For powerpc64 and sparc architectures that both have __float128 and 128bit long
double,
the __float128 is same type as long double/__iee128 and already formattable.
Remaining specializaiton make __float128 formattable on x86_64 via _Float128,
however __float128 is now not formattable on x86_32 (-m32) with
-mlong-double-128,
where __float128 is distinct type from long double that is 128bit IEEE.
PR libstdc++/119246
libstdc++-v3/ChangeLog:
* include/std/format (formatter<__float128, _Char_T): Define if
_GLIBCXX_FORMAT_F128 == 2.
---
This patch avoids dealing with cases when long double is 128bit and thus
__float128 may be same as long double (it is same for powerpc and will be for
sparc),
but distinct for x86_32/-mlong-double-128.
This preserve support formatting __float128 on x84_64, where it is formatted
using _Float128.
Tested on x86_64, powerpc64. For format test checked both
-mabi=ibmlongdouble,-mabi=ieeelongdouble.
Rainer Orth confirmed that this also work with his patch adding __float128 for
sparc.
OK for trunk?
libstdc++-v3/include/std/format | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format
index b1823db83bc..d1ca05105f9 100644
--- a/libstdc++-v3/include/std/format
+++ b/libstdc++-v3/include/std/format
@@ -2973,11 +2973,9 @@ namespace __format
};
#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.
+#if defined(__SIZEOF_FLOAT128__) && _GLIBCXX_FORMAT_F128 == 2
+ // Use __formatter_fp<C>::format<__format::__flt128_t, Out> for __float128,
+ // when long double is not 128bit IEEE type.
template<__format::__char _CharT>
struct formatter<__float128, _CharT>
{
@@ -2995,9 +2993,6 @@ namespace __format
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
--
2.49.0
