https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94249
--- Comment #11 from John David Anglin <danglin at gcc dot gnu.org> --- On hppa-linux, we have: #define __BIG_ENDIAN 4321 /* hppa1.1 big-endian. */ #ifndef _ENDIAN_H # error "Never use <bits/endian.h> directly; include <endian.h> instead." #endif #define __BYTE_ORDER __BIG_ENDIAN I don't see a define for __BIG_ENDIAN__.