Mercurial > cpython-lru_cache-weakref
diff Python/compile.c @ 45076:3f16ac915214 legacy-trunk
Issue #1678380. Fix a bug that identifies 0j and -0j when they appear
in the same code unit. The fix is essentially the same as the fix for a
previous bug identifying 0. and -0.
| author | Mark Dickinson <dickinsm@gmail.com> |
|---|---|
| date | Thu, 31 Jan 2008 22:17:37 +0000 |
| parents | 1c9ac00c4758 |
| children | 643c1397f954 |
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--- a/Python/compile.c Thu Jan 31 22:07:16 2008 +0000 +++ b/Python/compile.c Thu Jan 31 22:17:37 2008 +0000 @@ -907,24 +907,59 @@ { PyObject *t, *v; Py_ssize_t arg; + unsigned char *p, *q; + Py_complex z; + double d; + int real_part_zero, imag_part_zero; /* necessary to make sure types aren't coerced (e.g., int and long) */ /* _and_ to distinguish 0.0 from -0.0 e.g. on IEEE platforms */ if (PyFloat_Check(o)) { - double d = PyFloat_AS_DOUBLE(o); - unsigned char* p = (unsigned char*) &d; - /* all we need is to make the tuple different in either the 0.0 - * or -0.0 case from all others, just to avoid the "coercion". - */ - if (*p==0 && p[sizeof(double)-1]==0) - t = PyTuple_Pack(3, o, o->ob_type, Py_None); - else - t = PyTuple_Pack(2, o, o->ob_type); - } else { - t = PyTuple_Pack(2, o, o->ob_type); + d = PyFloat_AS_DOUBLE(o); + p = (unsigned char*) &d; + /* all we need is to make the tuple different in either the 0.0 + * or -0.0 case from all others, just to avoid the "coercion". + */ + if (*p==0 && p[sizeof(double)-1]==0) + t = PyTuple_Pack(3, o, o->ob_type, Py_None); + else + t = PyTuple_Pack(2, o, o->ob_type); + } + else if (PyComplex_Check(o)) { + /* complex case is even messier: we need to make complex(x, + 0.) different from complex(x, -0.) and complex(0., y) + different from complex(-0., y), for any x and y. In + particular, all four complex zeros should be + distinguished.*/ + z = PyComplex_AsCComplex(o); + p = (unsigned char*) &(z.real); + q = (unsigned char*) &(z.imag); + /* all that matters here is that on IEEE platforms + real_part_zero will be true if z.real == 0., and false if + z.real == -0. In fact, real_part_zero will also be true + for some other rarely occurring nonzero floats, but this + doesn't matter. Similar comments apply to + imag_part_zero. */ + real_part_zero = *p==0 && p[sizeof(double)-1]==0; + imag_part_zero = *q==0 && q[sizeof(double)-1]==0; + if (real_part_zero && imag_part_zero) { + t = PyTuple_Pack(4, o, o->ob_type, Py_True, Py_True); + } + else if (real_part_zero && !imag_part_zero) { + t = PyTuple_Pack(4, o, o->ob_type, Py_True, Py_False); + } + else if (!real_part_zero && imag_part_zero) { + t = PyTuple_Pack(4, o, o->ob_type, Py_False, Py_True); + } + else { + t = PyTuple_Pack(2, o, o->ob_type); + } + } + else { + t = PyTuple_Pack(2, o, o->ob_type); } if (t == NULL) - return -1; + return -1; v = PyDict_GetItem(dict, t); if (!v) {
