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Copy pathfloat2int_intbig.py
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99 lines (86 loc) · 2.61 KB
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# 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(14187745.))
print("%d" % 14187745.)
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 if (ll_type == 0 and ~is_64bit) else 11
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.**127., 'large neg', False)
fp2int_test(1.999999879*2.**127., '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))