From 069a21d972286a96800efb80fbcffecfc08b8f02 Mon Sep 17 00:00:00 2001
From: silentcicero <thenickdodson@gmail.com>
Date: Mon, 13 May 2019 17:42:21 +0100
Subject: [PATCH] sloadext

---
 core/vm/gas_table.go      | 4 ++++
 core/vm/instructions.go   | 9 +++++++++
 core/vm/jump_table.go     | 7 +++++++
 core/vm/opcodes.go        | 3 +++
 params/protocol_params.go | 1 +
 5 files changed, 24 insertions(+)

diff --git a/core/vm/gas_table.go b/core/vm/gas_table.go
index 8270300ba7..36ac43b380 100644
--- a/core/vm/gas_table.go
+++ b/core/vm/gas_table.go
@@ -365,6 +365,10 @@ func gasSLoad(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, me
 	return gt.SLoad, nil
 }
 
+func gasSLoadExt(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+	return gt.SLoad, nil
+}
+
 func gasExp(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
 	expByteLen := uint64((stack.data[stack.len()-2].BitLen() + 7) / 8)
 
diff --git a/core/vm/instructions.go b/core/vm/instructions.go
index 2a062d7e77..f9b4c6292a 100644
--- a/core/vm/instructions.go
+++ b/core/vm/instructions.go
@@ -633,6 +633,15 @@ func opSload(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory
 	return nil, nil
 }
 
+func opSloadExt(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	addr := common.BigToAddress(stack.pop())
+	loc := stack.pop()
+
+	val := interpreter.evm.StateDB.GetState(addr, common.BigToHash(loc))
+	loc.SetBytes(val.Bytes())
+	return nil, nil
+}
+
 func opSstore(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	loc := common.BigToHash(stack.pop())
 	val := stack.pop()
diff --git a/core/vm/jump_table.go b/core/vm/jump_table.go
index 425436f9e5..5001ebaf48 100644
--- a/core/vm/jump_table.go
+++ b/core/vm/jump_table.go
@@ -513,6 +513,13 @@ func newFrontierInstructionSet() [256]operation {
 			maxStack:   maxStack(1, 1),
 			valid:      true,
 		},
+		SLOADEXT: {
+			execute:    opSload,
+			dynamicGas: gasSLoad,
+			minStack:   minStack(2, 1),
+			maxStack:   maxStack(2, 1),
+			valid:      true,
+		},
 		SSTORE: {
 			execute:    opSstore,
 			dynamicGas: gasSStore,
diff --git a/core/vm/opcodes.go b/core/vm/opcodes.go
index 4349ffd295..3f68b7f9a6 100644
--- a/core/vm/opcodes.go
+++ b/core/vm/opcodes.go
@@ -110,6 +110,7 @@ const (
 	MSTORE
 	MSTORE8
 	SLOAD
+	SLOADEXT
 	SSTORE
 	JUMP
 	JUMPI
@@ -286,6 +287,7 @@ var opCodeToString = map[OpCode]string{
 	MSTORE:   "MSTORE",
 	MSTORE8:  "MSTORE8",
 	SLOAD:    "SLOAD",
+	SLOADEXT: "SLOADEXT",
 	SSTORE:   "SSTORE",
 	JUMP:     "JUMP",
 	JUMPI:    "JUMPI",
@@ -449,6 +451,7 @@ var stringToOp = map[string]OpCode{
 	"MSTORE":         MSTORE,
 	"MSTORE8":        MSTORE8,
 	"SLOAD":          SLOAD,
+	"SLOADEXT":       SLOADEXT,
 	"SSTORE":         SSTORE,
 	"JUMP":           JUMP,
 	"JUMPI":          JUMPI,
diff --git a/params/protocol_params.go b/params/protocol_params.go
index 14750f6a1a..a378716d44 100644
--- a/params/protocol_params.go
+++ b/params/protocol_params.go
@@ -26,6 +26,7 @@ const (
 	MaximumExtraDataSize  uint64 = 32    // Maximum size extra data may be after Genesis.
 	ExpByteGas            uint64 = 10    // Times ceil(log256(exponent)) for the EXP instruction.
 	SloadGas              uint64 = 50    // Multiplied by the number of 32-byte words that are copied (round up) for any *COPY operation and added.
+	SloadExtGas           uint64 = 50    // Multiplied by the number of 32-byte words that are copied (round up) for any *COPY operation and added.
 	CallValueTransferGas  uint64 = 9000  // Paid for CALL when the value transfer is non-zero.
 	CallNewAccountGas     uint64 = 25000 // Paid for CALL when the destination address didn't exist prior.
 	TxGas                 uint64 = 21000 // Per transaction not creating a contract. NOTE: Not payable on data of calls between transactions.