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From: Richard Henderson <rth@twiddle.net>
Message-ID: <563B215A.5030205@twiddle.net>
Date: Thu, 5 Nov 2015 10:28:58 +0100
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Subject: Re: [Qemu-devel] [PATCH] target-sparc: fix 32-bit truncation in
	fpackfix
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To: Paolo Bonzini <pbonzini@redhat.com>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Peter Maydell <peter.maydell@linaro.org>
Cc: Blue Swirl <blauwirbel@gmail.com>, QEMU Developers <qemu-devel@nongnu.org>

On 11/05/2015 10:25 AM, Paolo Bonzini wrote:
>
>
> On 05/11/2015 10:20, Richard Henderson wrote:
>>
>>>      /* Ugly code */
>>>      int64_t scaled = (uint64_t)(int64_t)src << scale;
>>
>> You mean
>>
>>    int64_t scaled = (int64_t)((uint64_t)src << scale);
>
> No, that also looks like a typo.
>
> I mean:
>
> - unnecessary cast to int64_t to get the sign extension while avoiding
> the impression of a typo

Huh.  This part doesn't seem a typo to me at all.

>
> - cast to uint64_t to avoid overflow
>
> - the shift is done in the uint64_t type
>
> - finally there is an implicit cast to int64_t


r~