Selfdestruct optimizations for Frontier and Homestead

CHANGELOG.md

@@ -48,6 +48,7 @@
 - Fixed: [#5666](https://github.com/ethereum/aleth/pull/5666) aleth-interpreter returns `EVMC_INVALID_INSTRUCTION` when `INVALID` opcode is encountered and `EVMC_UNKNOWN_INSTRUCTION` for undefined opcodes.
 - Fixed: [#5706](https://github.com/ethereum/aleth/pull/5706) Stop tracking sent transactions after they've been imported into the blockchain.
 - Fixed: [#5687](https://github.com/ethereum/aleth/pull/5687) Limit transaction queue's dropped transaction history to 1024 transactions.
+- Fixed: [#5718](https://github.com/ethereum/aleth/pull/5718) Avoid checking contract balance or destination account existence when executing self-destruct operations on Frontier and Homestead.
 
 ## [1.6.0] - 2019-04-16
 

libaleth-interpreter/VM.cpp

@@ -377,19 +377,19 @@ void VM::interpretCases()
             if (m_message->flags & EVMC_STATIC)
                 throwDisallowedStateChange();
 
-            evmc_address destination = toEvmC(asAddress(m_SP[0]));
+            evmc_address const destination = toEvmC(asAddress(m_SP[0]));
 
-            // After EIP158 zero-value suicides do not have to pay account creation gas.
-            u256 const balance =
-                fromEvmC(m_context->host->get_balance(m_context, &m_message->destination));
-            if (balance > 0 || m_rev < EVMC_SPURIOUS_DRAGON)
+            // Starting with EIP150 (Tangerine Whistle), self-destructs need to pay account creation
+            // gas. Starting with EIP158 (Spurious Dragon), 0-value suicides don't have to pay this
+            // charge.
+            if (m_rev >= EVMC_TANGERINE_WHISTLE)
             {
-                // After EIP150 hard fork charge additional cost of sending
-                // ethers to non-existing account.
-                int destinationExists =
-                    m_context->host->account_exists(m_context, &destination);
-                if (m_rev >= EVMC_TANGERINE_WHISTLE && !destinationExists)
-                    m_runGas += VMSchedule::callNewAccount;
+                if (m_rev == EVMC_TANGERINE_WHISTLE ||
+                    fromEvmC(m_context->host->get_balance(m_context, &m_message->destination)) > 0)
+                {
+                    if (!m_context->host->account_exists(m_context, &destination))
+                        m_runGas += VMSchedule::callNewAccount;
+                }
             }
 
             updateIOGas();
@@ -1442,4 +1442,4 @@ void VM::interpretCases()
     WHILE_CASES
 }
 }
-}
+}

libethcore/EVMSchedule.h

@@ -83,7 +83,6 @@ struct EVMSchedule
     boost::optional<u256> blockRewardOverwrite;
 
     bool staticCallDepthLimit() const { return !eip150Mode; }
-    bool suicideChargesNewAccountGas() const { return eip150Mode; }
     bool emptinessIsNonexistence() const { return eip158Mode; }
     bool zeroValueTransferChargesNewAccountGas() const { return !eip158Mode; }
 };

libevm/LegacyVM.cpp

@@ -331,15 +331,19 @@ void LegacyVM::interpretCases()
             if (m_ext->staticCall)
                 throwDisallowedStateChange();
 
+            // Self-destructs only have gas cost starting with EIP 150
             m_runGas = toInt63(m_schedule->suicideGas);
-            Address dest = asAddress(m_SP[0]);
 
-            // After EIP158 zero-value suicides do not have to pay account creation gas.
-            if (m_ext->balance(m_ext->myAddress) > 0 || m_schedule->zeroValueTransferChargesNewAccountGas())
-                // After EIP150 hard fork charge additional cost of sending
-                // ethers to non-existing account.
-                if (m_schedule->suicideChargesNewAccountGas() && !m_ext->exists(dest))
+            Address const dest = asAddress(m_SP[0]);
+            // Starting with EIP150, self-destructs need to pay both gas cost and account creation
+            // gas cost. Starting with EIP158, 0-value self-destructs don't need to pay this account
+            // creation cost.
+            if (m_schedule->eip150Mode &&
+                (!m_schedule->eip158Mode || m_ext->balance(m_ext->myAddress) > 0))
+            {
+                if (!m_ext->exists(dest))
                     m_runGas += m_schedule->callNewAccountGas;
+            }
 
             updateIOGas();
             m_ext->suicide(dest);