@@ -1237,6 +1237,34 @@ namespace __format
using __float128_t = __ieee128;
# define _GLIBCXX_FORMAT_F128 1
+#ifdef __LONG_DOUBLE_IEEE128__
+ // These overloads exist in the library, but are not declared.
+ // Make them available as std::__format::to_chars.
+ to_chars_result
+ to_chars(char*, char*, __ibm128) noexcept
+ __asm("_ZSt8to_charsPcS_e");
+
+ to_chars_result
+ to_chars(char*, char*, __ibm128, chars_format) noexcept
+ __asm("_ZSt8to_charsPcS_eSt12chars_format");
+
+ to_chars_result
+ to_chars(char*, char*, __ibm128, chars_format, int) noexcept
+ __asm("_ZSt8to_charsPcS_eSt12chars_formati");
+#elif __cplusplus == 202002L
+ to_chars_result
+ to_chars(char*, char*, __ieee128) noexcept
+ __asm("_ZSt8to_charsPcS_u9__ieee128");
+
+ to_chars_result
+ to_chars(char*, char*, __ieee128, chars_format) noexcept
+ __asm("_ZSt8to_charsPcS_u9__ieee128St12chars_format");
+
+ to_chars_result
+ to_chars(char*, char*, __ieee128, chars_format, int) noexcept
+ __asm("_ZSt8to_charsPcS_u9__ieee128St12chars_formati");
+#endif
+
#elif defined _GLIBCXX_LDOUBLE_IS_IEEE_BINARY128
// Format 128-bit floating-point types using long double.