On Wed, Apr 30, 2025 at 1:26 PM Tomasz Kamiński <[email protected]> wrote:
> This commits adjust the way how the arguments are stored in the _Arg_value
> (and thus basic_format_args), by preserving the types of fixed width
> floating-point types, that were previously converted to float, double,
> long double.
>
> The _Arg_value union now contains alternatives with std::bfloat16_t,
> std::float16_t, std::float32_t, std::float64_t that use pre-existing
> _Arg_bf16, _Arg_f16, _Arg_f32, _Arg_f32 argument types.
>
> This does not affect formatting, as specialization of formatters for
> formats them by casting to the corresponding standard floating point
> type.
>
> For the 128bit floating we need to handle the ppc64 architecture,
> (_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT) for which the long double may (per TU
> basis) designate either __ibm128 and __ieee128 type, we need to store both
> types in the _Arg_value and have two _Arg_types (_Arg_ibm128,
> _Arg_ieee128).
> On other architectures we use extra enumerator value to store __float128,
> that is different from long double and _Float128. This is consistent with
> ppc64,
> for which __float128 is same type as __ieee128 if present. We use
> _Arg_float128
> _M_float128 names that deviate from _Arg_fN naming scheme, to emphasize
> that
> this flag is not used for std::float128_t (_Float128_t) type, that is
> consistenly
> formatted via handle.
>
> The __format::_float128_t type is renamed to __format::__flt128_t, to
> mitigate
> visual confusion between this type and __float128. We also introduce
> __bflt16_t
> typedef instead of using of decltype.
>
> We add new alternative for the _Arg_value and allow them to be accessed
> via _S_get,
> when the types are available. However, we produce and handle corresponding
> _Arg_type,
> only when we can format them. See also r14-3329-g27d0cfcb2b33de.
>
> The formatter<_Float128, _CharT> that formats via __flt128_t is always
> provided, when type is available. It is still correct __flt128_t is
> _Float128_t.
>
> We also provide formatter<__float128, _CharT> that formats via __flt128_t.
> As this type may be disabled (-mno-float128), extra care needs to be taken,
> for situation when __float128 is same as long double. If the formatter
> would be
> defined in such case, the formatter<long double, charT> would be generated
> from
> different specializations, and have different mangling:
> * formatter<__float128, _CharT> if __float128 is present,
> * formatter<_format::__formattable_float, _CharT> otherwise.
> To best of my knowledge this happens only on ppc64 for __ieee128 and
> __float128,
> so the formatter is not defined in this case. static_assert is added to
> detect
> other configurations like that. In such case we should replace it with
> constraint.
>
> PR libstdc++/119246
>
> libstdc++-v3/ChangeLog:
>
> * include/std/format (__format::__bflt16_t): Define.
> (_GLIBCXX_FORMAT_F128): Separate value for cases where _Float128
> is used.
> (__format::__float128_t): Renamed to __format::_flt128_t.
> (std::formatter<_Float128, _CharT>): Define always if there is
> formattable
> 128bit float.
> (std::formatter<__float128, _CharT>): Define.
> (_Arg_type::_Arg_f128): Rename to _Arg_float128 and adjust value.
> (_Arg_type::_Arg_ibm128): Change value to _Arg_ldbl.
> (_Arg_type::_Arg_ieee128): Define as alias to _Arg_float128.
> (_Arg_value::_M_f128): Replaced with _M_ieee128 and _M_float128.
> (_Arg_value::_M_ieee128, _Arg_value::_M_float128,
> _Arg_value::_M_bf16)
> (_Arg_value::_M_f16, _Arg_value::_M_f32, _Arg_value::_M_f64):
> Define.
> (_Arg_value::_S_get, basic_format_arg::_S_to_enum): Handle
> __bflt16,
> _Float16, _Float32, _Float64, and __float128 types.
> (basic_format_arg::_S_to_arg_type): Preserve _bflt16, _Float16,
> _Float32, _Float64 and __float128 types.
> (basic_format_arg::_M_visit): Hadndle _Arg_float128, _Arg_ieee128,
> _Arg_b16, _Arg_f16, _Arg_f32, _Arg_f64.
