From 43821d7fd1217a44a64c3724e0db5d40651aaeea Mon Sep 17 00:00:00 2001
From: Matheus Aguiar <matheus.pit@gmail.com>
Date: Sat, 1 Jul 2023 18:23:08 -0300
Subject: [PATCH] Added GasMeter::gasPush

---
 libevmasm/ConstantOptimiser.cpp              |  5 +----
 libevmasm/GasMeter.cpp                       |  8 +++++++
 libevmasm/GasMeter.h                         |  3 +++
 libyul/backends/evm/EVMMetrics.cpp           | 22 ++++++++++++--------
 libyul/backends/evm/StackLayoutGenerator.cpp |  2 +-
 5 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/libevmasm/ConstantOptimiser.cpp b/libevmasm/ConstantOptimiser.cpp
index 1ce7ba920..bead74407 100644
--- a/libevmasm/ConstantOptimiser.cpp
+++ b/libevmasm/ConstantOptimiser.cpp
@@ -83,10 +83,7 @@ bigint ConstantOptimisationMethod::simpleRunGas(AssemblyItems const& _items, lan
 	bigint gas = 0;
 	for (AssemblyItem const& item: _items)
 		if (item.type() == Push)
-		{
-			auto const instruction = (item.data() == u256(0) && _evmVersion.hasPush0()) ? Instruction::PUSH0 : Instruction::PUSH1;
-			gas += GasMeter::runGas(instruction, _evmVersion);
-		}
+			gas += GasMeter::pushGas(item.data(), _evmVersion);
 		else if (item.type() == Operation)
 		{
 			if (item.instruction() == Instruction::EXP)
diff --git a/libevmasm/GasMeter.cpp b/libevmasm/GasMeter.cpp
index 271a6ce2d..b6c265142 100644
--- a/libevmasm/GasMeter.cpp
+++ b/libevmasm/GasMeter.cpp
@@ -277,6 +277,14 @@ unsigned GasMeter::runGas(Instruction _instruction, langutil::EVMVersion _evmVer
 	return 0;
 }
 
+unsigned GasMeter::pushGas(u256 _value, langutil::EVMVersion _evmVersion)
+{
+	return runGas(
+		(_evmVersion.hasPush0() && _value == u256(0)) ? Instruction::PUSH0 : Instruction::PUSH1,
+		_evmVersion
+	);
+}
+
 u256 GasMeter::dataGas(bytes const& _data, bool _inCreation, langutil::EVMVersion _evmVersion)
 {
 	bigint gas = 0;
diff --git a/libevmasm/GasMeter.h b/libevmasm/GasMeter.h
index ec1946644..9a7f6621f 100644
--- a/libevmasm/GasMeter.h
+++ b/libevmasm/GasMeter.h
@@ -223,6 +223,9 @@ public:
 	/// change with EVM versions)
 	static unsigned runGas(Instruction _instruction, langutil::EVMVersion _evmVersion);
 
+	/// @returns gas costs for push instructions (may change depending on EVM version)
+	static unsigned pushGas(u256 _value, langutil::EVMVersion _evmVersion);
+
 	/// @returns the gas cost of the supplied data, depending whether it is in creation code, or not.
 	/// In case of @a _inCreation, the data is only sent as a transaction and is not stored, whereas
 	/// otherwise code will be stored and have to pay "createDataGas" cost.
diff --git a/libyul/backends/evm/EVMMetrics.cpp b/libyul/backends/evm/EVMMetrics.cpp
index 095969838..1760b19a0 100644
--- a/libyul/backends/evm/EVMMetrics.cpp
+++ b/libyul/backends/evm/EVMMetrics.cpp
@@ -88,14 +88,16 @@ void GasMeterVisitor::operator()(FunctionCall const& _funCall)
 
 void GasMeterVisitor::operator()(Literal const& _lit)
 {
-	m_runGas += evmasm::GasMeter::runGas(evmasm::Instruction::PUSH1, m_dialect.evmVersion());
-	m_dataGas +=
-		singleByteDataGas() +
-		evmasm::GasMeter::dataGas(
-			toCompactBigEndian(valueOfLiteral(_lit), 1),
-			m_isCreation,
-			m_dialect.evmVersion()
-		);
+	m_runGas += evmasm::GasMeter::pushGas(valueOfLiteral(_lit), m_dialect.evmVersion());
+
+	if (!m_dialect.evmVersion().hasPush0() || valueOfLiteral(_lit) != u256(0))
+		m_dataGas +=
+			singleByteDataGas() +
+			evmasm::GasMeter::dataGas(
+				toCompactBigEndian(valueOfLiteral(_lit), 1),
+				m_isCreation,
+				m_dialect.evmVersion()
+			);
 }
 
 void GasMeterVisitor::operator()(Identifier const&)
@@ -121,5 +123,7 @@ void GasMeterVisitor::instructionCostsInternal(evmasm::Instruction _instruction)
 		m_runGas += evmasm::GasCosts::keccak256Gas + evmasm::GasCosts::keccak256WordGas;
 	else
 		m_runGas += evmasm::GasMeter::runGas(_instruction, m_dialect.evmVersion());
-	m_dataGas += singleByteDataGas();
+
+	if (_instruction != evmasm::Instruction::PUSH0)
+		m_dataGas += singleByteDataGas();
 }
diff --git a/libyul/backends/evm/StackLayoutGenerator.cpp b/libyul/backends/evm/StackLayoutGenerator.cpp
index 71bf19458..8501655f0 100644
--- a/libyul/backends/evm/StackLayoutGenerator.cpp
+++ b/libyul/backends/evm/StackLayoutGenerator.cpp
@@ -772,7 +772,7 @@ void StackLayoutGenerator::fillInJunk(CFG::BasicBlock const& _block, CFG::Functi
 					yulAssert(util::contains(m_currentFunctionInfo->returnVariables, get<VariableSlot>(_slot)));
 					// Strictly speaking the cost of the PUSH0 depends on the targeted EVM version, but the difference
 					// will not matter here.
-					opGas += evmasm::GasMeter::runGas(evmasm::pushInstruction(0), langutil::EVMVersion());;
+					opGas += evmasm::GasMeter::pushGas(u256(0), langutil::EVMVersion());
 				}
 			}
 		};