re PR libstdc++/13450 (std::pow(std::complex<double>(-1.,0.),0.5) yields (NaN,0))

2004-03-10  Paul Kienzle  <pkienzle@nist.gov>
	    Paolo Carlini  <pcarlini@suse.de>

	PR libstdc++/13450
	* include/std/std_complex.h (pow(const complex&, const _Tp&),
	pow(const _Tp&, const complex&)): Use cmath pow only when safe.
	* testsuite/26_numerics/complex/13450.cc: New.

	* testsuite/26_numerics/cmath/overloads.C: Rename to overloads.cc.
	* testsuite/26_numerics/complex/pow.C: Rename to pow.cc and fix.

From-SVN: r79227

5 files changed, 92 insertions, 7 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index fa10cd9..265b25a 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,6 +1,17 @@
+2004-03-10  Paul Kienzle  <pkienzle@nist.gov>
+	    Paolo Carlini  <pcarlini@suse.de>
+
+	PR libstdc++/13450
+	* include/std/std_complex.h (pow(const complex&, const _Tp&),
+	pow(const _Tp&, const complex&)): Use cmath pow only when safe.
+	* testsuite/26_numerics/complex/13450.cc: New.
+
+	* testsuite/26_numerics/cmath/overloads.C: Rename to overloads.cc.
+	* testsuite/26_numerics/complex/pow.C: Rename to pow.cc and fix.
+
 2004-03-10  Jerry Quinn  <jlquinn@optonline.net>
 
-	PR 3247
+	PR libstdc++/3247
 	* include/bits/gslice_array.h (gslice_array()): Make public.
 	(operator=(gslice_array)): Make public.  Implement.
 	* include/bits/indirect_array.h (indirect_array()): Make public.
diff --git a/libstdc++-v3/include/std/std_complex.h b/libstdc++-v3/include/std/std_complex.h
index 25c657f..d997867 100644
--- a/libstdc++-v3/include/std/std_complex.h
+++ b/libstdc++-v3/include/std/std_complex.h
@@ -705,7 +705,7 @@ namespace std
     complex<_Tp>
     pow(const complex<_Tp>& __x, const _Tp& __y)
     {
-      if (__x.imag() == _Tp())
+      if (__x.imag() == _Tp() && __x.real() > _Tp())
         return pow(__x.real(), __y);
 
       complex<_Tp> __t = log(__x);
@@ -723,9 +723,8 @@ namespace std
     inline complex<_Tp>
     pow(const _Tp& __x, const complex<_Tp>& __y)
     {
-      return __x == _Tp()
-        ? _Tp()
-        : std::polar(pow(__x, __y.real()), __y.imag() * log(__x));
+      return __x > _Tp() ? polar(pow(__x, __y.real()), __y.imag() * log(__x))
+	                 : pow(complex<_Tp>(__x, _Tp()), __y);
     }
 
   // 26.2.3  complex specializations
diff --git a/libstdc++-v3/testsuite/26_numerics/cmath/overloads.C b/libstdc++-v3/testsuite/26_numerics/cmath/overloads.cc
index 4d41a96..4d41a96 100644
--- a/libstdc++-v3/testsuite/26_numerics/cmath/overloads.C
+++ b/libstdc++-v3/testsuite/26_numerics/cmath/overloads.cc
diff --git a/libstdc++-v3/testsuite/26_numerics/complex/13450.cc b/libstdc++-v3/testsuite/26_numerics/complex/13450.cc
new file mode 100644
index 0000000..9df257d
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/complex/13450.cc
@@ -0,0 +1,75 @@
+// Copyright (C) 2004 Free Software Foundation
+//
+// 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 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 26.2.8 complex transcendentals
+
+#include <complex>
+#include <limits>
+#include <testsuite_hooks.h>
+
+template<typename T>
+  void test01_do(T a, T b)
+  {
+    using namespace std;
+    bool test __attribute__((unused)) = true;
+    typedef complex<T> cplx;
+
+    T eps = numeric_limits<T>::epsilon() * 10;
+    
+    cplx ref = pow(cplx(a, T()), cplx(b, T()));
+    cplx res1 = pow(a, cplx(b, T()));
+    cplx res2 = pow(cplx(a, T()), b);
+    
+    VERIFY( abs(ref - res1) < eps );
+    VERIFY( abs(ref - res2) < eps );
+    VERIFY( abs(res1 - res2) < eps );
+  }
+
+// libstdc++/13450
+void test01()
+{
+  float f1 = -1.0f;
+  float f2 = 0.5f;
+  test01_do(f1, f2);
+
+  f1 = -3.2f;
+  f2 = 1.4f;
+  test01_do(f1, f2);
+
+  double d1 = -1.0;
+  double d2 = 0.5;
+  test01_do(d1, d2);
+
+  d1 = -3.2;
+  d2 = 1.4;
+  test01_do(d1, d2);
+
+  long double ld1 = -1.0l;
+  long double ld2 = 0.5l;
+  test01_do(ld1, ld2);
+
+  ld1 = -3.2l;
+  ld2 = 1.4l;
+  test01_do(ld1, ld2);
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/26_numerics/complex/pow.C b/libstdc++-v3/testsuite/26_numerics/complex/pow.cc
index c3f8479..58d0fc5 100644
--- a/libstdc++-v3/testsuite/26_numerics/complex/pow.C
+++ b/libstdc++-v3/testsuite/26_numerics/complex/pow.cc
@@ -6,9 +6,9 @@
 
 int main()
 {
-   std::complex<double> z(0, 1) ;
+   std::complex<double> z;
 
-   VERIFY(pow(z, 1.0/3.0) == 0.0);
+   VERIFY( pow(z, 1.0/3.0) == 0.0 );
 
    return 0;
 }