From c632301bd4ddbd1207f4c737c925411916faf8c0 Mon Sep 17 00:00:00 2001 From: Mark Dickinson Date: Sun, 20 Apr 2008 18:30:05 +0000 Subject: [PATCH] Even more fixes for alpha Tru64, this time for the phase and polar methods. --- Modules/cmathmodule.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/Modules/cmathmodule.c b/Modules/cmathmodule.c index 347f88d9f8a..d6d1f27cb09 100644 --- a/Modules/cmathmodule.c +++ b/Modules/cmathmodule.c @@ -264,7 +264,8 @@ c_atan(Py_complex z) return r; } -/* Windows screws up atan2 for inf and nan */ +/* Windows screws up atan2 for inf and nan, and alpha Tru64 5.1 doesn't follow + C99 for atan2(0., 0.). */ static double c_atan2(Py_complex z) { @@ -282,6 +283,14 @@ c_atan2(Py_complex z) /* atan2(+-inf, x) == +-pi/2 for finite x */ return copysign(0.5*Py_MATH_PI, z.imag); } + if (Py_IS_INFINITY(z.real) || z.imag == 0.) { + if (copysign(1., z.real) == 1.) + /* atan2(+-y, +inf) = atan2(+-0, +x) = +-0. */ + return copysign(0., z.imag); + else + /* atan2(+-y, -inf) = atan2(+-0., -x) = +-pi. */ + return copysign(Py_MATH_PI, z.imag); + } return atan2(z.imag, z.real); }