diff --git a/libyul/CMakeLists.txt b/libyul/CMakeLists.txt
index 8cccb4457..432ddeb14 100644
--- a/libyul/CMakeLists.txt
+++ b/libyul/CMakeLists.txt
@@ -68,6 +68,8 @@ add_library(yul
optimiser/CommonSubexpressionEliminator.h
optimiser/ConditionalSimplifier.cpp
optimiser/ConditionalSimplifier.h
+ optimiser/ConditionalUnsimplifier.cpp
+ optimiser/ConditionalUnsimplifier.h
optimiser/ControlFlowSimplifier.cpp
optimiser/ControlFlowSimplifier.h
optimiser/DataFlowAnalyzer.cpp
diff --git a/libyul/optimiser/ConditionalUnsimplifier.cpp b/libyul/optimiser/ConditionalUnsimplifier.cpp
new file mode 100644
index 000000000..d1d167aa1
--- /dev/null
+++ b/libyul/optimiser/ConditionalUnsimplifier.cpp
@@ -0,0 +1,98 @@
+/*
+ This file is part of solidity.
+
+ solidity is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ solidity is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with solidity. If not, see .
+*/
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+using namespace std;
+using namespace dev;
+using namespace yul;
+
+void ConditionalUnsimplifier::operator()(Switch& _switch)
+{
+ visit(*_switch.expression);
+ if (_switch.expression->type() != typeid(Identifier))
+ {
+ ASTModifier::operator()(_switch);
+ return;
+ }
+ YulString expr = boost::get(*_switch.expression).name;
+ for (auto& _case: _switch.cases)
+ {
+ if (_case.value)
+ {
+ (*this)(*_case.value);
+ if (
+ !_case.body.statements.empty() &&
+ _case.body.statements.front().type() == typeid(Assignment)
+ )
+ {
+ Assignment const& assignment = boost::get(_case.body.statements.front());
+ if (
+ assignment.variableNames.size() == 1 &&
+ assignment.variableNames.front().name == expr &&
+ assignment.value->type() == typeid(Literal) &&
+ valueOfLiteral(boost::get(*assignment.value)) == valueOfLiteral(*_case.value)
+ )
+ _case.body.statements.erase(_case.body.statements.begin());
+ }
+ }
+ (*this)(_case.body);
+ }
+}
+
+void ConditionalUnsimplifier::operator()(Block& _block)
+{
+ iterateReplacingWindow<2>(
+ _block.statements,
+ [&](Statement& _stmt1, Statement& _stmt2) -> std::optional>
+ {
+ visit(_stmt1);
+ if (_stmt1.type() == typeid(If))
+ {
+ If& _if = boost::get(_stmt1);
+ if (
+ _if.condition->type() == typeid(Identifier) &&
+ !_if.body.statements.empty()
+ )
+ {
+ YulString condition = boost::get(*_if.condition).name;
+ if (
+ _stmt2.type() == typeid(Assignment) &&
+ TerminationFinder(m_dialect).controlFlowKind(_if.body.statements.back()) !=
+ TerminationFinder::ControlFlow::FlowOut
+ )
+ {
+ Assignment const& assignment = boost::get(_stmt2);
+ if (
+ assignment.variableNames.size() == 1 &&
+ assignment.variableNames.front().name == condition &&
+ assignment.value->type() == typeid(Literal) &&
+ valueOfLiteral(boost::get(*assignment.value)) == 0
+ )
+ return {make_vector(std::move(_stmt1))};
+ }
+ }
+ }
+ return {};
+ }
+ );
+}
diff --git a/libyul/optimiser/ConditionalUnsimplifier.h b/libyul/optimiser/ConditionalUnsimplifier.h
new file mode 100644
index 000000000..16358c9f7
--- /dev/null
+++ b/libyul/optimiser/ConditionalUnsimplifier.h
@@ -0,0 +1,51 @@
+/*
+ This file is part of solidity.
+
+ solidity is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ solidity is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with solidity. If not, see .
+*/
+#pragma once
+
+#include
+#include
+#include
+#include
+
+namespace yul
+{
+
+/**
+ * Reverse of conditional simplifier.
