std_cmath.h: Tweak.

      * include/c_std/bits/std_cmath.h: Tweak.  #define away abs, cos,
      fabs, sin, sqrt.  They are now implemented in terms of __builtin_
      variants.

From-SVN: r42595

1 files changed, 287 insertions, 320 deletions

diff --git a/libstdc++-v3/include/c_std/bits/std_cmath.h b/libstdc++-v3/include/c_std/bits/std_cmath.h
index d37f900..3f6f23d 100644
--- a/libstdc++-v3/include/c_std/bits/std_cmath.h
+++ b/libstdc++-v3/include/c_std/bits/std_cmath.h
@@ -40,6 +40,16 @@
 #include <bits/std_cstdlib.h>
  
 #pragma GCC system_header
+
+// Need to mangle these "C" functions.  Ideally, we could like to do the
+// same for the remaining of the "C" functions but they do not have
+// builtin implementations.  So, they are still of nuisance.
+#define abs __glibcpp_abs
+#define cos __glibcpp_cos
+#define fabs __glibcpp_fabs
+#define sin __glibcpp_sin
+#define sqrt __glibcpp_sqrt
+
 #include <math.h>
 
 // Get rid of those macros defined in <math.h> in lieu of real functions.
@@ -80,17 +90,21 @@ namespace std
       return __x < _Tp() ? -__x : __x;
     }
 
-#if _GLIBCPP_HAVE___BUILTIN_FABSF
-  inline float 
-  abs(float __x) { return __builtin_fabsf(__x); }
-#elif _GLIBCPP_HAVE_FABSF
-  inline float 
-  abs(float __x) { return ::fabsf(__x); }
-#else
-  inline float 
-  abs(float __x) { return __cmath_abs(__x); }
-#endif
+  // abs.
+  inline float
+  abs(float __x)
+  { return __builtin_fabsf(__x); }
 
+  inline double
+  abs(double __x)
+  { return __builtin_fabs(__x); }
+
+  inline long double
+  abs(long double __x)
+  { return __builtin_fabsl(__x); }
+
+
+  // acos.
 #if _GLIBCPP_HAVE_ACOSF
   inline float 
   acos(float __x) { return ::acosf(__x); }
@@ -99,6 +113,18 @@ namespace std
   acos(float __x) { return ::acos(static_cast<double>(__x)); }
 #endif
 
+  extern "C" double acos(double __x);
+  
+#if _GLIBCPP_HAVE_ACOSL
+  inline long double 
+  acos(long double __x) { return ::acosl(__x); }
+#else
+  inline long double 
+  acos(long double __x) { return ::acos(static_cast<double>(__x)); }
+#endif
+
+
+  // asin.
 #if _GLIBCPP_HAVE_ASINF
   inline float 
   asin(float __x) { return ::asinf(__x); }
@@ -107,6 +133,18 @@ namespace std
   asin(float __x) { return ::asin(static_cast<double>(__x)); }
 #endif
 
+  extern "C" double asin(double __x);
+
+#if _GLIBCPP_HAVE_ASINL
+  inline long double 
+  asin(long double __x) { return ::asinl(__x); }
+#else
+  inline long double 
+  asin(long double __x) { return ::asin(static_cast<double>(__x)); }
+#endif
+
+
+  // atan.
 #if _GLIBCPP_HAVE_ATANF
   inline float 
   atan(float __x) { return ::atanf(__x); }
@@ -115,6 +153,18 @@ namespace std
   atan(float __x) { return ::atan(static_cast<double>(__x)); }
 #endif
 
+  extern "C" double atan(double __x);
+
+#if _GLIBCPP_HAVE_ATANL
+  inline long double 
+  atan(long double __x) { return ::atanl(__x); }
+#else
+  inline long double 
+  atan(long double __x) { return ::atan(static_cast<double>(__x)); }
+#endif
+
+
+  // atan2.
 #if _GLIBCPP_HAVE_ATAN2F
   inline float 
   atan2(float __y, float __x) { return ::atan2f(__y, __x); }
@@ -124,6 +174,19 @@ namespace std
   { return ::atan2(static_cast<double>(__y), static_cast<double>(__x)); }
 #endif
 
