core/vm: handwrite push2 opcode

core/vm/instructions.go

@@ -17,6 +17,7 @@
 package vm
 
 import (
+	"encoding/binary"
 	"math"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -971,6 +972,23 @@ func opPush1(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]by
 	return nil, nil
 }
 
+// opPush1 is a specialized version of pushN
+func opPush2(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
+	var (
+		codeLen = uint64(len(scope.Contract.Code))
+		integer = new(uint256.Int)
+	)
+	if *pc+2 < codeLen {
+		scope.Stack.push(integer.SetUint64(uint64(binary.BigEndian.Uint16(scope.Contract.Code[*pc : *pc+2]))))
+	} else if *pc+1 < codeLen {
+		scope.Stack.push(integer.SetUint64(uint64(scope.Contract.Code[*pc]) << 8))
+	} else {
+		scope.Stack.push(integer.Clear())
+	}
+	*pc += 2
+	return nil, nil
+}
+
 // make push instruction function
 func makePush(size uint64, pushByteSize int) executionFunc {
 	return func(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {

core/vm/instructions_test.go

@@ -972,3 +972,32 @@ func TestPush(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkPush(b *testing.B) {
+	var (
+		code   = common.FromHex("0011223344556677889900aabbccddeeff0102030405060708090a0b0c0d0e0ff1e1d1c1b1a19181716151413121")
+		push32 = makePush(2, 2)
+		scope  = &ScopeContext{
+			Memory: nil,
+			Stack:  newstack(),
+			Contract: &Contract{
+				Code: code,
+			},
+		}
+		pc = new(uint64)
+	)
+
+	b.Run("makePush", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			push32(pc, nil, scope)
+			scope.Stack.pop()
+		}
+	})
+
+	b.Run("push", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			opPush2(pc, nil, scope)
+			scope.Stack.pop()
+		}
+	})
+}