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