> * testsuite/std/format/arguments/args.cc: Updated to illustrate
> that
> extended floating point types use handles now. Added test for
> __float128.
> * testsuite/std/format/parse_ctx.cc: Extended test to cover class
> to
> check_dynamic_spec with floating point types and handles.
> ---
> Tested on x86_64-linux and powerpc64le-unknown-linux-gnu.
> Running additional test on powerpc64le with
> unix\{-mabi=ibmlongdouble,-mabi=ieeelongdouble,-mno-float128}.
>
The -mabi=ibmlongdouble and -mabi=ieeelongdouble passed.
The -mno-float128 seem to be not handled on trunk due use of __float128
instead of __ieee128 here:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=libstdc%2B%2B-v3/include/std/charconv;h=dda49ce72d0b53c7a6e86c2e3fb510d0218fd5a6;hb=HEAD#l878
Interestingly from chars use __ieee128:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=libstdc%2B%2B-v3/include/std/charconv;h=dda49ce72d0b53c7a6e86c2e3fb510d0218fd5a6;hb=HEAD#l742
> OK for trunk?
>
> libstdc++-v3/include/std/format | 217 ++++++++++++------
> .../testsuite/std/format/arguments/args.cc | 45 ++--
> .../testsuite/std/format/parse_ctx.cc | 72 +++++-
> 3 files changed, 227 insertions(+), 107 deletions(-)
>
> diff --git a/libstdc++-v3/include/std/format
> b/libstdc++-v3/include/std/format
> index 054ce350440..73819f52f50 100644
> --- a/libstdc++-v3/include/std/format
> +++ b/libstdc++-v3/include/std/format
> @@ -1863,20 +1863,24 @@ namespace __format
> _Spec<_CharT> _M_spec{};
> };
>
> +#ifdef __BFLT16_DIG__
> + using __bflt16_t = decltype(0.0bf16);
> +#endif
> +
> // Decide how 128-bit floating-point types should be formatted (or not).
> - // When supported, the typedef __format::__float128_t is the type that
> - // format arguments should be converted to for storage in
> basic_format_arg.
> + // When supported, the typedef __format::__flt128_t is the type that
> + // format arguments should be converted before formatting code.
> // Define the macro _GLIBCXX_FORMAT_F128 to say they're supported.
> - // _GLIBCXX_FORMAT_F128=1 means __float128, _Float128 etc. will be
> formatted
> - // by converting them to long double (or __ieee128 for powerpc64le).
> - // _GLIBCXX_FORMAT_F128=2 means basic_format_arg needs to enable
> explicit
> - // support for _Float128, rather than formatting it as another type.
> + // The __float128, _Float128 will be formatted by converting them to:
> + // __ieee128 (same as __float128) _GLIBCXX_FORMAT_F128=1,
> + // long double if _GLIBCXX_FORMAT_F128=2,
> + // _Float128 if _GLIBCXX_FORMAT_F128=3.
> #undef _GLIBCXX_FORMAT_F128
>
> #ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
>
> // Format 128-bit floating-point types using __ieee128.
> - using __float128_t = __ieee128;
> + using __flt128_t = __ieee128;
> # define _GLIBCXX_FORMAT_F128 1
>
> #ifdef __LONG_DOUBLE_IEEE128__
> @@ -1910,14 +1914,14 @@ namespace __format
> #elif defined _GLIBCXX_LDOUBLE_IS_IEEE_BINARY128
>
> // Format 128-bit floating-point types using long double.
> - using __float128_t = long double;
> -# define _GLIBCXX_FORMAT_F128 1
> + using __flt128_t = long double;
> +# define _GLIBCXX_FORMAT_F128 2
>
> #elif __FLT128_DIG__ && defined(_GLIBCXX_HAVE_FLOAT128_MATH)
>
> // Format 128-bit floating-point types using _Float128.
> - using __float128_t = _Float128;
> -# define _GLIBCXX_FORMAT_F128 2
> + using __flt128_t = _Float128;
> +# define _GLIBCXX_FORMAT_F128 3
>
> # if __cplusplus == 202002L
> // These overloads exist in the library, but are not declared for C++20.
