[LLVMdev] proposed new rule for getelementptr

[Dan Gohman]

On Jul 22, 2009, at 5:23 PM, Chris Lattner wrote:

>
> On Jul 22, 2009, at 1:32 PM, Dan Gohman wrote:
>
>>>>
>>>> - A null pointer is associated with no addresses.
>>>>
>>>
>>> A null pointer in address space 0.
>>
>> I'm not fond of weird address-space semantics, but for consistency
>> with what the optimizer is currently doing, you're right.
>
> FWIW, this will be addressed when we finally get around to adding
> explicit support for trappability to load/store.

This won't free the optimizer to treat null as an invalid pointer  
though.
Some LLVM hacker thought it would be a good idea to use address
spaces 256 and 257 on x86 in a way that can require dereferences
of address 0 to be valid.

Dan