From: Duy Nguyen <pclouds@gmail.com>
Date: Thu, 31 Dec 2015 05:10:33 GMT
Subject: Re: [PATCH 1/2] avoid shifting signed integers 31 bits
Message-ID: <CACsJy8CAAqZFQCfadUov7DFhSgh=dtGfE-onbXZQXO-0Y2652g@mail.gmail.com>
In-Reply-To: <20151229063545.GA30340@sigill.intra.peff.net>

On Tue, Dec 29, 2015 at 1:35 PM, Jeff King <peff@peff.net> wrote:
> We sometimes use 32-bit unsigned integers as bit-fields.
> It's fine to access the MSB, because it's unsigned. However,
> doing so as "1 << 31" is wrong, because the constant "1" is
> a signed int, and we shift into the sign bit, causing
> undefined behavior.
>
> We can fix this by using "1U" as the constant.

We have this in cache.h, should it be fixed as well?

/* CE_EXTENDED2 is for future extension */
#define CE_EXTENDED2         (1 << 31)
-- 
Duy