Android: Conditionally enable long-double math.h inline overloads

[kastiglione]

Summary

On android, many of the math function overloads for long double are available starting with API level 21[1]. This change makes those long double overloads conditional on __ANDROID_API__ being at 21 or newer. In a couple of cases, the function was first available with API level 18, and those have been adjusted as well.

1. https://android.googlesource.com/platform/bionic/+/master/libc/include/math.h

[danalbert]

I don't really understand why we need this. This goes from always having it available to only being available if the NDK user is targeting L or newer (which is definitely the minority of users because most people won't choose to cut their user base by ~1/2). The NDK has a compatibility shim that provides definitions for these on older platforms.

[kastiglione]

@danalbert Thanks for the feedback. The issue I was hitting is that for 19 and earlier, math.h puts these long double functions inside a #if 0 block. Where does the compatibility shim come from? Does it include declarations for these long double functions?

[danalbert]

The shim is part of the NDK: https://android.googlesource.com/platform/ndk/+/master/sources/android/support/include/math.h

The issue I was hitting is that for 19 and earlier, math.h puts these long double functions inside a #if 0 block.

Which math.h are we talking about? There are three in play here: libc++'s, libc's, and libandroid_support's.

[kastiglione]

Which math.h are we talking about? There are three in play here: libc++'s, libc's, and libandroid_support's.

I'm not sure where it is on android.googlesource.com, but in the NDK release it's this one: platforms/android-19/arch-arm/usr/include/math.h.

[danalbert]

https://android.googlesource.com/platform/development/+/master/ndk/platforms/android-18/include/math.h#410

The current bionic header gives us a clearer picture: https://android.googlesource.com/platform/bionic/+/master/libc/include/math.h#240

So yes, most of these were missing until somewhat recently. libandroid_support provides these things though (if it's missing any, that's still the right place to fix this).

We've also debated just defaulting to using a static libm for Android since all that stuff can be safely statically linked across platform versions, so there's really no reason to not always use the latest version.

[kastiglione]

Thanks @danalbert

include/math.h

 long double
 abs(long double __lcpp_x) _NOEXCEPT {return fabsl(__lcpp_x);}
 #endif // !defined(_AIX)
 
 // acos
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       acos(float __lcpp_x) _NOEXCEPT       {return acosf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double acos(long double __lcpp_x) _NOEXCEPT {return acosl(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 acos(_A1 __lcpp_x) _NOEXCEPT {return acos((double)__lcpp_x);}
 
 // asin
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       asin(float __lcpp_x) _NOEXCEPT       {return asinf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double asin(long double __lcpp_x) _NOEXCEPT {return asinl(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 asin(_A1 __lcpp_x) _NOEXCEPT {return asin((double)__lcpp_x);}
 
 // atan
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       atan(float __lcpp_x) _NOEXCEPT       {return atanf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double atan(long double __lcpp_x) _NOEXCEPT {return atanl(__lcpp_x);}
 #endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 atan(_A1 __lcpp_x) _NOEXCEPT {return atan((double)__lcpp_x);}
 
 // atan2
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       atan2(float __lcpp_y, float __lcpp_x) _NOEXCEPT             {return atan2f(__lcpp_y, __lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double atan2(long double __lcpp_y, long double __lcpp_x) _NOEXCEPT {return atan2l(__lcpp_y, __lcpp_x);}
 #endif
+#endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::__lazy_enable_if
 <
     std::is_arithmetic<_A1>::value &&
     std::is_arithmetic<_A2>::value,
     std::__promote<_A1, _A2>

 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 ceil(_A1 __lcpp_x) _NOEXCEPT {return ceil((double)__lcpp_x);}
 
 // cos
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       cos(float __lcpp_x) _NOEXCEPT       {return cosf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double cos(long double __lcpp_x) _NOEXCEPT {return cosl(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 cos(_A1 __lcpp_x) _NOEXCEPT {return cos((double)__lcpp_x);}
 
 // cosh
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       cosh(float __lcpp_x) _NOEXCEPT       {return coshf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double cosh(long double __lcpp_x) _NOEXCEPT {return coshl(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 cosh(_A1 __lcpp_x) _NOEXCEPT {return cosh((double)__lcpp_x);}
 
