core/vm: added JIT segmenting / optimisations

* multi-push segments
* static jumps segments

core/vm/segments.go

@@ -0,0 +1,44 @@
+package vm
+
+import "math/big"
+
+type jumpSeg struct {
+	pos uint64
+	err error
+	gas *big.Int
+}
+
+func (j jumpSeg) do(program *Program, pc *uint64, env Environment, contract *Contract, memory *Memory, stack *stack) ([]byte, error) {
+	if !contract.UseGas(j.gas) {
+		return nil, OutOfGasError
+	}
+	if j.err != nil {
+		return nil, j.err
+	}
+	*pc = j.pos
+	return nil, nil
+}
+func (s jumpSeg) halts() bool { return false }
+func (s jumpSeg) Op() OpCode  { return 0 }
+
+type pushSeg struct {
+	data []*big.Int
+	gas  *big.Int
+}
+
+func (s pushSeg) do(program *Program, pc *uint64, env Environment, contract *Contract, memory *Memory, stack *stack) ([]byte, error) {
+	// Use the calculated gas. When insufficient gas is present, use all gas and return an
+	// Out Of Gas error
+	if !contract.UseGas(s.gas) {
+		return nil, OutOfGasError
+	}
+
+	for _, d := range s.data {
+		stack.push(new(big.Int).Set(d))
+	}
+	*pc += uint64(len(s.data))
+	return nil, nil
+}
+
+func (s pushSeg) halts() bool { return false }
+func (s pushSeg) Op() OpCode  { return 0 }