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Re: [Xen-devel] [PATCH] add canonical address checks to HVM

To: Jan Beulich <jbeulich@xxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] add canonical address checks to HVM
From: Keir Fraser <keir@xxxxxxxxxxxxx>
Date: Fri, 01 Dec 2006 10:12:12 +0000
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On 29/11/06 15:05, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote:

> +#ifdef __x86_64__
> +#define IS_CANO_ADDRESS(add) (((long)(add) >> 47) == ((long)(add) >> 63))
> +#else
> +#define IS_CANO_ADDRESS(add) 1
> +#endif
> +

Is there any guarantee that right-shift is signed when using gcc?

How about (int16_t)((add) >> 48) == -(int)(((add) >> 47) & 1) ??

 -- Keir


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