add an empty predecessor to every block with an (indirect) assert (63539591) · Commits · Adéla Štěpková / reverser

src/passes/findAsserts.cpp

+24 −2

Original line number	Diff line number	Diff line
		@@ -2,6 +2,7 @@
		#include "identifyFunctions.hpp"
		#include "llvm/IR/Dominators.h"
		#include "llvm/Analysis/LoopInfo.h"
		#include "llvm/Analysis/DomTreeUpdater.h"

		using namespace llvm;

		@@ -15,6 +16,7 @@ void addCalledAsserts(ModuleBundle& mod, FBoolMap& containsAssert)
		if (auto* call = dyn_cast<CallBase>(&I)) {
		if (containsAssert[call->getCalledFunction()]) {
		fBundle.calledAsserts[call] = nullptr;
		fBundle.BBscontainAssert[&BB] = true;
		}
		}
		}
		@@ -49,24 +51,44 @@ void subdivideEdgesBeforeFailed(ModuleBundle& mod)

		DominatorTree DT(*origF);
		LoopInfo LI(DT);
		DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Lazy);

		SmallVector<std::pair<BasicBlock, BasicBlock>, 16> edgesToSplit;
		SmallVector<BasicBlock*, 16> addFakePred;

		for (auto& [BB, contains] : fBundle.BBscontainAssert) {
		// outs() << *BB << '\n';
		if (contains) {
		// outs() << *BB << '\n';
		for (auto* predBB : predecessors(BB)) {
		if (LI.isLoopHeader(predBB)) {
		edgesToSplit.emplace_back(predBB, BB);
		}
		}

		// add fake predecessor if on a loop and has multiple preds
		if (LI.getLoopFor(BB) && pred_size(BB) > 1) {
		addFakePred.emplace_back(BB);
		}
		}
		}

		for (auto& [predBB, BB] : edgesToSplit) {
		SplitEdge(predBB, BB);
		}
		SplitEdge(predBB, BB, &DT);
		}

		for (auto& BB : addFakePred) {
		auto* firstNonPhi = BB->getFirstNonPHI();
		auto* newBB = SplitBlock(BB, BB->getFirstNonPHI(), &DT, &LI, nullptr, "", false);

		// outs() << *newBB << '\n';
		// outs() << *BB << '\n';
		// newBB now contains the old content of BB, BB is the predecessor
		fBundle.BBscontainAssert[newBB] = true;
		fBundle.BBscontainAssert[BB] = false;
		}
		// outs() << *origF << '\n';
		}
		}

		bool findAsserts(ModuleBundle& mod)