[PATCH] T3/T4 sparc shifts, plus more timings

David Miller davem at davemloft.net
Sun Mar 31 23:22:22 CEST 2013

From: Torbjorn Granlund <tg at gmplib.org>
Date: Sun, 31 Mar 2013 22:57:36 +0200

> David Miller <davem at davemloft.net> writes:
>   I'm going to play around with some things to try and fix this.
>   Interestingly, UltraSPARC-1 and UltraSPARC-2 would not group the
>   final cycle of the loop this way, because of it's requirement that
>   integer operations must occur in the first three instructions of
>   a group.
> But the code might not run well on US1/2 because shift needs to come
> before any other inter artithmetic op.

Unless the other is a condition code setting arithmetic op :-)

Yes, understood.  We have to transpose a few of the shifts with
their neighbouring arithmetic ops in this loop to make it optimal
for Ultra-I/II/IIi

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