6 files changed, 34 insertions, 70 deletions
diff --git a/libevmasm/Assembly.cpp b/libevmasm/Assembly.cpp
index df691e7d..5fab24e1 100644
--- a/libevmasm/Assembly.cpp
+++ b/libevmasm/Assembly.cpp
@@ -408,7 +408,10 @@ map<u256, u256> Assembly::optimiseInternal(
 		{
 			PeepholeOptimiser peepOpt(m_items);
 			while (peepOpt.optimise())
+			{
 				count++;
+				assertThrow(count < 64000, OptimizerException, "Peephole optimizer seems to be stuck.");
+			}
 		}
 
 		// This only modifies PushTags, we have to run again to actually remove code.
diff --git a/libevmasm/AssemblyItem.cpp b/libevmasm/AssemblyItem.cpp
index cfe91be0..64963021 100644
--- a/libevmasm/AssemblyItem.cpp
+++ b/libevmasm/AssemblyItem.cpp
@@ -17,8 +17,6 @@
 
 #include <libevmasm/AssemblyItem.h>
 
-#include <libevmasm/SemanticInformation.h>
-
 #include <libdevcore/CommonData.h>
 #include <libdevcore/FixedHash.h>
 
@@ -112,7 +110,7 @@ bool AssemblyItem::canBeFunctional() const
 	switch (m_type)
 	{
 	case Operation:
-		return !SemanticInformation::isDupInstruction(*this) && !SemanticInformation::isSwapInstruction(*this);
+		return !isDupInstruction(instruction()) && !isSwapInstruction(instruction());
 	case Push:
 	case PushString:
 	case PushTag:
diff --git a/libevmasm/EVMSchedule.h b/libevmasm/EVMSchedule.h
deleted file mode 100644
index 1695a59c..00000000
--- a/libevmasm/EVMSchedule.h
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
-	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 <http://www.gnu.org/licenses/>.
-*/
-/** @file EVMSchedule.h
- * @author Gav <i@gavwood.com>
- * @author Christian <c@ethdev.com>
- * @date 2015
- */
-
-#pragma once
-
-namespace dev
-{
-namespace solidity
-{
-
-struct EVMSchedule
-{
-	unsigned stackLimit = 1024;
-	unsigned expGas = 10;
-	unsigned expByteGas = 10;
-	unsigned keccak256Gas = 30;
-	unsigned keccak256WordGas = 6;
-	unsigned sloadGas = 200;
-	unsigned sstoreSetGas = 20000;
-	unsigned sstoreResetGas = 5000;
-	unsigned sstoreRefundGas = 15000;
-	unsigned jumpdestGas = 1;
-	unsigned logGas = 375;
-	unsigned logDataGas = 8;
-	unsigned logTopicGas = 375;
-	unsigned createGas = 32000;
-	unsigned callGas = 40;
-	unsigned callStipend = 2300;
-	unsigned callValueTransferGas = 9000;
-	unsigned callNewAccountGas = 25000;
-	unsigned selfdestructRefundGas = 24000;
-	unsigned memoryGas = 3;
-	unsigned quadCoeffDiv = 512;
-	unsigned createDataGas = 200;
-	unsigned txGas = 21000;
-	unsigned txCreateGas = 53000;
-	unsigned txDataZeroGas = 4;
-	unsigned txDataNonZeroGas = 68;
-	unsigned copyGas = 3;	
-};
-
-}
-}
diff --git a/libevmasm/Instruction.h b/libevmasm/Instruction.h
index afbef71d..d9c53900 100644
--- a/libevmasm/Instruction.h
+++ b/libevmasm/Instruction.h
@@ -197,6 +197,24 @@ enum class Instruction: uint8_t
 	SELFDESTRUCT = 0xff	///< halt execution and register account for later deletion
 };
 
