Summary:
This problem stems from the fact that instructions are allocated using new
in LLVM, i.e. there is no relationship that can be derived by just looking
at the pointer value.
This interface dispatches to appropriate dominance check given 2 instructions,
i.e. in case the instructions are in the same basic block, ordered basicblock
(with instruction numbering and caching) are used. Otherwise, dominator tree
is used.
This is a preparation patch for https://reviews.llvm.org/D32720
Reviewers: dberlin, hfinkel, davide
Subscribers: davide, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D33380
llvm-svn: 304764
