From af421922859182b795a9d122ad0e7abffece9dec Mon Sep 17 00:00:00 2001 From: Hanif Ariffin Date: Sat, 15 Mar 2025 13:55:25 +0800 Subject: [PATCH] Update test_math from CPython 3.13.2 Implemnted fma in math module. --- Lib/test/{ => mathdata}/cmath_testcases.txt | 3 + Lib/test/{ => mathdata}/ieee754.txt | 0 Lib/test/{ => mathdata}/math_testcases.txt | 0 Lib/test/test_math.py | 244 +++++++++++++++++++- stdlib/src/math.rs | 24 ++ 5 files changed, 268 insertions(+), 3 deletions(-) rename Lib/test/{ => mathdata}/cmath_testcases.txt (99%) rename Lib/test/{ => mathdata}/ieee754.txt (100%) rename Lib/test/{ => mathdata}/math_testcases.txt (100%) diff --git a/Lib/test/cmath_testcases.txt b/Lib/test/mathdata/cmath_testcases.txt similarity index 99% rename from Lib/test/cmath_testcases.txt rename to Lib/test/mathdata/cmath_testcases.txt index dd7e458ddcb..0165e17634f 100644 --- a/Lib/test/cmath_testcases.txt +++ b/Lib/test/mathdata/cmath_testcases.txt @@ -1536,6 +1536,7 @@ sqrt0141 sqrt -1.797e+308 -9.9999999999999999e+306 -> 3.7284476432057307e+152 -1 sqrt0150 sqrt 1.7976931348623157e+308 0.0 -> 1.3407807929942596355e+154 0.0 sqrt0151 sqrt 2.2250738585072014e-308 0.0 -> 1.4916681462400413487e-154 0.0 sqrt0152 sqrt 5e-324 0.0 -> 2.2227587494850774834e-162 0.0 +sqrt0153 sqrt 5e-324 1.0 -> 0.7071067811865476 0.7071067811865476 -- special values sqrt1000 sqrt 0.0 0.0 -> 0.0 0.0 @@ -1744,6 +1745,7 @@ cosh0023 cosh 2.218885944363501 2.0015727395883687 -> -1.94294321081968 4.129026 -- large real part cosh0030 cosh 710.5 2.3519999999999999 -> -1.2967465239355998e+308 1.3076707908857333e+308 cosh0031 cosh -710.5 0.69999999999999996 -> 1.4085466381392499e+308 -1.1864024666450239e+308 +cosh0032 cosh 720.0 0.0 -> inf 0.0 overflow -- Additional real values (mpmath) cosh0050 cosh 1e-150 0.0 -> 1.0 0.0 @@ -1853,6 +1855,7 @@ sinh0023 sinh 0.043713693678420068 0.22512549887532657 -> 0.042624198673416713 0 -- large real part sinh0030 sinh 710.5 -2.3999999999999999 -> -1.3579970564885919e+308 -1.24394470907798e+308 sinh0031 sinh -710.5 0.80000000000000004 -> -1.2830671601735164e+308 1.3210954193997678e+308 +sinh0032 sinh 720.0 0.0 -> inf 0.0 overflow -- Additional real values (mpmath) sinh0050 sinh 1e-100 0.0 -> 1.00000000000000002e-100 0.0 diff --git a/Lib/test/ieee754.txt b/Lib/test/mathdata/ieee754.txt similarity index 100% rename from Lib/test/ieee754.txt rename to Lib/test/mathdata/ieee754.txt diff --git a/Lib/test/math_testcases.txt b/Lib/test/mathdata/math_testcases.txt similarity index 100% rename from Lib/test/math_testcases.txt rename to Lib/test/mathdata/math_testcases.txt diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py index fa79456ed46..bb020416441 100644 --- a/Lib/test/test_math.py +++ b/Lib/test/test_math.py @@ -33,8 +33,8 @@ else: file = __file__ test_dir = os.path.dirname(file) or os.curdir -math_testcases = os.path.join(test_dir, 'math_testcases.txt') -test_file = os.path.join(test_dir, 'cmath_testcases.txt') +math_testcases = os.path.join(test_dir, 'mathdata', 'math_testcases.txt') +test_file = os.path.join(test_dir, 'mathdata', 'cmath_testcases.txt') def to_ulps(x): @@ -2628,9 +2628,247 @@ def test_fractions(self): self.assertAllNotClose(fraction_examples, rel_tol=1e-9) +class FMATests(unittest.TestCase): + """ Tests for math.fma. """ + + def test_fma_nan_results(self): + # Selected representative values. + values = [ + -math.inf, -1e300, -2.3, -1e-300, -0.0, + 