If you absolutely need to get at the 32-bit integer value, you can use
union mytype {
{ struct bits {
unsigned int a:6;
unsigned int b:4;
unsigned int c:8;
unsigned int d:5;
unsigned int e:9;
} b;
unsigned int v;
} variable;
then access the bit-fields like
unsigned int x = variable.b.e;
variable.b.a = 3;
x = variable.v;
On 08/28/2009 12:58 -0700, Ben Rosenberg wrote:
>> On Fri, Aug 28, 2009 at 11:40 AM, Randi Botse<nightdecoder@xxxxxxxxx> wrote:
>> > Ben, after assign all bitfield struct member, how to pack them to be a
>> > 32bit integer value?
>> >
>> > DEC BIN
>> > 43 101011 -> foo.a (6 bit)
>> > 11 1011 -> foo.b (4 bit)
>> > 120 01111000 -> foo.c (8 bit)
>> > 30 11110 -> foo.d (5 bit)
>> > 418 110100010 -> foo.e (9 bit)
>> >
>> > the bit pattern is : 10101110110111100011110110100010 or 2933800354 in
>> > 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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End of included message
--
+----------------------+
| Tim Walberg |
| 830 Carriage Dr. |
| Algonquin, IL 60102 |
| twalberg@xxxxxxxxxxx |
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