Make hardcoded parts of the optimizer sequence configurable

libsolidity/codegen/CompilerContext.cpp

@@ -547,6 +547,7 @@ void CompilerContext::optimizeYul(yul::Object& _object, yul::EVMDialect const& _
 		_object,
 		_optimiserSettings.optimizeStackAllocation,
 		_optimiserSettings.yulOptimiserSteps,
+		_optimiserSettings.yulOptimiserCleanupSteps,
 		isCreation? nullopt : make_optional(_optimiserSettings.expectedExecutionsPerDeployment),
 		_externalIdentifiers
 	);

libsolidity/interface/OptimiserSettings.h

@@ -59,6 +59,8 @@ struct OptimiserSettings
 		"]"
 		"jmul[jul] VcTOcul jmul";      // Make source short and pretty
 
+	static char constexpr DefaultYulOptimiserCleanupSteps[] = "fDnTOc";
+
 	/// No optimisations at all - not recommended.
 	static OptimiserSettings none()
 	{
@@ -146,6 +148,11 @@ struct OptimiserSettings
 	/// them just by setting this to an empty string. Set @a runYulOptimiser to false if you want
 	/// no optimisations.
 	std::string yulOptimiserSteps = DefaultYulOptimiserSteps;
+	/// Sequence of clean up optimisation steps after the above (default or user supplied) set of
+	/// optimisation steps is completed. Note that if the string is left empty, there will still
+	/// be hard-coded optimisation steps that will run regardless. Set @a runYulOptimiser to false
+	/// if you want no optimisations.
+	std::string yulOptimiserCleanupSteps = DefaultYulOptimiserCleanupSteps;
 	/// This specifies an estimate on how often each opcode in this assembly will be executed,
 	/// i.e. use a small value to optimise for size and a large value to optimise for runtime gas usage.
 	size_t expectedExecutionsPerDeployment = 200;

libsolidity/interface/StandardCompiler.cpp

@@ -472,7 +472,7 @@ std::optional<Json::Value> checkOptimizerDetail(Json::Value const& _details, std
 	return {};
 }
 
-std::optional<Json::Value> checkOptimizerDetailSteps(Json::Value const& _details, std::string const& _name, string& _setting)
+std::optional<Json::Value> checkOptimizerDetailSteps(Json::Value const& _details, std::string const& _name, string& _optimiserSetting, string& _cleanupSetting)
 {
 	if (_details.isMember(_name))
 	{
@@ -490,7 +490,12 @@ std::optional<Json::Value> checkOptimizerDetailSteps(Json::Value const& _details
 				);
 			}
 
-			_setting = _details[_name].asString();
+			std::string const fullSequence = _details[_name].asString();
+			auto const delimiterPos = fullSequence.find(":");
+			_optimiserSetting = fullSequence.substr(0, delimiterPos);
+
+			if (delimiterPos != string::npos)
+				_cleanupSetting = fullSequence.substr(delimiterPos + 1);
 		}
 		else
 			return formatFatalError("JSONError", "\"settings.optimizer.details." + _name + "\" must be a string");
@@ -616,7 +621,7 @@ std::variant<OptimiserSettings, Json::Value> parseOptimizerSettings(Json::Value
 				return *result;
 			if (auto error = checkOptimizerDetail(details["yulDetails"], "stackAllocation", settings.optimizeStackAllocation))
 				return *error;
-			if (auto error = checkOptimizerDetailSteps(details["yulDetails"], "optimizerSteps", settings.yulOptimiserSteps))
+			if (auto error = checkOptimizerDetailSteps(details["yulDetails"], "optimizerSteps", settings.yulOptimiserSteps, settings.yulOptimiserCleanupSteps))
 				return *error;
 		}
 	}

libyul/YulStack.cpp

@@ -209,6 +209,7 @@ void YulStack::optimize(Object& _object, bool _isCreation)
 		_object,
 		m_optimiserSettings.optimizeStackAllocation,
 		m_optimiserSettings.yulOptimiserSteps,
+		m_optimiserSettings.yulOptimiserCleanupSteps,
 		_isCreation ? nullopt : make_optional(m_optimiserSettings.expectedExecutionsPerDeployment),
 		{}
 	);

