From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@quanstro.net>
To: 9fans@cse.psu.edu, geoff@collyer.net
References: <2e567163be1a7bcfb00188625bc09359@collyer.net>
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Subject: Re: [9fans] structure allocation.
Message-Id: <20060307030035.617C311735@dexter-peak.quanstro.net>
Date: Mon,  6 Mar 2006 21:00:35 -0600
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okay.

many things about this interface don't make sense to me.
but it's hard at this point to tell if driver is obfuscated or what.

the space/time tradeoff here seems interesting. is pushing 3 more bytes
over a pci bus really slower than doing the alignment on an ad-hoc basis?

the trouble is these structures go on forever and have many
bitfields. (in one i count 46 fields, all integers of random width,
randomly intermixed.)

- erik

geoff@collyer.net writes

|
| You declare it like this:
|
| typedef struct {
| 	char	f;
| 	uchar	l[4];
| 	char	g;
| 	uchar	m[4];
| } Dac960fu;
|
| and convert l and m using the usual integer-to-bytes and
| bytes-to-integers macros or functions, presumably the little-endian
| versions.  Mylex were crazy to lay the data out this way.