Fix -Wdouble-promotion warnings.

Reviewers: mclow.lists

Subscribers: christof, ldionne, cfe-commits, libcxx-commits

Differential Revision: https://reviews.llvm.org/D62782

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@364798 91177308-0d34-0410-b5e6-96231b3b80d8

include/limits

@@ -409,7 +409,7 @@ protected:
     static _LIBCPP_CONSTEXPR const bool is_exact = false;
     static _LIBCPP_CONSTEXPR const int  radix = __FLT_RADIX__;
     _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __LDBL_EPSILON__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return 0.5;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return 0.5L;}
 
     static _LIBCPP_CONSTEXPR const int  min_exponent = __LDBL_MIN_EXP__;
     static _LIBCPP_CONSTEXPR const int  min_exponent10 = __LDBL_MIN_10_EXP__;

include/utility

@@ -1479,7 +1479,7 @@ struct _LIBCPP_TEMPLATE_VIS hash<float>
     size_t operator()(float __v) const _NOEXCEPT
     {
         // -0.0 and 0.0 should return same hash
-       if (__v == 0.0)
+       if (__v == 0.0f)
            return 0;
         return __scalar_hash<float>::operator()(__v);
     }
@@ -1507,7 +1507,7 @@ struct _LIBCPP_TEMPLATE_VIS hash<long double>
     size_t operator()(long double __v) const _NOEXCEPT
     {
         // -0.0 and 0.0 should return same hash
-        if (__v == 0.0)
+        if (__v == 0.0L)
             return 0;
 #if defined(__i386__)
         // Zero out padding bits