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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] [PATCH 3/3] tcg: declare internal helpers as const
	and pure
Date: Sun, 7 Mar 2010 22:39:12 +0000
References: <1267739110-26400-1-git-send-email-aurelien@aurel32.net>
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To: qemu-devel@nongnu.org
Cc: Andrzej Zaborowski <andrew.zaborowski@intel.com>, Aurelien Jarno <aurelien@aurel32.net>

> On Fri, Mar 05, 2010 at 11:15:45AM +0000, Paul Brook wrote:
> > > TCG internal helpers only access to the values passed in arguments, and
> > > do not modify the CPU internal state. Thus they can be declared as
> > > const and pure.
> >
> > I think this needs an explanatory comment. It's not immediately obvious
> > that tcg_gen_helperN and tcg_gen_helper{32,64} have significantly
> > different semantics.
> 
> What do you mean exactly? Mentioning explicitly tcg_gen_helper{32,64}
> instead of "TCG internal helpers".

I think the difference between tcg_gen_helperN and tcg_gen_helper{32,64} is 
sufficiently subtle that it deserves documenting.  It's not obvious that the 
latter may only be used for cont/pure helpers.  My guess is that the FIXME 
you're removing was added precisely because there was uncertainty whether this 
assumption was reasonable, and under which circumstances they are used.

Paul