+ *
+ */
+class ConditionalUnsimplifier: public ASTModifier
+{
+public:
+ static constexpr char const* name{"ConditionalUnsimplifier"};
+ static void run(OptimiserStepContext& _context, Block& _ast)
+ {
+ ConditionalUnsimplifier{_context.dialect}(_ast);
+ }
+
+ using ASTModifier::operator();
+ void operator()(Switch& _switch) override;
+ void operator()(Block& _block) override;
+
+private:
+ explicit ConditionalUnsimplifier(Dialect const& _dialect):
+ m_dialect(_dialect)
+ {}
+ Dialect const& m_dialect;
+};
+
+}
diff --git a/libyul/optimiser/Suite.cpp b/libyul/optimiser/Suite.cpp
index d9b689729..b0f84c6bd 100644
--- a/libyul/optimiser/Suite.cpp
+++ b/libyul/optimiser/Suite.cpp
@@ -26,6 +26,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -98,9 +99,9 @@ void OptimiserSuite::run(
EquivalentFunctionCombiner::name,
UnusedPruner::name,
BlockFlattener::name,
- ConditionalSimplifier::name,
ControlFlowSimplifier::name,
LiteralRematerialiser::name,
+ ConditionalUnsimplifier::name,
StructuralSimplifier::name,
ControlFlowSimplifier::name,
ForLoopConditionIntoBody::name,
@@ -138,6 +139,7 @@ void OptimiserSuite::run(
CommonSubexpressionEliminator::name,
ConditionalSimplifier::name,
LiteralRematerialiser::name,
+ ConditionalUnsimplifier::name,
StructuralSimplifier::name,
ForLoopConditionOutOfBody::name,
ControlFlowSimplifier::name,
@@ -207,13 +209,14 @@ void OptimiserSuite::run(
// SSA plus simplify
suite.runSequence({
ConditionalSimplifier::name,
+ LiteralRematerialiser::name,
+ ConditionalUnsimplifier::name,
CommonSubexpressionEliminator::name,
SSATransform::name,
RedundantAssignEliminator::name,
RedundantAssignEliminator::name,
LoadResolver::name,
ExpressionSimplifier::name,
- LiteralRematerialiser::name,
ForLoopConditionOutOfBody::name,
StructuralSimplifier::name,
BlockFlattener::name,
@@ -324,6 +327,7 @@ map> const& OptimiserSuite::allSteps()
BlockFlattener,
CommonSubexpressionEliminator,
ConditionalSimplifier,
+ ConditionalUnsimplifier,
ControlFlowSimplifier,
DeadCodeEliminator,
EquivalentFunctionCombiner,
diff --git a/test/libyul/yulOptimizerTests/fullSuite/aztec.yul b/test/libyul/yulOptimizerTests/fullSuite/aztec.yul
index a47172d70..0b82de7e9 100644
--- a/test/libyul/yulOptimizerTests/fullSuite/aztec.yul
+++ b/test/libyul/yulOptimizerTests/fullSuite/aztec.yul
@@ -233,11 +233,15 @@
// ----
// {
// {
-// mstore(0x80, 7673901602397024137095011250362199966051872585513276903826533215767972925880)
+// let _1 := 0x80
+// mstore(_1, 7673901602397024137095011250362199966051872585513276903826533215767972925880)
// mstore(0xa0, 8489654445897228341090914135473290831551238522473825886865492707826370766375)
-// let n := calldataload(add(0x04, calldataload(0x04)))
-// let _1 := 0x30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001
-// if gt(calldataload(0x24), n)
+// let notes := add(0x04, calldataload(0x04))
+// let m := calldataload(0x24)
+// let n := calldataload(notes)
+// let _2 := 0x30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001
+// let challenge := mod(calldataload(0x44), _2)
+// if gt(m, n)
// {
// mstore(0x00, 404)
// revert(0x00, 0x20)
@@ -245,95 +249,70 @@
// let kn := calldataload(add(calldatasize(), not(191)))
// mstore(0x2a0, caller())
// mstore(0x2c0, kn)
-// mstore(0x2e0, calldataload(0x24))
-// kn := mulmod(sub(_1, kn), mod(calldataload(0x44), _1), _1)
-// hashCommitments(add(0x04, calldataload(0x04)), n)
-// let b := add(0x300, mul(n, 0x80))
+// mstore(0x2e0, m)
+// kn := mulmod(sub(_2, kn), challenge, _2)
+// hashCommitments(notes, n)
+// let b := add(0x300, mul(n, _1))
// let i := 0
// for { } lt(i, n) { i := add(i, 0x01) }
// {
-// let _2 := add(calldataload(0x04), mul(i, 0xc0))
+// let _3 := add(calldataload(0x04), mul(i, 0xc0))
+// let noteIndex := add(_3, 0x24)
// let k := 0
-// let a := calldataload(add(_2, 0x44))
-// let c := mod(calldataload(0x44), _1)
-// let _3 := eq(add(i, 0x01), n)
-// let _4 := _3
-// let _5 := _3
-// let _6 := _3
-// switch _3
+// let a := calldataload(add(_3, 0x44))