+  extern "C" double atan2(double __y, double __x);
+
+#if _GLIBCPP_HAVE_ATAN2L
+  inline long double 
+  atan2(long double __y, long double __x) { return ::atan2l(__y, __x); }
+#else
+  inline long double 
+  atan2(long double __y, long double __x) 
+  { return ::atan2(static_cast<double>(__y), static_cast<double>(__x)); }
+#endif
+
+
+  // ceil.
 #if _GLIBCPP_HAVE_CEILF
   inline float 
   ceil(float __x) { return ::ceilf(__x); }
@@ -132,17 +195,32 @@ namespace std
   ceil(float __x) { return ::ceil(static_cast<double>(__x)); }
 #endif
 
-#if _GLIBCPP_HAVE___BUILTIN_COSF
-  inline float 
-  cos(float __x) { return __builtin_cosf(__x); }
-#elif _GLIBCPP_HAVE_COSF
-  inline float 
-  cos(float __x) { return ::cosf(__x); }
+  extern "C" double ceil(double __x);
+
+#if _GLIBCPP_HAVE_CEILL
+  inline long double 
+  ceil(long double __x) { return ::ceill(__x); }
 #else
-  inline float 
-  cos(float __x) { return ::cos(static_cast<double>(__x)); }
+  inline long double 
+  ceil(long double __x) { return ::ceil(static_cast<double>(__x)); }
 #endif
 
+
+  // cos.
+  inline float
+  cos(float __x)
+  { return __builtin_cosf(__x); }
+
+  inline double
+  cos(double __x)
+  { return __builtin_cos(__x); }
+
+  inline long double
+  cos(long double __x)
+  { return __builtin_cosl(__x); }
+
+
+  // cosh.
 #if _GLIBCPP_HAVE_COSHF
   inline float 
   cosh(float __x) { return ::coshf(__x); }
@@ -151,6 +229,18 @@ namespace std
   cosh(float __x) { return ::cosh(static_cast<double>(__x)); }
 #endif
 
+  extern "C" double cosh(double __x);
+
+#if _GLIBCPP_HAVE_COSHL
+  inline long double 
+  cosh(long double __x) { return ::coshl(__x); }
+#else
+  inline long double 
+  cosh(long double __x) { return ::cosh(static_cast<double>(__x)); }
+#endif
+
+
+  // exp.
 #if _GLIBCPP_HAVE_EXPF
   inline float 
   exp(float __x) { return ::expf(__x); }
@@ -159,17 +249,32 @@ namespace std
   exp(float __x) { return ::exp(static_cast<double>(__x)); }
 #endif
 
-#if _GLIBCPP_HAVE___BUILTIN_FABSF
-  inline float 
-  fabs(float __x) { return __builtin_fabsf(__x); }
-#elif _GLIBCPP_HAVE_FABSF
-  inline float 
-  fabs(float __x) { return ::fabsf(__x); }
+  extern "C" double exp(double __x);
+
+#if _GLIBCPP_HAVE_EXPL
+  inline long double 
+  exp(long double __x) { return ::expl(__x); }
 #else
-  inline float 
-  fabs(float __x) { return __cmath_abs(__x); }
+  inline long double 
+  exp(long double __x) { return ::exp(static_cast<double>(__x)); }
 #endif
 
+
+  // fabs.
+  inline float
+  fabs(float __x)
+  { return __builtin_fabsf(__x); }
+
+  inline double
+  fabs(double __x)
+  { return __builtin_fabs(__x); }
+
+  inline long double
+  fabs(long double __x)
+  { return __builtin_fabsl(__x); }
+
+
+  // floor.
 #if _GLIBCPP_HAVE_FLOORF
   inline float 
   floor(float __x) { return ::floorf(__x); }
@@ -178,6 +283,18 @@ namespace std
   floor(float __x) { return ::floor(static_cast<double>(__x)); }
 #endif
 
+  extern "C" double floor(double __x);
+
+#if _GLIBCPP_HAVE_FLOORL
+  inline long double 
+  floor(long double __x) { return ::floorl(__x); }
+#else
+  inline long double 
+  floor(long double __x) { return ::floor(static_cast<double>(__x)); }
+#endif
+
+
+  // fmod.
 #if _GLIBCPP_HAVE_FMODF
   inline float 
   fmod(float __x, float __y) { return ::fmodf(__x, __y); }
@@ -187,6 +304,19 @@ namespace std
   { return ::fmod(static_cast<double>(__x), static_cast<double>(__y)); }
 #endif
 