 // exp
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       exp(float __lcpp_x) _NOEXCEPT       {return expf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double exp(long double __lcpp_x) _NOEXCEPT {return expl(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 exp(_A1 __lcpp_x) _NOEXCEPT {return exp((double)__lcpp_x);}
 
 // fabs
 

 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 floor(_A1 __lcpp_x) _NOEXCEPT {return floor((double)__lcpp_x);}
 
 // fmod
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       fmod(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return fmodf(__lcpp_x, __lcpp_y);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double fmod(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return fmodl(__lcpp_x, __lcpp_y);}
 #endif
+#endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::__lazy_enable_if
 <
     std::is_arithmetic<_A1>::value &&
     std::is_arithmetic<_A2>::value,
     std::__promote<_A1, _A2>
 >::type
 fmod(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
 {
     typedef typename std::__promote<_A1, _A2>::type __result_type;
     static_assert((!(std::is_same<_A1, __result_type>::value &&
                      std::is_same<_A2, __result_type>::value)), "");
     return fmod((__result_type)__lcpp_x, (__result_type)__lcpp_y);
 }
 
 // frexp
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       frexp(float __lcpp_x, int* __lcpp_e) _NOEXCEPT       {return frexpf(__lcpp_x, __lcpp_e);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double frexp(long double __lcpp_x, int* __lcpp_e) _NOEXCEPT {return frexpl(__lcpp_x, __lcpp_e);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 frexp(_A1 __lcpp_x, int* __lcpp_e) _NOEXCEPT {return frexp((double)__lcpp_x, __lcpp_e);}
 
 // ldexp
 

 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 log(_A1 __lcpp_x) _NOEXCEPT {return log((double)__lcpp_x);}
 
 // log10
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       log10(float __lcpp_x) _NOEXCEPT       {return log10f(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double log10(long double __lcpp_x) _NOEXCEPT {return log10l(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 log10(_A1 __lcpp_x) _NOEXCEPT {return log10((double)__lcpp_x);}
 
 // modf
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       modf(float __lcpp_x, float* __lcpp_y) _NOEXCEPT             {return modff(__lcpp_x, __lcpp_y);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double modf(long double __lcpp_x, long double* __lcpp_y) _NOEXCEPT {return modfl(__lcpp_x, __lcpp_y);}
 #endif
+#endif
 
 // pow
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       pow(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return powf(__lcpp_x, __lcpp_y);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double pow(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return powl(__lcpp_x, __lcpp_y);}
 #endif
+#endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::__lazy_enable_if
 <
     std::is_arithmetic<_A1>::value &&
     std::is_arithmetic<_A2>::value,
     std::__promote<_A1, _A2>
 >::type
 pow(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
 {
     typedef typename std::__promote<_A1, _A2>::type __result_type;
     static_assert((!(std::is_same<_A1, __result_type>::value &&
                      std::is_same<_A2, __result_type>::value)), "");
     return pow((__result_type)__lcpp_x, (__result_type)__lcpp_y);
 }
 
 // sin
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       sin(float __lcpp_x) _NOEXCEPT       {return sinf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double sin(long double __lcpp_x) _NOEXCEPT {return sinl(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 sin(_A1 __lcpp_x) _NOEXCEPT {return sin((double)__lcpp_x);}
 
 // sinh
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       sinh(float __lcpp_x) _NOEXCEPT       {return sinhf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double sinh(long double __lcpp_x) _NOEXCEPT {return sinhl(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 sinh(_A1 __lcpp_x) _NOEXCEPT {return sinh((double)__lcpp_x);}
 
 // sqrt
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       sqrt(float __lcpp_x) _NOEXCEPT       {return sqrtf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double sqrt(long double __lcpp_x) _NOEXCEPT {return sqrtl(__lcpp_x);}
 #endif
+#endif
 
 #endif // __sun__
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 sqrt(_A1 __lcpp_x) _NOEXCEPT {return sqrt((double)__lcpp_x);}
 #ifndef __sun__
 
 // tan
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       tan(float __lcpp_x) _NOEXCEPT       {return tanf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double tan(long double __lcpp_x) _NOEXCEPT {return tanl(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 tan(_A1 __lcpp_x) _NOEXCEPT {return tan((double)__lcpp_x);}
 
