Push call data on stack - CALLDATALOAD

evmcc/Compiler.cpp

@@ -298,6 +298,14 @@ std::unique_ptr<llvm::Module> Compiler::compile(const dev::bytes& bytecode)
 			break;
 		}
 
+		case Instruction::CALLDATALOAD:
+		{
+			auto index = stack.pop();
+			auto value = ext.calldataload(index);
+			stack.push(value);
+			break;
+		}
+
 		case Instruction::GASPRICE:
 		{
 			auto value = ext.gasprice();

evmcc/ExecutionEngine.cpp

@@ -74,7 +74,7 @@ int ExecutionEngine::run(std::unique_ptr<llvm::Module> _module)
 	ext->origin = dev::Address(101010101010101010);
 	ext->value = 0xabcd;
 	ext->gasPrice = 1002;
-	std::string calldata = "Hello World!";
+	std::string calldata = "Hello the Beautiful World of Ethereum!";
 	ext->data = calldata;
 	Ext::init(std::move(ext));
 

evmcc/Ext.cpp

@@ -69,6 +69,7 @@ Ext::Ext(llvm::IRBuilder<>& _builder)
 	m_init = Function::Create(FunctionType::get(m_builder.getVoidTy(), extDataTy->getPointerTo(), false), Linkage::ExternalLinkage, "ext_init", module);
 	m_store = Function::Create(TypeBuilder<void(i<256>*, i<256>*), true>::get(ctx), Linkage::ExternalLinkage, "ext_store", module);
 	m_setStore = Function::Create(TypeBuilder<void(i<256>*, i<256>*), true>::get(ctx), Linkage::ExternalLinkage, "ext_setStore", module);
+	m_calldataload = Function::Create(TypeBuilder<void(i<256>*, i<256>*), true>::get(ctx), Linkage::ExternalLinkage, "ext_calldataload", module);
 
 	m_builder.CreateCall(m_init, m_data);
 }
@@ -100,6 +101,13 @@ Value* Ext::callvalue() { return getDataElem(3, "callvalue"); }
 Value* Ext::calldatasize() { return getDataElem(5, "calldatasize"); }
 Value* Ext::gasprice() { return getDataElem(4, "gasprice"); }
 
+Value* Ext::calldataload(Value* _index)
+{
+	m_builder.CreateStore(_index, m_args[0]);
+	m_builder.CreateCall(m_calldataload, m_args);
+	return m_builder.CreateLoad(m_args[1]);
+}
+
 extern "C"
 {
 
@@ -128,6 +136,16 @@ EXPORT void ext_setStore(i256* _index, i256* _value)
 	g_ext->setStore(index, value);
 }
 
+EXPORT void ext_calldataload(i256* _index, i256* _value)
+{
+	auto index = static_cast<size_t>(llvm2eth(*_index));
+	assert(index + 31 > index); // TODO: Handle large index
+	auto b = reinterpret_cast<byte*>(_value);
+	for (size_t i = index, j = 31; i <= index + 31; ++i, --j)
+		b[j] = i < g_ext->data.size() ? g_ext->data[i] : 0;
+	// TODO: It all can be done by adding padding to data or by using min() algorithm without branch
+}
+
 }
 
 }

evmcc/Ext.h

@@ -26,6 +26,8 @@ public:
 	llvm::Value* calldatasize();
 	llvm::Value* gasprice();
 
+	llvm::Value* calldataload(llvm::Value* _index);
+
 private:
 	llvm::Value* getDataElem(unsigned _index, const llvm::Twine& _name = "");
 
@@ -37,6 +39,7 @@ private:
 	llvm::Function* m_init;
 	llvm::Function* m_store;
 	llvm::Function* m_setStore;
+	llvm::Function* m_calldataload;
 };
 	
 

evmcc/Utils.h

@@ -9,6 +9,7 @@ namespace evmcc
 {
 
 /// Representation of 256-bit value binary compatible with LLVM i256
+// TODO: Replace with h256
 struct i256
 {
 	uint64_t a;

evmcc/bytecode/ext_test.evm

@@ -1 +1 @@
-30333234363a
+30333234363a600035602635601335

evmcc/lll/ext_test.lll

@@ -6,4 +6,10 @@ ORIGIN
 CALLVALUE
 CALLDATASIZE
 GASPRICE
+0
+CALLDATALOAD
+38
+CALLDATALOAD
+19
+CALLDATALOAD
 )