+  extern "C" double fmod(double __x, double __y);
+
+#if _GLIBCPP_HAVE_FMODL
+  inline long double 
+  fmod(long double __x, long double __y) { return ::fmodl(__x, __y); }
+#else
+  inline long double 
+  fmod(long double __x, long double __y) 
+  { return ::fmod(static_cast<double>(__x), static_cast<double>(__y)); }
+#endif
+
+
+  // frexp.
 #if _GLIBCPP_HAVE_FREXPF
   inline float 
   frexp(float __x, int* __exp) { return ::frexpf(__x, __exp); }
@@ -195,6 +325,19 @@ namespace std
   frexp(float __x, int* __exp) { return ::frexp(__x, __exp); }
 #endif
 
+  extern "C" double frexp(double __x, int* __exp);
+
+#if _GLIBCPP_HAVE_FREXPL
+  inline long double 
+  frexp(long double __x, int* __exp) { return ::frexpl(__x, __exp); }
+#else
+  inline long double 
+  frexp(long double __x, int* __exp) 
+  { return ::frexp(static_cast<double>(__x), __exp); }
+#endif
+
+
+  // ldexp.
 #if _GLIBCPP_HAVE_LDEXPF
   inline float 
   ldexp(float __x, int __exp) { return ::ldexpf(__x, __exp); }
@@ -204,6 +347,19 @@ namespace std
   { return ::ldexp(static_cast<double>(__x), __exp); }
 #endif
 
+  extern "C" double ldexp(double __x, int __exp);
+
+#if _GLIBCPP_HAVE_LDEXPL
+  inline long double 
+  ldexp(long double __x, int __exp) { return ::ldexpl(__x, __exp); }
+#else
+  inline long double 
+  ldexp(long double __x, int __exp) 
+  { return ::ldexp(static_cast<double>(__x), __exp); }
+#endif
+
+
+  // log.
 #if _GLIBCPP_HAVE_LOGF
   inline float 
   log(float __x) { return ::logf(__x); }
@@ -212,6 +368,18 @@ namespace std
   { return ::log(static_cast<double>(__x)); }
 #endif
 
+  extern "C" double log(double __x);
+
+#if _GLIBCPP_HAVE_LOGL
+  inline long double 
+  log(long double __x) { return ::logl(__x); }
+#else
+  inline long double 
+  log(long double __x) { return ::log(static_cast<double>(__x)); }
+#endif
+
+
+  // log10.
 #if _GLIBCPP_HAVE_LOG10F
   inline float 
   log10(float __x) { return ::log10f(__x); }
@@ -220,6 +388,18 @@ namespace std
   log10(float __x) { return ::log10(static_cast<double>(__x)); }
 #endif
 
+  extern "C" double log10(double __x);
+
+#if _GLIBCPP_HAVE_LOG10L
+  inline long double 
+  log10(long double __x) { return ::log10l(__x); }
+#else
+  inline long double 
+  log10(long double __x) { return ::log10(static_cast<double>(__x)); }
+#endif
+
+
+  // modf.
 #if _GLIBCPP_HAVE_MODFF
   inline float 
   modf(float __x, float* __iptr) { return ::modff(__x, __iptr); }
@@ -234,6 +414,24 @@ namespace std
   }
 #endif
 
+  extern "C" double modf(double __x, double* __iptr);
+
+#if _GLIBCPP_HAVE_MODFL
+  inline long double 
+  modf(long double __x, long double* __iptr) { return ::modfl(__x, __iptr); }
+#else
+  inline long double 
+  modf(long double __x, long double* __iptr) 
+  { 
+    double __tmp;
+    double __res = ::modf(static_cast<double>(__x), &__tmp);
+    * __iptr = static_cast<long double>(__tmp);
+    return __res;
+  }
+#endif
+
+
+  // pow.
   template<typename _Tp>
     inline _Tp
     __pow_helper(_Tp __x, int __n)
@@ -252,110 +450,22 @@ namespace std
   { return ::pow(static_cast<double>(__x), static_cast<double>(__y)); }
 #endif
 