> @@ -2947,8 +2951,8 @@ namespace __format
> };
> #endif
>
> -#if defined(__FLT128_DIG__) && _GLIBCXX_FORMAT_F128 == 1
> - // Reuse __formatter_fp<C>::format<__float128_t, Out> for _Float128.
> +#if defined(__FLT128_DIG__) && _GLIBCXX_FORMAT_F128
> + // Use __formatter_fp<C>::format<__format::flt128_t, Out> for _Float128.
> template<__format::__char _CharT>
> struct formatter<_Float128, _CharT>
> {
> @@ -2962,17 +2966,45 @@ namespace __format
> template<typename _Out>
> typename basic_format_context<_Out, _CharT>::iterator
> format(_Float128 __u, basic_format_context<_Out, _CharT>& __fc)
> const
> - { return _M_f.format((__format::__float128_t)__u, __fc); }
> + { return _M_f.format((__format::__flt128_t)__u, __fc); }
> +
> + private:
> + __format::__formatter_fp<_CharT> _M_f;
> + };
> +#endif
> +
> +#if defined(__SIZEOF_FLOAT128__) && _GLIBCXX_FORMAT_F128 != 1
> + // Reuse __formatter_fp<C>::format<__format::_flt128_t, Out> for
> __float128.
> + // This formatter is not declared if _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
> is true,
> + // as __float128 when present is same type as __ieee128, which may be
> same as
> + // long double.
> + template<__format::__char _CharT>
> + struct formatter<__float128, _CharT>
> + {
> + formatter() = default;
> +
> + [[__gnu__::__always_inline__]]
> + constexpr typename basic_format_parse_context<_CharT>::iterator
> + parse(basic_format_parse_context<_CharT>& __pc)
> + { return _M_f.parse(__pc); }
> +
> + template<typename _Out>
> + typename basic_format_context<_Out, _CharT>::iterator
> + format(__float128 __u, basic_format_context<_Out, _CharT>& __fc)
> const
> + { return _M_f.format((__format::__flt128_t)__u, __fc); }
>
> private:
> __format::__formatter_fp<_CharT> _M_f;
> +
> + static_assert( !is_same_v<__float128, long double>,
> + "This specialization should not be used for long
> double" );
> };
> #endif
>
> #if defined(__STDCPP_BFLOAT16_T__) &&
> defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> // Reuse __formatter_fp<C>::format<float, Out> for bfloat16_t.
> template<__format::__char _CharT>
> - struct formatter<__gnu_cxx::__bfloat16_t, _CharT>
> + struct formatter<__format::__bflt16_t, _CharT>
> {
> formatter() = default;
>
> @@ -3795,16 +3827,14 @@ namespace __format
> enum _Arg_t : unsigned char {
> _Arg_none, _Arg_bool, _Arg_c, _Arg_i, _Arg_u, _Arg_ll, _Arg_ull,
> _Arg_flt, _Arg_dbl, _Arg_ldbl, _Arg_str, _Arg_sv, _Arg_ptr,
> _Arg_handle,
> - _Arg_i128, _Arg_u128,
> - _Arg_bf16, _Arg_f16, _Arg_f32, _Arg_f64, // These are unused.
> + _Arg_i128, _Arg_u128, _Arg_float128,
> + _Arg_bf16, _Arg_f16, _Arg_f32, _Arg_f64,
> + _Arg_max_,
> +
> #ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
> - _Arg_next_value_,
> - _Arg_f128 = _Arg_ldbl,
> - _Arg_ibm128 = _Arg_next_value_,
> -#else
> - _Arg_f128,
> + _Arg_ibm128 = _Arg_ldbl,
> + _Arg_ieee128 = _Arg_float128,
> #endif
> - _Arg_max_
> };
>
> template<typename _Context>
> @@ -3831,6 +3861,12 @@ namespace __format
> double _M_dbl;
> #ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT // No long double if it's
> ambiguous.
