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##############################################################################
#
# Copyright (c) 2022 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
import struct
import unittest
import zope.interface # noqa: try to load a C module for side effects
class TestFloatingPoint(unittest.TestCase):
def test_no_fast_math_optimization(self):
# Building with -Ofast enables -ffast-math, which sets certain FPU
# flags that can cause breakage elsewhere. A library such as BTrees
# has no business changing global FPU flags for the entire process.
zero_bits = struct.unpack("!Q", struct.pack("!d", 0.0))[0]
next_up = zero_bits + 1
smallest_subnormal = struct.unpack("!d", struct.pack("!Q", next_up))[0]
self.assertNotEqual(smallest_subnormal, 0.0)
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