-  inline float 
-  pow(float __x, int __n)
-  {
-    return __pow_helper(__x, __n);
-  }
-
-#if _GLIBCPP_HAVE___BUILTIN_SINF
-  inline float 
-  sin(float __x) { return __builtin_sinf(__x); }
-#elif _GLIBCPP_HAVE_SINF
-  inline float 
-  sin(float __x) { return ::sinf(__x); }
-#else
-  inline float 
-  sin(float __x) { return ::sin(static_cast<double>(__x)); }
-#endif
-
-#if _GLIBCPP_HAVE_SINHF
-  inline float 
-  sinh(float __x) { return ::sinhf(__x); }
-#else
-  inline float 
-  sinh(float __x) { return ::sinh(static_cast<double>(__x)); }
-#endif
-
-#if _GLIBCPP_HAVE___BUILTIN_SQRTF
-  inline float 
-  sqrt(float __x) { return __builtin_sqrtf(__x); }
-#elif _GLIBCPP_HAVE_SQRTF
-  inline float 
-  sqrt(float __x) { return ::sqrtf(__x); }
-#else
-  inline float 
-  sqrt(float __x) { return ::sqrt(static_cast<double>(__x)); }
-#endif
+  extern "C" double pow(double __x, double __y);
 
-#if _GLIBCPP_HAVE_TANF
-  inline float 
-  tan(float __x) { return ::tanf(__x); }
+#if _GLIBCPP_HAVE_POWL
+  inline long double 
+  pow(long double __x, long double __y) { return ::powl(__x, __y); }
 #else
-  inline float 
-  tan(float __x) { return ::tan(static_cast<double>(__x)); }
+  inline long double 
+  pow(long double __x, long double __y) 
+  { return ::pow(static_cast<double>(__x), static_cast<double>(__y)); }
 #endif
 
-#if _GLIBCPP_HAVE_TANHF
-  inline float 
-  tanh(float __x) { return ::tanhf(__x); }
-#else
   inline float 
-  tanh(float __x) { return ::tanh(static_cast<double>(__x)); }
-#endif
-
-
-  extern "C" double acos(double __x);
-
-  extern "C" double asin(double __x);
-
-  extern "C" double atan(double __x);
-
-  extern "C" double atan2(double __y, double __x);
-
-  extern "C" double ceil(double __x);
-
-#if _GLIBCPP_HAVE___BUILTIN_COS
-  inline double 
-  cos(double __x) { return __builtin_cos(__x); }
-#else
-  extern "C" double cos(double __x);
-#endif
-
-  extern "C" double cosh(double __x);
-
-  extern "C" double exp(double __x);
-
-#if _GLIBCPP_HAVE___BUILTIN_FABS
-  inline double 
-  fabs(double __x) { return __builtin_fabs(__x); }
-#else
-  extern "C" double fabs(double __x);
-#endif
-
-#if _GLIBCPP_HAVE___BUILTIN_FABS
-  inline double 
-  abs(double __x) { return __builtin_fabs(__x); }
-#else
-  inline double
-  abs(double __x) { return fabs(__x); }
-#endif
-
-  extern "C" double floor(double __x);
-
-  extern "C" double fmod(double __x, double __y);
-
-  extern "C" double frexp(double __x, int* __exp);
-
-  extern "C" double ldexp(double __x, int __exp);
-
-  extern "C" double log(double __x);
-
-  extern "C" double log10(double __x);
-
-  extern "C" double modf(double __x, double* __iptr);
-
-  extern "C" double pow(double __x, double __y);
+  pow(float __x, int __n)
+  {
+    return __pow_helper(__x, __n);
+  }
 
   inline double 
   pow(double __x, int __i)
@@ -363,234 +473,91 @@ namespace std
     return __pow_helper(__x, __i);
   }
 
-#if _GLIBCPP_HAVE___BUILTIN_SIN
-  inline double 
-  sin(double __x) { return __builtin_sin(__x); }
-#else
-  extern "C" double sin(double __x);
-#endif
-
-  extern "C" double sinh(double __x);
-
-#if _GLIBCPP_HAVE___BUILTIN_SQRT
-  inline double 
-  sqrt(double __x) { return __builtin_fsqrt(__x); }
-#else
-  extern "C" double sqrt(double __x);
-#endif
-
-  extern "C" double tan(double __x);
-
-  extern "C" double tanh(double __x);
-
-
-#if _GLIBCPP_HAVE___BUILTIN_FABSL
-  inline long double 
-  abs(long double __x) { return __builtin_fabsl(__x); }
-#elif _GLIBCPP_HAVE_FABSL
-  inline long double 
-  abs(long double __x) { return ::fabsl(__x); }
-#else
-  inline long double 
-  abs(long double __x) { return __cmath_abs(__x); }
-#endif
-
-#if _GLIBCPP_HAVE_ACOSL
-  inline long double 
-  acos(long double __x) { return ::acosl(__x); }
-#else
   inline long double 
-  acos(long double __x) { return ::acos(static_cast<double>(__x)); }
-#endif
+  pow(long double __x, int __n)
+  {
+    return __pow_helper(__x, __n);
+  }
 