0.0, 1e-300, 2.3, 1e300, math.inf, math.nan + ] + + # If any input is a NaN, the result should be a NaN, too. + for a, b in itertools.product(values, repeat=2): + self.assertIsNaN(math.fma(math.nan, a, b)) + self.assertIsNaN(math.fma(a, math.nan, b)) + self.assertIsNaN(math.fma(a, b, math.nan)) + + def test_fma_infinities(self): + # Cases involving infinite inputs or results. + positives = [1e-300, 2.3, 1e300, math.inf] + finites = [-1e300, -2.3, -1e-300, -0.0, 0.0, 1e-300, 2.3, 1e300] + non_nans = [-math.inf, -2.3, -0.0, 0.0, 2.3, math.inf] + + # ValueError due to inf * 0 computation. + for c in non_nans: + for infinity in [math.inf, -math.inf]: + for zero in [0.0, -0.0]: + with self.assertRaises(ValueError): + math.fma(infinity, zero, c) + with self.assertRaises(ValueError): + math.fma(zero, infinity, c) + + # ValueError when a*b and c both infinite of opposite signs. + for b in positives: + with self.assertRaises(ValueError): + math.fma(math.inf, b, -math.inf) + with self.assertRaises(ValueError): + math.fma(math.inf, -b, math.inf) + with self.assertRaises(ValueError): + math.fma(-math.inf, -b, -math.inf) + with self.assertRaises(ValueError): + math.fma(-math.inf, b, math.inf) + with self.assertRaises(ValueError): + math.fma(b, math.inf, -math.inf) + with self.assertRaises(ValueError): + math.fma(-b, math.inf, math.inf) + with self.assertRaises(ValueError): + math.fma(-b, -math.inf, -math.inf) + with self.assertRaises(ValueError): + math.fma(b, -math.inf, math.inf) + + # Infinite result when a*b and c both infinite of the same sign. + for b in positives: + self.assertEqual(math.fma(math.inf, b, math.inf), math.inf) + self.assertEqual(math.fma(math.inf, -b, -math.inf), -math.inf) + self.assertEqual(math.fma(-math.inf, -b, math.inf), math.inf) + self.assertEqual(math.fma(-math.inf, b, -math.inf), -math.inf) + self.assertEqual(math.fma(b, math.inf, math.inf), math.inf) + self.assertEqual(math.fma(-b, math.inf, -math.inf), -math.inf) + self.assertEqual(math.fma(-b, -math.inf, math.inf), math.inf) + self.assertEqual(math.fma(b, -math.inf, -math.inf), -math.inf) + + # Infinite result when a*b finite, c infinite. + for a, b in itertools.product(finites, finites): + self.assertEqual(math.fma(a, b, math.inf), math.inf) + self.assertEqual(math.fma(a, b, -math.inf), -math.inf) + + # Infinite result when a*b infinite, c finite. + for b, c in itertools.product(positives, finites): + self.assertEqual(math.fma(math.inf, b, c), math.inf) + self.assertEqual(math.fma(-math.inf, b, c), -math.inf) + self.assertEqual(math.fma(-math.inf, -b, c), math.inf) + self.assertEqual(math.fma(math.inf, -b, c), -math.inf) + + self.assertEqual(math.fma(b, math.inf, c), math.inf) + self.assertEqual(math.fma(b, -math.inf, c), -math.inf) + self.assertEqual(math.fma(-b, -math.inf, c), math.inf) + self.assertEqual(math.fma(-b, math.inf, c), -math.inf) + + # gh-73468: On some platforms, libc fma() doesn't implement IEE 754-2008 + # properly: it doesn't use the right sign when the result is zero. + @unittest.skipIf( + sys.platform.startswith(("freebsd", "wasi", "netbsd")) + or (sys.platform == "android" and platform.machine() == "x86_64"), + f"this platform doesn't implement IEE 754-2008 properly") + def test_fma_zero_result(self): + nonnegative_finites = [0.0, 1e-300, 2.3, 1e300] + + # Zero results from exact zero inputs. + for b in nonnegative_finites: + self.assertIsPositiveZero(math.fma(0.0, b, 