https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87498
--- Comment #1 from Miro Kropacek <miro.kropacek at gmail dot com> --- > For x86_64's gmp, host is passed as "none-pc-linux-gnu", thus disabling > assembly and passing -DNO_ASM to CFLAGS from gmp's configure (making the > toplevel AM_CFLAGS useless). I must correct myself here - the fact gmp's CFLAGS contain -DNO_ASM means nothing here as CFLAGS is overriden by AM_CFLAGS. So the question / issue remains why AM_CFLAGS always pass -DNO_ASM but in m68k case do not use "none" as the host.