maarten Lankhorst wrote:
> > op 17-10-13 12:52, Peter Zijlstra schreef:
> > > On Thu, Oct 17, 2013 at 07:45:29PM +0900, Tetsuo Handa wrote:
> > >> Commit 040a0a37 "mutex: Add support for wound/wait style locks" used
> > >> "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression
> > >> correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y.
> > > So I completely forgot all about this, but wouldn't something like:
> > >
> > >  !(__builtin_constant_p(p) && p == NULL)
> > >
> > > Not also work and generate the same code?
> > >
> > See earlier discussion. It was already answered why that was undesirable. ;)
> 
> OK; I forgot if we covered that particular option.. I so hate this
> patch; but I'm afraid we'll have to take it :-/
> 

I see. Ingo, would you send this patch via your tree?
Then, I'll post a patch for 3.11-stable which differs white spaces.
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