-#if _GLIBCPP_HAVE_ASINL
-  inline long double 
-  asin(long double __x) { return ::asinl(__x); }
-#else
-  inline long double 
-  asin(long double __x) { return ::asin(static_cast<double>(__x)); }
-#endif
 
-#if _GLIBCPP_HAVE_ATANL
-  inline long double 
-  atan(long double __x) { return ::atanl(__x); }
-#else
-  inline long double 
-  atan(long double __x) { return ::atan(static_cast<double>(__x)); }
-#endif
+  // sin.
+  inline float
+  sin(float __x)
+  { return __builtin_sinf(__x); }
 
-#if _GLIBCPP_HAVE_ATAN2L
-  inline long double 
-  atan2(long double __y, long double __x) { return ::atan2l(__y, __x); }
-#else
-  inline long double 
-  atan2(long double __y, long double __x) 
-  { return ::atan2(static_cast<double>(__y), static_cast<double>(__x)); }
-#endif
-
-#if _GLIBCPP_HAVE_CEILL
-  inline long double 
-  ceil(long double __x) { return ::ceill(__x); }
-#else
-  inline long double 
-  ceil(long double __x) { return ::ceil(static_cast<double>(__x)); }
-#endif
-
-#if _GLIBCPP_HAVE___BUILTIN_COSL
-  inline long double 
-  cos(long double __x) { return __builtin_cosl(__x); }
-#elif _GLIBCPP_HAVE_COSL
-  inline long double 
-  cos(long double __x) { return ::cosl(__x); }
-#else
-  inline long double 
-  cos(long double __x) { return ::cos(static_cast<double>(__x)); }
-#endif
+  inline double
+  sin(double __x)
+  { return __builtin_sin(__x); }
 
-#if _GLIBCPP_HAVE_COSHL
-  inline long double 
-  cosh(long double __x) { return ::coshl(__x); }
-#else
-  inline long double 
-  cosh(long double __x) { return ::cosh(static_cast<double>(__x)); }
-#endif
+  inline long double
+  sin(long double __x)
+  { return __builtin_sinl(__x); }
 
-#if _GLIBCPP_HAVE_EXPL
-  inline long double 
-  exp(long double __x) { return ::expl(__x); }
+  
+  // sinh.
+#if _GLIBCPP_HAVE_SINHF
+  inline float 
+  sinh(float __x) { return ::sinhf(__x); }
 #else
-  inline long double 
-  exp(long double __x) { return ::exp(static_cast<double>(__x)); }
+  inline float 
+  sinh(float __x) { return ::sinh(static_cast<double>(__x)); }
 #endif
 
-#if _GLIBCPP_HAVE___BUILTIN_FABSL
-  inline long double 
-  fabs(long double __x) { return __builtin_fabsl(__x); }
-#elif _GLIBCPP_HAVE_FABSL
-  inline long double 
-  fabs(long double __x) { return ::fabsl(__x); }
-#else
-  inline long double 
-  fabs(long double __x) { return __cmath_abs(__x); }
-#endif
+  extern "C" double sinh(double __x);
 
-#if _GLIBCPP_HAVE_FLOORL
+#if _GLIBCPP_HAVE_SINHL
   inline long double 
-  floor(long double __x) { return ::floorl(__x); }
+  sinh(long double __x) { return ::sinhl(__x); }
 #else
   inline long double 
-  floor(long double __x) { return ::floor(static_cast<double>(__x)); }
+  sinh(long double __x) { return ::sinh(static_cast<double>(__x)); }
 #endif
 
-#if _GLIBCPP_HAVE_FMODL
-  inline long double 
-  fmod(long double __x, long double __y) { return ::fmodl(__x, __y); }
-#else
-  inline long double 
-  fmod(long double __x, long double __y) 
-  { return ::fmod(static_cast<double>(__x), static_cast<double>(__y)); }
-#endif
 
-#if _GLIBCPP_HAVE_FREXPL
-  inline long double 
-  frexp(long double __x, int* __exp) { return ::frexpl(__x, __exp); }
-#else
-  inline long double 
-  frexp(long double __x, int* __exp) 
-  { return ::frexp(static_cast<double>(__x), __exp); }
-#endif
+  // sqrt.
+  inline float
+  sqrt(float __x)
+  { return __builtin_sqrtf(__x); }
 
