[PATCH] D129561: [RS4GC] Fix over-restrictive assert in atomic memcpy/move handling

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp:1705
       auto GetBaseAndOffset = [&](Value *Derived) {
-        assert(PointerToBase.count(Derived));
         unsigned AddressSpace = Derived->getType()->getPointerAddressSpace();
----------------
mkazantsev wrote:
> apilipenko wrote:
> > I suggest handling the undef case explicitly. Just return undef if the input is undef. 
> Same goes for poison I guess.
It's a no-go. Aside from undef and poison, here can be things like
```
i32 addrspace(1)* bitcast (i8 addrspace(1)* getelementptr inbounds (i8, i8 addrspace(1)* null, i64 16) to i32 addrspace(1)*)
```
etc. So the expression can be arbitrarily complex.


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https://reviews.llvm.org/D129561