diff --git a/Lib/test/test_complex.py b/Lib/test/test_complex.py index 179556f57e884f..fd002fb00ac338 100644 --- a/Lib/test/test_complex.py +++ b/Lib/test/test_complex.py @@ -299,6 +299,22 @@ def test_mul(self): self.assertRaises(TypeError, operator.mul, 1j, None) self.assertRaises(TypeError, operator.mul, None, 1j) + for z, w, r in [(1e300+1j, complex(INF, INF), complex(NAN, INF)), + (1e300+1j, complex(NAN, INF), complex(-INF, INF)), + (1e300+1j, complex(INF, NAN), complex(INF, INF)), + (complex(INF, 1), complex(NAN, INF), complex(NAN, INF)), + (complex(INF, 1), complex(INF, NAN), complex(INF, NAN)), + (complex(NAN, 1), complex(1, INF), complex(-INF, NAN)), + (complex(1, NAN), complex(1, INF), complex(NAN, INF)), + (complex(1e200, NAN), complex(1e200, NAN), complex(INF, NAN)), + (complex(1e200, NAN), complex(NAN, 1e200), complex(NAN, INF)), + (complex(NAN, 1e200), complex(1e200, NAN), complex(NAN, INF)), + (complex(NAN, 1e200), complex(NAN, 1e200), complex(-INF, NAN)), + (complex(NAN, NAN), complex(NAN, NAN), complex(NAN, NAN))]: + with self.subTest(z=z, w=w, r=r): + self.assertComplexesAreIdentical(z * w, r) + self.assertComplexesAreIdentical(w * z, r) + def test_mod(self): # % is no longer supported on complex numbers with self.assertRaises(TypeError): @@ -340,6 +356,7 @@ def test_pow(self): self.assertAlmostEqual(pow(1j, 200), 1) self.assertRaises(ValueError, pow, 1+1j, 1+1j, 1+1j) self.assertRaises(OverflowError, pow, 1e200+1j, 1e200+1j) + self.assertRaises(OverflowError, pow, 1e200+1j, 5) self.assertRaises(TypeError, pow, 1j, None) self.assertRaises(TypeError, pow, None, 1j) self.assertAlmostEqual(pow(1j, 0.5), 0.7071067811865476+0.7071067811865475j) diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-06-04-08-26-25.gh-issue-120010._z-AWz.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-06-04-08-26-25.gh-issue-120010._z-AWz.rst new file mode 100644 index 00000000000000..7954c7f5927397 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-06-04-08-26-25.gh-issue-120010._z-AWz.rst @@ -0,0 +1,2 @@ +Correct invalid corner cases which resulted in ``(nan+nanj)`` output in complex +multiplication, e.g., ``(1e300+1j)*(nan+infj)``. Patch by Sergey B Kirpichev. diff --git a/Objects/complexobject.c b/Objects/complexobject.c index 8fbca3cb02d80a..bf6187efac941f 100644 --- a/Objects/complexobject.c +++ b/Objects/complexobject.c @@ -85,11 +85,63 @@ _Py_c_neg(Py_complex a) } Py_complex -_Py_c_prod(Py_complex a, Py_complex b) +_Py_c_prod(Py_complex z, Py_complex w) { - Py_complex r; - r.real = a.real*b.real - a.imag*b.imag; - r.imag = a.real*b.imag + a.imag*b.real; + double a = z.real, b = z.imag, c = w.real, d = w.imag; + double ac = a*c, bd = b*d, ad = a*d, bc = b*c; + Py_complex r = {ac - bd, ad + bc}; + + /* Recover infinities that computed as nan+nanj. See e.g. the C11, + Annex G.5.1, routine _Cmultd(). */ + if (isnan(r.real) && isnan(r.imag)) { + int recalc = 0; + + if (isinf(a) || isinf(b)) { /* z is infinite */ + /* "Box" the infinity and change nans in the other factor to 0 */ + a = copysign(isinf(a) ? 1.0 : 0.0, a); + b = copysign(isinf(b) ? 1.0 : 0.0, b); + if (isnan(c)) { + c = copysign(0.0, c); + } + if (isnan(d)) { + d = copysign(0.0, d); + } + recalc = 1; + } + if (isinf(c) || isinf(d)) { /* w is infinite */ + /* "Box" the infinity and change nans in the other factor to 0 */ + c = copysign(isinf(c) ? 1.0 : 0.0, c); + d = copysign(isinf(d) ? 1.0 : 0.0, d); + if (isnan(a)) { + a = copysign(0.0, a); + } + if (isnan(b)) { + b = copysign(0.0, b); + } + recalc = 1; + } + if (!recalc && (isinf(ac) || isinf(bd) || isinf(ad) || isinf(bc))) { + /* Recover infinities from overflow by changing nans to 0 */ + if (isnan(a)) { + a = copysign(0.0, a); + } + if (isnan(b)) { + b = copysign(0.0, b); + } + if (isnan(c)) { + c = copysign(0.0, c); + } + if (isnan(d)) { + d = copysign(0.0, d); + } + recalc = 1; + } + if (recalc) { + r.real = Py_INFINITY*(a*c - b*d); + r.imag = Py_INFINITY*(a*d + b*c); + } + } + return r; }