Implement word size transform for if.

libyul/CMakeLists.txt

@@ -36,14 +36,14 @@ add_library(yul
 	backends/evm/EVMDialect.h
 	backends/evm/EVMObjectCompiler.cpp
 	backends/evm/EVMObjectCompiler.h
+	backends/evm/NoOutputAssembly.h
+	backends/evm/NoOutputAssembly.cpp
 	backends/wasm/EWasmCodeTransform.cpp
 	backends/wasm/EWasmCodeTransform.h
 	backends/wasm/EWasmObjectCompiler.cpp
 	backends/wasm/EWasmObjectCompiler.h
 	backends/wasm/EWasmToText.cpp
 	backends/wasm/EWasmToText.h
-	backends/evm/NoOutputAssembly.h
-	backends/evm/NoOutputAssembly.cpp
 	backends/wasm/WasmDialect.cpp
 	backends/wasm/WasmDialect.h
 	backends/wasm/WordSizeTransform.cpp

libyul/backends/wasm/WordSizeTransform.cpp

@@ -44,9 +44,14 @@ void WordSizeTransform::operator()(FunctionCall& _fc)
 	rewriteFunctionCallArguments(_fc.arguments);
 }
 
-void WordSizeTransform::operator()(If&)
+void WordSizeTransform::operator()(If& _if)
 {
-	yulAssert(false, "If statement not implemented.");
+	_if.condition = make_unique<Expression>(FunctionCall{
+		locationOf(*_if.condition),
+		Identifier{locationOf(*_if.condition), "or_bool"_yulstring}, // TODO make sure this is not used
+		expandValueToVector(*_if.condition)
+	});
+	(*this)(_if.body);
 }
 
 void WordSizeTransform::operator()(Switch&)
@@ -181,12 +186,7 @@ void WordSizeTransform::rewriteFunctionCallArguments(vector<Expression>& _args)
 		_args,
 		[&](Expression& _e) -> boost::optional<vector<Expression>>
 		{
-			// ExpressionSplitter guarantees arguments to be Identifier or Literal
+			return expandValueToVector(_e);
-			yulAssert(_e.type() == typeid(Identifier) || _e.type() == typeid(Literal), "");
-			vector<Expression> ret;
-			for (auto& v: expandValue(_e))
-				ret.push_back(*v);
-			return ret;
 		}
 	);
 }
@@ -236,3 +236,11 @@ array<unique_ptr<Expression>, 4> WordSizeTransform::expandValue(Expression const
 	return ret;
 }
 
+vector<Expression> WordSizeTransform::expandValueToVector(Expression const& _e)
+{
+	vector<Expression> ret;
+	for (unique_ptr<Expression>& val: expandValue(_e))
+		ret.emplace_back(std::move(*val));
+	return ret;
+}
+

libyul/backends/wasm/WordSizeTransform.h

@@ -47,6 +47,12 @@ namespace yul
  * the value of c4 should be
  *	((a1*(2^192) + a2*(2^128) + a3(2^64) + a4) * (b1*(2^192) + b2*(2^128) + b3(2^64) + b4)) & ((1<<64)-1)
  *
+ * The resulting code still uses the EVM builtin functions but assumes that they
+ * take four times the parameters and each of type u64.
+ * In addition, it uses a single other builtin function called `or_bool` that
+ * takes four u64 parameters and is supposed to return the logical disjunction
+ * of them es a u64 value.
+ *
  * Prerequisite: Disambiguator, ExpressionSplitter
  */
 class WordSizeTransform: public ASTModifier
@@ -72,6 +78,7 @@ private:
 
 	std::array<YulString, 4> generateU64IdentifierNames(YulString const& _s);
 	std::array<std::unique_ptr<Expression>, 4> expandValue(Expression const& _e);
+	std::vector<Expression> expandValueToVector(Expression const& _e);
 
 	NameDispenser& m_nameDispenser;
 	/// maps original u256 variable's name to corresponding u64 variables' names

test/libyul/YulOptimizerTest.cpp

@@ -268,7 +268,7 @@ TestCase::TestResult YulOptimizerTest::run(ostream& _stream, string const& _line
 	else if (m_optimizerStep == "wordSizeTransform")
 	{
 		disambiguate();
-		NameDispenser nameDispenser{*m_dialect, *m_ast}; // TODO: Support WasmDialect in yulOptimizerTest
+		NameDispenser nameDispenser{*m_dialect, *m_ast};
 		ExpressionSplitter{*m_dialect, nameDispenser}(*m_ast);
 		WordSizeTransform::run(*m_ast, nameDispenser);
 	}