[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PULL 03/13] target-ppc: Use 32-bit rotate instead of d

From: Thomas Huth
Subject: Re: [Qemu-devel] [PULL 03/13] target-ppc: Use 32-bit rotate instead of deposit + 64-bit rotate
Date: Mon, 20 Jun 2016 10:21:44 +0200
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0

On 18.06.2016 06:02, Anton Blanchard wrote:
> Hi,
>>>> Bother.  I've tentatively put a revert into ppc-for-2.7.  Richard,
>>>> do you have a better idea how to fix it?    
>>> Please try the following.  
>> Thanks! This passes my tests. Feel free to add:
>> Tested-by: Anton Blanchard <address@hidden>
> Actually I think I've found a problem:
>         lis     r4,address@hidden
>         ori     r4,r4,address@hidden
>         rlwinm  r3,r4,0,25,1
> 32 bit rotate is defined as a 64 bit rotate of 2 copies of the 32 bit
> value, so we expect 0x7fffffff4000007f, but get 0x4000007f.
> Not sure if anything out there depends on it though.

Would it maybe make sense to add some tests for this stuff to the
tests/tcg/ folder to make sure that such regressions do not sneak back
in in the future?


reply via email to

[Prev in Thread] Current Thread [Next in Thread]