Merge pull request #8267 from ghallak/prune-unnecessary-funcs

[Yul] Prune functions that call each other but are otherwise unreferenced

test/libyul/YulOptimizerTest.cpp

@@ -28,6 +28,7 @@
 #include <libyul/optimiser/DeadCodeEliminator.h>
 #include <libyul/optimiser/Disambiguator.h>
 #include <libyul/optimiser/CallGraphGenerator.h>
+#include <libyul/optimiser/CircularReferencesPruner.h>
 #include <libyul/optimiser/ConditionalUnsimplifier.h>
 #include <libyul/optimiser/ConditionalSimplifier.h>
 #include <libyul/optimiser/CommonSubexpressionEliminator.h>
@@ -250,6 +251,7 @@ TestCase::TestResult YulOptimizerTest::run(ostream& _stream, string const& _line
 		CommonSubexpressionEliminator::run(*m_context, *m_ast);
 		ExpressionSimplifier::run(*m_context, *m_ast);
 		UnusedPruner::run(*m_context, *m_ast);
+		CircularReferencesPruner::run(*m_context, *m_ast);
 		DeadCodeEliminator::run(*m_context, *m_ast);
 		ExpressionJoiner::run(*m_context, *m_ast);
 		ExpressionJoiner::run(*m_context, *m_ast);
@@ -259,6 +261,12 @@ TestCase::TestResult YulOptimizerTest::run(ostream& _stream, string const& _line
 		disambiguate();
 		UnusedPruner::run(*m_context, *m_ast);
 	}
+	else if (m_optimizerStep == "circularReferencesPruner")
+	{
+		disambiguate();
+		FunctionHoister::run(*m_context, *m_ast);
+		CircularReferencesPruner::run(*m_context, *m_ast);
+	}
 	else if (m_optimizerStep == "deadCodeEliminator")
 	{
 		disambiguate();

test/libyul/yulOptimizerTests/circularReferencesPruner/called_from_non_function.yul

@@ -0,0 +1,20 @@
+{
+    let a
+    function f() -> x { x := g() }
+    function g() -> y { y := f() }
+    function h() -> z { z := g() }
+    a := h()
+}
+// ====
+// step: circularReferencesPruner
+// ----
+// {
+//     let a
+//     a := h()
+//     function f() -> x
+//     { x := g() }
+//     function g() -> y
+//     { y := f() }
+//     function h() -> z
+//     { z := g() }
+// }

test/libyul/yulOptimizerTests/circularReferencesPruner/nested_different_names.yul

@@ -0,0 +1,14 @@
+{
+    {
+    	function a() -> x { x := b() }
+    	function b() -> y { y := a() }
+    }
+    {
+    	function c() -> z { z := d() }
+    	function d() -> w { w := c() }
+    }
+}
+// ====
+// step: circularReferencesPruner
+// ----
+// { }

test/libyul/yulOptimizerTests/circularReferencesPruner/nested_same_name.yul

@@ -0,0 +1,14 @@
+{
+    {
+    	function z() -> x { x := y() }
+    	function y() -> x { x := z() }
+    }
+    {
+    	function z() -> x { x := y() }
+    	function y() -> x { x := z() }
+    }
+}
+// ====
+// step: circularReferencesPruner
+// ----
+// { }

test/libyul/yulOptimizerTests/circularReferencesPruner/trivial.yul

@@ -0,0 +1,8 @@
+{
+    function f() -> x { x := g() }
+    function g() -> x { x := f() }
+}
+// ====
+// step: circularReferencesPruner
+// ----
+// { }

test/yulPhaser/Chromosome.cpp

@@ -92,7 +92,7 @@ BOOST_AUTO_TEST_CASE(output_operator_should_create_concise_and_unambiguous_strin
 
 	BOOST_TEST(chromosome.length() == allSteps.size());
 	BOOST_TEST(chromosome.optimisationSteps() == allSteps);
-	BOOST_TEST(toString(chromosome) == "fcCUnDvejsxIOoighTLMrmVatud");
+	BOOST_TEST(toString(chromosome) == "flcCUnDvejsxIOoighTLMrmVatud");
 }
 
 BOOST_AUTO_TEST_SUITE_END()