From: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
To: Siddhesh Poyarekar <siddhesh@gotplt.org>,
"libc-alpha@sourceware.org" <libc-alpha@sourceware.org>
Cc: nd <nd@arm.com>
Subject: Re: [PATCH 6/6] Remove slow paths from sin/cos
Date: Tue, 13 Mar 2018 15:29:00 -0000 [thread overview]
Message-ID: <DB6PR0801MB20532683C77AD97228B69FD183D20@DB6PR0801MB2053.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <2a4f8559-9978-42ee-2b8a-df5d7335b425@gotplt.org>
Siddhesh Poyarekar wrote:
> On Monday 12 March 2018 11:01 PM, Wilco Dijkstra wrote:
>> I had lots of issues due to parts of functions being included in sincos.c, so I had to
>> disable sincos during development. The new version is much easier to maintain.
>
> That's subjective; someone half a decade down the line might differ when
> they see bits of code duplicated across files :)
This code won't last half a decade - it should be further simplified and made much faster.
This pattern is repeated 6 times with slight variations. It may be feasible to
merge it all into do_sin:
if (k < 0x3fd00000)
{
xx = x * x;
t = POLYNOMIAL (xx) * (xx * x);
*sinx = x + t;
}
else
*sinx = __copysign (do_sin (x, 0), x);
The other is:
/* |x| < 2.426265. */
y = hp0 - fabs (x);
a = y + hp1;
da = (y - a) + hp1;
That's tiny enough that I don't see an issue.
Wilco
prev parent reply other threads:[~2018-03-13 15:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-09 15:53 Wilco Dijkstra
2018-03-09 16:02 ` Siddhesh Poyarekar
2018-03-12 17:31 ` Wilco Dijkstra
2018-03-13 8:46 ` Siddhesh Poyarekar
2018-03-13 15:29 ` Wilco Dijkstra [this message]
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