libyul/optimiser/Suite.cpp

@@ -93,6 +93,7 @@ void OptimiserSuite::run(
 	Object& _object,
 	bool _optimizeStackAllocation,
 	string_view _optimisationSequence,
+	string_view _optimisationCleanupSequence,
 	optional<size_t> _expectedExecutionsPerDeployment,
 	set<YulString> const& _externallyUsedIdentifiers
 )
@@ -139,7 +140,10 @@ void OptimiserSuite::run(
 			_optimizeStackAllocation,
 			stackCompressorMaxIterations
 		);
-	suite.runSequence("fDnTOc g", ast);
+
+	// Run the user supplied (otherwise default) clean up sequence
+	suite.runSequence(_optimisationCleanupSequence, ast);
+	suite.runSequence("g", ast);
 
 	if (evmDialect)
 	{
@@ -296,6 +300,7 @@ map<char, string> const& OptimiserSuite::stepAbbreviationToNameMap()
 void OptimiserSuite::validateSequence(string_view _stepAbbreviations)
 {
 	int8_t nestingLevel = 0;
+	int8_t colonDelimiters = 0;
 	for (char abbreviation: _stepAbbreviations)
 		switch (abbreviation)
 		{
@@ -310,6 +315,10 @@ void OptimiserSuite::validateSequence(string_view _stepAbbreviations)
 			nestingLevel--;
 			assertThrow(nestingLevel >= 0, OptimizerException, "Unbalanced brackets");
 			break;
+		case ':':
+			assertThrow(nestingLevel == 0, OptimizerException, "Cleanup delimiter may only be placed at nesting level zero");
+			assertThrow(++colonDelimiters <=1, OptimizerException, "Too many colon delimiters");
+			break;
 		default:
 		{
 			yulAssert(

libyul/optimiser/Suite.h

@@ -51,7 +51,7 @@ public:
 
 	/// Special characters that do not represent optimiser steps but are allowed in abbreviation sequences.
 	/// Some of them (like whitespace) are ignored, others (like brackets) are a part of the syntax.
-	static constexpr char NonStepAbbreviations[] = " \n[]";
+	static constexpr char NonStepAbbreviations[] = " \n[]:";
 
 	enum class Debug
 	{
@@ -68,6 +68,7 @@ public:
 		Object& _object,
 		bool _optimizeStackAllocation,
 		std::string_view _optimisationSequence,
+		std::string_view _optimisationCleanupSequence,
 		std::optional<size_t> _expectedExecutionsPerDeployment,
 		std::set<YulString> const& _externallyUsedIdentifiers = {}
 	);

solc/CommandLineParser.cpp

@@ -266,7 +266,14 @@ OptimiserSettings CommandLineOptions::optimiserSettings() const
 		settings.expectedExecutionsPerDeployment = optimizer.expectedExecutionsPerDeployment.value();
 
 	if (optimizer.yulSteps.has_value())
-		settings.yulOptimiserSteps = optimizer.yulSteps.value();
+	{
+		std::string const fullSequence = optimizer.yulSteps.value();
+		auto const delimiterPos = fullSequence.find(":");
+		settings.yulOptimiserSteps = fullSequence.substr(0, delimiterPos);
+
+		if (delimiterPos != string::npos)
+			settings.yulOptimiserCleanupSteps = fullSequence.substr(delimiterPos + 1);
+	}
 
 	return settings;
 }

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_invalid_nested_delimiter/args

@@ -0,0 +1 @@
+--pretty-json --json-indent 4

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_invalid_nested_delimiter/in.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+contract C {
+    function f() public pure {}
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_invalid_nested_delimiter/input.json

@@ -0,0 +1,16 @@
+{
+    "language": "Solidity",
+    "sources": {
+        "A": {"urls": ["standard_optimizer_yulDetails_optimiserSteps_invalid_nested_delimiter/in.sol"]}
+    },
+    "settings": {
+        "optimizer": {
+            "details": {
+                "yul": true,
+                "yulDetails": {
+                    "optimizerSteps": "dhfoDgvulfnTUtnIf\n[    xar:rscLM\n]\njmuljuljul VcTOcul jmul"
+                }
+            }
+        }
+    }
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_invalid_nested_delimiter/output.json

