From: André Hentschel <nerv@dawncrow.de>
Subject: Re: krnl386.exe16: Avoid shift overflows in DMA_ioport_in.
Message-Id: <55E35328.9060700@dawncrow.de>
Date: Sun, 30 Aug 2015 21:02:00 +0200

Am 29.08.2015 um 22:51 schrieb Gerald Pfeifer:
> Use 0xFFu isntead 0xFF to indicate we are looking at an unsigned
> value/constant.
> 
> Gerald
> ---

I think the change in gcc origins in the fact that there are different shift implementations which vary across cpu architecture.
Personally I have ARM in mind which shifts different from x86, so I highly value your work on it.