gcc 1.36 on Next / NextStep 2.1 with flags '-g' / '-g -fomit_frame_pointer' :
  The calculated offset to a6 for parameter access in free_svalue() is wrong.
  Symptom: mud crashes early.
  Makeshift solution: use '-O -fomit-frame-pointer'
gcc 2.2.2 , when told to optimize interpret.c , usually dies with a segv
  or currupted internal data structures in cc1.
gcc 2.3.3 , when told to optimize lex.c , will garble the code for #include.
  Symptom: load_object will fail when #include is used, saying it can't
  #include the file.
gcc 2.x on 680x0 hardware: the large interpret.c switch table is built with
  unsigned short words, but is processed like signed short words.
  The special thing about 680x0 is that the switch in interpret.c is
  shorter than 64 KB.
  Symptoms: when LPC instructions are to be executed the code to which
  lies beyond the first 32 KB of the switch(), there is weird behaviour,
  a C-level illegal intruction or a crash with undetermined, although most
  times quite short, latency.
  Makeshift solution: fix the assembler code in interpret.s to handle
  unsigned short offsets.