# check cases converting float to int, relying only on single precision float try: import ustruct as struct except: import struct import sys maxsize_bits = 0 maxsize = sys.maxsize while maxsize: maxsize >>= 1 maxsize_bits += 1 # work out configuration values is_64bit = maxsize_bits > 32 # 0 = none, 1 = long long, 2 = mpz ll_type = None if is_64bit: if maxsize_bits < 63: ll_type = 0 else: if maxsize_bits < 31: ll_type = 0 if ll_type is None: one = 1 if one << 65 < one << 62: ll_type = 1 else: ll_type = 2 # basic conversion print(int(14187744.)) print("%d" % 14187744.) if ll_type == 2: print(int(2.**100)) print("%d" % 2.**100) testpass = True p2_rng = ((30,63,127),(62,63,127))[is_64bit][ll_type] for i in range(0,p2_rng): bitcnt = len(bin(int(2.**i))) - 3; if i != bitcnt: print('fail: 2.**%u was %u bits long' % (i, bitcnt)); testpass = False print("power of 2 test: %s" % (testpass and 'passed' or 'failed')) # TODO why does 10**12 fail this test for single precision float? testpass = True p10_rng = 9 for i in range(0,p10_rng): digcnt = len(str(int(10.**i))) - 1; if i != digcnt: print('fail: 10.**%u was %u digits long' % (i, digcnt)); testpass = False print("power of 10 test: %s" % (testpass and 'passed' or 'failed')) def fp2int_test(num, name, should_fail): try: x = int(num) passed = ~should_fail except: passed = should_fail print('%s: %s' % (name, passed and 'passed' or 'failed')) if ll_type != 2: if ll_type == 0: if is_64bit: neg_bad_fp = -1.00000005*2.**62. pos_bad_fp = 2.**62. neg_good_fp = -2.**62. pos_good_fp = 0.99999993*2.**62. else: neg_bad_fp = -1.00000005*2.**30. pos_bad_fp = 2.**30. neg_good_fp = -2.**30. pos_good_fp = 0.9999999499*2.**30. else: neg_bad_fp = -0.51*2.**64. pos_bad_fp = 2.**63. neg_good_fp = -2.**63. pos_good_fp = 1.9999998*2.**62. fp2int_test(neg_bad_fp, 'neg bad', True) fp2int_test(pos_bad_fp, 'pos bad', True) fp2int_test(neg_good_fp, 'neg good', False) fp2int_test(pos_good_fp, 'pos good', False) else: fp2int_test(-1.999999879*2.**126., 'large neg', False) fp2int_test(1.999999879*2.**126., 'large pos', False) fp2int_test(float('inf'), 'inf test', True) fp2int_test(float('nan'), 'NaN test', True) # test numbers < 1 (this used to fail; see issue #1044) fp2int_test(0.0001, 'small num', False) struct.pack('I', int(1/2))