and IEEE S and T floating datum loads and stores. VAX floating data
types not yet supported, and in the future will only be supported if
FIX_UNALIGNED_VAX_FP is defined. (No point in wasting the space when
most of the time there will never be VAX FP loads and stores.) Right
now, these features can be controlled only by sysctl. The (boolean)
integer sysctls machdep.unaligned_print, machdep.unaligned_fix, and
machdep.unaligned_sigbus control printing about unaligned accesses
(defaults on), fixing up of unaligned accesses (defaults on), and
forcing a SIGBUS on unaligned accesses (defaults off). If an access
is not fixed up (for lack of method or explicit decision), a SIGBUS is
always generated to keep programs from using bogus data. At some point,
these three choices should be controlled by per-process flags, as well.
containing a substruct (the hardware frame) and an array of registers,
treat it like one big array of registers, for easier and prettier
access. Update everything to deal with that.
thorpej