Fixes and workarounds

- Fix data copy: padding memory was not zero'd.
- Fix inter-block stack optimization: incorrect phi node in first block.
- Workaround incorrect llvm::APInt::urem() implementation.

evmjit/libevmjit/Arith256.cpp

@@ -456,40 +456,42 @@ llvm::Value* Arith256::exp(llvm::Value* _arg1, llvm::Value* _arg2)
 
 llvm::Value* Arith256::addmod(llvm::Value* _arg1, llvm::Value* _arg2, llvm::Value* _arg3)
 {
-	if (auto c1 = llvm::dyn_cast<llvm::ConstantInt>(_arg1))
-	{
-		if (auto c2 = llvm::dyn_cast<llvm::ConstantInt>(_arg2))
-		{
-			if (auto c3 = llvm::dyn_cast<llvm::ConstantInt>(_arg3))
-			{
-				if (!c3->getValue())
-					return Constant::get(0);
-				auto s = c1->getValue().zext(256+64) + c2->getValue().zext(256+64);
-				auto r = s.urem(c3->getValue().zext(256+64)).trunc(256);
-				return Constant::get(r);
-			}
-		}
-	}
+	// FIXME: Disabled because of llvm::APInt::urem bug
+//	if (auto c1 = llvm::dyn_cast<llvm::ConstantInt>(_arg1))
+//	{
+//		if (auto c2 = llvm::dyn_cast<llvm::ConstantInt>(_arg2))
+//		{
+//			if (auto c3 = llvm::dyn_cast<llvm::ConstantInt>(_arg3))
+//			{
+//				if (!c3->getValue())
+//					return Constant::get(0);
+//				auto s = c1->getValue().zext(256+64) + c2->getValue().zext(256+64);
+//				auto r = s.urem(c3->getValue().zext(256+64)).trunc(256);
+//				return Constant::get(r);
+//			}
+//		}
+//	}
 
 	return createCall(getAddModFunc(), {_arg1, _arg2, _arg3});
 }
 
 llvm::Value* Arith256::mulmod(llvm::Value* _arg1, llvm::Value* _arg2, llvm::Value* _arg3)
 {
-	if (auto c1 = llvm::dyn_cast<llvm::ConstantInt>(_arg1))
-	{
-		if (auto c2 = llvm::dyn_cast<llvm::ConstantInt>(_arg2))
-		{
-			if (auto c3 = llvm::dyn_cast<llvm::ConstantInt>(_arg3))
-			{
-				if (!c3->getValue())
-					return Constant::get(0);
-				auto p = c1->getValue().zext(512) * c2->getValue().zext(512);
-				auto r = p.urem(c3->getValue().zext(512)).trunc(256);
-				return Constant::get(r);
-			}
-		}
-	}
+	// FIXME: Disabled because of llvm::APInt::urem bug
+//	if (auto c1 = llvm::dyn_cast<llvm::ConstantInt>(_arg1))
+//	{
+//		if (auto c2 = llvm::dyn_cast<llvm::ConstantInt>(_arg2))
+//		{
+//			if (auto c3 = llvm::dyn_cast<llvm::ConstantInt>(_arg3))
+//			{
+//				if (!c3->getValue())
+//					return Constant::get(0);
+//				auto p = c1->getValue().zext(512) * c2->getValue().zext(512);
+//				auto r = p.urem(c3->getValue().zext(512)).trunc(256);
+//				return Constant::get(r);
+//			}
+//		}
+//	}
 
 	return createCall(getMulModFunc(), {_arg1, _arg2, _arg3});
 }

evmjit/libevmjit/BasicBlock.cpp

@@ -236,7 +236,7 @@ void BasicBlock::linkLocalStacks(std::vector<BasicBlock*> basicBlocks, llvm::IRB
 		for (auto predIt = llvm::pred_begin(bb); predIt != llvm::pred_end(bb); ++predIt)
 		{
 			auto predInfoEntry = cfg.find(*predIt);
-			if (predInfoEntry != cfg.end())
+			if (predInfoEntry != cfg.end()) // FIXME: It is wrong - will skip entry block
 				info.predecessors.push_back(&predInfoEntry->second);
 		}
 	}
@@ -258,6 +258,9 @@ void BasicBlock::linkLocalStacks(std::vector<BasicBlock*> basicBlocks, llvm::IRB
 		{
 			auto& info = pair.second;
 
+			if (&info.bblock == basicBlocks.front())
+				info.inputItems = 0; // we cannot use phi nodes for first block as it is a successor of entry block
+
 			if (info.predecessors.empty())
 				info.inputItems = 0; // no consequences for other blocks, so leave valuesChanged false
 

evmjit/libevmjit/Memory.cpp

@@ -231,14 +231,16 @@ void Memory::copyBytes(llvm::Value* _srcPtr, llvm::Value* _srcSize, llvm::Value*
 	auto dataLeftSize = m_builder.CreateNUWSub(size64, idx64);
 	auto outOfBound = m_builder.CreateICmpUGT(reqBytes, dataLeftSize);
 	auto bytesToCopyInner = m_builder.CreateSelect(outOfBound, dataLeftSize, reqBytes);
-	auto bytesToCopy = m_builder.CreateSelect(isOutsideData, m_builder.getInt64(0), bytesToCopyInner);
+	auto bytesToCopy = m_builder.CreateSelect(isOutsideData, m_builder.getInt64(0), bytesToCopyInner, "bytesToCopy");
+	auto bytesToZero = m_builder.CreateNUWSub(reqBytes, bytesToCopy, "bytesToZero");
 
 	auto src = m_builder.CreateGEP(_srcPtr, idx64, "src");
 	auto dstIdx = m_builder.CreateTrunc(_destMemIdx, Type::Size, "dstIdx"); // Never allow memory index be a type bigger than i64
+	auto padIdx = m_builder.CreateNUWAdd(dstIdx, bytesToCopy, "padIdx");
 	auto dst = m_memory.getPtr(getRuntimeManager().getMem(), dstIdx);
-	auto dst2 = m_builder.CreateGEP(getData(), dstIdx, "dst2");
+	auto pad = m_memory.getPtr(getRuntimeManager().getMem(), padIdx);
 	m_builder.CreateMemCpy(dst, src, bytesToCopy, 0);
-	m_builder.CreateMemCpy(dst2, src, bytesToCopy, 0);
+	m_builder.CreateMemSet(pad, m_builder.getInt8(0), bytesToZero, 0);
 }
 
 }