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| author | Jakub Jelinek <jakub@redhat.com> | 2022-11-02 13:35:53 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2022-11-02 13:35:53 +0100 |
| commit | 0c86a667486362e8bc6a92e5d36acaac4242c59f (patch) | |
| tree | d7fd16e72b857d6cff207befab72a718cc3cdb5d | |
| parent | c3299cde4f33121f82a7a25d10c152ac96d2b035 (diff) | |
| download | gcc-0c86a667486362e8bc6a92e5d36acaac4242c59f.zip gcc-0c86a667486362e8bc6a92e5d36acaac4242c59f.tar.gz gcc-0c86a667486362e8bc6a92e5d36acaac4242c59f.tar.bz2 | |
libstdc++: _Bfloat16 for <compare>
Jon pointed out that we have TODO: _Bfloat16 in <compare>.
Right now _S_fp_fmt() returns _Binary16 for _Float16, __fp16 as well
as __bf16 and it actually works because we don't have a special handling
of _Binary16. So, either we could just document that, but I'm a little bit
afraid if HPPA or MIPS don't start supporting _Float16 and/or __bf16.
If they do, we have the
#if defined __hppa__ || (defined __mips__ && !defined __mips_nan2008)
// IEEE 754-1985 allowed the meaning of the quiet/signaling
// bit to be reversed. Flip that to give desired ordering.
if (__builtin_isnan(__x) && __builtin_isnan(__y))
{
using _Int = decltype(__ix);
constexpr int __nantype = __fmt == _Binary32 ? 22
: __fmt == _Binary64 ? 51
: __fmt == _Binary128 ? 111
: -1;
constexpr _Int __bit = _Int(1) << __nantype;
__ix ^= __bit;
__iy ^= __bit;
}
#endif
code, the only one where we actually care whether something is
_Binary{32,64,128} (elsewhere we just care about the x86 and m68k 80bits
or double double or just floating point type's sizeof) and we'd need
to handle there _Binary16 and/or _Bfloat16.
So this patch uses different enum for it even when it isn't needed right
now, after all _Binary16 isn't needed either and we could just use
_Binary32...
2022-11-02 Jakub Jelinek <jakub@redhat.com>
* libsupc++/compare (_Strong_order::_Fp_fmt): Add _Bfloat16.
(_Strong_order::_Bfloat16): New static data member.
(_Strong_order::_S_fp_fmt): Return _Bfloat16 for std::bfloat16_t.
| -rw-r--r-- | libstdc++-v3/libsupc++/compare | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/libstdc++-v3/libsupc++/compare b/libstdc++-v3/libsupc++/compare index 066867e..e25f4ef 100644 --- a/libstdc++-v3/libsupc++/compare +++ b/libstdc++-v3/libsupc++/compare @@ -672,7 +672,7 @@ namespace std _GLIBCXX_VISIBILITY(default) _X86_80bit, // x86 80-bit extended precision _M68k_80bit, // m68k 80-bit extended precision _Dbldbl, // IBM 128-bit double-double - // TODO: _Bfloat16, + _Bfloat16, // std::bfloat16_t }; #ifndef __cpp_using_enum @@ -684,6 +684,7 @@ namespace std _GLIBCXX_VISIBILITY(default) static constexpr _Fp_fmt _X86_80bit = _Fp_fmt::_X86_80bit; static constexpr _Fp_fmt _M68k_80bit = _Fp_fmt::_M68k_80bit; static constexpr _Fp_fmt _Dbldbl = _Fp_fmt::_Dbldbl; + static constexpr _Fp_fmt _Bfloat16 = _Fp_fmt::_Bfloat16; #endif // Identify the format used by a floating-point type. @@ -714,6 +715,10 @@ namespace std _GLIBCXX_VISIBILITY(default) if constexpr (__is_same(_Tp, __float80)) return _X86_80bit; #endif +#ifdef __STDCPP_BFLOAT16_T__ + if constexpr (__is_same(_Tp, decltype(0.0bf16))) + return _Bfloat16; +#endif constexpr int __width = sizeof(_Tp) * __CHAR_BIT__; |