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Groups > comp.sys.acorn.programmer > #865

Re: Setting & Clearing flags and C/C++ operators...

From Chris Johnson <chrisjohnson+news@spamcop.net>
Subject Re: Setting & Clearing flags and C/C++ operators...
Newsgroups comp.sys.acorn.programmer
Date 2011-10-10 14:34 +0100
Message-ID <522000e1e6chrisjohnson+news@spamcop.net> (permalink)
References <1c3f2663-1631-4eff-86b7-01676ec2eb64@i28g2000yqn.googlegroups.com>
Organization None

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In article
<1c3f2663-1631-4eff-86b7-01676ec2eb64@i28g2000yqn.googlegroups.com>,
   Gazza <usenet@garethlock.com> wrote:
> erstand what they are in C and I think I have most of them
> covered. It's the usage of the tilde that I don't understand and it's
> direct equivalent in BASIC.

The tilde is the bitmap negation operator - 1's become 0, and 0's
become one.

I guess something like  number% AND NOT 3 which would e.g. be used to
word align an address.

3 is %00000000000000000000000000000011 while
~3 is %11111111111111111111111111111100

(I think that's 32 bits above.

-- 
Chris Johnson

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Thread

Setting & Clearing flags and C/C++ operators... Gazza <usenet@garethlock.com> - 2011-10-10 04:58 -0700
  Re: Setting & Clearing flags and C/C++ operators... Chris Johnson <chrisjohnson+news@spamcop.net> - 2011-10-10 14:34 +0100
    Re: Setting & Clearing flags and C/C++ operators... Chris Johnson <chrisjohnson+news@spamcop.net> - 2011-10-10 14:40 +0100

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