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Bitfields

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Bitfields

Mar 13th, 2008

How does gcc order bitfields on a little-endian machine? Is the first entry the most significant bit or what?

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Re: Bitfields

Mar 13th, 2008

bump

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Re: Bitfields

Mar 13th, 2008

>Is the first entry the most significant bit or what?
IIRC, it's or what.

>bump
Don't bump your threads, it's rude. I mean really, is 30 minutes really that long to wait? It's not like Daniweb is a real-time chat with paid people helping 24/7 or anything.

Last edited by Narue; Mar 13th, 2008 at 5:07 pm.

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Re: Bitfields

Mar 13th, 2008

As for the question?

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Re: Bitfields

Mar 13th, 2008

>As for the question?
Sorry, I guess my joke was too subtle. The answer is "or what". IIRC, when you have the following in gcc, a is the least significant bit:

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struct foo {
  unsigned int a:1;
  unsigned int b:1;
};
struct foo {
  unsigned int a:1;
  unsigned int b:1;
};

Last edited by Narue; Mar 13th, 2008 at 5:39 pm.

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Re: Bitfields

Mar 14th, 2008

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Originally Posted by os.hacker64

How does gcc order bitfields on a little-endian machine? Is the first entry the most significant bit or what?

endianness referrs to byte ordering, not bits. bit ordering is always the same. endianness describes the direction that bytes are stored in increasing memory locations. big-endian means "big end first". little-endian means "little end first"

but really, it all comes down to the fact that the Blefuscudians are stupid fools who ruin perfectly good soft-boiled eggs.

Last edited by jephthah; Mar 14th, 2008 at 3:24 pm.