test_fma_zero_result fails due to unexpected zero instead of negative zero on NetBSD

[furkanonder]

Bug report

Bug description:

home$ ./python -m test test_math -m test_fma_zero_result

Using random seed: 4191327291
0:00:00 load avg: 0.57 Run 1 test sequentially in a single process
0:00:00 load avg: 0.57 [1/1] test_math
test test_math failed -- Traceback (most recent call last):
  File "/home/blue/cpython/Lib/test/test_math.py", line 2773, in test_fma_zero_result
    self.assertIsNegativeZero(math.fma(x-y, x+y, -z))
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/blue/cpython/Lib/test/test_math.py", line 2876, in assertIsNegativeZero
    self.assertTrue(
    ~~~~~~~~~~~~~~~^
        value == 0 and math.copysign(1, value) < 0,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        msg="Expected a negative zero, got {!r}".format(value)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
AssertionError: False is not true : Expected a negative zero, got 0.0

test_math failed (1 failure)

== Tests result: FAILURE ==

1 test failed:
    test_math

Total duration: 358 ms
Total tests: run=1 (filtered) failures=1
Total test files: run=1/1 (filtered) failed=1
Result: FAILURE
home$

OS: NetBSD 10.0

CPython versions tested on:

CPython main branch

Operating systems tested on:

Other

Linked PRs

• gh-125150: Skip test_fma_zero_result on NetBSD due to IEE 754-2008 implementation issues #125151
• [3.13] gh-125150: Skip test_fma_zero_result on NetBSD due to IEE 754-2008 implementation issues (GH-125151) #125173

[skirpichev]

Does exists an upstream issue for that?