Merged revisions 77614-77616,77663 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
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r77614 | mark.dickinson | 2010-01-20 17:36:31 +0000 (Wed, 20 Jan 2010) | 5 lines
Various dtoa.c cleanups. 1. Despagghetify _Py_dg_strtod parsing code
and exit points. 2. Simplify bigcomp comparison loop. 3. Don't set
ERANGE on _Py_dg_strtod underflow (it was set inconsistently anyway).
4. Remove unused dsign field from BCinfo struct.
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r77615 | mark.dickinson | 2010-01-20 18:02:41 +0000 (Wed, 20 Jan 2010) | 1 line
Don't try to put a value into a NULL pointer.
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r77616 | mark.dickinson | 2010-01-20 21:23:25 +0000 (Wed, 20 Jan 2010) | 1 line
Additional explanatory comments for _Py_dg_strtod.
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r77663 | mark.dickinson | 2010-01-21 17:02:53 +0000 (Thu, 21 Jan 2010) | 1 line
Additional testcases for strtod.
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diff --git a/Lib/test/test_strtod.py b/Lib/test/test_strtod.py
index 7830021..13b008b 100644
--- a/Lib/test/test_strtod.py
+++ b/Lib/test/test_strtod.py
@@ -100,6 +100,49 @@
"Incorrectly rounded str->float conversion for {}: "
"expected {}, got {}".format(s, expected, got))
+ def test_short_halfway_cases(self):
+ # exact halfway cases with a small number of significant digits
+ for k in 0, 5, 10, 15, 20:
+ # upper = smallest integer >= 2**54/5**k
+ upper = -(-2**54//5**k)
+ # lower = smallest odd number >= 2**53/5**k
+ lower = -(-2**53//5**k)
+ if lower % 2 == 0:
+ lower += 1
+ for i in range(10 * TEST_SIZE):
+ # Select a random odd n in [2**53/5**k,
+ # 2**54/5**k). Then n * 10**k gives a halfway case
+ # with small number of significant digits.
+ n, e = random.randrange(lower, upper, 2), k
+
+ # Remove any additional powers of 5.
+ while n % 5 == 0:
+ n, e = n // 5, e + 1
+ assert n % 10 in (1, 3, 7, 9)
+
+ # Try numbers of the form n * 2**p2 * 10**e, p2 >= 0,
+ # until n * 2**p2 has more than 20 significant digits.
+ digits, exponent = n, e
+ while digits < 10**20:
+ s = '{}e{}'.format(digits, exponent)
+ self.check_strtod(s)
+ # Same again, but with extra trailing zeros.
+ s = '{}e{}'.format(digits * 10**40, exponent - 40)
+ self.check_strtod(s)
+ digits *= 2
+
+ # Try numbers of the form n * 5**p2 * 10**(e - p5), p5
+ # >= 0, with n * 5**p5 < 10**20.
+ digits, exponent = n, e
+ while digits < 10**20:
+ s = '{}e{}'.format(digits, exponent)
+ self.check_strtod(s)
+ # Same again, but with extra trailing zeros.
+ s = '{}e{}'.format(digits * 10**40, exponent - 40)
+ self.check_strtod(s)
+ digits *= 5
+ exponent -= 1
+
def test_halfway_cases(self):
# test halfway cases for the round-half-to-even rule
for i in range(1000):
@@ -164,10 +207,10 @@
self.check_strtod(s)
def test_bigcomp(self):
- DIG10 = 10**50
- for i in range(1000):
- for j in range(TEST_SIZE):
- digits = random.randrange(DIG10)
+ for ndigs in 5, 10, 14, 15, 16, 17, 18, 19, 20, 40, 41, 50:
+ dig10 = 10**ndigs
+ for i in range(100 * TEST_SIZE):
+ digits = random.randrange(dig10)
exponent = random.randrange(-400, 400)
s = '{}e{}'.format(digits, exponent)
self.check_strtod(s)
@@ -254,11 +297,59 @@
# demonstration that original fix for issue 7632 bug 1 was
# buggy; the exit condition was too strong
'247032822920623295e-341',
+ # demonstrate similar problem to issue 7632 bug1: crash
+ # with 'oversized quotient in quorem' message.
+ '99037485700245683102805043437346965248029601286431e-373',
+ '99617639833743863161109961162881027406769510558457e-373',
+ '98852915025769345295749278351563179840130565591462e-372',
+ '99059944827693569659153042769690930905148015876788e-373',
+ '98914979205069368270421829889078356254059760327101e-372',
# issue 7632 bug 5: the following 2 strings convert differently
'1000000000000000000000000000000000000000e-16',
'10000000000000000000000000000000000000000e-17',
+ # issue 7632 bug 7
+ '991633793189150720000000000000000000000000000000000000000e-33',
+ # And another, similar, failing halfway case
+ '4106250198039490000000000000000000000000000000000000000e-38',
# issue 7632 bug 8: the following produced 10.0
'10.900000000000000012345678912345678912345',
+ # exercise exit conditions in bigcomp comparison loop
+ '2602129298404963083833853479113577253105939995688e2',
+ '260212929840496308383385347911357725310593999568896e0',
+ '26021292984049630838338534791135772531059399956889601e-2',
+ '260212929840496308383385347911357725310593999568895e0',
+ '260212929840496308383385347911357725310593999568897e0',
+ '260212929840496308383385347911357725310593999568996e0',
+ '260212929840496308383385347911357725310593999568866e0',
+ # 2**53
+ '9007199254740992.00',
+ # 2**1024 - 2**970: exact overflow boundary. All values
+ # smaller than this should round to something finite; any value
+ # greater than or equal to this one overflows.
+ '179769313486231580793728971405303415079934132710037' #...
+ '826936173778980444968292764750946649017977587207096' #...
+ '330286416692887910946555547851940402630657488671505' #...
+ '820681908902000708383676273854845817711531764475730' #...
+ '270069855571366959622842914819860834936475292719074' #...
+ '168444365510704342711559699508093042880177904174497792',
+ # 2**1024 - 2**970 - tiny
+ '179769313486231580793728971405303415079934132710037' #...
+ '826936173778980444968292764750946649017977587207096' #...
+ '330286416692887910946555547851940402630657488671505' #...
+ '820681908902000708383676273854845817711531764475730' #...
+ '270069855571366959622842914819860834936475292719074' #...
+ '168444365510704342711559699508093042880177904174497791.999',
+ # 2**1024 - 2**970 + tiny
+ '179769313486231580793728971405303415079934132710037' #...
+ '826936173778980444968292764750946649017977587207096' #...
+ '330286416692887910946555547851940402630657488671505' #...
+ '820681908902000708383676273854845817711531764475730' #...
+ '270069855571366959622842914819860834936475292719074' #...
+ '168444365510704342711559699508093042880177904174497792.001',
+ # 1 - 2**-54, +-tiny
+ '999999999999999944488848768742172978818416595458984375e-54',
+ '9999999999999999444888487687421729788184165954589843749999999e-54',
+ '9999999999999999444888487687421729788184165954589843750000001e-54',
]
for s in test_strings:
self.check_strtod(s)