[Mesa-dev] [PATCH v2] ac/nir: set lod to 0 for ac_image_load_mip

[Nicolai Hähnle]

On 27.04.2018 10:05, Samuel Pitoiset wrote:
> On 04/26/2018 01:51 PM, Nicolai Hähnle wrote:
>> Is there any reason why we can't just use ac_image_load in such cases?
> 
> For nit_texop_txf_ms we need one more coordinate for the sample index, 
> if we use ac_image_load we only loads 2 coordinates instead of 4 with 
> ac_image_load_mip. Though, I have to admit that I'm a bit confused.

That's odd. But with multisample textures, ac_image_load_mip makes even 
less sense, considering that those can't actually have mip levels.

ac_image_load with ac_image_2dmsaa should load 3 coordinates (see 
ac_num_coords). We should be choosing ac_image_2dmsaa in that case, at 
least I'd expect the glsl_sampler_dim to be GLSL_SAMPLER_DIM_MS.

Cheers,
Nicolai

> 
> Any thoughts on this?
> 
>>
>> On 26.04.2018 13:18, Samuel Pitoiset wrote:
>>> Otherwise we hit an assertion in ac_build_image_opcode()
>>> for ac_image_load_mip.
>>>
>>> v2: - set only for ac_image_load_mip
>>>
>>> Fixes: 24fb3e6aa16 ("ac/nir: use ac_build_image_opcode for image 
>>> intrinsics")
>>> Cc: 18.1 <mesa-stable at lists.freedesktop.org>
>>> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
>>> ---
>>>   src/amd/common/ac_nir_to_llvm.c | 2 ++
>>>   1 file changed, 2 insertions(+)
>>>
>>> diff --git a/src/amd/common/ac_nir_to_llvm.c 
>>> b/src/amd/common/ac_nir_to_llvm.c
>>> index e4ae6ef49ad..fb8e44509e9 100644
>>> --- a/src/amd/common/ac_nir_to_llvm.c
>>> +++ b/src/amd/common/ac_nir_to_llvm.c
>>> @@ -1276,6 +1276,8 @@ static LLVMValueRef build_tex_intrinsic(struct 
>>> ac_nir_context *ctx,
>>>           args->opcode = args->level_zero ||
>>>                      instr->sampler_dim == GLSL_SAMPLER_DIM_MS ?
>>>                       ac_image_load : ac_image_load_mip;
>>> +        if (args->opcode == ac_image_load_mip && !args->lod)
>>> +            args->lod = ctx->ac.i32_0;
>>>           args->level_zero = false;
>>>           break;
>>>       case nir_texop_txs:
>>>
>>
>>


-- 
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.