Count gas for additional memory

[#79942174]

evmcc/Compiler.cpp

@@ -196,9 +196,9 @@ std::unique_ptr<llvm::Module> Compiler::compile(const dev::bytes& bytecode)
 	createBasicBlocks(bytecode);
 
 	// Init runtime structures.
-	auto memory = Memory(builder, module.get());
-	auto ext = Ext(builder, module.get());
 	GasMeter gasMeter(builder, module.get());
+	Memory memory(builder, module.get(), gasMeter);
+	Ext ext(builder, module.get());
 
 	// Jump to first instruction
 	builder.CreateBr(basicBlocks.begin()->second);

evmcc/GasMeter.cpp

@@ -114,4 +114,11 @@ void GasMeter::check(Instruction _inst)
 	}	
 }
 
+void GasMeter::checkMemory(llvm::Value* _additionalMemoryInWords, llvm::IRBuilder<>& _builder)
+{
+	// Memory uses other builder, but that can be changes later
+	auto cost = _builder.CreateMul(_additionalMemoryInWords, _builder.getIntN(256, static_cast<uint64_t>(c_memoryGas)), "memcost");
+	_builder.CreateCall(m_gasCheckFunc, cost);
+}
+
 }

evmcc/GasMeter.h

@@ -18,6 +18,9 @@ public:
 
 	void check(dev::eth::Instruction _inst);
 
+	/// Generate code that checks the cost of additional memory used by program
+	void checkMemory(llvm::Value* _additionalMemoryInWords, llvm::IRBuilder<>& _builder);
+
 private:
 	/// Cumulative gas cost of a block of instructions
 	/// @TODO Handle overflow

evmcc/Memory.cpp

@@ -13,6 +13,7 @@
 
 #include "Type.h"
 #include "Runtime.h"
+#include "GasMeter.h"
 
 #ifdef _MSC_VER
 	#define EXPORT __declspec(dllexport)
@@ -23,8 +24,8 @@
 namespace evmcc
 {
 
-Memory::Memory(llvm::IRBuilder<>& _builder, llvm::Module* _module)
+Memory::Memory(llvm::IRBuilder<>& _builder, llvm::Module* _module, GasMeter& _gasMeter):
-	: m_builder(_builder)
+	m_builder(_builder)
 {
 	auto voidTy	= m_builder.getVoidTy();
 	auto i64Ty = m_builder.getInt64Ty();
@@ -51,12 +52,12 @@ Memory::Memory(llvm::IRBuilder<>& _builder, llvm::Module* _module)
 	m_size->setUnnamedAddr(true); // Address is not important
 
 	m_resize = llvm::Function::Create(llvm::FunctionType::get(Type::BytePtr, Type::WordPtr, false), llvm::Function::ExternalLinkage, "mem_resize", _module);
-	m_loadWord = createFunc(false, Type::i256, _module);
+	m_loadWord = createFunc(false, Type::i256, _module, _gasMeter);
-	m_storeWord = createFunc(true, Type::i256, _module);
+	m_storeWord = createFunc(true, Type::i256, _module, _gasMeter);
-	m_storeByte = createFunc(true, Type::Byte, _module);
+	m_storeByte = createFunc(true, Type::Byte, _module, _gasMeter);
 }
 
-llvm::Function* Memory::createFunc(bool _isStore, llvm::Type* _valueType, llvm::Module* _module)
+llvm::Function* Memory::createFunc(bool _isStore, llvm::Type* _valueType, llvm::Module* _module, GasMeter& _gasMeter)
 {
 	auto isWord = _valueType == Type::i256;
 
@@ -69,6 +70,7 @@ llvm::Function* Memory::createFunc(bool _isStore, llvm::Type* _valueType, llvm::
 	auto resizeBB = llvm::BasicBlock::Create(func->getContext(), "resize", func);
 	auto accessBB = llvm::BasicBlock::Create(func->getContext(), "access", func);
 
+	// BB "check"
 	llvm::IRBuilder<> builder(checkBB);
 	llvm::Value* index = func->arg_begin();
 	index->setName("index");
@@ -78,12 +80,20 @@ llvm::Function* Memory::createFunc(bool _isStore, llvm::Type* _valueType, llvm::
 	auto resizeNeeded = builder.CreateICmpULE(size, sizeRequired, "resizeNeeded");
 	builder.CreateCondBr(resizeNeeded, resizeBB, accessBB); // OPT branch weights?
 
+	// BB "resize"
 	builder.SetInsertPoint(resizeBB);
+	// Check gas first
+	auto wordsRequired = builder.CreateUDiv(builder.CreateAdd(sizeRequired, builder.getIntN(256, 31)), builder.getIntN(256, 32), "wordsRequired");
+	auto words = builder.CreateUDiv(builder.CreateAdd(size, builder.getIntN(256, 31)), builder.getIntN(256, 32), "words");
+	auto newWords = builder.CreateSub(wordsRequired, words, "addtionalWords");
+	_gasMeter.checkMemory(newWords, builder);
+	// Resize
 	builder.CreateStore(sizeRequired, m_size);
 	auto newData = builder.CreateCall(m_resize, m_size, "newData");
 	builder.CreateStore(newData, m_data);
 	builder.CreateBr(accessBB);
 
+	// BB "access"
 	builder.SetInsertPoint(accessBB);
 	auto data = builder.CreateLoad(m_data, "data");
 	auto ptr = builder.CreateGEP(data, index, "ptr");

evmcc/Memory.h

@@ -6,11 +6,12 @@
 
 namespace evmcc
 {
+class GasMeter;
 
 class Memory
 {
 public:
-	Memory(llvm::IRBuilder<>& _builder, llvm::Module* _module);
+	Memory(llvm::IRBuilder<>& _builder, llvm::Module* _module, GasMeter& _gasMeter);
 	Memory(const Memory&) = delete;
 	void operator=(Memory) = delete;
 
@@ -22,7 +23,7 @@ public:
 	void dump(uint64_t _begin, uint64_t _end = 0);
 
 private:
-	llvm::Function* createFunc(bool _isStore, llvm::Type* _type, llvm::Module* _module);
+	llvm::Function* createFunc(bool _isStore, llvm::Type* _type, llvm::Module* _module, GasMeter& _gasMeter);
 
 private:
 	llvm::IRBuilder<>& m_builder;