https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105417
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- >From what I can see, the --with-long-double-format=ibm libstdc++.a has following _M_extract_int symbols (for simplicity only listing Ij symbols, I[lmtxy] are present/absent next to it: compatibility-ldbl-alt128.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ieee1287num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intIjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ 0000000000000000 W _ZNKSt17__gnu_cxx_ieee1287num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intIjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ cxx11-locale-inst.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ldbl1287num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intB5cxx11IjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ cxx11-wlocale-inst.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ldbl1287num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intB5cxx11IjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ locale-inst.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ldbl1287num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intIjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ 0000000000000000 W _ZNKSt7num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intIjEES3_S3_S3_RSt8ios_baseRSt12_Ios_IostateRT_ wlocale-inst.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ldbl1287num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intIjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ 0000000000000000 W _ZNKSt7num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intIjEES3_S3_S3_RSt8ios_baseRSt12_Ios_IostateRT_ while --with-long-double-format=ieee libstdc++.a has: compatibility-ldbl-alt128.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ldbl1287num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intIjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ 0000000000000000 W _ZNKSt17__gnu_cxx_ldbl1287num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intIjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ 0000000000000000 W _ZNKSt7num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intIjEES3_S3_S3_RSt8ios_baseRSt12_Ios_IostateRT_ 0000000000000000 W _ZNKSt7num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intIjEES3_S3_S3_RSt8ios_baseRSt12_Ios_IostateRT_ cxx11-locale-inst.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ieee1287num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intB5cxx11IjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ cxx11-wlocale-inst.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ieee1287num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intB5cxx11IjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ locale-inst.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ieee1287num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intIjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ wlocale-inst.o: 0000000000000000 W _ZNKSt17__gnu_cxx_ieee1287num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intIjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ Now, the symbols in compatibility-ldbl-alt128.o and {,w}locale-inst.o match between the 2 builds, basically for each narrow and wide we export all of std::num_get, std::__gnu_cxx_ldbl128::num_get and std::__gnu_cxx_ieee128::num_get symbols. But the cxx11 ABI symbols are not. On x86_64, I see we have _ZNKSt7num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intB5cxx11IjEES3_S3_S3_RSt8ios_baseRSt12_Ios_IostateRT_ in cxx11-locale-inst.o and _ZNKSt7num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intB5cxx11IjEES3_S3_S3_RSt8ios_baseRSt12_Ios_IostateRT_ in cxx11-wlocale-inst.o, but we don't export those, similarly we don't export those _ZNKSt17__gnu_cxx_ldbl1287num_getIcSt19istreambuf_iteratorIcSt11char_traitsIcEEE14_M_extract_intB5cxx11IjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ and _ZNKSt17__gnu_cxx_ldbl1287num_getIwSt19istreambuf_iteratorIwSt11char_traitsIwEEE14_M_extract_intB5cxx11IjEES4_S4_S4_RSt8ios_baseRSt12_Ios_IostateRT_ on targets which switched long double from double to something wider in the past (including powerpc64*), but we do export the __gnu_cxx_ieee128 ones, which is why we get those extra symbols on --with-long-double-format=ieee builds. Are those cxx11 symbols never needed and so it was a mistake that they've been exported? Or is it an omission that they are not exported?