-#if _GLIBCPP_HAVE_LDEXPL
-  inline long double 
-  ldexp(long double __x, int __exp) { return ::ldexpl(__x, __exp); }
-#else
-  inline long double 
-  ldexp(long double __x, int __exp) 
-  { return ::ldexp(static_cast<double>(__x), __exp); }
-#endif
+  inline double
+  sqrt(double __x)
+  { return __builtin_fsqrt(__x); }
 
-#if _GLIBCPP_HAVE_LOGL
-  inline long double 
-  log(long double __x) { return ::logl(__x); }
-#else
-  inline long double 
-  log(long double __x) { return ::log(static_cast<double>(__x)); }
-#endif
+  inline long double
+  sqrt(long double __x)
+  { return __builtin_sqrtl(__x); }
 
-#if _GLIBCPP_HAVE_LOG10L
-  inline long double 
-  log10(long double __x) { return ::log10l(__x); }
-#else
-  inline long double 
-  log10(long double __x) { return ::log10(static_cast<double>(__x)); }
-#endif
 
-#if _GLIBCPP_HAVE_MODFL
-  inline long double 
-  modf(long double __x, long double* __iptr) { return ::modfl(__x, __iptr); }
-#else
-  inline long double 
-  modf(long double __x, long double* __iptr) 
-  { 
-    double __tmp;
-    double __res = ::modf(static_cast<double>(__x), &__tmp);
-    * __iptr = static_cast<long double>(__tmp);
-    return __res;
-  }
-#endif
-
-#if _GLIBCPP_HAVE_POWL
-  inline long double 
-  pow(long double __x, long double __y) { return ::powl(__x, __y); }
+  // tan.
+#if _GLIBCPP_HAVE_TANF
+  inline float 
+  tan(float __x) { return ::tanf(__x); }
 #else
-  inline long double 
-  pow(long double __x, long double __y) 
-  { return ::pow(static_cast<double>(__x), static_cast<double>(__y)); }
+  inline float 
+  tan(float __x) { return ::tan(static_cast<double>(__x)); }
 #endif
 
-  inline long double 
-  pow(long double __x, int __n)
-  {
-    return __pow_helper(__x, __n);
-  }
+  extern "C" double tan(double __x);
 
-#if _GLIBCPP_HAVE___BUILTIN_SINL
-  inline long double 
-  sin(long double __x) { return __builtin_sinl(__x); }
-#elif _GLIBCPP_HAVE_SINL
+#if _GLIBCPP_HAVE_TANL
   inline long double 
-  sin(long double __x) { return ::sinl(__x); }
+  tan(long double __x) { return ::tanl(__x); }
 #else
   inline long double 
-  sin(long double __x) { return ::sin(static_cast<double>(__x)); }
+  tan(long double __x) { return ::tan(static_cast<double>(__x)); }
 #endif
 
-#if _GLIBCPP_HAVE_SINHL
-  inline long double 
-  sinh(long double __x) { return ::sinhl(__x); }
-#else
-  inline long double 
-  sinh(long double __x) { return ::sinh(static_cast<double>(__x)); }
-#endif
 
-#if _GLIBCPP_HAVE___BUILTIN_SQRTL
-  inline long double 
-  sqrt(long double __x) { return __builtin_sqrtl(__x); }
-#elif _GLIBCPP_HAVE_SQRTL
-  inline long double 
-  sqrt(long double __x) { return ::sqrtl(__x); }
+  // tanh.
+#if _GLIBCPP_HAVE_TANHF
+  inline float 
+  tanh(float __x) { return ::tanhf(__x); }
 #else
-  inline long double 
-  sqrt(long double __x) { return ::sqrt(static_cast<double>(__x)); }
+  inline float 
+  tanh(float __x) { return ::tanh(static_cast<double>(__x)); }
 #endif
 
-#if _GLIBCPP_HAVE_TANL
-  inline long double 
-  tan(long double __x) { return ::tanl(__x); }
-#else
-  inline long double 
-  tan(long double __x) { return ::tan(static_cast<double>(__x)); }
-#endif
+  extern "C" double tanh(double __x);
 
 #if _GLIBCPP_HAVE_TANHL
   inline long double