> long double _M_ldbl;
> +#else
> + __ibm128 _M_ibm128;
> + __ieee128 _M_ieee128;
> +#endif
> +#ifdef __SIZEOF_FLOAT128__
> + __float128 _M_float128;
> #endif
> const _CharT* _M_str;
> basic_string_view<_CharT> _M_sv;
> @@ -3840,11 +3876,17 @@ namespace __format
> __int128 _M_i128;
> unsigned __int128 _M_u128;
> #endif
> -#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
> - __ieee128 _M_f128;
> - __ibm128 _M_ibm128;
> -#elif _GLIBCXX_FORMAT_F128 == 2
> - __float128_t _M_f128;
> +#ifdef __BFLT16_DIG__
> + __bflt16_t _M_bf16;
> +#endif
> +#ifdef __FLT16_DIG__
> + _Float16 _M_f16;
> +#endif
> +#ifdef __FLT32_DIG__
> + _Float32 _M_f32;
> +#endif
> +#ifdef __FLT64_DIG__
> + _Float64 _M_f64;
> #endif
> };
>
> @@ -3882,10 +3924,14 @@ namespace __format
> else if constexpr (is_same_v<_Tp, long double>)
> return __u._M_ldbl;
> #else
> - else if constexpr (is_same_v<_Tp, __ieee128>)
> - return __u._M_f128;
> else if constexpr (is_same_v<_Tp, __ibm128>)
> return __u._M_ibm128;
> + else if constexpr (is_same_v<_Tp, __ieee128>)
> + return __u._M_ieee128;
> +#endif
> +#ifdef __SIZEOF_FLOAT128__
> + else if constexpr (is_same_v<_Tp, __float128>)
> + return __u._M_float128;
> #endif
> else if constexpr (is_same_v<_Tp, const _CharT*>)
> return __u._M_str;
> @@ -3899,9 +3945,21 @@ namespace __format
> else if constexpr (is_same_v<_Tp, unsigned __int128>)
> return __u._M_u128;
> #endif
> -#if _GLIBCXX_FORMAT_F128 == 2
> - else if constexpr (is_same_v<_Tp, __float128_t>)
> - return __u._M_f128;
> +#ifdef __BFLT16_DIG__
> + else if constexpr (is_same_v<_Tp, __bflt16_t>)
> + return __u._M_bf16;
> +#endif
> +#ifdef __FLT16_DIG__
> + else if constexpr (is_same_v<_Tp, _Float16>)
> + return __u._M_f16;
> +#endif
> +#ifdef __FLT32_DIG__
> + else if constexpr (is_same_v<_Tp, _Float32>)
> + return __u._M_f32;
> +#endif
> +#ifdef __FLT64_DIG__
> + else if constexpr (is_same_v<_Tp, _Float64>)
> + return __u._M_f64;
> #endif
> else if constexpr (derived_from<_Tp, _HandleBase>)
> return static_cast<_Tp&>(__u._M_handle);
> @@ -4080,36 +4138,25 @@ namespace __format
> else if constexpr (is_same_v<_Td, __ieee128>)
> return type_identity<__ieee128>();
> #endif
> -
> -#if defined(__FLT16_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> - else if constexpr (is_same_v<_Td, _Float16>)
> - return type_identity<float>();
> +#if defined(__SIZEOF_FLOAT128__) && _GLIBCXX_FORMAT_F128
> + else if constexpr (is_same_v<_Td, __float128>)
> + return type_identity<__float128>();
> #endif
> -
> -#if defined(__BFLT16_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> - else if constexpr (is_same_v<_Td, decltype(0.0bf16)>)
> - return type_identity<float>();
> +#if defined(__STDCPP_BFLOAT16_T__) &&
> defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> + else if constexpr (is_same_v<_Td, __format::__bflt16_t>)
> + return type_identity<__format::__bflt16_t>();
> +#endif
> +#if defined(__STDCPP_FLOAT16_T__) &&
> defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> + else if constexpr (is_same_v<_Td, _Float16>)
> + return type_identity<_Float16>();
> #endif
> -
> #if defined(__FLT32_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> else if constexpr (is_same_v<_Td, _Float32>)
> - return type_identity<float>();
> + return type_identity<_Float32>();
> #endif
> -
> #if defined(__FLT64_DIG__) && defined(_GLIBCXX_DOUBLE_IS_IEEE_BINARY64)
> else if constexpr (is_same_v<_Td, _Float64>)
> - return type_identity<double>();
> -#endif
> -
> -#if _GLIBCXX_FORMAT_F128
> -# if __FLT128_DIG__
