Commit Graph

2 Commits

Author SHA1 Message Date
Johannes Doerfert fe799c97fa [MustExecute] Forward iterate over conditional branches
Summary:
If a conditional branch is encountered we can try to find a join block
where the execution is known to continue. This means finding a suitable
block, e.g., the immediate post dominator of the conditional branch, and
proofing control will always reach that block.

This patch implements different techniques that work with and without
provided analysis.

Reviewers: uenoku, sstefan1, hfinkel

Subscribers: hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68933
2019-10-31 00:06:43 -05:00
Johannes Doerfert a5b10b464e [MustExec] Add a generic "must-be-executed-context" explorer
Given an instruction I, the MustBeExecutedContextExplorer allows to
easily traverse instructions that are guaranteed to be executed whenever
I is. For now, these instruction have to be statically "after" I, in
the same or different basic blocks.

This patch also adds a pass which prints the must-be-executed-context
for each instruction in a module. It is used to test the
MustBeExecutedContextExplorer, for now on the examples given in the
class comment of the MustBeExecutedIterator.

Differential Revision: https://reviews.llvm.org/D65186

llvm-svn: 369765
2019-08-23 15:17:27 +00:00