 // tanh
 
 #if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
 inline _LIBCPP_INLINE_VISIBILITY float       tanh(float __lcpp_x) _NOEXCEPT       {return tanhf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double tanh(long double __lcpp_x) _NOEXCEPT {return tanhl(__lcpp_x);}
 #endif
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 tanh(_A1 __lcpp_x) _NOEXCEPT {return tanh((double)__lcpp_x);}
 
 // acosh
 
 #ifndef _LIBCPP_MSVCRT
 inline _LIBCPP_INLINE_VISIBILITY float       acosh(float __lcpp_x) _NOEXCEPT       {return acoshf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double acosh(long double __lcpp_x) _NOEXCEPT {return acoshl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 acosh(_A1 __lcpp_x) _NOEXCEPT {return acosh((double)__lcpp_x);}
 #endif
 
 // asinh
 
 #ifndef _LIBCPP_MSVCRT
 inline _LIBCPP_INLINE_VISIBILITY float       asinh(float __lcpp_x) _NOEXCEPT       {return asinhf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double asinh(long double __lcpp_x) _NOEXCEPT {return asinhl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 asinh(_A1 __lcpp_x) _NOEXCEPT {return asinh((double)__lcpp_x);}
 #endif
 
 // atanh
 
 #ifndef _LIBCPP_MSVCRT
 inline _LIBCPP_INLINE_VISIBILITY float       atanh(float __lcpp_x) _NOEXCEPT       {return atanhf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double atanh(long double __lcpp_x) _NOEXCEPT {return atanhl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 atanh(_A1 __lcpp_x) _NOEXCEPT {return atanh((double)__lcpp_x);}
 #endif
 
 // cbrt
 
 #ifndef _LIBCPP_MSVCRT
 inline _LIBCPP_INLINE_VISIBILITY float       cbrt(float __lcpp_x) _NOEXCEPT       {return cbrtf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double cbrt(long double __lcpp_x) _NOEXCEPT {return cbrtl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 cbrt(_A1 __lcpp_x) _NOEXCEPT {return cbrt((double)__lcpp_x);}
 #endif
 
 // copysign
copysign(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
     return copysign((__result_type)__lcpp_x, (__result_type)__lcpp_y);
 }
 
 #ifndef _LIBCPP_MSVCRT
 
 // erf
 
 inline _LIBCPP_INLINE_VISIBILITY float       erf(float __lcpp_x) _NOEXCEPT       {return erff(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double erf(long double __lcpp_x) _NOEXCEPT {return erfl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 erf(_A1 __lcpp_x) _NOEXCEPT {return erf((double)__lcpp_x);}
 
 // erfc
 
 inline _LIBCPP_INLINE_VISIBILITY float       erfc(float __lcpp_x) _NOEXCEPT       {return erfcf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double erfc(long double __lcpp_x) _NOEXCEPT {return erfcl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 erfc(_A1 __lcpp_x) _NOEXCEPT {return erfc((double)__lcpp_x);}
 
 // exp2
 
 inline _LIBCPP_INLINE_VISIBILITY float       exp2(float __lcpp_x) _NOEXCEPT       {return exp2f(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double exp2(long double __lcpp_x) _NOEXCEPT {return exp2l(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 exp2(_A1 __lcpp_x) _NOEXCEPT {return exp2((double)__lcpp_x);}
 
 // expm1
 
 inline _LIBCPP_INLINE_VISIBILITY float       expm1(float __lcpp_x) _NOEXCEPT       {return expm1f(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double expm1(long double __lcpp_x) _NOEXCEPT {return expm1l(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 expm1(_A1 __lcpp_x) _NOEXCEPT {return expm1((double)__lcpp_x);}
 
 // fdim
 
fdim(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
     static_assert((!(std::is_same<_A1, __result_type>::value &&
                      std::is_same<_A2, __result_type>::value)), "");
     return fdim((__result_type)__lcpp_x, (__result_type)__lcpp_y);
 }
 
