From efc32877dec232c572e4799b6d557058cf97e127 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Mon, 1 Oct 2018 13:12:43 +0200
Subject: [PATCH] core/vm: do less hashing in CREATE2

---
 core/vm/evm.go   | 27 +++++++++++++++++++++------
 crypto/crypto.go |  6 +++---
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/core/vm/evm.go b/core/vm/evm.go
index fc040c6216..e604d79822 100644
--- a/core/vm/evm.go
+++ b/core/vm/evm.go
@@ -352,8 +352,21 @@ func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte
 	return ret, contract.Gas, err
 }
 
+type codeAndHash struct {
+	code []byte
+	hash *common.Hash
+}
+
+func (c *codeAndHash) Hash() common.Hash {
+	if c.hash == nil {
+		h := crypto.Keccak256Hash(c.code)
+		c.hash = &h
+	}
+	return *c.hash
+}
+
 // create creates a new contract using code as deployment code.
-func (evm *EVM) create(caller ContractRef, code []byte, gas uint64, value *big.Int, address common.Address) ([]byte, common.Address, uint64, error) {
+func (evm *EVM) create(caller ContractRef, codeAndHash codeAndHash, gas uint64, value *big.Int, address common.Address) ([]byte, common.Address, uint64, error) {
 	// Depth check execution. Fail if we're trying to execute above the
 	// limit.
 	if evm.depth > int(params.CallCreateDepth) {
@@ -382,14 +395,14 @@ func (evm *EVM) create(caller ContractRef, code []byte, gas uint64, value *big.I
 	// EVM. The contract is a scoped environment for this execution context
 	// only.
 	contract := NewContract(caller, AccountRef(address), value, gas)
-	contract.SetCallCode(&address, crypto.Keccak256Hash(code), code)
+	contract.SetCallCode(&address, codeAndHash.Hash(), codeAndHash.code)
 
 	if evm.vmConfig.NoRecursion && evm.depth > 0 {
 		return nil, address, gas, nil
 	}
 
 	if evm.vmConfig.Debug && evm.depth == 0 {
-		evm.vmConfig.Tracer.CaptureStart(caller.Address(), address, true, code, gas, value)
+		evm.vmConfig.Tracer.CaptureStart(caller.Address(), address, true, codeAndHash.code, gas, value)
 	}
 	start := time.Now()
 
@@ -432,8 +445,9 @@ func (evm *EVM) create(caller ContractRef, code []byte, gas uint64, value *big.I
 
 // Create creates a new contract using code as deployment code.
 func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
+	codeAndHash := codeAndHash{code: code}
 	contractAddr = crypto.CreateAddress(caller.Address(), evm.StateDB.GetNonce(caller.Address()))
-	return evm.create(caller, code, gas, value, contractAddr)
+	return evm.create(caller, codeAndHash, gas, value, contractAddr)
 }
 
 // Create2 creates a new contract using code as deployment code.
@@ -441,8 +455,9 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
 // The different between Create2 with Create is Create2 uses sha3(0xff ++ msg.sender ++ salt ++ sha3(init_code))[12:]
 // instead of the usual sender-and-nonce-hash as the address where the contract is initialized at.
 func (evm *EVM) Create2(caller ContractRef, code []byte, gas uint64, endowment *big.Int, salt *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
-	contractAddr = crypto.CreateAddress2(caller.Address(), common.BigToHash(salt), code)
-	return evm.create(caller, code, gas, endowment, contractAddr)
+	codeAndHash := codeAndHash{code: code}
+	contractAddr = crypto.CreateAddress2(caller.Address(), common.BigToHash(salt), codeAndHash.Hash().Bytes())
+	return evm.create(caller, codeAndHash, gas, endowment, contractAddr)
 }
 
 // ChainConfig returns the environment's chain configuration
diff --git a/crypto/crypto.go b/crypto/crypto.go
index 3211957e0a..9b3e76d406 100644
--- a/crypto/crypto.go
+++ b/crypto/crypto.go
@@ -77,9 +77,9 @@ func CreateAddress(b common.Address, nonce uint64) common.Address {
 }
 
 // CreateAddress2 creates an ethereum address given the address bytes, initial
-// contract code and a salt.
-func CreateAddress2(b common.Address, salt [32]byte, code []byte) common.Address {
-	return common.BytesToAddress(Keccak256([]byte{0xff}, b.Bytes(), salt[:], Keccak256(code))[12:])
+// contract code hash and a salt.
+func CreateAddress2(b common.Address, salt [32]byte, inithash []byte) common.Address {
+	return common.BytesToAddress(Keccak256([]byte{0xff}, b.Bytes(), salt[:], inithash)[12:])
 }
 
 // ToECDSA creates a private key with the given D value.