98 lines
2.6 KiB
Python
98 lines
2.6 KiB
Python
# check cases converting float to int, relying only on single precision float
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import struct
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import sys
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maxsize_bits = 0
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maxsize = sys.maxsize
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while maxsize:
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maxsize >>= 1
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maxsize_bits += 1
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# work out configuration values
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is_64bit = maxsize_bits > 32
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# 0 = none, 1 = long long, 2 = mpz
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ll_type = None
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if is_64bit:
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if maxsize_bits < 63:
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ll_type = 0
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else:
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if maxsize_bits < 31:
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ll_type = 0
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if ll_type is None:
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one = 1
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if one << 65 < one << 62:
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ll_type = 1
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else:
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ll_type = 2
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# basic conversion
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print(int(14187744.0))
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print("%d" % 14187744.0)
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if ll_type == 2:
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print(int(2.0**100))
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print("%d" % 2.0**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(2.0**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(10.0**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 * 2.0**62.0
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pos_bad_fp = 2.0**62.0
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neg_good_fp = -(2.0**62.0)
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pos_good_fp = 0.99999993 * 2.0**62.0
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else:
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neg_bad_fp = -1.00000005 * 2.0**30.0
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pos_bad_fp = 2.0**30.0
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neg_good_fp = -(2.0**30.0)
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pos_good_fp = 0.9999999499 * 2.0**30.0
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else:
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neg_bad_fp = -0.51 * 2.0**64.0
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pos_bad_fp = 2.0**63.0
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neg_good_fp = -(2.0**63.0)
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pos_good_fp = 1.9999998 * 2.0**62.0
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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 * 2.0**126.0, "large neg", False)
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fp2int_test(1.999999879 * 2.0**126.0, "large pos", False)
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fp2int_test(float("inf"), "inf test", True)
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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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