[Libre-soc-bugs] [Bug 238] POWER Compressed Formal Standard writeup

bugzilla-daemon at libre-soc.org bugzilla-daemon at libre-soc.org
Tue Dec 1 00:25:40 GMT 2020


https://bugs.libre-soc.org/show_bug.cgi?id=238

--- Comment #152 from Jacob Lifshay <programmerjake at gmail.com> ---
(In reply to Alexandre Oliva from comment #147)
> in the pseudo code of phase 1, since we're talking about two separate insns,
> it would be desirable to make it explicit whether the Ms, Ns, and extc_id
> that appear there are taken from previ or from nexti.
> 
> I'm also missing code to handle previ.mode == v3.0B_then_16bit.  it's
> particularly important to specify how the conflict is resolved when nexti is
> a 10-bit insn: does the return-to-16-bit direction prevail over the M bit in
> nexti, or vice-versa, or is that conflict to be rejected?

In the example decoder code I wrote and in the compressed encoding demo:
Standard-for-1-then-Compressed Mode has priority over the swap to compressed
bit. I think that option is better for consistency (since
standard-then-compressed can be thought of as an override) though best is
probably trapping on mismatch.

-- 
You are receiving this mail because:
You are on the CC list for the bug.


More information about the libre-soc-bugs mailing list