@@ -0,0 +1,12 @@
+{
+    "errors":
+    [
+        {
+            "component": "general",
+            "formattedMessage": "Invalid optimizer step sequence in \"settings.optimizer.details.optimizerSteps\": Cleanup delimiter may only be placed at nesting level zero",
+            "message": "Invalid optimizer step sequence in \"settings.optimizer.details.optimizerSteps\": Cleanup delimiter may only be placed at nesting level zero",
+            "severity": "error",
+            "type": "JSONError"
+        }
+    ]
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_mutliple_delimiters/args

@@ -0,0 +1 @@
+--pretty-json --json-indent 4

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_mutliple_delimiters/in.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+contract C {
+    function f() public pure {}
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_mutliple_delimiters/input.json

@@ -0,0 +1,16 @@
+{
+    "language": "Solidity",
+    "sources": {
+        "A": {"urls": ["standard_optimizer_yulDetails_optimiserSteps_mutliple_delimiters/in.sol"]}
+    },
+    "settings": {
+        "optimizer": {
+            "details": {
+                "yul": true,
+                "yulDetails": {
+                    "optimizerSteps": "dhfoDgvu:lfnTUtnIf\n[    xarrscLM\n]\njmuljulj:ul VcTOcul jmul"
+                }
+            }
+        }
+    }
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_mutliple_delimiters/output.json

@@ -0,0 +1,12 @@
+{
+    "errors":
+    [
+        {
+            "component": "general",
+            "formattedMessage": "Invalid optimizer step sequence in \"settings.optimizer.details.optimizerSteps\": Too many colon delimiters",
+            "message": "Invalid optimizer step sequence in \"settings.optimizer.details.optimizerSteps\": Too many colon delimiters",
+            "severity": "error",
+            "type": "JSONError"
+        }
+    ]
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_cleanup_sequence/args

@@ -0,0 +1 @@
+--pretty-json --json-indent 4

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_cleanup_sequence/in.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+contract C {
+    function f() public pure {}
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_cleanup_sequence/input.json

@@ -0,0 +1,16 @@
+{
+    "language": "Solidity",
+    "sources": {
+        "A": {"urls": ["standard_optimizer_yulDetails_optimiserSteps_with_cleanup_sequence/in.sol"]}
+    },
+    "settings": {
+        "optimizer": {
+            "details": {
+                "yul": true,
+                "yulDetails": {
+                    "optimizerSteps": "dhfoDgvulfnTUtnIf\n[    xarrscLM\n]\njmuljuljul VcTOcul jmul:fDnTOc"
+                }
+            }
+        }
+    }
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_cleanup_sequence/output.json

@@ -0,0 +1,9 @@
+{
+    "sources":
+    {
+        "A":
+        {
+            "id": 0
+        }
+    }
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_cleanup_sequence/args

@@ -0,0 +1 @@
+--pretty-json --json-indent 4

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_cleanup_sequence/in.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+contract C {
+    function f() public pure {}
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_cleanup_sequence/input.json

@@ -0,0 +1,16 @@
+{
+    "language": "Solidity",
+    "sources": {
+        "A": {"urls": ["standard_optimizer_yulDetails_optimiserSteps_with_cleanup_sequence/in.sol"]}
+    },
+    "settings": {
+        "optimizer": {
+            "details": {
+                "yul": true,
+                "yulDetails": {
+                    "optimizerSteps": "dhfoDgvulfnTUtnIf\n[    xarrscLM\n]\njmuljuljul VcTOcul jmul:"
+                }
+            }
+        }
+    }
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_cleanup_sequence/output.json

@@ -0,0 +1,9 @@
+{
+    "sources":
+    {
+        "A":
+        {
+            "id": 0
+        }
+    }
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_optimisation_sequence/args

@@ -0,0 +1 @@
+--pretty-json --json-indent 4

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_optimisation_sequence/in.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+contract C {
+    function f() public pure {}
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_optimisation_sequence/input.json

