jwakely added inline comments.
================ Comment at: clang/lib/Parse/ParseExprCXX.cpp:2245 + case tok::kw___ibm128: + DS.SetTypeSpecType(DeclSpec::TST_ibm128, Loc, PrevSpec, DiagID, Policy); + break; ---------------- hubert.reinterpretcast wrote: > qiucf wrote: > > hubert.reinterpretcast wrote: > > > qiucf wrote: > > > > hubert.reinterpretcast wrote: > > > > > Not sure what the best method is to implement this, but `long double` > > > > > and `__ibm128` are the same type for GCC when `-mabi=ibmlongdouble` > > > > > is in effect. > > > > Seems clang is also different from GCC under `-mabi=ieeelongdouble`? I > > > > saw `__float128` and `long double` are the same for GCC but not for > > > > clang. > > > Have you checked whether the new libstdc++ for which this support is > > > being added needs the GCC behaviour to work properly? > > > > > > The GCC behaviour allows the following to be compiled without introducing > > > novel overload resolution tiebreakers: > > > ``` > > > void f(__float128); > > > void f(__ibm128); > > > void f(int); > > > > > > long double ld; > > > > > > int main() { f(ld); } > > > ``` > > As I saw both GCC and clang have error for ambiguous `operator<<` for: > > > > ``` > > std::cout << "long double:\n"; > > std::cout << std::numeric_limits<long double>::max() << std::endl; > > std::cout << std::numeric_limits<long double>::min() << std::endl; > > > > std::cout << "__float128:\n"; > > std::cout << std::numeric_limits<__float128>::max() << std::endl; > > std::cout << std::numeric_limits<__float128>::min() << std::endl; > > > > std::cout << "__ibm128:\n"; > > std::cout << std::numeric_limits<__ibm128>::max() << std::endl; > > std::cout << std::numeric_limits<__ibm128>::min() << std::endl; > > ``` > @jwakely, are the overload resolution errors expected? @qiucf, are you sure > you have a sufficiently new libstdc++? > @jwakely, are the overload resolution errors expected? Yes. Iostreams support `long double` but not `__float128`, unless that happens to be the same type as `long double` (due to a `-mabi=ieeelongdouble` option). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D93377/new/ https://reviews.llvm.org/D93377 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits