5f0bccc3d1
This patch splits a restore point to allow it to only post-dominate blocks reachable by use or def of CSRs(Callee Saved Registers)/FI(Frame Index). Benchmarking this on SPEC2017, this gives around 4% improvement on povray and no significant change for others. Co-authored-by: junbuml Differential Revision: https://reviews.llvm.org/D42600