Re: Concertlina II: Full Circle

On Tue, 18 Jun 2024 23:57:54 +0000, mitchalsup@aol.com (MitchAlsup1)
wrote:

John Savard wrote:

And so you indicate this explicitly in VVM as well. I tended to assume
only a limited number of registers would be needed to live in, plus I
have both floating and integer register files, hence the differences.

>
It ends up that the majority of register uses in a loop do not need to
be visible outside of the loop. This is almost the contrapositive of
annotating which registers are temporary in the loop. 90%+ of loops do
not even need the index register to be live outside of the loop.
>

You have convinced me here to learn from your wisdom: I will do two
things. One is to add a bit that decides whether my 1 bits (confined
to a single group of 8 registers) are live-in or live-out bits. The
other is to specify clearly to implementors that if a register is
specified as "live-in" but is never actually used in a loop, this must
not cause any problems.

John Savard