[LLVMdev] proposed new rule for getelementptr
gohman at apple.com
Wed Jul 22 20:51:36 CDT 2009
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
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.
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