Basic block compilation in separated function

evmcc/Compiler.cpp

@@ -172,8 +172,52 @@ std::unique_ptr<llvm::Module> Compiler::compile(const bytes& bytecode)
 	for (auto basicBlockPairIt = basicBlocks.begin(); basicBlockPairIt != basicBlocks.end(); ++basicBlockPairIt)
 	{
 		auto& basicBlock = basicBlockPairIt->second;
+		auto iterCopy = basicBlockPairIt;
+		++iterCopy;
+		auto nextBasicBlock = (iterCopy != basicBlocks.end()) ? iterCopy->second.llvm() : nullptr;
+		compileBasicBlock(basicBlock, bytecode, memory, ext, gasMeter, nextBasicBlock);
+	}
+
+	// Code for special blocks:
+	// TODO: move to separate function.
+	// Note: Right now the codegen for special blocks depends only on createBasicBlock(),
+	// not on the codegen for 'regular' blocks. But it has to be done before linkBasicBlocks().
+	m_builder.SetInsertPoint(m_stopBB);
+	m_builder.CreateRet(Constant::get(ReturnCode::Stop));
+
+	m_builder.SetInsertPoint(m_badJumpBlock->llvm());
+	m_builder.CreateRet(Constant::get(ReturnCode::BadJumpDestination));
+
+	m_builder.SetInsertPoint(m_jumpTableBlock->llvm());
+	if (m_indirectJumpTargets.size() > 0)
+	{
+		auto& stack = m_jumpTableBlock->getStack();
+
+		auto dest = stack.pop();
+		auto switchInstr = 	m_builder.CreateSwitch(dest, m_badJumpBlock->llvm(),
+		                   	                     m_indirectJumpTargets.size());
+		for (auto it = m_indirectJumpTargets.cbegin(); it != m_indirectJumpTargets.cend(); ++it)
+		{
+			auto& bb = *it;
+			auto dest = Constant::get(bb->begin());
+			switchInstr->addCase(dest, bb->llvm());
+		}
+	}
+	else
+	{
+		m_builder.CreateBr(m_badJumpBlock->llvm());
+	}
+
+	linkBasicBlocks();
+
+	return module;
+}
+
+
+void Compiler::compileBasicBlock(BasicBlock& basicBlock, const bytes& bytecode, Memory& memory, Ext& ext, GasMeter& gasMeter, llvm::BasicBlock* nextBasicBlock)
+{
 	auto& stack = basicBlock.getStack();
-		m_builder.SetInsertPoint(basicBlock);
+	m_builder.SetInsertPoint(basicBlock.llvm());
 
 	for (auto currentPC = basicBlock.begin(); currentPC != basicBlock.end(); ++currentPC)
 	{
@@ -557,19 +601,16 @@ std::unique_ptr<llvm::Module> Compiler::compile(const bytes& bytecode)
 				auto cond = m_builder.CreateICmpNE(val, zero, "nonzero");
 
 				// Assume the basic blocks are properly ordered:
-					auto nextBBIter = basicBlockPairIt;
-					++nextBBIter;
-					assert (nextBBIter != basicBlocks.end());
-					auto& followBlock = nextBBIter->second;
+				assert(nextBasicBlock); // FIXME: JUMPI can be last instruction
 
 				if (targetBlock)
 				{
 					stack.pop();
-						m_builder.CreateCondBr(cond, targetBlock->llvm(), followBlock.llvm());
+					m_builder.CreateCondBr(cond, targetBlock->llvm(), nextBasicBlock);
 				}
 				else
 				{
-						m_builder.CreateCondBr(cond, m_jumpTableBlock->llvm(), followBlock.llvm());
+					m_builder.CreateCondBr(cond, m_jumpTableBlock->llvm(), nextBasicBlock);
 				}
 			}
 
@@ -831,47 +872,10 @@ std::unique_ptr<llvm::Module> Compiler::compile(const bytes& bytecode)
 		else
 		{
 			// Branch to the next block.
-				auto iterCopy = basicBlockPairIt;
-				++iterCopy;
-				auto& next = iterCopy->second;
-				m_builder.CreateBr(next);
-			}
+			assert(nextBasicBlock);
+			m_builder.CreateBr(nextBasicBlock);
 		}
 	}
-
-	// Code for special blocks:
-	// TODO: move to separate function.
-	// Note: Right now the codegen for special blocks depends only on createBasicBlock(),
-	// not on the codegen for 'regular' blocks. But it has to be done before linkBasicBlocks().
-	m_builder.SetInsertPoint(m_stopBB);
-	m_builder.CreateRet(Constant::get(ReturnCode::Stop));
-
-	m_builder.SetInsertPoint(m_badJumpBlock->llvm());
-	m_builder.CreateRet(Constant::get(ReturnCode::BadJumpDestination));
-
-	m_builder.SetInsertPoint(m_jumpTableBlock->llvm());
-	if (m_indirectJumpTargets.size() > 0)
-	{
-		auto& stack = m_jumpTableBlock->getStack();
-
-		auto dest = stack.pop();
-		auto switchInstr = 	m_builder.CreateSwitch(dest, m_badJumpBlock->llvm(),
-		                   	                     m_indirectJumpTargets.size());
-		for (auto it = m_indirectJumpTargets.cbegin(); it != m_indirectJumpTargets.cend(); ++it)
-		{
-			auto& bb = *it;
-			auto dest = Constant::get(bb->begin());
-			switchInstr->addCase(dest, bb->llvm());
-		}
-	}
-	else
-	{
-		m_builder.CreateBr(m_badJumpBlock->llvm());
-	}
-
-	linkBasicBlocks();
-
-	return module;
 }
 
 

evmcc/Compiler.h

@@ -28,6 +28,8 @@ private:
 
 	void createBasicBlocks(const bytes& bytecode);
 
+	void compileBasicBlock(BasicBlock& basicBlock, const bytes& bytecode, class Memory& memory, class Ext& ext, class GasMeter& gasMeter, llvm::BasicBlock* nextBasicBlock);
+
 	void linkBasicBlocks();
 
 	llvm::IRBuilder<> m_builder;