imcc code generation problem

[Nick Glencross]

Guys,

I'll log a bug for this if need be, but I'd rather solve the problem myself 
(with some help). I'm in the middle of writing a routine (MD5 hashing for 
fun), and stumbled upon the following code generation problem in imcc.

In the attached code, I've got

     $I10 = word & 0x000000ff
     $I11 = word & 0x0000ff00
     $I12 = word & 0x00ff0000
     $I13 = word & 0xff000000
and the resulting code becomes

        band I17, I16, 0x000000ff
        band I17, I16, 0x0000ff00
        band I17, I16, 0x00ff0000
        band I16, I16, 0xff000000
Although $I10 to $I13 are all temps that are never used, I16 seems to become 
corrupted.

Can anyone shed some light on the area that I should be looking at; I 
guessing that it's to do with the code paths confusing things, or simply 
that the values are never used. Actually using $I13 seems to fix the problem 
(e.g. print $I13).

Some hints (such as deciphering parrot -d 8) would be appreciated,

Regards,

Nick Glencross
# Snip ...
.sub _md5_create_buffer

    .param string str
    .param Array  buffer
    .param int endian

     .local int counter
     .local int subcounter
     .local int slow_counter

     .local int word

     $I0 = length str
     $I1 = $I0 / 64
     $I2 = $I0 % 64

     $I3 = 64 * $I1
     $I4 = $I3 / 4

     buffer = $I4

     word = 0

     counter      = 0
     subcounter   = 0
     slow_counter = 0

md5_create_buffer_loop:     

     if counter >= $I3 goto md5_create_buffer_break

     $I5 = counter + subcounter
     $S0 = str[$I5]
     $I4 = ord $S0

     word = word << 8
     word = word | $I4

     subcounter = subcounter + 1

     if subcounter != 4 goto md5_create_buffer_loop

     if endian goto endian_ok

     $I10 = word & 0x000000ff
     $I11 = word & 0x0000ff00
     $I12 = word & 0x00ff0000
     $I13 = word & 0xff000000

     # Some code snipped

endian_ok:

     buffer[slow_counter] = word

     counter      = counter + 4
     subcounter   = 0
     slow_counter = slow_counter + 1

     goto md5_create_buffer_loop

md5_create_buffer_break:

    .return 0
.end

# Snip ...