cgen-dis.in

[Patrick Macdonald]

Comrades,

Starting from scratch... think of yesterday as my first day.

Doug, you are correct, this conditional inside print_insn () is 
causing me pain.  

  if (CGEN_INSN_BITSIZE (insn) > cd->base_insn_bitsize &&
      (CGEN_INSN_BITSIZE (insn) / 8) <= sizeof (unsigned long)) 
   {
     read in 32 bits;
     extract information;
   }
  else
    extract information;

The patch that I provided solved my problem but I was requested to
keep looking for a better solution (perhaps off the 'else' branch).
I'm trying to get a handle on what a better solution encompasses.

Just getting to the 'else' branch, as requested, is not straight
forward.  One problem is that the instructions in question satisfy 
the if conditional.  I could add a condition such that only big endian
insns get through but that's kind of bogus besides probably being
blatantly wrong.       

Just to refresh your memory:  I have an ISA with a 16 bit base insn
bitsize, little endian.  Several instructions have an instruction length
of 32 (16 bit instruction + 16 bit immediate).  If I had an instruction,
0xabcd, and an immediate 0x1234, it's written to the obj as cdab 3412.
The 16 bit instruction is read in, 0xabcd, but then hits this conditional
as:  if (32 > 16 && 32/8 <= 4).  So... this is true.  The instruction is
reread as a 32 bit, little endian instruction which returns 0x1234abcd.
This is why I had to flip the hi/lo bytes.  If this had of been a big
endian target, all would be well.  This is probably why we have not been
stung by this before.

So, where does this leave me?  Well, I need help to fix this problem.  The
help of people in the know.  My cgen internal knowledge is minimal and having
me hack here and there without direction is a waste of time.  Yeah, I could
hunker down for weeks and attempt to bring myself up to your gentlefellows
level, but that's not realistic.  Guidance is requested and required.

Thanks,
Patrick