@@ -0,0 +1,16 @@
+{
+    "language": "Solidity",
+    "sources": {
+        "A": {"urls": ["standard_optimizer_yulDetails_optimiserSteps_with_cleanup_sequence/in.sol"]}
+    },
+    "settings": {
+        "optimizer": {
+            "details": {
+                "yul": true,
+                "yulDetails": {
+                    "optimizerSteps": ":dhfoDgvulfnTUtnIf\n[    xarrscLM\n]\njmuljuljul VcTOcul jmul"
+                }
+            }
+        }
+    }
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_optimisation_sequence/output.json

@@ -0,0 +1,9 @@
+{
+    "sources":
+    {
+        "A":
+        {
+            "id": 0
+        }
+    }
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_sequence/args

@@ -0,0 +1 @@
+--pretty-json --json-indent 4

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_sequence/in.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+contract C {
+    function f() public pure {}
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_sequence/input.json

@@ -0,0 +1,16 @@
+{
+    "language": "Solidity",
+    "sources": {
+        "A": {"urls": ["standard_optimizer_yulDetails_optimiserSteps_with_cleanup_sequence/in.sol"]}
+    },
+    "settings": {
+        "optimizer": {
+            "details": {
+                "yul": true,
+                "yulDetails": {
+                    "optimizerSteps": ":"
+                }
+            }
+        }
+    }
+}

test/cmdlineTests/standard_optimizer_yulDetails_optimiserSteps_with_empty_sequence/output.json

@@ -0,0 +1,9 @@
+{
+    "sources":
+    {
+        "A":
+        {
+            "id": 0
+        }
+    }
+}

test/cmdlineTests/yul_optimizer_steps_invalid_nested_delimiter/args

@@ -0,0 +1 @@
+--ir-optimized --optimize --yul-optimizations dhfo[Dg:vu]lfnTUtnIf

test/cmdlineTests/yul_optimizer_steps_invalid_nested_delimiter/err

@@ -0,0 +1 @@
+Invalid optimizer step sequence in --yul-optimizations: Cleanup delimiter may only be placed at nesting level zero

test/cmdlineTests/yul_optimizer_steps_invalid_nested_delimiter/exit

@@ -0,0 +1 @@
+1

test/cmdlineTests/yul_optimizer_steps_invalid_nested_delimiter/input.sol

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+contract C
+{
+    function f() public pure {}
+}

test/cmdlineTests/yul_optimizer_steps_multiple_delimiters/args

@@ -0,0 +1 @@
+--ir-optimized --optimize --yul-optimizations dhfoDg:vulfn:TUtnIf

test/cmdlineTests/yul_optimizer_steps_multiple_delimiters/err

@@ -0,0 +1 @@
+Invalid optimizer step sequence in --yul-optimizations: Too many colon delimiters

test/cmdlineTests/yul_optimizer_steps_multiple_delimiters/exit

@@ -0,0 +1 @@
+1

test/cmdlineTests/yul_optimizer_steps_multiple_delimiters/input.sol

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+contract C
+{
+    function f() public pure {}
+}

test/cmdlineTests/yul_optimizer_steps_short_sequence/args

@@ -0,0 +1 @@
+--ir-optimized --optimize --yul-optimizations iDu

test/cmdlineTests/yul_optimizer_steps_short_sequence/input.sol

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+pragma abicoder v2;
+
+contract C {
+    constructor() payable {
+        assembly ("memory-safe") {
+            let a := 0
+            revert(0, a)
+        }
+    }
+}

test/cmdlineTests/yul_optimizer_steps_short_sequence/output

@@ -0,0 +1,24 @@
+Optimized IR:
+/// @use-src 0:"yul_optimizer_steps_short_sequence/input.sol"
+object "C_8" {
+    code {
+        {
+            /// @src 0:80:221  "contract C {..."
+            mstore(64, memoryguard(0x80))
+            /// @src 0:129:213  "assembly (\"memory-safe\") {..."
+            let usr$a := 0
+            revert(usr$a, usr$a)
+        }
+    }
+    /// @use-src 0:"yul_optimizer_steps_short_sequence/input.sol"
+    object "C_8_deployed" {
+        code {
+            {
+                /// @src 0:80:221  "contract C {..."
+                mstore(64, memoryguard(0x80))
+                revert(0, 0)
+            }
+        }
+        data ".metadata" hex"<BYTECODE REMOVED>"
+    }
+}

