Really split structural simplifier.

test/libyul/YulOptimizerTest.cpp

@@ -231,10 +231,14 @@ TestCase::TestResult YulOptimizerTest::run(ostream& _stream, string const& _line
 		SSATransform::run(*m_ast, nameDispenser);
 		RedundantAssignEliminator::run(*m_dialect, *m_ast);
 	}
-	else if (m_optimizerStep == "structuralSimplifier")
+	else if (m_optimizerStep == "controlFlowSimplifier")
 	{
 		disambiguate();
 		ControlFlowSimplifier{}(*m_ast);
+	}
+	else if (m_optimizerStep == "structuralSimplifier")
+	{
+		disambiguate();
 		StructuralSimplifier{*m_dialect}(*m_ast);
 	}
 	else if (m_optimizerStep == "equivalentFunctionCombiner")

test/libyul/yulOptimizerTests/controlFlowSimplifier/empty_if_movable_condition.yul

@@ -1,6 +1,6 @@
 { let a := mload(0) if a {} }
 // ====
-// step: structuralSimplifier
+// step: controlFlowSimplifier
 // ----
 // {
 //     let a := mload(0)

test/libyul/yulOptimizerTests/controlFlowSimplifier/empty_if_non_movable_condition.yul

@@ -1,5 +1,5 @@
 { if mload(0) {} }
 // ====
-// step: structuralSimplifier
+// step: controlFlowSimplifier
 // ----
 // { pop(mload(0)) }

test/libyul/yulOptimizerTests/controlFlowSimplifier/switch_only_default.yul

@@ -2,7 +2,7 @@
 	switch mload(0) default { mstore(1, 2) }
 }
 // ====
-// step: structuralSimplifier
+// step: controlFlowSimplifier
 // ----
 // {
 //     pop(mload(0))

test/libyul/yulOptimizerTests/controlFlowSimplifier/switch_remove_empty_all.yul

@@ -11,7 +11,7 @@
 	default { }
 }
 // ====
-// step: structuralSimplifier
+// step: controlFlowSimplifier
 // ----
 // {
 //     let y := 200

test/libyul/yulOptimizerTests/controlFlowSimplifier/switch_remove_empty_case.yul

@@ -6,7 +6,7 @@
 	case 2 { y := 10 }
 }
 // ====
-// step: structuralSimplifier
+// step: controlFlowSimplifier
 // ----
 // {
 //     let y := 200

test/libyul/yulOptimizerTests/controlFlowSimplifier/switch_remove_empty_cases.yul

@@ -6,7 +6,7 @@
 	default { }
 }
 // ====
-// step: structuralSimplifier
+// step: controlFlowSimplifier
 // ----
 // {
 //     let y := 200

test/libyul/yulOptimizerTests/controlFlowSimplifier/switch_remove_empty_default_case.yul

@@ -6,7 +6,7 @@
 	default { }
 }
 // ====
-// step: structuralSimplifier
+// step: controlFlowSimplifier
 // ----
 // {
 //     let y := 200

test/libyul/yulOptimizerTests/controlFlowSimplifier/switch_to_if.yul

@@ -2,7 +2,7 @@
 	switch calldataload(0) case 2 { mstore(0, 0) }
 }
 // ====
-// step: structuralSimplifier
+// step: controlFlowSimplifier
 // ----
 // {
 //     if eq(2, calldataload(0)) { mstore(0, 0) }

test/tools/yulopti.cpp

@@ -32,6 +32,7 @@
 #include <libyul/optimiser/BlockFlattener.h>
 #include <libyul/optimiser/Disambiguator.h>
 #include <libyul/optimiser/CommonSubexpressionEliminator.h>
+#include <libyul/optimiser/ControlFlowSimplifier.h>
 #include <libyul/optimiser/NameCollector.h>
 #include <libyul/optimiser/EquivalentFunctionCombiner.h>
 #include <libyul/optimiser/ExpressionSplitter.h>
@@ -130,7 +131,7 @@ public:
 			cout << "  (e)xpr inline/(i)nline/(s)implify/varname c(l)eaner/(u)nusedprune/ss(a) transform/" << endl;
 			cout << "  (r)edundant assign elim./re(m)aterializer/f(o)r-loop-pre-rewriter/" << endl;
 			cout << "  s(t)ructural simplifier/equi(v)alent function combiner/ssa re(V)erser/? " << endl;
-			cout << "  stack com(p)ressor/(D)ead code eliminator/? " << endl;
+			cout << "  co(n)trol flow simplifier/stack com(p)ressor/(D)ead code eliminator/? " << endl;
 			cout.flush();
 			int option = readStandardInputChar();
 			cout << ' ' << char(option) << endl;
@@ -177,6 +178,9 @@ public:
 			case 't':
 				(StructuralSimplifier{*m_dialect})(*m_ast);
 				break;
+			case 'n':
+				(ControlFlowSimplifier{})(*m_ast);
+				break;
 			case 'u':
 				UnusedPruner::runUntilStabilised(*m_dialect, *m_ast);
 				break;