+/// @returns true if the instruction is a PUSH
+inline bool isPushInstruction(Instruction _inst)
+{
+	return Instruction::PUSH1 <= _inst && _inst <= Instruction::PUSH32;
+}
+
+/// @returns true if the instruction is a DUP
+inline bool isDupInstruction(Instruction _inst)
+{
+	return Instruction::DUP1 <= _inst && _inst <= Instruction::DUP16;
+}
+
+/// @returns true if the instruction is a SWAP
+inline bool isSwapInstruction(Instruction _inst)
+{
+	return Instruction::SWAP1 <= _inst && _inst <= Instruction::SWAP16;
+}
+
 /// @returns the number of PUSH Instruction _inst
 inline unsigned getPushNumber(Instruction _inst)
 {
diff --git a/libevmasm/PeepholeOptimiser.cpp b/libevmasm/PeepholeOptimiser.cpp
index 31fdd317..168d1109 100644
--- a/libevmasm/PeepholeOptimiser.cpp
+++ b/libevmasm/PeepholeOptimiser.cpp
@@ -249,6 +249,11 @@ void applyMethods(OptimiserState& _state, Method, OtherMethods... _other)
 		applyMethods(_state, _other...);
 }
 
+size_t numberOfPops(AssemblyItems const& _items)
+{
+	return std::count(_items.begin(), _items.end(), Instruction::POP);
+}
+
 }
 
 bool PeepholeOptimiser::optimise()
@@ -257,8 +262,10 @@ bool PeepholeOptimiser::optimise()
 	while (state.i < m_items.size())
 		applyMethods(state, PushPop(), OpPop(), DoublePush(), DoubleSwap(), JumpToNext(), UnreachableCode(), TagConjunctions(), Identity());
 	if (m_optimisedItems.size() < m_items.size() || (
-		m_optimisedItems.size() == m_items.size() &&
-		eth::bytesRequired(m_optimisedItems, 3) < eth::bytesRequired(m_items, 3)
+		m_optimisedItems.size() == m_items.size() && (
+			eth::bytesRequired(m_optimisedItems, 3) < eth::bytesRequired(m_items, 3) ||
+			numberOfPops(m_optimisedItems) > numberOfPops(m_items)
+		)
 	))
 	{
 		m_items = std::move(m_optimisedItems);
diff --git a/libevmasm/SemanticInformation.cpp b/libevmasm/SemanticInformation.cpp
index ceb3fbdd..61a6ccda 100644
--- a/libevmasm/SemanticInformation.cpp
+++ b/libevmasm/SemanticInformation.cpp
@@ -90,14 +90,14 @@ bool SemanticInformation::isDupInstruction(AssemblyItem const& _item)
 {
 	if (_item.type() != Operation)
 		return false;
-	return Instruction::DUP1 <= _item.instruction() && _item.instruction() <= Instruction::DUP16;
+	return solidity::isDupInstruction(_item.instruction());
 }
 
 bool SemanticInformation::isSwapInstruction(AssemblyItem const& _item)
 {
 	if (_item.type() != Operation)
 		return false;
-	return Instruction::SWAP1 <= _item.instruction() && _item.instruction() <= Instruction::SWAP16;
+	return solidity::isSwapInstruction(_item.instruction());
 }
 
 bool SemanticInformation::isJumpInstruction(AssemblyItem const& _item)
@@ -198,6 +198,7 @@ bool SemanticInformation::invalidInPureFunctions(Instruction _instruction)
 	case Instruction::ORIGIN:
 	case Instruction::CALLER:
 	case Instruction::CALLVALUE:
+	case Instruction::GAS:
 	case Instruction::GASPRICE:
 	case Instruction::EXTCODESIZE:
 	case Instruction::EXTCODECOPY:
@@ -223,7 +224,6 @@ bool SemanticInformation::invalidInViewFunctions(Instruction _instruction)
 	case Instruction::SSTORE:
 	case Instruction::JUMP:
 	case Instruction::JUMPI:
-	case Instruction::GAS:
 	case Instruction::LOG0:
 	case Instruction::LOG1:
 	case Instruction::LOG2: