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#
# Copyright (C) 2001-2012 Python Software Foundation. All Rights Reserved.
# Modified and extended by Stefan Krah.
#
# Usage: ../../../python bench.py
import time
import sys
from functools import wraps
from test.support.import_helper import import_fresh_module
C = import_fresh_module('decimal', fresh=['_decimal'])
P = import_fresh_module('decimal', blocked=['_decimal'])
#
# NOTE: This is the pi function from the decimal documentation, modified
# for benchmarking purposes. Since floats do not have a context, the higher
# intermediate precision from the original is NOT used, so the modified
# algorithm only gives an approximation to the correctly rounded result.
# For serious use, refer to the documentation or the appropriate literature.
#
def pi_float():
"""native float"""
lasts, t, s, n, na, d, da = 0, 3.0, 3, 1, 0, 0, 24
while s != lasts:
lasts = s
n, na = n+na, na+8
d, da = d+da, da+32
t = (t * n) / d
s += t
return s
def pi_cdecimal():
"""cdecimal"""
D = C.Decimal
lasts, t, s, n, na, d, da = D(0), D(3), D(3), D(1), D(0), D(0), D(24)
while s != lasts:
lasts = s
n, na = n+na, na+8
d, da = d+da, da+32
t = (t * n) / d
s += t
return s
def pi_decimal():
"""decimal"""
D = P.Decimal
lasts, t, s, n, na, d, da = D(0), D(3), D(3), D(1), D(0), D(0), D(24)
while s != lasts:
lasts = s
n, na = n+na, na+8
d, da = d+da, da+32
t = (t * n) / d
s += t
return s
def factorial(n, m):
if (n > m):
return factorial(m, n)
elif m == 0:
return 1
elif n == m:
return n
else:
return factorial(n, (n+m)//2) * factorial((n+m)//2 + 1, m)
# Fix failed test cases caused by CVE-2020-10735 patch.
# See gh-95778 for details.
def increase_int_max_str_digits(maxdigits):
def _increase_int_max_str_digits(func, maxdigits=maxdigits):
@wraps(func)
def wrapper(*args, **kwargs):
previous_int_limit = sys.get_int_max_str_digits()
sys.set_int_max_str_digits(maxdigits)
ans = func(*args, **kwargs)
sys.set_int_max_str_digits(previous_int_limit)
return ans
return wrapper
return _increase_int_max_str_digits
def test_calc_pi():
print("\n# ======================================================================")
print("# Calculating pi, 10000 iterations")
print("# ======================================================================\n")
to_benchmark = [pi_float, pi_decimal]
if C is not None:
to_benchmark.insert(1, pi_cdecimal)
for prec in [9, 19]:
print("\nPrecision: %d decimal digits\n" % prec)
for func in to_benchmark:
start = time.time()
if C is not None:
C.getcontext().prec = prec
P.getcontext().prec = prec
for i in range(10000):
x = func()
print("%s:" % func.__name__.replace("pi_", ""))
print("result: %s" % str(x))
print("time: %fs\n" % (time.time()-start))
@increase_int_max_str_digits(maxdigits=10000000)
def test_factorial():
print("\n# ======================================================================")
print("# Factorial")
print("# ======================================================================\n")
if C is not None:
c = C.getcontext()
c.prec = C.MAX_PREC
c.Emax = C.MAX_EMAX
c.Emin = C.MIN_EMIN
for n in [100000, 1000000]:
print("n = %d\n" % n)
if C is not None:
# C version of decimal
start_calc = time.time()
x = factorial(C.Decimal(n), 0)
end_calc = time.time()
start_conv = time.time()
sx = str(x)
end_conv = time.time()
print("cdecimal:")
print("calculation time: %fs" % (end_calc-start_calc))
print("conversion time: %fs\n" % (end_conv-start_conv))
# Python integers
start_calc = time.time()
y = factorial(n, 0)
end_calc = time.time()
start_conv = time.time()
sy = str(y)
end_conv = time.time()
print("int:")
print("calculation time: %fs" % (end_calc-start_calc))
print("conversion time: %fs\n\n" % (end_conv-start_conv))
if C is not None:
assert(sx == sy)
if __name__ == "__main__":
test_calc_pi()
test_factorial()
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