Re: [PATCH 1/2] Make cramfs little endian only

["Jörn Engel" <joern@logfs.org>]

On Wed, 5 December 2007 14:21:02 -0800, Linus Torvalds wrote:
> 
> No, no, what I meant about not having any #ifdef __LITTLE_ENDIAN was to do 
> the code do the same thing *regardless* of endianness. In other words, a 
> simple:
> 
> 	struct cramfs_inode {
> 		__le32 mode_uid;	/* CRAMFS_MODE_WIDTH:CRAMFS_UID_WIDTH */
> 		__le32 size_gid;	/* CRAMFS_SIZE_WIDTH:CRAMFS_GID_WIDTH */
> 		__le32 namelen_offset;	/* CRAMFS_NAMELEN_WIDTH:CRAMFS_OFFSET_WIDTH */
> 	};

Mode and uid are both 16bit.  So maybe we can change the structure:

	struct cramfs_inode {
		__le16 uid;
		__le16 mode;
		__le32 size_gid;	/* CRAMFS_SIZE_WIDTH:CRAMFS_GID_WIDTH */
		__le32 namelen_offset;	/* CRAMFS_NAMELEN_WIDTH:CRAMFS_OFFSET_WIDTH */
	};

That way masks and shifts are only needed for the remaining two shared
variables.

> (No, the above is not tested in any way, shape, or form, and no, I didn't 
> double-check that I actually extracted the right bits, but you get the 
> idea).

Same warning applies to my code as well.

Jörn

-- 
Rules of Optimization:
Rule 1: Don't do it.
Rule 2 (for experts only): Don't do it yet.
-- M.A. Jackson
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