This has broken building the mainline glibc testsuite with GCC mainline for platforms where long double has binary128 format.
Recall that _FloatN type names are not supported for C++, because of the expectation that any C++ bindings for such types would be class-based like the TR 24733 DFP support rather than using built-in types such as _Float128. Thus glibc uses __float128 to define _Float128 internally for C++ where __float128 is available, but where it is not available but long double has that format, the headers use long double to implement _Float128. Thus you get conflicting declarations, headers declaring sqrtf128 to use a typedef for long double but the built-in functions using the internal _Float128 type that has no built-in name referring directly to it for C++. One obvious possible fix would be for the builtins.def macros never to define public names such as sqrtf128 for C++, only ever for C. That would be on the basis that C++ code is expected to be using a sqrt overload anyway - so making the built-in function available under a public name, in the case where __float128 exists for C++, is a matter for libstdc++ headers. -- Joseph S. Myers jos...@codesourcery.com
