https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81193
Bug ID: 81193 Summary: PowerPC GCC __builtin_cpu_is and __builtin_cpu_supports should warn about old libraries Product: gcc Version: 8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: meissner at gcc dot gnu.org Target Milestone: --- If GCC is configured with a new glibc, it supports the __builtin_cpu_is and __builtin_cpu_supports built-in functions. However, if GCC is configured with an old glibc, the various __builtin_cpu* functions just return 0. GCC should do either: 1) Warn that __builtin_cpu_is/__builtin_cpu_supports is not supported; (or) 2) It should call getauxval and check the HWCAP/HWCAP2 bits directly. Perhaps there should be a helper function in libgcc that stands the built-in calls and the code generated for the built-in functions.