Codegen for SIGNEXTEND [Delivers #81700414]

evmcc/test/arith/arith_bnot.evm

@@ -0,0 +1 @@
+6201e2406000546000530960005460206000f2

evmcc/test/arith/arith_bnot.lll

@@ -0,0 +1,14 @@
+
+(asm 
+123456
+0
+MSTORE
+0
+MLOAD
+BNOT
+0
+MSTORE
+32
+0
+RETURN
+)

evmcc/test/ext/store_delete.evm

@@ -0,0 +1 @@
+6104d26063576000606357

evmcc/test/ext/store_delete.lll

@@ -0,0 +1,9 @@
+
+(asm 
+1234
+99
+SSTORE
+0
+99
+SSTORE
+)

libevmjit/Compiler.cpp

@@ -374,10 +374,9 @@ void Compiler::compileBasicBlock(BasicBlock& basicBlock, bytesConstRef bytecode,
 
 		case Instruction::BNOT:
 		{
-			auto top = stack.pop();
-			auto allones = llvm::ConstantInt::get(Type::i256, llvm::APInt::getAllOnesValue(256));
-			auto res = m_builder.CreateXor(top, allones);
-			stack.push(res);
+			auto value = stack.pop();
+			auto ret = m_builder.CreateXor(value, llvm::APInt(256, -1, true), "bnot");
+			stack.push(ret);
 			break;
 		}
 
@@ -507,28 +506,29 @@ void Compiler::compileBasicBlock(BasicBlock& basicBlock, bytesConstRef bytecode,
 
 		case Instruction::SIGNEXTEND:
 		{
-			auto k = stack.pop();
-			auto b = stack.pop();
-			auto k32 = m_builder.CreateTrunc(k, m_builder.getIntNTy(5), "k_32");
-			auto k32ext = m_builder.CreateZExt(k32, Type::i256);
-			auto k32x8 = m_builder.CreateMul(k32ext, Constant::get(8), "kx8");
+			auto idx = stack.pop();
+			auto word = stack.pop();
+
+			auto k32_ = m_builder.CreateTrunc(idx, m_builder.getIntNTy(5), "k_32");
+			auto k32 = m_builder.CreateZExt(k32_, Type::i256);
+			auto k32x8 = m_builder.CreateMul(k32, Constant::get(8), "kx8");
 
 			// test for b >> (k * 8 + 7)
-			auto val = m_builder.CreateAdd(k32x8, llvm::ConstantInt::get(Type::i256, 7));
-			auto tmp = m_builder.CreateAShr(b, val);
-			auto bitset = m_builder.CreateTrunc(tmp, m_builder.getInt1Ty());
+			auto bitpos = m_builder.CreateAdd(k32x8, Constant::get(7), "bitpos");
+			auto bitval = m_builder.CreateLShr(word, bitpos, "bitval");
+			auto bittest = m_builder.CreateTrunc(bitval, m_builder.getInt1Ty(), "bittest");
 
-			// shift left by (31 - k) * 8 = (248 - k*8), then do arithmetic shr by the same amount.
-			auto shiftSize = m_builder.CreateSub(llvm::ConstantInt::get(Type::i256, 31 * 8), k32x8);
-			auto bshl = m_builder.CreateShl(b, shiftSize);
-			auto bshr = m_builder.CreateAShr(bshl, shiftSize);
+			auto mask_ = m_builder.CreateShl(Constant::get(1), bitpos);
+			auto mask = m_builder.CreateSub(mask_, Constant::get(1), "mask");
 
-			// bshr is our final value if 0 <= k <= 30 and bitset is true,
-			// otherwise we push back b unchanged
-			auto kInRange = m_builder.CreateICmpULE(k, llvm::ConstantInt::get(Type::i256, 30));
-			auto cond = m_builder.CreateAnd(kInRange, bitset);
+			auto negmask = m_builder.CreateXor(mask, llvm::ConstantInt::getAllOnesValue(Type::i256), "negmask");
+			auto val1 = m_builder.CreateOr(word, negmask);
+			auto val0 = m_builder.CreateAnd(word, mask);
 
-			auto result = m_builder.CreateSelect(cond, bshr, b);
+			auto kInRange = m_builder.CreateICmpULE(idx, llvm::ConstantInt::get(Type::i256, 30));
+			auto result = m_builder.CreateSelect(kInRange,
+			                                     m_builder.CreateSelect(bittest, val1, val0),
+			                                     word);
 			stack.push(result);
 
 			break;

libevmjit/Ext.cpp

@@ -6,6 +6,7 @@
 #include <llvm/IR/IntrinsicInst.h>
 
 #include <libdevcrypto/SHA3.h>
+#include <libevm/FeeStructure.h>
 
 #include "Runtime.h"
 #include "Type.h"
@@ -24,12 +25,6 @@ inline u256 fromAddress(Address _a)
 	return (u160)_a;
 }
 