test/cmdlineTests/yul_optimizer_steps_with_cleanup_sequence/args

@@ -0,0 +1 @@
+--ir-optimized --optimize --yul-optimizations dhfoDgvulfnTUtnIf:fDnTOc

test/cmdlineTests/yul_optimizer_steps_with_cleanup_sequence/input.sol

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+pragma abicoder v2;
+
+contract C
+{
+    constructor() {}
+}

test/cmdlineTests/yul_optimizer_steps_with_cleanup_sequence/output

@@ -0,0 +1,34 @@
+Optimized IR:
+/// @use-src 0:"yul_optimizer_steps_with_cleanup_sequence/input.sol"
+object "C_7" {
+    code {
+        {
+            /// @src 0:80:115  "contract C..."
+            mstore(64, memoryguard(0x80))
+            if callvalue()
+            {
+                revert_error_ca66f745a3ce8ff40e2ccaf1ad45db7774001b90d25810abd9040049be7bf4bb()
+            }
+            let _1 := allocate_unbounded()
+            codecopy(_1, dataoffset("C_7_deployed"), datasize("C_7_deployed"))
+            return(_1, datasize("C_7_deployed"))
+        }
+        function allocate_unbounded() -> memPtr
+        { memPtr := mload(64) }
+        function revert_error_ca66f745a3ce8ff40e2ccaf1ad45db7774001b90d25810abd9040049be7bf4bb()
+        { revert(0, 0) }
+    }
+    /// @use-src 0:"yul_optimizer_steps_with_cleanup_sequence/input.sol"
+    object "C_7_deployed" {
+        code {
+            {
+                /// @src 0:80:115  "contract C..."
+                mstore(64, memoryguard(0x80))
+                revert_error_42b3090547df1d2001c96683413b8cf91c1b902ef5e3cb8d9f6f304cf7446f74()
+            }
+            function revert_error_42b3090547df1d2001c96683413b8cf91c1b902ef5e3cb8d9f6f304cf7446f74()
+            { revert(0, 0) }
+        }
+        data ".metadata" hex"<BYTECODE REMOVED>"
+    }
+}

test/cmdlineTests/yul_optimizer_steps_with_empty_cleanup_sequence/args

@@ -0,0 +1 @@
+--ir-optimized --optimize --yul-optimizations iDu:

test/cmdlineTests/yul_optimizer_steps_with_empty_cleanup_sequence/input.sol

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+pragma abicoder v2;
+
+contract C {
+    constructor() payable {
+        assembly ("memory-safe") {
+            let a := 0
+            revert(0, a)
+        }
+    }
+}

test/cmdlineTests/yul_optimizer_steps_with_empty_cleanup_sequence/output

@@ -0,0 +1,24 @@
+Optimized IR:
+/// @use-src 0:"yul_optimizer_steps_with_empty_cleanup_sequence/input.sol"
+object "C_8" {
+    code {
+        {
+            /// @src 0:80:221  "contract C {..."
+            mstore(64, memoryguard(0x80))
+            /// @src 0:129:213  "assembly (\"memory-safe\") {..."
+            let usr$a := 0
+            revert(0, usr$a)
+        }
+    }
+    /// @use-src 0:"yul_optimizer_steps_with_empty_cleanup_sequence/input.sol"
+    object "C_8_deployed" {
+        code {
+            {
+                /// @src 0:80:221  "contract C {..."
+                mstore(64, memoryguard(0x80))
+                revert(0, 0)
+            }
+        }
+        data ".metadata" hex"<BYTECODE REMOVED>"
+    }
+}

