Control Dependence Analysis Pass

[AyaElAkhras]

Added a ControlDependenceAnalysis pass and instantiated it in a Transform pass called FuncSSAToGSA

[Jiahui17]

Hiii! Thanks for the contribution! Here I directly quote the comments that @lucas-rami wrote in another PR:

Please follow our contribution guidelines. In particular, set up and run clang-format/clang-tidy on your code and fix any warning that pops up. The PR needs a description (this doesn't have to be long, just a description of the contribution's content that I can base myself on to make the future commit message). See past PRs for examples.

[AyaElAkhras]

Thanks @Jiahui17 for your feedback :)

[Jiahui17]

In the description of the PR, it would be nice to provide some way to run the changed parts. For instance, here is a bash script that runs your pass on one of the benchmarks in integration-test:

#!/bin/bash

# Call this script in the dynamatic directory

echo "set-dynamatic-path .; \
  set-src ./integration-test/fir/fir.c; \
  compile --simple-buffers; \
  exit" \
  | bin/dynamatic --exit-on-failure --debug

./bin/dynamatic-opt \
  ./integration-test/fir/out/comp/std_transformed.mlir \
  --func-ssa-to-gsa \
  --debug

[AyaElAkhras]

Hi Jiahui, thanks again for your feedback. I accounted for most of your suggestions and marked them as resolved :) I left a comment for the suggestions of replacing vectors with sets above. I'm missing a few more comments that I left unresolved but will try to come back to later...

[lucas-rami]

Is this ready for review? If so then conflicts with main need to be resolved. If a smaller contribution that does not conflict can be extracted from the current state of the branch (e.g., just the new analysis) then feel free to remove the other stuff from this branch.

[lucas-rami]

Conflicts with main need to be resolved before I review this.

[AyaElAkhras]

I deleted conflicting files and limited the contribution of this PR to one analysis pass that adds a source file (ControlDependenceAnalysis.cpp), a header file (ControlDependenceAnalysis.h) and the updated CMakeLists.txt

[AyaElAkhras]

Accounted for the cosmetic stuff and left one comment about deleting the getter functions. Will get to the rest of the comments later.

[lucas-rami]

I realize that Jiahui pointed out the vector to set thing as well and that you were worried that doing so would prevent you from easily modifying elements in your data-structure. It's in fact easier to modify in a set than a vector as well as being O(1) instead of O(n) in general, see example below.

mlir::DenseSet<Block*> blocks;
// ... do something to the set ...

// Removing
Block* toRemove = ...;
if (blocks.erase(toRemove)) {
  // The removed block was part of the set and was removed
} else {
  // The removed block was *not* part of the set, nothing happened
}

// Inserting
Block* toInsert = ...;
if (auto [_, newElem] = blocks.insert(toInsert); newElem) {
  // The inserted block was not part of the set and was inserted
} else {
  // The inserted block was *already* part of the set, nothing happened
}

[AyaElAkhras]

Accounted for all comments and retested the implementation. There are some remaining warnings from clang-tidy, but I do not have time to resolve them now. It seems to me that they have to do with variable names--will check later.