initial implementation of memory

evmcc/Compiler.cpp

@@ -3,6 +3,7 @@
 
 #include <llvm/IR/IRBuilder.h>
 
+#include "Memory.h"
 #include "Stack.h"
 
 namespace evmcc
@@ -41,24 +42,6 @@ std::unique_ptr<llvm::Module> Compiler::compile(const dev::bytes& bytecode)
 	auto module = std::make_unique<Module>("main", context);
 	IRBuilder<> builder(context);
 
-	// Create globals for memory, memory size, stack and stack top
-	auto memory = new GlobalVariable(*module, Types.word8ptr, false,
-		GlobalValue::LinkageTypes::PrivateLinkage,
-		Constant::getNullValue(Types.word8ptr), "memory");
-	auto memSize = new GlobalVariable(*module, Types.size, false,
-		GlobalValue::LinkageTypes::PrivateLinkage,
-		ConstantInt::get(Types.size, 0), "memsize");
-	auto stack2 = new GlobalVariable(*module, Types.word256arr, false,
-		GlobalValue::LinkageTypes::PrivateLinkage,
-		ConstantAggregateZero::get(Types.word256arr), "stack");
-	auto stackTop2 = new GlobalVariable(*module, Types.size, false,
-		GlobalValue::LinkageTypes::PrivateLinkage,
-		ConstantInt::get(Types.size, 0), "stackTop");
-
-	// Create value for void* malloc(size_t)
-	auto mallocVal = Function::Create(FunctionType::get(Types.word8ptr, { Types.size }, false),
-		GlobalValue::LinkageTypes::ExternalLinkage, "malloc", module.get());
-
 	// Create main function
 	FunctionType* funcType = FunctionType::get(llvm::Type::getInt32Ty(context), false);
 	Function* mainFunc = Function::Create(funcType, Function::ExternalLinkage, "main", module.get());
@@ -66,13 +49,9 @@ std::unique_ptr<llvm::Module> Compiler::compile(const dev::bytes& bytecode)
 	BasicBlock* entryBlock = BasicBlock::Create(context, "entry", mainFunc);
 	builder.SetInsertPoint(entryBlock);
 
-	// Initialize memory with call to malloc, update memsize
-	std::vector<Value*> mallocMemArgs = { ConstantInt::get(Types.size, 100) };
-	auto mallocMemCall = builder.CreateCall(mallocVal, mallocMemArgs, "malloc_mem");
-	builder.CreateStore(mallocMemCall, memory);
-	builder.CreateStore(ConstantInt::get(Types.size, 100), memSize);
 
 	auto stack = Stack(builder, module.get());
+	auto memory = Memory(builder, module.get());
 
 	uint64_t words[] = { 1, 2, 3, 4 };
 	auto val = llvm::APInt(256, 4, words);
@@ -83,18 +62,17 @@ std::unique_ptr<llvm::Module> Compiler::compile(const dev::bytes& bytecode)
 
 	auto top = stack.top();
 	stack.push(top);	// dup
-
 	stack.pop();
 
+	auto index = ConstantInt::get(Types.word256, 123);
+	memory.storeWord(index, c);
 
-	/*
+	memory.dump(123, 123+32);
-	std::vector<Value*> mallocStackArgs = { ConstantInt::get(sizeTy, 200) };
-	auto mallocStackCall = builder.CreateCall(mallocVal, mallocStackArgs, "malloc_stack");
-	auto mallocCast = builder.CreatePointerBitCastOrAddrSpaceCast(mallocStackCall, int256ptr);
-	builder.CreateStore(mallocCast, stackVal);
-	*/
 
-	builder.CreateRet(ConstantInt::get(Type::getInt32Ty(context), 13));
+	auto index2 = ConstantInt::get(Types.word256, 123 + 16);
+	auto byte = memory.loadByte(index2);
+	auto result = builder.CreateZExt(byte, builder.getInt32Ty());
+	builder.CreateRet(result); // should return 3
 
