Re: Bit Swizzling

From	"John Levine" <johnl@taugh.com>
Newsgroups	comp.arch, comp.compilers
Subject	Re: Bit Swizzling
Date	2020-09-05 18:50 +0000
Organization	Taughannock Networks
Message-ID	<20-09-016@comp.compilers> (permalink)
References	<riumcj$3j9$1@dont-email.me> <rivvah$1neg$2@gioia.aioe.org> <20-09-014@comp.compilers>

Cross-posted to 2 groups.

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In article <rivvah$1neg$2@gioia.aioe.org>,
>> -----
>> Are there any algorithms which take a known-at-compile-time sequence
>> of bitwise operations on an 8-bit to 64-bit quantity, and optimize
>> them down to their minimal set of operations?

>Why not just use a lookup table ?. Minimum ops and fast...

Assuming you're looking for something you can implement in logic
rather than by table lookup, it sounds like a set of Karnaugh maps.

--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

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Bit swizzling "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2020-09-05 12:05 -0400
  Re: Bit swizzling Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2020-09-05 19:38 +0200
  Re: Bit Swizzling "John Levine" <johnl@taugh.com> - 2020-09-05 18:50 +0000
    Re: Bit Swizzling Chris <xxx.syseng.yyy@gfsys.co.uk> - 2020-09-06 17:48 +0100
  Re: Bit swizzling Kaz Kylheku <793-849-0957@kylheku.com> - 2020-09-05 20:15 +0000
  Re: Bit swizzling "davidl...@gmail.com" <davidlovemore@gmail.com> - 2020-09-06 00:31 -0700
  Re: Bit swizzling Martin Ward <martin@gkc.org.uk> - 2020-09-07 12:08 +0100
    Re: Bit swizzling Tom Crick <tomcrick@gmail.com> - 2020-09-08 09:35 +0100
  Re: Bit swizzling "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2020-09-07 10:55 -0400
    Re: Bit swizzling Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2020-09-08 01:45 +0200
  Re: Bit swizzling gah4 <gah4@u.washington.edu> - 2020-09-10 10:34 -0700
    Re: Bit swizzling "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2020-09-10 17:13 -0400

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