Do not remove dead blocks during compilation.

evmjit/libevmjit/Compiler.cpp

@@ -174,8 +174,6 @@ std::unique_ptr<llvm::Module> Compiler::compile(code_iterator _begin, code_itera
 	m_builder.SetInsertPoint(m_abortBB);
 	runtimeManager.exit(ReturnCode::OutOfGas);
 
-	removeDeadBlocks();
-
 	// Link jump table target index
 	if (m_jumpTableBlock)
 	{
@@ -840,36 +838,6 @@ void Compiler::compileBasicBlock(BasicBlock& _basicBlock, RuntimeManager& _runti
 }
 
 
-void Compiler::removeDeadBlocks()
-{
-	// Remove dead basic blocks
-	auto sthErased = false;
-	do
-	{
-		sthErased = false;
-		for (auto it = m_basicBlocks.begin(); it != m_basicBlocks.end();)
-		{
-			auto llvmBB = it->second.llvm();
-			if (llvm::pred_begin(llvmBB) == llvm::pred_end(llvmBB))
-			{
-				llvmBB->eraseFromParent();
-				m_basicBlocks.erase(it++);
-				sthErased = true;
-			}
-			else
-				++it;
-		}
-	}
-	while (sthErased);
-
-	if (m_jumpTableBlock && llvm::pred_begin(m_jumpTableBlock->llvm()) == llvm::pred_end(m_jumpTableBlock->llvm()))
-	{
-		m_jumpTableBlock->llvm()->eraseFromParent();
-		m_jumpTableBlock.reset();
-	}
-}
-
-
 }
 }
 }

evmjit/libevmjit/Compiler.h

@@ -36,8 +36,6 @@ private:
 
 	llvm::BasicBlock* getJumpTableBlock();
 
-	void removeDeadBlocks();
-
 	/// Compiler options
 	Options const& m_options;
 

evmjit/libevmjit/Optimizer.cpp

@@ -114,6 +114,7 @@ bool LowerEVMPass::doFinalization(llvm::Module&)
 bool prepare(llvm::Module& _module)
 {
 	auto pm = llvm::legacy::PassManager{};
+	pm.add(llvm::createCFGSimplificationPass());
 	pm.add(llvm::createDeadCodeEliminationPass());
 	pm.add(new LowerEVMPass{});
 	return pm.run(_module);