+2019-03-06 Edward Smith-Rowland <3dw4rd@verizon.net>
+
+ PR libstdc++/86655 - std::assoc_legendre should not constrain
+ the value of m (or x).
+ * include/tr1/legendre_function.tcc (__assoc_legendre_p,
+ __sph_legendre): If degree > order Don't throw, return 0.
+ (__legendre_p, __assoc_legendre_p): Don't constrain x either.
+ * testsuite/special_functions/02_assoc_legendre/pr86655.cc: New test.
+ * testsuite/special_functions/20_sph_legendre/pr86655.cc: New test.
+ * testsuite/tr1/5_numerical_facilities/special_functions/
+ 02_assoc_legendre/pr86655.cc: New test.
+ * testsuite/tr1/5_numerical_facilities/special_functions/
+ 22_sph_legendre/pr86655.cc: New test.
+
2019-03-06 Ville Voutilainen <ville.voutilainen@gmail.com>
Rewrite variant.
__poly_legendre_p(unsigned int __l, _Tp __x)
{
- if ((__x < _Tp(-1)) || (__x > _Tp(+1)))
- std::__throw_domain_error(__N("Argument out of range"
- " in __poly_legendre_p."));
- else if (__isnan(__x))
+ if (__isnan(__x))
return std::numeric_limits<_Tp>::quiet_NaN();
else if (__x == +_Tp(1))
return +_Tp(1);
* @f[
* P_l^m(x) = (1 - x^2)^{m/2}\frac{d^m}{dx^m}P_l(x)
* @f]
+ * @note @f$ P_l^m(x) = 0 @f$ if @f$ m > l @f$.
*
* @param l The degree of the associated Legendre function.
* @f$ l >= 0 @f$.
* @param m The order of the associated Legendre function.
- * @f$ m <= l @f$.
* @param x The argument of the associated Legendre function.
* @f$ |x| <= 1 @f$.
* @param phase The phase of the associated Legendre function.
_Tp __phase = _Tp(+1))
{
- if (__x < _Tp(-1) || __x > _Tp(+1))
- std::__throw_domain_error(__N("Argument out of range"
- " in __assoc_legendre_p."));
- else if (__m > __l)
- std::__throw_domain_error(__N("Degree out of range"
- " in __assoc_legendre_p."));
+ if (__m > __l)
+ return _Tp(0);
else if (__isnan(__x))
return std::numeric_limits<_Tp>::quiet_NaN();
else if (__m == 0)
* and so this function is stable for larger differences of @f$ l @f$
* and @f$ m @f$.
* @note Unlike the case for __assoc_legendre_p the Condon-Shortley
- * phase factor @f$ (-1)^m @f$ is present here.
+ * phase factor @f$ (-1)^m @f$ is present here.
+ * @note @f$ Y_l^m(\theta) = 0 @f$ if @f$ m > l @f$.
*
* @param l The degree of the spherical associated Legendre function.
* @f$ l >= 0 @f$.
* @param m The order of the spherical associated Legendre function.
- * @f$ m <= l @f$.
* @param theta The radian angle argument of the spherical associated
* Legendre function.
*/
const _Tp __x = std::cos(__theta);
- if (__l < __m)
- {
- std::__throw_domain_error(__N("Bad argument "
- "in __sph_legendre."));
- }
+ if (__m > __l)
+ return _Tp(0);
else if (__m == 0)
{
_Tp __P = __poly_legendre_p(__l, __x);
_Tp __y_lm = _Tp(0);
// Compute Y_l^m, l > m+1, upward recursion on l.