0.0)) + self.assertIsPositiveZero(math.fma(0.0, b, -0.0)) + self.assertIsNegativeZero(math.fma(0.0, -b, -0.0)) + self.assertIsPositiveZero(math.fma(0.0, -b, 0.0)) + self.assertIsPositiveZero(math.fma(-0.0, -b, 0.0)) + self.assertIsPositiveZero(math.fma(-0.0, -b, -0.0)) + self.assertIsNegativeZero(math.fma(-0.0, b, -0.0)) + self.assertIsPositiveZero(math.fma(-0.0, b, 0.0)) + + self.assertIsPositiveZero(math.fma(b, 0.0, 0.0)) + self.assertIsPositiveZero(math.fma(b, 0.0, -0.0)) + self.assertIsNegativeZero(math.fma(-b, 0.0, -0.0)) + self.assertIsPositiveZero(math.fma(-b, 0.0, 0.0)) + self.assertIsPositiveZero(math.fma(-b, -0.0, 0.0)) + self.assertIsPositiveZero(math.fma(-b, -0.0, -0.0)) + self.assertIsNegativeZero(math.fma(b, -0.0, -0.0)) + self.assertIsPositiveZero(math.fma(b, -0.0, 0.0)) + + # Exact zero result from nonzero inputs. + self.assertIsPositiveZero(math.fma(2.0, 2.0, -4.0)) + self.assertIsPositiveZero(math.fma(2.0, -2.0, 4.0)) + self.assertIsPositiveZero(math.fma(-2.0, -2.0, -4.0)) + self.assertIsPositiveZero(math.fma(-2.0, 2.0, 4.0)) + + # Underflow to zero. + tiny = 1e-300 + self.assertIsPositiveZero(math.fma(tiny, tiny, 0.0)) + self.assertIsNegativeZero(math.fma(tiny, -tiny, 0.0)) + self.assertIsPositiveZero(math.fma(-tiny, -tiny, 0.0)) + self.assertIsNegativeZero(math.fma(-tiny, tiny, 0.0)) + self.assertIsPositiveZero(math.fma(tiny, tiny, -0.0)) + self.assertIsNegativeZero(math.fma(tiny, -tiny, -0.0)) + self.assertIsPositiveZero(math.fma(-tiny, -tiny, -0.0)) + self.assertIsNegativeZero(math.fma(-tiny, tiny, -0.0)) + + # Corner case where rounding the multiplication would + # give the wrong result. + x = float.fromhex('0x1p-500') + y = float.fromhex('0x1p-550') + z = float.fromhex('0x1p-1000') + self.assertIsNegativeZero(math.fma(x-y, x+y, -z)) + self.assertIsPositiveZero(math.fma(y-x, x+y, z)) + self.assertIsNegativeZero(math.fma(y-x, -(x+y), -z)) + self.assertIsPositiveZero(math.fma(x-y, -(x+y), z)) + + def test_fma_overflow(self): + a = b = float.fromhex('0x1p512') + c = float.fromhex('0x1p1023') + # Overflow from multiplication. + with self.assertRaises(OverflowError): + math.fma(a, b, 0.0) + self.assertEqual(math.fma(a, b/2.0, 0.0), c) + # Overflow from the addition. + with self.assertRaises(OverflowError): + math.fma(a, b/2.0, c) + # No overflow, even though a*b overflows a float. + self.assertEqual(math.fma(a, b, -c), c) + + # Extreme case: a * b is exactly at the overflow boundary, so the + # tiniest offset makes a difference between overflow and a finite + # result. + a = float.fromhex('0x1.ffffffc000000p+511') + b = float.fromhex('0x1.0000002000000p+512') + c = float.fromhex('0x0.0000000000001p-1022') + with self.assertRaises(OverflowError): + math.fma(a, b, 0.0) + with self.assertRaises(OverflowError): + math.fma(a, b, c) + self.assertEqual(math.fma(a, b, -c), + float.fromhex('0x1.fffffffffffffp+1023')) + + # Another extreme case: here a*b is about as large as possible subject + # to math.fma(a, b, c) being finite. + a = float.fromhex('0x1.ae565943785f9p+512') + b = float.fromhex('0x1.3094665de9db8p+512') + c = float.fromhex('0x1.fffffffffffffp+1023') + self.assertEqual(math.fma(a, b, -c), c) + + def test_fma_single_round(self): + a = float.fromhex('0x1p-50') + self.assertEqual(math.fma(a - 1.0, a + 1.0, 1.0), a*a) + + def test_random(self): + # A collection of randomly generated inputs for which the naive FMA + # (with two rounds) gives a different