[Mesa-dev] [PATCH] i965: Extend the negative 32-bit deltas to 64-bits

[Sergii Romantsov]

Hello Chris and Emil.
Could we make a final decision? Because I'm bit confused what you are
expecting exactly.

I would prefer to left initial patch as is (if its possible).

On Tue, Mar 27, 2018 at 9:20 AM, Sergii Romantsov <
sergii.romantsov at gmail.com> wrote:

> Hello Stuart,
> Nice to hear.
> And thanks for your time and contribution.
>
> On Tue, Mar 27, 2018 at 8:40 AM, Stuart Young <cefiar at gmail.com> wrote:
>
>> Hi Sergii,
>>
>> I built this into mesa 17.3.7 and it seems to solve all the issues I've
>> seen that were mentioned in 101408.
>>
>> This includes not just the issues with the Mortar, but the other visual
>> artefacts that I've noticed with the player models and with other weapons
>> in the game.
>>
>> Many thanks for digging into this.
>>
>>
>> On 26 March 2018 at 23:22, Sergii Romantsov <
>> sergii.romantsov at globallogic.com> wrote:
>>
>>> Hello, Stuart.
>>> Could You, please, test this patch?
>>>
>>> On Mon, Mar 26, 2018 at 3:16 PM, Sergii Romantsov <
>>> sergii.romantsov at gmail.com> wrote:
>>>
>>>> Negative deltas are used to fake a range in a large buffer.
>>>> See 900a5c91eeb3
>>>> "i965: Use negative relocation deltas to minimise vertex uploads"
>>>>
>>>> Gen8+ use 48-bit address relocations so need to extend the sign
>>>> to 64-bit return value. Without it we have higher bits zeroed
>>>> and missing the negavive values.
>>>> Haswell and older use 32-bit deltas so are unaffected by this issue.
>>>>
>>>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101408
>>>> Signed-off-by: Sergii Romantsov <sergii.romantsov at globallogic.com>
>>>> Tested-by: Andriy Khulap <andriy.khulap at globallogic.com>
>>>> ---
>>>>  src/mesa/drivers/dri/i965/intel_batchbuffer.c | 4 +++-
>>>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/src/mesa/drivers/dri/i965/intel_batchbuffer.c
>>>> b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
>>>> index d824ff2..128da77 100644
>>>> --- a/src/mesa/drivers/dri/i965/intel_batchbuffer.c
>>>> +++ b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
>>>> @@ -1124,8 +1124,10 @@ emit_reloc(struct intel_batchbuffer *batch,
>>>>     /* Using the old buffer offset, write in what the right data would
>>>> be, in
>>>>      * case the buffer doesn't move and we can short-circuit the
>>>> relocation
>>>>      * processing in the kernel
>>>> +    *
>>>> +    * Some target_offsets may be negative, so extend the sign to 64
>>>> bits.
>>>>      */
>>>> -   return entry->offset + target_offset;
>>>> +   return entry->offset + (int64_t)((int32_t)target_offset);
>>>>  }
>>>>
>>>>  uint64_t
>>>> --
>>>> 2.7.4
>>>>
>>>> _______________________________________________
>>>> mesa-dev mailing list
>>>> mesa-dev at lists.freedesktop.org
>>>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>>>
>>>
>>>
>>>
>>> --
>>> Sergii Romantsov
>>> GlobalLogic Inc.
>>> www.globallogic.com
>>>
>>
>>
>>
>> --
>> Stuart Young (aka Cefiar)
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20180327/6e578b60/attachment.html>