The legacy PM is deprecated, so update a bunch of lit tests running
opt to use the new PM syntax when specifying the pipeline.
In this patch focus has been put on test cases for ConstantMerge,
ConstraintElimination, CorrelatedValuePropagation, GlobalDCE,
GlobalOpt, SCCP, TailCallElim and PredicateInfo.
Differential Revision: https://reviews.llvm.org/D114516
This patch adds a new undef lattice state, which is used to represent
UndefValue constants or instructions producing undef.
The main difference to the unknown state is that merging undef values
with constants (or single element constant ranges) produces the
constant/constant range, assuming all uses of the merge result will be
replaced by the found constant.
Contrary, merging non-single element ranges with undef needs to go to
overdefined. Using unknown for UndefValues currently causes mis-compiles
in CVP/LVI (PR44949) and will become problematic once we use
ValueLatticeElement for SCCP.
Reviewers: efriedma, reames, davide, nikic
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D75120
Bjorn Pettersson