Re: RFC: avoid asmlinkage on x86 traps/interrupts

[Linus Torvalds]

On Thu, 4 Nov 2004, Andrea Arcangeli wrote:
> 
> I wonder why they don't forbid it completely then. I mean, what's magic
> about an input parmeter here? Clobbers are about the internals of
> the asm

Actually, they are mostly about register allocation. And that's apparently 
why the gcc rules ended up changing: by setting a clobber, you basically 
allocate that register for the instruction, and tell gcc that it's dead.

That's also likely why such a register cannot be an input (or an output): 
it cannot be allocated.

		Linus
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