From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ben Rosenberg <scdlbx@gmail.com>
Subject: Re: Help on bit operation
Date: Fri, 28 Aug 2009 12:58:00 -0700
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To: Randi Botse <nightdecoder@gmail.com>
Cc: linux-c-programming@vger.kernel.org

On Fri, Aug 28, 2009 at 11:40 AM, Randi Botse<nightdecoder@gmail.com> w=
rote:
> Ben, after assign all bitfield struct member, how to pack them to be =
a
> 32bit integer value?
>
> DEC =A0 =A0 =A0BIN
> 43 =A0 =A0 =A0 =A0101011 =A0 =A0 =A0 =A0-> foo.a (6 bit)
> 11 =A0 =A0 =A0 =A01011 =A0 =A0 =A0 =A0 =A0 =A0-> foo.b (4 bit)
> 120 =A0 =A0 =A001111000 =A0 =A0-> foo.c (8 bit)
> 30 =A0 =A0 =A0 =A011110 =A0 =A0 =A0 =A0 =A0-> foo.d (5 bit)
> 418 =A0 =A0 =A0110100010 =A0-> foo.e (9 bit)
>
> the bit pattern is : 10101110110111100011110110100010 or 2933800354 i=
n
> decimal, is this possible?
>
> while with masking and shift i can pack them with:
> ((foo.a & 0x3f) << 26) | ((foo.b & 0xf) << 22) | ((foo,c & 0xff) <<
> 14) | ((foo.d & 0x1f) << 9) | (foo.e & 0x1ff)
>
>

The bitfield struct is already packed, you don't need to do anything
else. Just assign values to the different parts.

Ben
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