> - else if constexpr (is_same_v<_Td, _Float128>)
> - return type_identity<__format::__float128_t>();
> -# endif
> -# if __SIZEOF_FLOAT128__
> - else if constexpr (is_same_v<_Td, __float128>)
> - return type_identity<__format::__float128_t>();
> -# endif
> + return type_identity<_Float64>();
> #endif
> else if constexpr (__is_specialization_of<_Td, basic_string_view>
> || __is_specialization_of<_Td, basic_string>)
> @@ -4165,7 +4212,27 @@ namespace __format
> else if constexpr (is_same_v<_Tp, __ibm128>)
> return _Arg_ibm128;
> else if constexpr (is_same_v<_Tp, __ieee128>)
> - return _Arg_f128;
> + return _Arg_ieee128;
> +#endif
> +#if defined(__SIZEOF_FLOAT128__) && _GLIBCXX_FORMAT_F128
> + else if constexpr (is_same_v<_Tp, __float128>)
> + return _Arg_float128;
> +#endif
> +#if defined(__STDCPP_BFLOAT16_T__) &&
> defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> + else if constexpr (is_same_v<_Tp, __format::__bflt16_t>)
> + return _Arg_bf16;
> +#endif
> +#if defined(__STDCPP_FLOAT16_T__) &&
> defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> + else if constexpr (is_same_v<_Tp, _Float16>)
> + return _Arg_f16;
> +#endif
> +#if defined(__FLT32_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> + else if constexpr (is_same_v<_Tp, _Float32>)
> + return _Arg_f32;
> +#endif
> +#if defined(__FLT64_DIG__) && defined(_GLIBCXX_DOUBLE_IS_IEEE_BINARY64)
> + else if constexpr (is_same_v<_Tp, _Float64>)
> + return _Arg_f64;
> #endif
> else if constexpr (is_same_v<_Tp, const _CharT*>)
> return _Arg_str;
> @@ -4179,11 +4246,6 @@ namespace __format
> else if constexpr (is_same_v<_Tp, unsigned __int128>)
> return _Arg_u128;
> #endif
> -
> -#if _GLIBCXX_FORMAT_F128 == 2
> - else if constexpr (is_same_v<_Tp, __format::__float128_t>)
> - return _Arg_f128;
> -#endif
> else if constexpr (is_same_v<_Tp, handle>)
> return _Arg_handle;
> }
> @@ -4256,13 +4318,33 @@ namespace __format
> #ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
> case _Arg_ldbl:
> return std::forward<_Visitor>(__vis)(_M_val._M_ldbl);
> +#if defined(__SIZEOF_FLOAT128__) && _GLIBCXX_FORMAT_F128
> + case _Arg_float128:
> + return std::forward<_Visitor>(__vis)(_M_val._M_float128);
> +#endif
> #else
> - case _Arg_f128:
> - return std::forward<_Visitor>(__vis)(_M_val._M_f128);
> case _Arg_ibm128:
> return std::forward<_Visitor>(__vis)(_M_val._M_ibm128);
> + case _Arg_ieee128:
> + return std::forward<_Visitor>(__vis)(_M_val._M_ieee128);
> #endif
> +#if defined(__STDCPP_BFLOAT16_T__) &&
> defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> + case _Arg_bf16:
> + return std::forward<_Visitor>(__vis)(_M_val._M_bf16);
> +#endif
> +#if defined(__STDCPP_FLOAT16_T__) &&
> defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> + case _Arg_f16:
> + return std::forward<_Visitor>(__vis)(_M_val._M_f16);
> +#endif
> +#if defined(__FLT32_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
> + case _Arg_f32:
> + return std::forward<_Visitor>(__vis)(_M_val._M_f32);
> #endif
> +#if defined(__FLT64_DIG__) && defined(_GLIBCXX_DOUBLE_IS_IEEE_BINARY64)
> + case _Arg_f64:
> + return std::forward<_Visitor>(__vis)(_M_val._M_f64);
> +#endif
> +#endif // __glibcxx_to_chars
> case _Arg_str:
> return std::forward<_Visitor>(__vis)(_M_val._M_str);
> case _Arg_sv:
> @@ -4280,14 +4362,7 @@ namespace __format
> case _Arg_u128:
> return std::forward<_Visitor>(__vis)(_M_val._M_u128);
> #endif
> -
> -#if _GLIBCXX_FORMAT_F128 == 2
> - case _Arg_f128:
> - return std::forward<_Visitor>(__vis)(_M_val._M_f128);
> -#endif
> -
> default:
> - // _Arg_f16 etc.