 // fma
 
 inline _LIBCPP_INLINE_VISIBILITY float       fma(float __lcpp_x, float __lcpp_y, float __lcpp_z) _NOEXCEPT                   {return fmaf(__lcpp_x, __lcpp_y, __lcpp_z);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double fma(long double __lcpp_x, long double __lcpp_y, long double __lcpp_z) _NOEXCEPT {return fmal(__lcpp_x, __lcpp_y, __lcpp_z);}
+#endif
 
 template <class _A1, class _A2, class _A3>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::__lazy_enable_if
 <
     std::is_arithmetic<_A1>::value &&
     std::is_arithmetic<_A2>::value &&
     std::is_arithmetic<_A3>::value,
fmin(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
     static_assert((!(std::is_same<_A1, __result_type>::value &&
                      std::is_same<_A2, __result_type>::value)), "");
     return fmin((__result_type)__lcpp_x, (__result_type)__lcpp_y);
 }
 
 // hypot
 
 inline _LIBCPP_INLINE_VISIBILITY float       hypot(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return hypotf(__lcpp_x, __lcpp_y);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double hypot(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return hypotl(__lcpp_x, __lcpp_y);}
+#endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::__lazy_enable_if
 <
     std::is_arithmetic<_A1>::value &&
     std::is_arithmetic<_A2>::value,
     std::__promote<_A1, _A2>

 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, int>::type
 ilogb(_A1 __lcpp_x) _NOEXCEPT {return ilogb((double)__lcpp_x);}
 
 // lgamma
 
 inline _LIBCPP_INLINE_VISIBILITY float       lgamma(float __lcpp_x) _NOEXCEPT       {return lgammaf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double lgamma(long double __lcpp_x) _NOEXCEPT {return lgammal(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 lgamma(_A1 __lcpp_x) _NOEXCEPT {return lgamma((double)__lcpp_x);}
 
 // llrint
 
 inline _LIBCPP_INLINE_VISIBILITY long long llrint(float __lcpp_x) _NOEXCEPT       {return llrintf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long long llrint(long double __lcpp_x) _NOEXCEPT {return llrintl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, long long>::type
 llrint(_A1 __lcpp_x) _NOEXCEPT {return llrint((double)__lcpp_x);}
 
 // llround
 

 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 log1p(_A1 __lcpp_x) _NOEXCEPT {return log1p((double)__lcpp_x);}
 
 // log2
 
 inline _LIBCPP_INLINE_VISIBILITY float       log2(float __lcpp_x) _NOEXCEPT       {return log2f(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 18
 inline _LIBCPP_INLINE_VISIBILITY long double log2(long double __lcpp_x) _NOEXCEPT {return log2l(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 log2(_A1 __lcpp_x) _NOEXCEPT {return log2((double)__lcpp_x);}
 
 // logb
 
 inline _LIBCPP_INLINE_VISIBILITY float       logb(float __lcpp_x) _NOEXCEPT       {return logbf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 18
 inline _LIBCPP_INLINE_VISIBILITY long double logb(long double __lcpp_x) _NOEXCEPT {return logbl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 logb(_A1 __lcpp_x) _NOEXCEPT {return logb((double)__lcpp_x);}
 
 // lrint
 
 inline _LIBCPP_INLINE_VISIBILITY long lrint(float __lcpp_x) _NOEXCEPT       {return lrintf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long lrint(long double __lcpp_x) _NOEXCEPT {return lrintl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, long>::type
 lrint(_A1 __lcpp_x) _NOEXCEPT {return lrint((double)__lcpp_x);}
 
 // lround
 
 inline _LIBCPP_INLINE_VISIBILITY long lround(float __lcpp_x) _NOEXCEPT       {return lroundf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long lround(long double __lcpp_x) _NOEXCEPT {return lroundl(__lcpp_x);}
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, long>::type
 lround(_A1 __lcpp_x) _NOEXCEPT {return lround((double)__lcpp_x);}
 
 // nan
 
 // nearbyint
 
 inline _LIBCPP_INLINE_VISIBILITY float       nearbyint(float __lcpp_x) _NOEXCEPT       {return nearbyintf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double nearbyint(long double __lcpp_x) _NOEXCEPT {return nearbyintl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 nearbyint(_A1 __lcpp_x) _NOEXCEPT {return nearbyint((double)__lcpp_x);}
 