- for (unsigned int __ll = __m + 2; __ll <= __l; ++__ll)
+ for (int __ll = __m + 2; __ll <= __l; ++__ll)
{
const _Tp __rat1 = _Tp(__ll - __m) / _Tp(__ll + __m);
const _Tp __rat2 = _Tp(__ll - __m - 1) / _Tp(__ll + __m - 1);
--- /dev/null
+// { dg-do run { target c++11 } }
+// { dg-options "-D__STDCPP_WANT_MATH_SPEC_FUNCS__ -ffp-contract=off" }
+
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <initializer_list>
+#include <cmath>
+#if defined(__TEST_DEBUG)
+# include <iostream>
+# define VERIFY(A) \
+ if (!(A)) \
+ { \
+ std::cout << "line " << __LINE__ \
+ << " std::assoc_legendre(l, m, x) == 0: " << (A) \
+ << '\n'; \
+ }
+#else
+# include <testsuite_hooks.h>
+#endif
+
+template<typename _Tp>
+ void
+ test_m_gt_l()
+ {
+ bool test __attribute__((unused)) = true;
+ for (auto l : {0u, 1u, 2u, 5u})
+ for (auto m : {l + 1u, l + 2u})
+ for (auto i : {-2, -1, 0, 1, 2})
+ {
+ auto x = _Tp(i * 0.5L);
+ VERIFY(std::assoc_legendre(l, m, x) == _Tp(0));
+ }
+ }
+
+int
+main()
+{
+ test_m_gt_l<float>();
+ test_m_gt_l<double>();
+ test_m_gt_l<long double>();
+}
--- /dev/null
+// { dg-do run { target c++11 } }
+// { dg-options "-D__STDCPP_WANT_MATH_SPEC_FUNCS__ -ffp-contract=off" }
+
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <initializer_list>
+#include <cmath>
+#if defined(__TEST_DEBUG)
+# include <iostream>
+# define VERIFY(A) \
+ if (!(A)) \
+ { \
+ std::cout << "line " << __LINE__ \
+ << " std::sph_legendre(l, m, x) == 0: " << (A) \
+ << '\n'; \
+ }
+#else
+# include <testsuite_hooks.h>
+#endif
+
+template<typename _Tp>
+ void
+ test_m_gt_l()
+ {
+ bool test __attribute__((unused)) = true;
+ for (auto l : {0u, 1u, 2u, 5u})
+ for (auto m : {l + 1u, l + 2u})
+ for (auto i : {-2, -1, 0, 1, 2})
+ {
+ auto theta = std::acos(_Tp(i * 0.5L));
+ VERIFY(std::sph_legendre(l, m, theta) == _Tp(0));
+ }
+ }
+
+int
+main()
+{
+ test_m_gt_l<float>();
+ test_m_gt_l<double>();
+ test_m_gt_l<long double>();
+}
--- /dev/null
+// { dg-do run }
+// { dg-options "-std=c++98 -ffp-contract=off" }
+
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <tr1/cmath>
+#if defined(__TEST_DEBUG)
+# include <iostream>
+# define VERIFY(A) \
+ if (!(A)) \
+ { \
+ std::cout << "line " << __LINE__ \
+ << " std::tr1::assoc_legendre(l, m, x) == 0: " << (A) \
+ << '\n'; \
+ }
+#else
+# include <testsuite_hooks.h>
+#endif
+
+template<typename _Tp>
+ void
+ test_m_gt_l()
+ {
+ bool test __attribute__((unused)) = true;
+ unsigned int larr[4] = {0u, 1u, 2u, 5u};
+ for (unsigned int l = 0; l < 4; ++l)
+ for (unsigned int m = larr[l] + 1u; m <= larr[l] + 2u; ++m)
+ for (int i = -2; i <= +2; ++i)
+ {
+ _Tp x = _Tp(i * 0.5L);
+ VERIFY(std::tr1::assoc_legendre(larr[l], m, x) == _Tp(0));
+ }
+ }
+
+int
+main()
+{
+ test_m_gt_l<float>();
+ test_m_gt_l<double>();
+ test_m_gt_l<long double>();
+}
--- /dev/null
+// { dg-do run }
+// { dg-options "-std=c++98 -ffp-contract=off" }
+
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <tr1/cmath>
+#if defined(__TEST_DEBUG)
+# include <iostream>
+# define VERIFY(A) \
+ if (!(A)) \
+ { \
+ std::cout << "line " << __LINE__ \
+ << " std::sph_legendre(l, m, x) == 0: " << (A) \
+ << '\n'; \
+ }
+#else
+# include <testsuite_hooks.h>
+#endif
+
+template<typename _Tp>
+ void
+ test_m_gt_l()
+ {
+ bool test __attribute__((unused)) = true;
+ unsigned int larr[4] = {0u, 1u, 2u, 5u};
+ for (unsigned int l = 0; l < 4; ++l)
+ for (unsigned int m = larr[l] + 1u; m <= larr[l] + 2u; ++m)
+ for (int i = -2; i <= +2; ++i)
+ {
+ _Tp theta = std::acos(_Tp(i * 0.5L));
+ VERIFY(std::tr1::sph_legendre(larr[l], m, theta) == _Tp(0));
+ }
+ }
+
+int
+main()
+{
+ test_m_gt_l<float>();
+ test_m_gt_l<double>();
+ test_m_gt_l<long double>();
+}
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