> __builtin_unreachable();
> }
> }
> diff --git a/libstdc++-v3/testsuite/std/format/arguments/args.cc
> b/libstdc++-v3/testsuite/std/format/arguments/args.cc
> index 4c50bc74319..60296753919 100644
> --- a/libstdc++-v3/testsuite/std/format/arguments/args.cc
> +++ b/libstdc++-v3/testsuite/std/format/arguments/args.cc
> @@ -164,24 +164,6 @@ void test_visited_as_handle()
> #endif
> }
>
> -template<typename E, typename S>
> -void test_visited_as()
> -{
> - auto v = static_cast<S>(1.0);
> - auto store = std::make_format_args(v);
> - std::format_args args = store;
> -
> - auto is_expected_val = [v](auto arg) {
> - if constexpr (std::is_same_v<decltype(arg), E>)
> - return arg == static_cast<E>(v);
> - return false;
> - };
> - VERIFY( std::visit_format_arg(is_expected_val, args.get(0)) );
> -#if __cpp_lib_format >= 202306L // C++26 adds std::basic_format_arg::visit
> - VERIFY( args.get(0).visit(is_expected_val) );
> -#endif
> -}
> -
> template<typename T>
> concept can_format = std::is_default_constructible_v<std::formatter<T,
> char>>;
>
> @@ -195,30 +177,31 @@ int main()
> test_visited_as_handle<__int128>();
> test_visited_as_handle<unsigned __int128>();
> #endif
> -// TODO: This should be visited as handle.
> -#ifdef __STDCPP_FLOAT16_T__
> - if constexpr (can_format<_Float16>)
> - test_visited_as<float, _Float16>();
> -#endif
> -#ifdef __STDCPP_BFLOAT16_T__
> +#ifdef __BFLT16_DIG__
> if constexpr (can_format<__gnu_cxx::__bfloat16_t>)
> - test_visited_as<float, __gnu_cxx::__bfloat16_t>();
> + test_visited_as_handle<__gnu_cxx::__bfloat16_t>();
> +#endif
> +#ifdef __FLT16_DIG__
> + if constexpr (can_format<_Float16>)
> + test_visited_as_handle<_Float16>();
> #endif
> #ifdef __FLT32_DIG__
> if constexpr (can_format<_Float32>)
> - test_visited_as<float, _Float32>();
> + test_visited_as_handle<_Float32>();
> #endif
> #ifdef __FLT64_DIG__
> if constexpr (can_format<_Float64>)
> - test_visited_as<double, _Float64>();
> + test_visited_as_handle<_Float64>();
> #endif
> #ifdef __FLT128_DIG__
> if constexpr (can_format<_Float128>)
> -# ifdef _GLIBCXX_LDOUBLE_IS_IEEE_BINARY128
> - test_visited_as<long double, _Float128>();
> -# else
> test_visited_as_handle<_Float128>();
> -# endif
> +#endif
> +#ifdef __SIZEOF_FLOAT128__
> + // __ieee128 is same type as __float128, and may be long double
> + if constexpr (!std::is_same_v<__float128, long double>)
> + if constexpr (can_format<__float128>)
> + test_visited_as_handle<__float128>();
> #endif
> #ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
> if constexpr (!std::is_same_v<__ieee128, long double>)
> diff --git a/libstdc++-v3/testsuite/std/format/parse_ctx.cc
> b/libstdc++-v3/testsuite/std/format/parse_ctx.cc
> index b5dd7cdba78..adafc58c183 100644
> --- a/libstdc++-v3/testsuite/std/format/parse_ctx.cc
> +++ b/libstdc++-v3/testsuite/std/format/parse_ctx.cc
> @@ -443,6 +443,8 @@ test_custom()
> }
>
> #if __cpp_lib_format >= 202305
> +#include <stdfloat>
> +
> struct X { };
