core/vm: minor trivial clean up (ethereum#25880)

* dropped `vm.keccakState` for `crypto.KeccakState`

* cleaned up `OpCode.IsPush()`

Author: lmittmann

core/vm/instructions.go

@@ -21,9 +21,9 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/holiman/uint256"
-	"golang.org/x/crypto/sha3"
 )
 
 func opAdd(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
@@ -238,7 +238,7 @@ func opKeccak256(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) (
 	data := scope.Memory.GetPtr(int64(offset.Uint64()), int64(size.Uint64()))
 
 	if interpreter.hasher == nil {
-		interpreter.hasher = sha3.NewLegacyKeccak256().(keccakState)
+		interpreter.hasher = crypto.NewKeccakState()
 	} else {
 		interpreter.hasher.Reset()
 	}

core/vm/interpreter.go

@@ -17,10 +17,9 @@
 package vm
 
 import (
-	"hash"
-
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/log"
 )
 
@@ -44,21 +43,13 @@ type ScopeContext struct {
 	Contract *Contract
 }
 
-// keccakState wraps sha3.state. In addition to the usual hash methods, it also supports
-// Read to get a variable amount of data from the hash state. Read is faster than Sum
-// because it doesn't copy the internal state, but also modifies the internal state.
-type keccakState interface {
-	hash.Hash
-	Read([]byte) (int, error)
-}
-
 // EVMInterpreter represents an EVM interpreter
 type EVMInterpreter struct {
 	evm *EVM
 	cfg Config
 
-	hasher    keccakState // Keccak256 hasher instance shared across opcodes
-	hasherBuf common.Hash // Keccak256 hasher result array shared aross opcodes
+	hasher    crypto.KeccakState // Keccak256 hasher instance shared across opcodes
+	hasherBuf common.Hash        // Keccak256 hasher result array shared aross opcodes
 
 	readOnly   bool   // Whether to throw on stateful modifications
 	returnData []byte // Last CALL's return data for subsequent reuse

core/vm/opcodes.go

@@ -25,11 +25,7 @@ type OpCode byte
 
 // IsPush specifies if an opcode is a PUSH opcode.
 func (op OpCode) IsPush() bool {
-	switch op {
-	case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
-		return true
-	}
-	return false
+	return PUSH1 <= op && op <= PUSH32
 }
 
 // 0x0 range - arithmetic ops.