[Mesa-dev] [PATCH] ac: fix texture query LOD for 1D textures on GFX9

[Nicolai Hähnle]

On 25.04.2018 16:46, Samuel Pitoiset wrote:
> 
> 
> On 04/25/2018 04:10 PM, Nicolai Hähnle wrote:
>> On 25.04.2018 11:58, Samuel Pitoiset wrote:
>>> 1D textures are allocated as 2D which means we only need
>>> one coordinate for texture query LOD.
>>>
>>> Fixes: 625dcbbc456 ("amd/common: pass address components individually to
>>> ac_build_image_intrinsic")
>>> Cc: 18.1 <mesa-stable at lists.freedesktop.org>
>>> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
>>> ---
>>>   src/amd/common/ac_llvm_build.c | 10 ++++++++++
>>>   1 file changed, 10 insertions(+)
>>>
>>> diff --git a/src/amd/common/ac_llvm_build.c 
>>> b/src/amd/common/ac_llvm_build.c
>>> index f21a5d2623c..be7379f72ef 100644
>>> --- a/src/amd/common/ac_llvm_build.c
>>> +++ b/src/amd/common/ac_llvm_build.c
>>> @@ -1533,6 +1533,16 @@ LLVMValueRef ac_build_image_opcode(struct 
>>> ac_llvm_context *ctx,
>>>           default:
>>>               break;
>>>           }
>>> +
>>> +        /* Fixup for GFX9 which allocates 1D textures as 2D, because at
>>> +         * this point we don't know the orignal sampler dimension.
>>> +         */
>>> +        if (ctx->chip_class >= GFX9) {
>>> +            if ((a->dim == ac_image_2darray ||
>>> +                 a->dim == ac_image_2d) && !a->coords[1]) {
>>> +                num_coords = 1;
>>> +            }
>>> +        }
>>
>> Can we do this fixup in ac_nir_to_llvm instead, please? Pretty sure 
>> that that's needed for correctness anyway: with this change, the 
>> second coordinate will be basically random, which can probably affect 
>> the hardware's LOD even when the texture's height is 1.
> 
> Yes, I can do that, but what should we put in coords[1]? just zero?

Yes, that seems best.

Thanks,
Nicolai


> 
>>
>> Thanks,
>> Nicolai
>>
>>>       }
>>>       if (a->offset)
>>>
>>
>>


-- 
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