[LLVMdev] Declaration of a va_list should be an intrinsic?

[Chris Lattner]

On Tue, 3 Apr 2007, Nicolas Geoffray wrote:
>> Right now, vaarg
>> handling is not target independent at the llvm level.
> Isn't this an error at the conception level? llvm bytecode should be
> target independent.

Ideally yes.  However, llvm-gcc does a number of non-portable things 
already.  For example, I think it currently lowers vaarg to pointer 
arithmetic, instead of using the correct intrinsic.  If you'd like to look 
into fixing this stuff, it would be great, but I think some of the 
problems will be harder to fix than others.

>> I agree that a
>> va_list alloc intrinsic would go a long way towards abstracting the
>> target ABI from a vaarg function.

> So you agree that it's the correct way to implement this target-dependant
> feature? Updating all backends shouldn't be too hard.

This sounds like a great way to go to me.  Updating llvm and the backends 
won't be hard.  It may be more difficult to coax this intrinsic out of the 
f.e.

-Chris

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