[LLVMdev] cmpxchg instruction with pointer operands

[Filip Pizlo]

You can bitcast to pointer-sized int!

-Filip

> On Sep 6, 2014, at 2:31 PM, Chuan Qiu <qiuc12 at gmail.com> wrote:
> 
> cmpxchg only support exchange on int operands, but pointer values can be very useful here, e.g. stack<T> in a linked-list, the top can be atomic<Node<T>*>. 
> in clang++, cmpxchg operations on atomic<T*>  are bitcasted i64 and do the operation, which is ugly.
> 
> Any reason or concern why cmpxchg doesn't support pointer operands?
> 
> Thanks
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