90 lines
2.5 KiB
Python
90 lines
2.5 KiB
Python
# check cases converting float to int, relying only on single precision float
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try:
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import ustruct as struct
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except:
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import struct
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# work out configuration values
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is_64bit = struct.calcsize("P") == 8
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# 0 = none, 1 = long long, 2 = mpz
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try:
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dummy = 0x7fffffffffffffff
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try:
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if (0xffffffffffffffff + 1) > 0:
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ll_type = 2
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else:
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ll_type = 1
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except:
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# in case the sum in the if statement above changes to raising an exception on overflow
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ll_type = 1
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except:
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ll_type = 0
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# basic conversion
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print(int(14187744.))
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print("%d" % 14187744.)
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if ll_type == 2:
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print(int(2.**100))
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print("%d" % 2.**100)
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testpass = True
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p2_rng = ((30,63,127),(62,63,127))[is_64bit][ll_type]
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for i in range(0,p2_rng):
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bitcnt = len(bin(int(2.**i))) - 3;
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if i != bitcnt:
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print('fail: 2.**%u was %u bits long' % (i, bitcnt));
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testpass = False
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print("power of 2 test: %s" % (testpass and 'passed' or 'failed'))
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# TODO why does 10**12 fail this test for single precision float?
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testpass = True
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p10_rng = 9
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for i in range(0,p10_rng):
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digcnt = len(str(int(10.**i))) - 1;
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if i != digcnt:
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print('fail: 10.**%u was %u digits long' % (i, digcnt));
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testpass = False
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print("power of 10 test: %s" % (testpass and 'passed' or 'failed'))
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def fp2int_test(num, name, should_fail):
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try:
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x = int(num)
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passed = ~should_fail
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except:
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passed = should_fail
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print('%s: %s' % (name, passed and 'passed' or 'failed'))
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if ll_type != 2:
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if ll_type == 0:
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if is_64bit:
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neg_bad_fp = -1.00000005*2.**62.
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pos_bad_fp = 2.**62.
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neg_good_fp = -2.**62.
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pos_good_fp = 0.99999993*2.**62.
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else:
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neg_bad_fp = -1.00000005*2.**30.
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pos_bad_fp = 2.**30.
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neg_good_fp = -2.**30.
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pos_good_fp = 0.9999999499*2.**30.
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else:
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neg_bad_fp = -0.51*2.**64.
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pos_bad_fp = 2.**63.
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neg_good_fp = -2.**63.
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pos_good_fp = 1.9999998*2.**62.
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fp2int_test(neg_bad_fp, 'neg bad', True)
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fp2int_test(pos_bad_fp, 'pos bad', True)
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fp2int_test(neg_good_fp, 'neg good', False)
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fp2int_test(pos_good_fp, 'pos good', False)
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else:
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fp2int_test(-1.999999879*2.**126., 'large neg', False)
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fp2int_test(1.999999879*2.**126., 'large pos', False)
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fp2int_test(float('inf'), 'inf test', True)
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fp2int_test(float('nan'), 'NaN test', True)
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# test numbers < 1 (this used to fail; see issue #1044)
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fp2int_test(0.0001, 'small num', False)
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struct.pack('I', int(1/2))
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