test/cmdlineTests/yul_optimizer_steps_with_empty_optimization_sequence/args

@@ -0,0 +1 @@
+--ir-optimized --optimize --yul-optimizations :iDu

test/cmdlineTests/yul_optimizer_steps_with_empty_optimization_sequence/input.sol

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+pragma abicoder v2;
+
+contract C {
+    constructor() payable {
+        assembly ("memory-safe") {
+            let a := 0
+            revert(0, a)
+        }
+    }
+}

test/cmdlineTests/yul_optimizer_steps_with_empty_optimization_sequence/output

@@ -0,0 +1,24 @@
+Optimized IR:
+/// @use-src 0:"yul_optimizer_steps_with_empty_optimization_sequence/input.sol"
+object "C_8" {
+    code {
+        {
+            /// @src 0:80:221  "contract C {..."
+            mstore(64, memoryguard(0x80))
+            /// @src 0:129:213  "assembly (\"memory-safe\") {..."
+            let usr$a := 0
+            revert(0, usr$a)
+        }
+    }
+    /// @use-src 0:"yul_optimizer_steps_with_empty_optimization_sequence/input.sol"
+    object "C_8_deployed" {
+        code {
+            {
+                /// @src 0:80:221  "contract C {..."
+                mstore(64, memoryguard(0x80))
+                revert(0, 0)
+            }
+        }
+        data ".metadata" hex"<BYTECODE REMOVED>"
+    }
+}

test/cmdlineTests/yul_optimizer_steps_with_empty_sequences/args

@@ -0,0 +1 @@
+--ir-optimized --optimize --yul-optimizations :

test/cmdlineTests/yul_optimizer_steps_with_empty_sequences/input.sol

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+pragma abicoder v2;
+
+contract C
+{
+    constructor() {}
+}

test/cmdlineTests/yul_optimizer_steps_with_empty_sequences/output

@@ -0,0 +1,42 @@
+Optimized IR:
+/// @use-src 0:"yul_optimizer_steps_with_empty_sequences/input.sol"
+object "C_7" {
+    code {
+        {
+            /// @src 0:80:115  "contract C..."
+            mstore(64, memoryguard(0x80))
+            if callvalue()
+            {
+                revert_error_ca66f745a3ce8ff40e2ccaf1ad45db7774001b90d25810abd9040049be7bf4bb()
+            }
+            constructor_C()
+            let _1 := allocate_unbounded()
+            codecopy(_1, dataoffset("C_7_deployed"), datasize("C_7_deployed"))
+            return(_1, datasize("C_7_deployed"))
+        }
+        function allocate_unbounded() -> memPtr
+        { memPtr := mload(64) }
+        function revert_error_ca66f745a3ce8ff40e2ccaf1ad45db7774001b90d25810abd9040049be7bf4bb()
+        { revert(0, 0) }
+        /// @ast-id 6 @src 0:97:113  "constructor() {}"
+        function constructor_C()
+        { }
+    }
+    /// @use-src 0:"yul_optimizer_steps_with_empty_sequences/input.sol"
+    object "C_7_deployed" {
+        code {
+            {
+                /// @src 0:80:115  "contract C..."
+                mstore(64, memoryguard(0x80))
+                revert_error_42b3090547df1d2001c96683413b8cf91c1b902ef5e3cb8d9f6f304cf7446f74()
+            }
+            function shift_right_unsigned(value) -> newValue
+            { newValue := shr(224, value) }
+            function allocate_unbounded() -> memPtr
+            { memPtr := mload(64) }
+            function revert_error_42b3090547df1d2001c96683413b8cf91c1b902ef5e3cb8d9f6f304cf7446f74()
+            { revert(0, 0) }
+        }
+        data ".metadata" hex"<BYTECODE REMOVED>"
+    }
+}

test/libyul/YulOptimizerTestCommon.cpp

@@ -339,6 +339,7 @@ YulOptimizerTestCommon::YulOptimizerTestCommon(
 				*m_object,
 				true,
 				frontend::OptimiserSettings::DefaultYulOptimiserSteps,
+				frontend::OptimiserSettings::DefaultYulOptimiserCleanupSteps,
 				frontend::OptimiserSettings::standard().expectedExecutionsPerDeployment
 			);
 		}},