https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71806
Bug ID: 71806 Summary: PowerPC -mcpu=power9 enables __float128 without an explicit -mfloat128 Product: gcc Version: 6.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: meissner at gcc dot gnu.org Target Milestone: --- The macro ISA_3_0_MASKS_SERVER includes OPTION_MASK_FLOAT128_HW, which enables the -mfloat128 option. The -mfloat128 option being on by default means that some of the libraries (libstdc++, libquadmath, etc.) will add code for IEEE 128-bit floating point. Until all of the libraries are updated to support IEEE 128-bit, the -mcpu=power9 support should not enable IEEE 128-bit floating point support (either hardware or software). In addition, if you configure the compiler with the --with-cpu=power9 option, it should not enable IEEE 128-bit floating point support by default. If the user uses -mcpu=power9 -mfloat128, it should enable the hardware support that is available in ISA 3.0.