From: Alinabi <alexander.the.average@gmail.com>
Subject: Re: sub-optimal code for packed boolean arrays -- bug or inherent limitation
Date: Tue, 03 Jul 2007 18:17:42 -0000
Date: 2007-07-03T18:17:42+00:00 [thread overview]
Message-ID: <1183486662.806585.71680@q69g2000hsb.googlegroups.com> (raw)
In-Reply-To: <1183486195.764567.297420@k29g2000hsd.googlegroups.com>
One more thing: some inline assembly is unavoidable. There are two
other bitboard operations that are required: First_One(Bitboard_T)
returns Natural and Last_One(Bitboard_T) returns Natural; They return
the position of the least significant and most significant set bit
respectively. On x86 processors you can do this with one instruction
BSF (bit scan forward) and BSR (bit scan reverse), and you cannot
expect a compiler to generate them.
next prev parent reply other threads:[~2007-07-03 18:17 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-02 19:34 sub-optimal code for packed boolean arrays -- bug or inherent limitation Alinabi
2007-07-02 20:08 ` Ludovic Brenta
2007-07-03 1:01 ` Jeffrey R. Carter
2007-07-03 7:22 ` Harald Korneliussen
2007-07-03 8:37 ` Georg Bauhaus
2007-07-03 7:59 ` gautier_niouzes
2007-07-03 9:25 ` Stefan Lucks
2007-07-03 12:40 ` Stefan Lucks
2007-07-03 15:42 ` Adam Beneschan
2007-07-03 18:04 ` Alinabi
2007-07-03 18:09 ` Alinabi
2007-07-03 18:17 ` Alinabi [this message]
2007-07-10 2:06 ` Randy Brukardt
2007-07-03 18:36 ` Jeffrey R. Carter
2007-07-03 19:42 ` Alinabi
2007-07-04 1:12 ` Jeffrey R. Carter
2007-07-04 10:15 ` Jeffrey Creem
2007-07-04 18:28 ` Jeffrey R. Carter
2007-07-04 3:22 ` Steve
2007-07-04 6:31 ` Harald Korneliussen
2007-07-08 22:53 ` Robert A Duff
2007-07-09 6:09 ` tmoran
2007-07-04 9:00 ` Jean-Pierre Rosen
2007-07-04 18:27 ` tmoran
2007-07-04 19:16 ` Pascal Obry
2007-07-05 1:45 ` tmoran
2007-07-05 4:53 ` Jeffrey R. Carter
2007-07-04 18:51 ` tmoran
2007-07-08 22:58 ` Robert A Duff
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