>
> template<>
> @@ -458,13 +460,20 @@ struct std::formatter<X, char>
> if (spec == "int")
> {
> pc.check_dynamic_spec_integral(pc.next_arg_id());
> - integer = true;
> + type = Type::integral;
> }
> else if (spec == "str")
> {
> pc.check_dynamic_spec_string(pc.next_arg_id());
> - integer = false;
> + type = Type::string;
> + }
> + else if (spec == "float")
> + {
> + pc.check_dynamic_spec<float, double, long double>(pc.next_arg_id());
> + type = Type::floating;
> }
> + else if (spec == "other")
> + type = Type::other;
> else
> throw std::format_error("invalid format-spec");
> return pc.begin() + spec.size();
> @@ -474,13 +483,44 @@ struct std::formatter<X, char>
> format(X, std::format_context& c) const
> {
> std::visit_format_arg([this]<typename T>(T) { // { dg-warning
> "deprecated" "" { target c++26 } }
> - if (is_integral_v<T> != this->integer)
> - throw std::format_error("invalid argument type");
> + constexpr bool is_handle
> + =
> std::is_same_v<std::basic_format_arg<std::format_context>::handle, T>;
> + constexpr bool is_integral
> + = std::is_same_v<int, T> || std::is_same_v<unsigned int, T>
> + || is_same_v<long long, T> || std::is_same_v<unsigned long
> long, T>;
> + constexpr bool is_string
> + = std::is_same_v<const char*, T> ||
> std::is_same_v<std::string_view, T>;
> + constexpr bool is_floating
> + = std::is_same_v<float, T> || std::is_same_v<double, T>
> + || std::is_same_v<long double, T>;
> + switch (this->type)
> + {
> + case Type::other:
> + if (is_handle) return;
> + break;
> + case Type::integral:
> + if (is_integral) return;
> + break;
> + case Type::string:
> + if (is_string) return;
> + break;
> + case Type::floating:
> + if (is_floating) return;
> + break;
> + }
> + throw std::format_error("invalid argument type");
> }, c.arg(1));
> return c.out();
> }
> private:
> - bool integer = false;
> + enum class Type
> + {
> + other,
> + integral,
> + string,
> + floating,
> + };
> + Type type = Type::other;
> };
> #endif
>
> @@ -497,6 +537,28 @@ test_dynamic_type_check()
>
> (void) std::format("{:int}", X{}, 42L);
> (void) std::format("{:str}", X{}, "H2G2");
> + (void) std::format("{:float}", X{}, 10.0);
> +
> +#ifdef __STDCPP_FLOAT16_T__
> + if constexpr (std::formattable<std::bfloat16_t, char>)
> + (void) std::format("{:other}", X{}, 10.0bf16);
> +#endif
> +#ifdef __STDCPP_FLOAT16_T__
> + if constexpr (std::formattable<std::float16_t, char>)
> + (void) std::format("{:other}", X{}, 10.0f16);
> +#endif
> +#ifdef __STDCPP_FLOAT32_T__
> + if constexpr (std::formattable<std::float32_t, char>)
> + (void) std::format("{:other}", X{}, 10.0f32);
> +#endif
> +#ifdef __STDCPP_FLOAT64_T__
> + if constexpr (std::formattable<std::float64_t, char>)
> + (void) std::format("{:other}", X{}, 10.0f64);
> +#endif
> +#ifdef __STDCPP_FLOAT128_T__
> + if constexpr (std::formattable<std::float128_t, char>)
> + (void) std::format("{:other}", X{}, 10.0f128);
> +#endif
> #endif
> }
>
> --
> 2.49.0
>
>
