From c54ee87278889cad186e8615bb4e246ed03dcd3c Mon Sep 17 00:00:00 2001 From: "Miss Islington (bot)" <31488909+miss-islington@users.noreply.github.com> Date: Tue, 17 Sep 2024 10:39:44 +0200 Subject: [PATCH] [3.12] gh-123836: Check zero signs in math_testcases.txt (GH-123854) (#124162) gh-123836: Check zero signs in math_testcases.txt (GH-123854) Just like cmath_testcases.txt. These tests require IEEE 754 anyway. Correct zero sign for sqrt tests to match math.h convention. (cherry picked from commit 28aea5d07d163105b42acd81c1651397ef95ea57) Co-authored-by: Sergey B Kirpichev --- Lib/test/test_math.py | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py index ef1f54f1fcc..90967c769c5 100644 --- a/Lib/test/test_math.py +++ b/Lib/test/test_math.py @@ -187,6 +187,9 @@ def result_check(expected, got, ulp_tol=5, abs_tol=0.0): # Check exactly equal (applies also to strings representing exceptions) if got == expected: + if not got and not expected: + if math.copysign(1, got) != math.copysign(1, expected): + return f"expected {expected}, got {got} (zero has wrong sign)" return None failure = "not equal" @@ -2051,6 +2054,13 @@ class MathTests(unittest.TestCase): except OverflowError: result = 'OverflowError' + # C99+ says for math.h's sqrt: If the argument is +∞ or ±0, it is + # returned, unmodified. On another hand, for csqrt: If z is ±0+0i, + # the result is +0+0i. Lets correct zero sign of er to follow + # first convention. + if id in ['sqrt0002', 'sqrt0003', 'sqrt1001', 'sqrt1023']: + er = math.copysign(er, ar) + # Default tolerances ulp_tol, abs_tol = 5, 0.0