StackLifetime class collects lifetime marker of an `alloca` by collect
the user of `BitCast` who is the user of the `alloca`. However, either
the `alloca` itself could be used with the lifetime marker or the `BitCast`
of the `alloca` could be transformed to other instructions. (e.g.,
it may be transformed to all zero reps in `InstCombine` pass).
This patch tries to fix this process in `collectMarkers` functions.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D85399
If we can't identify alloca used in lifetime marker we
need to assume to worst case scenario.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D84630
If we can't identify alloca used in lifetime marker we
need to assume to worst case scenario.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D84630
Code does not track terminators and do not expose them through interface.
State there is just a state of the last instruction or entry.
So this information is just redundant and doesn't need to be tested.
Summary:
Extend StackLifetime with option to calculate liveliness
where alloca is only considered alive on basic block entry
if all non-dead predecessors had it alive at terminators.
Depends on D82043.
Reviewers: eugenis
Reviewed By: eugenis
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82124
Vitaly Buka