-struct ExtData
-{
-	const byte* calldata;
-	const byte* code;
-};
-
 Ext::Ext(RuntimeManager& _runtimeManager):
 	RuntimeHelper(_runtimeManager),
 	m_data()
@@ -184,7 +179,12 @@ extern "C"
 	{
 		auto index = llvm2eth(*_index);
 		auto value = llvm2eth(*_value);
-		_rt->getExt().setStore(index, value); // Interface uses native endianness
+		auto& ext = _rt->getExt();
+
+		if (value == 0 && ext.store(index) != 0)	// If delete
+			ext.sub.refunds += c_sstoreRefundGas;	// Increase refund counter
+
+		ext.setStore(index, value);	// Interface uses native endianness
 	}
 
 	EXPORT void ext_calldataload(Runtime* _rt, i256* _index, i256* _value)

libevmjit/GasMeter.cpp

@@ -28,11 +28,9 @@ uint64_t getStepCost(Instruction inst) // TODO: Add this function to FeeSructure
 	{
 	case Instruction::STOP:
 	case Instruction::SUICIDE:
+	case Instruction::SSTORE: // Handle cost of SSTORE separately in GasMeter::countSStore()
 		return 0;
 
-	case Instruction::SSTORE:
-		return static_cast<uint64_t>(c_sstoreResetGas); // FIXME: Check store gas
-
 	case Instruction::SLOAD:
 		return static_cast<uint64_t>(c_sloadGas);
 
@@ -118,8 +116,7 @@ void GasMeter::count(Instruction _inst)
 		m_checkCall = m_builder.CreateCall(m_gasCheckFunc, llvm::UndefValue::get(Type::i256));
 	}
 
-	if (_inst != Instruction::SSTORE) // Handle cost of SSTORE separately in countSStore()
-		m_blockCost += getStepCost(_inst);
+	m_blockCost += getStepCost(_inst);
 
 	if (isCostBlockEnd(_inst))
 		commitCostBlock();
@@ -129,20 +126,15 @@ void GasMeter::countSStore(Ext& _ext, llvm::Value* _index, llvm::Value* _newValu
 {
 	assert(!m_checkCall); // Everything should've been commited before
 
-	static const auto sstoreCost = static_cast<uint64_t>(c_sstoreResetGas); // FIXME: Check store gas
-
-	// [ADD] if oldValue == 0 and newValue != 0  =>  2*cost
-	// [DEL] if oldValue != 0 and newValue == 0  =>  0
-
 	auto oldValue = _ext.store(_index);
 	auto oldValueIsZero = m_builder.CreateICmpEQ(oldValue, Constant::get(0), "oldValueIsZero");
 	auto newValueIsZero = m_builder.CreateICmpEQ(_newValue, Constant::get(0), "newValueIsZero");
 	auto oldValueIsntZero = m_builder.CreateICmpNE(oldValue, Constant::get(0), "oldValueIsntZero");
 	auto newValueIsntZero = m_builder.CreateICmpNE(_newValue, Constant::get(0), "newValueIsntZero");
-	auto isAdd = m_builder.CreateAnd(oldValueIsZero, newValueIsntZero, "isAdd");
-	auto isDel = m_builder.CreateAnd(oldValueIsntZero, newValueIsZero, "isDel");
-	auto cost = m_builder.CreateSelect(isAdd, Constant::get(2 * sstoreCost), Constant::get(sstoreCost), "cost");
-	cost = m_builder.CreateSelect(isDel, Constant::get(0), cost, "cost");
+	auto isInsert = m_builder.CreateAnd(oldValueIsZero, newValueIsntZero, "isInsert");
+	auto isDelete = m_builder.CreateAnd(oldValueIsntZero, newValueIsZero, "isDelete");
+	auto cost = m_builder.CreateSelect(isInsert, Constant::get(c_sstoreSetGas), Constant::get(c_sstoreResetGas), "cost");
+	cost = m_builder.CreateSelect(isDelete, Constant::get(0), cost, "cost");
 	createCall(m_gasCheckFunc, cost);
 }
 

libevmjit/Type.cpp

@@ -41,6 +41,16 @@ llvm::ConstantInt* Constant::get(uint64_t _n)
 	return llvm::ConstantInt::get(Type::i256, _n);
 }
 
+llvm::ConstantInt* Constant::get(u256 _n)
+{
+	auto& backend = _n.backend();
+	auto words = reinterpret_cast<uint64_t*>(backend.limbs());
+	auto nWords = backend.limb_bits == 64 ? backend.size() : (backend.size() + 1) / 2;
+	llvm::APInt n(256, nWords, words);
+	assert(n.toString(10, false) == _n.str());
+	return static_cast<llvm::ConstantInt*>(llvm::ConstantInt::get(Type::i256, n));
+}
+
 llvm::ConstantInt* Constant::get(ReturnCode _returnCode)
 {
 	return llvm::ConstantInt::get(Type::MainReturn, static_cast<uint64_t>(_returnCode));

libevmjit/Type.h

@@ -3,6 +3,7 @@
 
 #include <llvm/IR/Type.h>
 #include <llvm/IR/Constants.h>
+#include <libdevcore/Common.h>
 
 namespace dev
 {
@@ -51,6 +52,7 @@ struct Constant
 {
 	/// Returns word-size constant
 	static llvm::ConstantInt* get(uint64_t _n);
+	static llvm::ConstantInt* get(u256 _n);
 
 	static llvm::ConstantInt* get(ReturnCode _returnCode);
 };