Fix local stack max size calculation.

evmjit/libevmjit/BasicBlock.cpp

@@ -44,7 +44,7 @@ void LocalStack::push(llvm::Value* _value)
 {
 	assert(_value->getType() == Type::Word);
 	m_currentStack.push_back(_value);
-	m_maxSize = std::max(m_maxSize, m_currentStack.size()); // FIXME: This is wrong too. + add min size;
+	m_maxSize = std::max(m_maxSize, size());
 }
 
 llvm::Value* LocalStack::pop()
@@ -57,6 +57,7 @@ llvm::Value* LocalStack::pop()
 	else
 		++m_globalPops;
 
+	m_minSize = std::min(m_minSize, size());
 	return item;
 }
 

evmjit/libevmjit/BasicBlock.h

@@ -36,11 +36,11 @@ public:
 	/// @param _index Index of value to be swaped. Must be > 0.
 	void swap(size_t _index);
 
-	ssize_t getDiff() const { return static_cast<ssize_t>(m_currentStack.size()) - static_cast<ssize_t>(m_globalPops); }
-	size_t getMaxSize() const { return m_maxSize; }
+	ssize_t size() const { return static_cast<ssize_t>(m_currentStack.size()) - static_cast<ssize_t>(m_globalPops); }
+	ssize_t minSize() const { return m_minSize; }
+	ssize_t maxSize() const { return m_maxSize; }
 
-	/// TODO: comment
-	/// TODO: It must be the same builder as in global stack.
+	/// Finalize local stack: check the requirements and update of the global stack.
 	void finalize(llvm::IRBuilder<>& _builder, llvm::BasicBlock& _bb);
 
 private:
@@ -63,9 +63,11 @@ private:
 	/// top of the stack or changes existing items.
 	std::vector<llvm::Value*> m_currentStack;
 
-	size_t m_globalPops = 0; ///< Number of items poped from global stack. In other words: global - local stack overlap.
-	Stack& m_global;
-	size_t m_maxSize = 0; ///< Max size reached by the stack.
+	Stack& m_global;			///< Reference to global stack.
+
+	size_t m_globalPops = 0; 	///< Number of items poped from global stack. In other words: global - local stack overlap.
+	ssize_t m_minSize = 0;		///< Minimum reached local stack size. Can be negative.
+	ssize_t m_maxSize = 0; 		///< Maximum reached local stack size.
 };
 
 class BasicBlock

evmjit/libevmjit/Compiler.cpp

@@ -835,8 +835,8 @@ void Compiler::compileBasicBlock(BasicBlock& _basicBlock, RuntimeManager& _runti
 
 	stack.finalize(m_builder, *_basicBlock.llvm()); // TODO: Use references
 
-	m_builder.SetInsertPoint(_basicBlock.llvm()->getFirstNonPHI());
-	_runtimeManager.checkStackLimit(stack.getMaxSize(), stack.getDiff());
+	m_builder.SetInsertPoint(_basicBlock.llvm()->getFirstNonPHI()); // TODO: Move to LocalStack::finalize
+	_runtimeManager.checkStackLimit(stack.maxSize(), stack.size());
 }