[Diffusion] rL282150: [RS4GC] Remat in presence of phi and use live value

[Anna Thomas via llvm-commits]

anna added subscribers: llvm-commits, anna.
anna added a comment.

Forgot to amend the commit before submit:

Summary:
When rematerializing for geps and casts in presence of phis, we need to make
sure that unrelocated values (the current Phi node) should never be used.
The relocation is only done for the base version of the phi, which is generated
by findBasePointers function.

This is a fix when IR verifier for safepoints identifies uses of unrelocated values,
which was generated due to commit https://reviews.llvm.org/rL279975.

Reviewers: Philip

Differential Revision: https://reviews.llvm.org/D24399


https://reviews.llvm.org/rL282150