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From: Paolo Bonzini <pbonzini@redhat.com>
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Date: Thu, 5 Nov 2015 10:43:34 +0100
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Subject: Re: [Qemu-devel] [PATCH] target-sparc: fix 32-bit truncation in
	fpackfix
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To: Richard Henderson <rth@twiddle.net>, 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 05/11/2015 10:28, Richard Henderson wrote:
> 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.

A cast _is_ obviously necessary, because src is int32_t and the result
is int64_t:

         int32_t src = rs2 >> (word * 32);
         int64_t scaled = (uint64_t)src << scale;

having uint64_t on the RHS and int64_t on the LHS definitely would be a
WTF cause for me.

Paolo