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Byte swapping question

Started by Mr Furious Sep 11, 2005 at 11:14 PM 0 replies 450+ views

Original Post

Sep 11, 2005 at 11:14 PM

I've recently been looking into cross platform memory management and was thinking about byte swapping for "endian-ness".


typedef unsigned short u16;

u16 endianSwap16(u16 var)
{
	u16 left  = (((var) & 0xff) << 8);
	u16 right = (((var) >> 8) & 0xff);

	return left | right;
}

My question concerns the "0xff". Why even bother having it? Shouldn't shifting by 8 just push the unwanted bits out of the way anyhow? This seems redundant to me.

MaulingMonkey

Sep 12, 2005 at 1:08 AM

Quote:
Original post by Mr Furious
My question concerns the "0xff". Why even bother having it? Shouldn't shifting by 8 just push the unwanted bits out of the way anyhow? This seems redundant to me.

It's a readability issue I'd say, making clear that they're explicitly moving one byte. Ditto with "(var)" instead of "var", although that's actually counterproductive, IMO.

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