Sadly my last SPARC box (ancient Ultra-80) has died but I wonder if you could emulate the architecture. Googling QEMU SPARC resulted in several links. Just a thought.

Possibly try Amiga Forever running Amiga OS4.1?

I presume this for loop is within Perl code after a read of a binary file? You should consider pack() and unpack() to get the data into a Perl binary value (big endian). The right kind of pack() or unpack() is dependent upon the architecture (endianness).

It would be helpful to show some code and a short explanation of why you are accessing the individual bytes of what apparently is a multi-byte integer?
Update: too many bytes for an int.. I guess this is a float? It is quite common for binary values to written with big endian values to disk, etc.

It would be helpful to show some code

Yes, it might have been clearer if I'd phrased the question in terms of pack/unpack.
On my 64-bit little-endian machine (Ubuntu-18.04), running a perl whose NV is the extended precision (80-bit) long double, I get:

$ perl -le 'print unpack "h*", pack "D", sqrt 2;'
4846ed9f333f405bfff3000000000000
[download]

If I ran the identical one-liner on a 64-bit *big-endian* machine,running a perl whose NV is the extended precision (80-bit) long double, where would that substring of 12 consecutive zeroes appear ? Would it still appear at the end of the string (as was the case on my little-endian machine), or would it appear at the beginning ?

I have long-standing C code in Math-MPFR (MPFR.xs) that presumes that the substring in question will appear at the end of the string, irrespective of endianess:

....
  n = bits == 64 ? 10 : 16;
#ifdef MPFR_HAVE_BENDIAN /* Big Endian architecture */
  for (i = 0; i < n; i++) {
#else
  for (i = n - 1; i >= 0; i--) {
#endif
  // code that does something with byte i
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but I don't recall having ever established the correctness of that code for the big-endian case.

If it were incorrect, then the test suite should expose the error - but then I don't know if Math::MPFR has ever been built on a big-endian machine, using a perl whose NV is the 80-bit long double.

Cheers,
Rob

I am not sure that I can help. current Pack docs. I am on Perl 5.24 and it appears to me that you are using a feature from Perl 5.30? This "D" option to pack() appears in red in my browser.

If Perl source code of:

$ perl -le 'print unpack "h*", pack "D", sqrt 2;'
4846ed9f333f405bfff3000000000000
[download]

works? I am also unsure about what will happen on a different architecture. My main machine is Intel (little endian). I have a Raspberry PI which I think is big endian, but I have a lot of hardware cables to screw around with to get it working. Sorry.

D  A float of long-double precision in native format.
         (Long doubles are available only if your system supports
          long double values _and_ if Perl has been compiled to
          support those.  Raises an exception otherwise.
          Note that there are different long double formats.)

h  A hex string (low nybble first).
H  A hex string (high nybble first).
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