[swift-dev] Having 64-bit swift_retain/release ignore all negative pointer values

[John McCall]

> On Oct 13, 2016, at 2:14 PM, Joe Groff via swift-dev <swift-dev at swift.org> wrote:
> 
> 
>> On Oct 13, 2016, at 2:04 PM, Alexis <abeingessner at apple.com> wrote:
>> 
>> Correct me if I’m wrong, but aren’t all kernel addresses negative on x64 and AArch64? Would this then mean any attempt to use Swift in kernel-space requires a distinct ABI?
> 
> That's correct, but we'd likely already have to have a separate "kernel" ABI due to our assumptions about spare bits in pointers.

This is exactly my thinking.

John.