[LLVMdev] C embedded extensions and LLVM

[Chris Lattner]

On Wed, 14 Nov 2007, John Regehr wrote:
>> This should just be a bitcast from one pointer to another pointer type.
>
> Here's a likely counterexample: the AVR (8 bit embedded) has a
> byte-addressed data space and word-addressed code space.

ok, presumably these would be two address spaces then.

> While the embedded C standard permits a way out where the compiler
> understands that code space and data space pointers are different, I don't
> see any way that pointer casts (for example, from an unqualified pointer
> to either code ptr or data ptr) can be nops.

I'm just talking about the representation of the code in the LLVM IR, how 
the bitcast from one memory address space to the other is code generated 
should be up to the target.

-Chris

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