我尝试用顺序双调排序对列表进行排序，并希望通过对numpy数组而不是列表进行排序来使其更快，但它只会变得更慢。我做错了什么？
以下是排序算法：

from datetime import datetime
import numpy as np

def compAndSwap(a, i, j, dire):
    if (dire == 1 and a[i] > a[j]) or (dire == 0 and a[i] < a[j]):
        a[i], a[j] = a[j], a[i]

def bitonicMerge(a, low, cnt, dire):
    if cnt > 1:
        k = cnt // 2
        for i in range(low, low + k):
            compAndSwap(a, i, i + k, dire)
        bitonicMerge(a, low, k, dire)
        bitonicMerge(a, low + k, k, dire)

def bitonicSort(a, low, cnt, dire):
    if cnt > 1:
        k = cnt // 2
        bitonicSort(a, low, k, 1)
        bitonicSort(a, low + k, k, 0)
        bitonicMerge(a, low, cnt, dire)

def sort_(a, N, up):
    bitonicSort(a, 0, N, up)

这里是运行这个算法的一部分：

with open('data.txt') as f:
    
    line = f.readline()
    a = line[1:-2].split(', ')
    a = list(map(int, a))

n = len(a)

up = 1

time1 = datetime.now()

sort_(a, n, up)

time2 = datetime.now()

print("\nCurrent Time =", time2-time1)

下面是numpy数组：

with open('data.txt') as f:
    line = f.readline()
    a = np.array(line[1:-2].split(', ')).astype('int32')

n = a.size
up = 1

time1 = datetime.now()

sort_(a, n, up)

time2 = datetime.now()

print("\nCurrent Time =", time2-time1)

我错过了什么？