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

[Samuel Pitoiset]

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?

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