对Lua、js、Python等脚本语言浮点数运算进行简单性能测试.

README.md

简单的浮点数运算示例

CPU	主频
i5-10400	2.9GHz

• CPU - i5-10400 2.9GHz

• OS - Linux

测试代码

各个测试脚本可从下面找到.

示例1

1亿次分解成整数部分和小数部分 - 使用modf函数耗时在9秒左右.

示例2

1亿次分解成整数部分和小数部分 - 使用强制类型转换耗时在12秒左右.

示例3与4

1亿次分解成整数部分和小数部分 - 使用操作符的(取模、取整)实现耗时4秒左右.

lua 与 luajit 测试

同样的代码实现, 完成测试lua需要0.746秒luajit仅需0.026秒.

Nodejs测试

Node v10.24版本中, js完成测试仅需0.42秒.

test.js

let f, i
for (let index = 0; index < 100000000; index++){
  f = 3.1415 % 1
  i = 3.1415 - f
}
console.log(f, i)


/*
root@server:~/test$ time node main.js 
0.14150000000000018 3

real    0m0.424s
user    0m0.414s
sys     0m0.010s
root@server:~/test$ time node main.js 
0.14150000000000018 3

real    0m0.426s
user    0m0.406s
sys     0m0.021s
root@server:~/test$ time node main.js 
0.14150000000000018 3

real    0m0.427s
user    0m0.407s
sys     0m0.021s
*/

test.lua

local i, f
for _ = 1, 1e8 do
  f = 3.1415 % 1
  i = 3.1415 - f
end

print(f, i)

--[[
## 使用5.3
root@server:~/test$ time lua script/main.lua
0.1415  3.0

real    0m0.746s
user    0m0.745s
sys     0m0.000s
root@server:~/test$ time lua script/main.lua
0.1415  3.0

real    0m0.742s
user    0m0.740s
sys     0m0.000s
root@server:~/test$ time lua script/main.lua
0.1415  3.0

real    0m0.749s
user    0m0.748s
sys     0m0.000s

## 使用luajit
root@server:~/test$ time luajit script/main.lua
0.1415  3

real    0m0.028s
user    0m0.027s
sys     0m0.000s

root@server:~/test$ time luajit script/main.lua
0.1415  3

real    0m0.027s
user    0m0.026s
sys     0m0.000s

root@server:~/test$ time luajit script/main.lua
0.1415  3

real    0m0.027s
user    0m0.026s
sys     0m0.000s

--]]

test1.py

#!/usr/bin/python
import sys
if sys.version_info >= (3, 0):
  xrange = range

import math
modf = math.modf
for _ in xrange(int(1e8)) :
  f, i = modf(3.1415)
print(f, i)

'''
root@server:~/test$ time python main.py
(0.14150000000000018, 3.0)

real    0m8.912s
user    0m8.885s
sys     0m0.010s
root@server:~/test$ time python main.py
(0.14150000000000018, 3.0)

real    0m8.833s
user    0m8.786s
sys     0m0.030s
root@server:~/test$ time python main.py
(0.14150000000000018, 3.0)

real    0m9.472s
user    0m9.454s
sys     0m0.000s
'''

test2.py

#!/usr/bin/python
import sys
if sys.version_info >= (3, 0):
  xrange = range

# import math
# modf = math.modf
for _ in xrange(int(1e8)) :
  i = int(3.1415)
  f =  3.1415 - i
  
print(f, i)

'''
root@server:~/test$ time python main.py
(0.14150000000000018, 3)

real    0m12.760s
user    0m12.735s
sys     0m0.000s
root@server:~/test$ time python main.py
(0.14150000000000018, 3)

real    0m12.901s
user    0m12.870s
sys     0m0.000s
root@server:~/test$ time python main.py
(0.14150000000000018, 3)

real    0m12.830s
user    0m12.804s
sys     0m0.000s
'''

test3.py

#!/usr/bin/python
import sys
if sys.version_info >= (3, 0):
  xrange = range

for _ in xrange(int(1e8)) :
  f = 3.1415 % 1
  i = 3.1415 - f

print(f, i)

'''
root@server:~/test$ time python main.py
(0.14150000000000018, 3.0)

real    0m4.914s
user    0m4.905s
sys     0m0.000s
root@server:~/test$ time python main.py
(0.14150000000000018, 3.0)

real    0m4.898s
user    0m4.889s
sys     0m0.000s
root@server:~/test$ time python main.py
(0.14150000000000018, 3.0)

real    0m4.896s
user    0m4.887s
sys     0m0.000s
'''

test4.py

#!/usr/bin/python
import sys
if sys.version_info >= (3, 0):
  xrange = range

for _ in xrange(int(1e8)) :
  i = 3.1415 // 1
  f = 3.1415 - i

print(i, f)

'''
root@server:~/test$ time python main.py
(0.14150000000000018, 3.0)

real    0m4.912s
user    0m4.882s
sys     0m0.020s
root@server:~/test$ time python main.py
(0.14150000000000018, 3.0)

real    0m4.929s
user    0m4.911s
sys     0m0.010s
root@server:~/test$ time python main.py
(0.14150000000000018, 3.0)

real    0m4.926s
user    0m4.916s
sys     0m0.000s
'''