+// let c := challenge
+// let _4 := add(i, 0x01)
+// switch eq(_4, n)
// case 1 {
-// _3 := 0x01
-// _4 := _3
-// _5 := _3
-// _6 := _3
// k := kn
-// if eq(calldataload(0x24), n) { k := sub(_1, kn) }
+// if eq(m, n) { k := sub(_2, kn) }
// }
-// case 0 {
-// _3 := 0
-// _4 := _3
-// _5 := _3
-// _6 := _3
-// k := calldataload(add(_2, 0x24))
-// }
-// validateCommitment(add(_2, 0x24), k, a)
-// let _7 := gt(add(i, 0x01), calldataload(0x24))
-// let _8 := _7
-// let _9 := _7
-// let _10 := _7
-// switch _7
+// case 0 { k := calldataload(noteIndex) }
+// validateCommitment(noteIndex, k, a)
+// switch gt(_4, m)
// case 1 {
-// _7 := 0x01
-// _8 := _7
-// _9 := _7
-// _10 := _7
-// kn := addmod(kn, sub(_1, k), _1)
-// let x := mod(mload(0), _1)
-// k := mulmod(k, x, _1)
-// a := mulmod(a, x, _1)
-// c := mulmod(c, x, _1)
+// kn := addmod(kn, sub(_2, k), _2)
+// let x := mod(mload(0), _2)
+// k := mulmod(k, x, _2)
+// a := mulmod(a, x, _2)
+// c := mulmod(challenge, x, _2)
// mstore(0, keccak256(0, 0x20))
// }
-// case 0 {
-// _7 := 0
-// _8 := _7
-// _9 := _7
-// _10 := _7
-// kn := addmod(kn, k, _1)
-// }
-// calldatacopy(0xe0, add(_2, 164), 0x40)
-// calldatacopy(0x20, add(_2, 100), 0x40)
-// mstore(0x120, sub(_1, c))
+// case 0 { kn := addmod(kn, k, _2) }
+// let _5 := 0x40
+// calldatacopy(0xe0, add(_3, 164), _5)
+// calldatacopy(0x20, add(_3, 100), _5)
+// mstore(0x120, sub(_2, c))
// mstore(0x60, k)
// mstore(0xc0, a)
-// let result := call(gas(), 7, 0, 0xe0, 0x60, 0x1a0, 0x40)
-// let result_1 := and(result, call(gas(), 7, 0, 0x20, 0x60, 0x120, 0x40))
-// let result_2 := and(result_1, call(gas(), 7, 0, 0x80, 0x60, 0x160, 0x40))
-// let result_3 := and(result_2, call(gas(), 6, 0, 0x120, 0x80, 0x160, 0x40))
-// result := and(result_3, call(gas(), 6, 0, 0x160, 0x80, b, 0x40))
-// if eq(i, calldataload(0x24))
+// let result := call(gas(), 7, 0, 0xe0, 0x60, 0x1a0, _5)
+// let result_1 := and(result, call(gas(), 7, 0, 0x20, 0x60, 0x120, _5))
+// let result_2 := and(result_1, call(gas(), 7, 0, _1, 0x60, 0x160, _5))
+// let result_3 := and(result_2, call(gas(), 6, 0, 0x120, _1, 0x160, _5))
+// result := and(result_3, call(gas(), 6, 0, 0x160, _1, b, _5))
+// if eq(i, m)
// {
// mstore(0x260, mload(0x20))
-// mstore(0x280, mload(0x40))
+// mstore(0x280, mload(_5))
// mstore(0x1e0, mload(0xe0))
// mstore(0x200, sub(0x30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47, mload(0x100)))
// }
-// if gt(i, calldataload(0x24))
+// if gt(i, m)
// {
// mstore(0x60, c)
-// let result_4 := and(result, call(gas(), 7, 0, 0x20, 0x60, 0x220, 0x40))
-// let result_5 := and(result_4, call(gas(), 6, 0, 0x220, 0x80, 0x260, 0x40))
-// result := and(result_5, call(gas(), 6, 0, 0x1a0, 0x80, 0x1e0, 0x40))
+// let result_4 := and(result, call(gas(), 7, 0, 0x20, 0x60, 0x220, _5))
+// let result_5 := and(result_4, call(gas(), 6, 0, 0x220, _1, 0x260, _5))
+// result := and(result_5, call(gas(), 6, 0, 0x1a0, _1, 0x1e0, _5))
// }
// if iszero(result)
// {
// mstore(0, 400)
// revert(0, 0x20)
// }
-// b := add(b, 0x40)
+// b := add(b, _5)
// }
-// if lt(calldataload(0x24), n) { validatePairing(0x64) }
-// if iszero(eq(mod(keccak256(0x2a0, add(b, not(671))), _1), mod(calldataload(0x44), _1)))
+// if lt(m, n) { validatePairing(0x64) }
+// if iszero(eq(mod(keccak256(0x2a0, add(b, not(671))), _2), challenge))
// {
// mstore(0, 404)
// revert(0, 0x20)
diff --git a/test/libyul/yulOptimizerTests/fullSuite/clear_after_if_continue.yul b/test/libyul/yulOptimizerTests/fullSuite/clear_after_if_continue.yul
index f4147bc17..19816b445 100644
--- a/test/libyul/yulOptimizerTests/fullSuite/clear_after_if_continue.yul
+++ b/test/libyul/yulOptimizerTests/fullSuite/clear_after_if_continue.yul
@@ -12,16 +12,10 @@
// {
// {
// let y := mload(0x20)
-// for { }
-// and(y, 8)
-// {
-// if y { revert(0, 0) }
-// y := 0
-// }
+// for { } and(y, 8) { if y { revert(0, 0) } }
// {
// if y { continue }
-// y := 0
-// sstore(1, y)
+// sstore(1, 0)
// }
// if y { revert(0, 0) }
// }