 	return module;
 }

evmcc/Memory.cpp

@@ -0,0 +1,145 @@
+#include "Memory.h"
+
+#include <vector>
+#include <iostream>
+#include <iomanip>
+#include <cstdint>
+#include <cassert>
+
+#include <llvm/IR/Function.h>
+
+#include <libdevcore/Common.h>
+
+#ifdef _MSC_VER
+	#define EXPORT __declspec(dllexport)
+#else
+	#define EXPORT
+#endif
+
+namespace evmcc
+{
+
+struct i256
+{
+	uint64_t a;
+	uint64_t b;
+	uint64_t c;
+	uint64_t d;
+};
+static_assert(sizeof(i256) == 32, "Wrong i256 size");
+
+using MemoryImpl = dev::bytes;
+
+
+Memory::Memory(llvm::IRBuilder<>& _builder, llvm::Module* _module)
+	: m_builder(_builder)
+{
+	auto memoryCreate = llvm::Function::Create(llvm::FunctionType::get(m_builder.getVoidTy(), false),
+	                                           llvm::GlobalValue::LinkageTypes::ExternalLinkage,
+	                                           "evmccrt_memory_create", _module);
+	m_builder.CreateCall(memoryCreate);
+
+
+	auto memRequireTy = llvm::FunctionType::get(m_builder.getInt8PtrTy(), m_builder.getInt64Ty(), false);
+	m_memRequire = llvm::Function::Create(memRequireTy,
+	                                      llvm::GlobalValue::LinkageTypes::ExternalLinkage,
+	                                      "evmccrt_memory_require", _module);
+
+	auto i64Ty = m_builder.getInt64Ty();
+	std::vector<llvm::Type*> argTypes = {i64Ty, i64Ty};
+	auto dumpTy = llvm::FunctionType::get(m_builder.getVoidTy(), llvm::ArrayRef<llvm::Type*>(argTypes), false);
+ 	m_memDump = llvm::Function::Create(dumpTy, llvm::GlobalValue::LinkageTypes::ExternalLinkage,
+ 	                                   "evmccrt_memory_dump", _module);
+}
+
+
+llvm::Value* Memory::loadByte(llvm::Value* _addr)
+{
+	// trunc _addr (an i256) to i64 index and use it to index the memory
+	auto index = m_builder.CreateTrunc(_addr, m_builder.getInt64Ty(), "index");
+
+	// load from evmccrt_memory_require()[index]
+	auto base = m_builder.CreateCall(m_memRequire, index, "base");
+	auto ptr = m_builder.CreateGEP(base, index, "ptr");
+	auto byte = m_builder.CreateLoad(ptr, "byte");
+	return byte;
+}
+
+void Memory::storeWord(llvm::Value* _addr, llvm::Value* _word)
+{
+	auto index = m_builder.CreateTrunc(_addr, m_builder.getInt64Ty(), "index");
+	auto index32 = m_builder.CreateAdd(index, llvm::ConstantInt::get(m_builder.getInt64Ty(), 32), "index32");
+
+	auto base = m_builder.CreateCall(m_memRequire, index32, "base");
+	auto ptr = m_builder.CreateGEP(base, index, "ptr");
+
+	auto i256ptrTy = m_builder.getIntNTy(256)->getPointerTo();
+	auto wordPtr = m_builder.CreateBitCast(ptr, i256ptrTy, "wordptr");
+	m_builder.CreateStore(_word, wordPtr);
+}
+
+void Memory::storeByte(llvm::Value* _addr, llvm::Value* _byte)
+{
+	auto index = m_builder.CreateTrunc(_addr, m_builder.getInt64Ty(), "index");
+
+	auto base = m_builder.CreateCall(m_memRequire, index, "base");
+	auto ptr = m_builder.CreateGEP(base, index, "ptr");
+	m_builder.CreateStore(_byte, ptr);
+}
+
+void Memory::dump(uint64_t _begin, uint64_t _end)
+{
+	auto beginVal = llvm::ConstantInt::get(m_builder.getInt64Ty(), _begin);
+	auto endVal = llvm::ConstantInt::get(m_builder.getInt64Ty(), _end);
+
+	std::vector<llvm::Value*> args = {beginVal, endVal};
+	m_builder.CreateCall(m_memDump, llvm::ArrayRef<llvm::Value*>(args));
+}
+
+} // namespace evmcc
+
+extern "C"
+{
+	using namespace evmcc;
+
+EXPORT MemoryImpl* evmccrt_memory;
+
+EXPORT void evmccrt_memory_create(void)
+{
+	evmccrt_memory = new MemoryImpl(1);
+	std::cerr << "MEMORY: create(), initial size = " << evmccrt_memory->size()
+			  << std::endl;
+}
+
+// Resizes memory to contain at least _size bytes and returns the base address.
+EXPORT void* evmccrt_memory_require(uint64_t _size)
+{
+	std::cerr << "MEMORY: require(), current size = " << evmccrt_memory->size()
+			  << ", required size = " << _size
+			  << std::endl;
+
+	if (evmccrt_memory->size() < _size)
+		evmccrt_memory->resize(_size);
+
+	return &(*evmccrt_memory)[0];
+}
+
+EXPORT void evmccrt_memory_dump(uint64_t _begin, uint64_t _end)
+{
+	std::cerr << "Memory dump from " << std::hex << _begin << " to " << std::hex << _end << ":";
+	if (_end <= _begin)
+		return;
+
+	_begin = _begin / 16 * 16;
+	for (size_t i = _begin; i < _end; i++)
+	{
+		if ((i - _begin) % 16 == 0)
+			std::cerr << '\n' << std::dec << i << ":  ";
+
+		uint8_t b = (*evmccrt_memory)[i];
+		std::cerr << std::hex << std::setw(2) << static_cast<int>(b) << ' ';
+	}
+	std::cerr << std::endl;
+}
+
+}	// extern "C"

evmcc/Memory.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <llvm/IR/IRBuilder.h>
+
+namespace evmcc
+{
+
+class Memory
+{
+public:
+	Memory(llvm::IRBuilder<>& _builder, llvm::Module* _module);
+
+	llvm::Value* loadByte(llvm::Value* _addr);
+	void storeWord(llvm::Value* _addr, llvm::Value* _word);
+	void storeByte(llvm::Value* _addr, llvm::Value* _byte);
+
+	void dump(uint64_t _begin, uint64_t _end);
+
+private:
+	llvm::IRBuilder<>& m_builder;
+
+	llvm::Function* m_memRequire;
+	llvm::Function* m_memDump;
+};
+
+}