 // nextafter
 
 inline _LIBCPP_INLINE_VISIBILITY float       nextafter(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return nextafterf(__lcpp_x, __lcpp_y);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double nextafter(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return nextafterl(__lcpp_x, __lcpp_y);}
+#endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::__lazy_enable_if
 <
     std::is_arithmetic<_A1>::value &&
     std::is_arithmetic<_A2>::value,
     std::__promote<_A1, _A2>
 >::type
 nextafter(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
 {
     typedef typename std::__promote<_A1, _A2>::type __result_type;
     static_assert((!(std::is_same<_A1, __result_type>::value &&
                      std::is_same<_A2, __result_type>::value)), "");
     return nextafter((__result_type)__lcpp_x, (__result_type)__lcpp_y);
 }
 
 // nexttoward
 
 inline _LIBCPP_INLINE_VISIBILITY float       nexttoward(float __lcpp_x, long double __lcpp_y) _NOEXCEPT       {return nexttowardf(__lcpp_x, __lcpp_y);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 18
 inline _LIBCPP_INLINE_VISIBILITY long double nexttoward(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return nexttowardl(__lcpp_x, __lcpp_y);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 nexttoward(_A1 __lcpp_x, long double __lcpp_y) _NOEXCEPT {return nexttoward((double)__lcpp_x, __lcpp_y);}
 
 // remainder
 
 inline _LIBCPP_INLINE_VISIBILITY float       remainder(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return remainderf(__lcpp_x, __lcpp_y);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double remainder(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return remainderl(__lcpp_x, __lcpp_y);}
+#endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::__lazy_enable_if
 <
     std::is_arithmetic<_A1>::value &&
     std::is_arithmetic<_A2>::value,
     std::__promote<_A1, _A2>
 >::type
 remainder(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
 {
     typedef typename std::__promote<_A1, _A2>::type __result_type;
     static_assert((!(std::is_same<_A1, __result_type>::value &&
                      std::is_same<_A2, __result_type>::value)), "");
     return remainder((__result_type)__lcpp_x, (__result_type)__lcpp_y);
 }
 
 // remquo
 
 inline _LIBCPP_INLINE_VISIBILITY float       remquo(float __lcpp_x, float __lcpp_y, int* __lcpp_z) _NOEXCEPT             {return remquof(__lcpp_x, __lcpp_y, __lcpp_z);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double remquo(long double __lcpp_x, long double __lcpp_y, int* __lcpp_z) _NOEXCEPT {return remquol(__lcpp_x, __lcpp_y, __lcpp_z);}
+#endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::__lazy_enable_if
 <
     std::is_arithmetic<_A1>::value &&
     std::is_arithmetic<_A2>::value,
     std::__promote<_A1, _A2>
 >::type
 remquo(_A1 __lcpp_x, _A2 __lcpp_y, int* __lcpp_z) _NOEXCEPT
 {
     typedef typename std::__promote<_A1, _A2>::type __result_type;
     static_assert((!(std::is_same<_A1, __result_type>::value &&
                      std::is_same<_A2, __result_type>::value)), "");
     return remquo((__result_type)__lcpp_x, (__result_type)__lcpp_y, __lcpp_z);
 }
 
 // rint
 
 inline _LIBCPP_INLINE_VISIBILITY float       rint(float __lcpp_x) _NOEXCEPT       {return rintf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double rint(long double __lcpp_x) _NOEXCEPT {return rintl(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 rint(_A1 __lcpp_x) _NOEXCEPT {return rint((double)__lcpp_x);}
 
 // round
 

 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 scalbn(_A1 __lcpp_x, int __lcpp_y) _NOEXCEPT {return scalbn((double)__lcpp_x, __lcpp_y);}
 
 // tgamma
 
 inline _LIBCPP_INLINE_VISIBILITY float       tgamma(float __lcpp_x) _NOEXCEPT       {return tgammaf(__lcpp_x);}
+#if !defined(__ANDROID__) || __ANDROID_API__ >= 21
 inline _LIBCPP_INLINE_VISIBILITY long double tgamma(long double __lcpp_x) _NOEXCEPT {return tgammal(__lcpp_x);}
+#endif
 
 template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 tgamma(_A1 __lcpp_x) _NOEXCEPT {return tgamma((double)__lcpp_x);}
 
 // trunc