From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@labs.coraid.com>
Date: Wed, 16 Jun 2010 11:26:55 -0400
To: maht-9fans@maht0x0r.net, 9fans@9fans.net
Message-ID: <9013d88b6219f01a48b8fee28a2b5d6c@coraid.com>
In-Reply-To: <4C18D1D8.2060301@maht0x0r.net>
References: <AANLkTinYjxYQEDBK5u2kohjRwdZA-wIB9hK8nVVnITuV@mail.gmail.com>
	<4C18D1D8.2060301@maht0x0r.net>
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Subject: Re: [9fans] portability question
Topicbox-Message-UUID: 345adb16-ead6-11e9-9d60-3106f5b1d025

> check the ASM, looks like c is being cast as signed and then sign
> extended into a long and then ORed with l.
>
> perhaps this would solve it :
>
> l |= ((unsigned long) c) << 24

that works.  the extra () are unnecessary.

i think that gcc is using 6.3.1.1 and converting
c to an int (since it fits) so the original expression
is evaulated as
	(int)0xab << (int)24
	-> (int)0xab000000
if there is any sign extension here, it is shifted
away.  then gcc sign-extends this into 8 bytes,
giving the value you see.

- erik