result from a singly-rounded FMA. + + # tuples (a, b, c, expected) + test_values = [ + ('0x1.694adde428b44p-1', '0x1.371b0d64caed7p-1', + '0x1.f347e7b8deab8p-4', '0x1.19f10da56c8adp-1'), + ('0x1.605401ccc6ad6p-2', '0x1.ce3a40bf56640p-2', + '0x1.96e3bf7bf2e20p-2', '0x1.1af6d8aa83101p-1'), + ('0x1.e5abd653a67d4p-2', '0x1.a2e400209b3e6p-1', + '0x1.a90051422ce13p-1', '0x1.37d68cc8c0fbbp+0'), + ('0x1.f94e8efd54700p-2', '0x1.123065c812cebp-1', + '0x1.458f86fb6ccd0p-1', '0x1.ccdcee26a3ff3p-1'), + ('0x1.bd926f1eedc96p-1', '0x1.eee9ca68c5740p-1', + '0x1.960c703eb3298p-2', '0x1.3cdcfb4fdb007p+0'), + ('0x1.27348350fbccdp-1', '0x1.3b073914a53f1p-1', + '0x1.e300da5c2b4cbp-1', '0x1.4c51e9a3c4e29p+0'), + ('0x1.2774f00b3497bp-1', '0x1.7038ec336bff0p-2', + '0x1.2f6f2ccc3576bp-1', '0x1.99ad9f9c2688bp-1'), + ('0x1.51d5a99300e5cp-1', '0x1.5cd74abd445a1p-1', + '0x1.8880ab0bbe530p-1', '0x1.3756f96b91129p+0'), + ('0x1.73cb965b821b8p-2', '0x1.218fd3d8d5371p-1', + '0x1.d1ea966a1f758p-2', '0x1.5217b8fd90119p-1'), + ('0x1.4aa98e890b046p-1', '0x1.954d85dff1041p-1', + '0x1.122b59317ebdfp-1', '0x1.0bf644b340cc5p+0'), + ('0x1.e28f29e44750fp-1', '0x1.4bcc4fdcd18fep-1', + '0x1.fd47f81298259p-1', '0x1.9b000afbc9995p+0'), + ('0x1.d2e850717fe78p-3', '0x1.1dd7531c303afp-1', + '0x1.e0869746a2fc2p-2', '0x1.316df6eb26439p-1'), + ('0x1.cf89c75ee6fbap-2', '0x1.b23decdc66825p-1', + '0x1.3d1fe76ac6168p-1', '0x1.00d8ea4c12abbp+0'), + ('0x1.3265ae6f05572p-2', '0x1.16d7ec285f7a2p-1', + '0x1.0b8405b3827fbp-1', '0x1.5ef33c118a001p-1'), + ('0x1.c4d1bf55ec1a5p-1', '0x1.bc59618459e12p-2', + '0x1.ce5b73dc1773dp-1', '0x1.496cf6164f99bp+0'), + ('0x1.d350026ac3946p-1', '0x1.9a234e149a68cp-2', + '0x1.f5467b1911fd6p-2', '0x1.b5cee3225caa5p-1'), + ] + for a_hex, b_hex, c_hex, expected_hex in test_values: + a = float.fromhex(a_hex) + b = float.fromhex(b_hex) + c = float.fromhex(c_hex) + expected = float.fromhex(expected_hex) + self.assertEqual(math.fma(a, b, c), expected) + self.assertEqual(math.fma(b, a, c), expected) + + # Custom assertions. + def assertIsNaN(self, value): + self.assertTrue( + math.isnan(value), + msg="Expected a NaN, got {!r}".format(value) + ) + + def assertIsPositiveZero(self, value): + self.assertTrue( + value == 0 and math.copysign(1, value) > 0, + msg="Expected a positive zero, got {!r}".format(value) + ) + + def assertIsNegativeZero(self, value): + self.assertTrue( + value == 0 and math.copysign(1, value) < 0, + msg="Expected a negative zero, got {!r}".format(value) + ) + + def load_tests(loader, tests, pattern): from doctest import DocFileSuite - tests.addTest(DocFileSuite("ieee754.txt")) + tests.addTest(DocFileSuite(os.path.join("mathdata", "ieee754.txt"))) return tests if __name__ == '__main__': diff --git a/stdlib/src/math.rs b/stdlib/src/math.rs index 6665ee8b492..a7da60949cf 100644 --- a/stdlib/src/math.rs +++ b/stdlib/src/math.rs @@ -975,4 +975,28 @@ mod math { Ok(result) } + + #[pyfunction] + fn fma( + x: ArgIntoFloat, + y: ArgIntoFloat, + z: ArgIntoFloat, + vm: &VirtualMachine, + ) -> PyResult { + let result = (*x).mul_add(*y, *z); + + if result.is_finite() { + return Ok(result); + } + + if result.is_nan() { + if !x.is_nan() && !y.is_nan() && !z.is_nan() { + return Err(vm.new_value_error("invalid operation in fma".to_string())); + } + } else if x.is_finite() && y.is_finite() && z.is_finite() { + return Err(vm.new_overflow_error("overflow in fma".to_string())); + } + + Ok(result) + } }