| Re: [eigen] State of eigen support for small integers(16 bit, signed/unsigned) |
[ Thread Index |
Date Index
| More lists.tuxfamily.org/eigen Archives
]
- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] State of eigen support for small integers(16 bit, signed/unsigned)
- From: Rohit Garg <rpg.314@xxxxxxxxx>
- Date: Fri, 21 Aug 2009 18:59:03 +0530
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=uHhW//k/+PRFPKsP7wvjFH4oiKfMFB6u/9ZD1A7jfI8=; b=RZ/JMNCgMVDYhn28x9SJsWW21NTbMJsSVJuIgjjwDH6Gb5ygUPuZE9oGQXj3TESkMn 6sEdIvlq6KBNBHl74/QYRY5INltMoHBSE4cw3JpuhxX9IP+jglXMJIUenApytP8f4hXq Nb8y1L+hpABeql/j0PNePJpmzAlo95eX78prs=
- Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=Sow0VMt5avrVAB8JU5ZBtIjDv3IL3JCkdVPwqIYf3eE881QDNQYli3OnlJ/JoYkxAH 0HA1Nc/vHqbDmsKW/lwvvQ1mcKOMsGck7PdBuH/rinsnpdR7vNFbF7iG6JP7tx23yQBs ArJ/IYAj8DxoSqooYriZIvTPEDSQd9bvitfqA=
On Fri, Aug 21, 2009 at 1:38 AM, Benoit Jacob<jacob.benoit.1@xxxxxxxxx> wrote:
> OK, let me try to put all my answers in 1 mail:
Thanks. This mail was really helpful.
The problem with bit shifts is there can be two type of bit shifts.
a) scalar bit shift. All elements are shifted by the same amount in
the same direction and manner. So the second operand is a scalar.
b) vector bit shift. All elements are shifted by different amounts, as
specified using another vector. So the second operand is a matrix of
the same size.
AFAIK, using SSEx, there is no way of doing (b). The best you can do
is by looping over scalars. I am interested in (a), which is supported
by SSE2. .cwise() always takes a matrix/vector parameter, afaik. So I
suppose, doing this will be more like abs() than cwise().mul().
--
Rohit Garg
http://rpg-314.blogspot.com/
Senior Undergraduate
Department of Physics
Indian Institute of Technology
Bombay