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

David Miller davem at davemloft.net
Sat Mar 30 03:14:05 CET 2013

From: Torbjorn Granlund <tg at gmplib.org>
Date: Sat, 30 Mar 2013 03:11:56 +0100

> David Miller <davem at davemloft.net> writes:
>   Looks good, and here is my lshiftc:
>   	add	up, -8, up
>   	srlx	u1, tcnt, %l4
>   	andn	%l3, %l4, r0
>   	stx	r0, [rp + 0]
>   	bnz,pt	%xcc, L(loop0)
>   	 sllx	u1, cnt, %l3
> I'd claim that branch is taken with probability 0, so the "pt" moniker
> is an exaggeration.  :-)
> Good performance again!  It matches my http://gmplib.org/devel/asm.html
> predictions...

Great.  Let's sort out the strange hang behavior I get with your code.

I think it's rshift.  I actually happened to be working on rshift when
you sent your combined code, and I also get strange hangs with my
rshift too.

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