[virglrenderer-devel] [PATCH 08/10] shader: add texture image samples query support.

[Erik Faye-Lund]

On 26. juli 2018 17:11, Gert Wollny wrote:
> Am Mittwoch, den 25.07.2018, 09:00 +1000 schrieb Dave Airlie:
>> From: Dave Airlie <airlied at redhat.com>
>>
>> This adds support for the TXQS opcode, and RESQ	w channel
>> ---
>>   src/vrend_shader.c | 45 ++++++++++++++++++++++++++++++++++++++++++
>> ---
>>   1 file changed, 42 insertions(+), 3 deletions(-)
>>
>> diff --git a/src/vrend_shader.c b/src/vrend_shader.c
>> index f82762a..dd39632 100644
>> --- a/src/vrend_shader.c
>> +++ b/src/vrend_shader.c
>> @@ -59,6 +59,7 @@ extern int vrend_dump_shaders;
>>   #define SHADER_REQ_IMAGE_LOAD_STORE   (1 << 15)
>>   #define SHADER_REQ_ES31_COMPAT        (1 << 16)
>>   #define SHADER_REQ_IMAGE_SIZE         (1 << 17)
>> +#define SHADER_REQ_TXQS               (1 << 18)
>>   
>>   struct vrend_shader_io {
>>      unsigned                name;
>> @@ -226,6 +227,7 @@ static const struct vrend_shader_table
>> shader_req_table[] = {
>>       { SHADER_REQ_IMAGE_LOAD_STORE, "GL_ARB_shader_image_load_store"
>> },
>>       { SHADER_REQ_ES31_COMPAT, "GL_ARB_ES3_1_compatibility" },
>>       { SHADER_REQ_IMAGE_SIZE, "GL_ARB_shader_image_size" },
>> +    { SHADER_REQ_TXQS, "GL_ARB_shader_texture_image_samples" },
>>   };
>>   
>>   enum vrend_type_qualifier {
>> @@ -1772,6 +1774,31 @@ static int emit_txq(struct dump_ctx *ctx,
>>      return 0;
>>   }
>>   
>> +/* sample queries are pretty much separate */
>> +static int emit_txqs(struct dump_ctx *ctx,
>> +                     struct tgsi_full_instruction *inst,
>> +                     uint32_t sreg_index,
>> +                     char srcs[4][255],
>> +                     char dsts[3][255])
>> +{
>> +   char buf[512];
>> +   const int sampler_index = 0;
>> +   bool is_shad;
>> +   enum vrend_type_qualifier dtypeprefix = INT_BITS_TO_FLOAT;
>> +
>> +   ctx->shader_req_bits |= SHADER_REQ_TXQS;
>> +   if (set_texture_reqs(ctx, inst, sreg_index, &is_shad) == false)
>> +      return FALSE;
>> +
>> +   if (inst->Texture.Texture != TGSI_TEXTURE_2D_MSAA &&
>> +       inst->Texture.Texture != TGSI_TEXTURE_2D_ARRAY_MSAA)
>> +      return FALSE;
>> +
>> +   snprintf(buf, 255, "%s = %s(textureSamples(%s));\n", dsts[0],
>> get_string(dtypeprefix), srcs[sampler_index]);

Nit: Wrap this long line, perhaps?

>> +   EMIT_BUF_WITH_RET(ctx, buf);
>> +   return 0;
>> +}
>> +
>>   static const char *get_tex_inst_ext(struct tgsi_full_instruction
>> *inst)
>>   {
>>      const char *tex_ext = "";
>> @@ -2404,9 +2431,16 @@ translate_resq(struct dump_ctx *ctx, struct
>> tgsi_full_instruction *inst,
>>      const struct tgsi_full_src_register *src = &inst->Src[0];
>>   
>>      if (src->Register.File == TGSI_FILE_IMAGE) {
>> -      ctx->shader_req_bits |= SHADER_REQ_IMAGE_SIZE;
>> -      snprintf(buf, 255, "%s = %s(imageSize(%s));\n", dsts[0],
>> get_string(INT_BITS_TO_FLOAT), srcs[0]);
>> -      EMIT_BUF_WITH_RET(ctx, buf);
>> +      if (inst->Dst[0].Register.WriteMask & 0x8) {
> The TGSI docu says that the values goes into the X component, so
> shouldn't the test mask be 0x1? (I've seen that on r600 the value is
> also routed into W though).

I don't think so. According to the TGSI docs on RESQ 
(http://gallium.readthedocs.io/en/latest/tgsi.html#opcode-RESQ):

- XYZ is the image-size
- W is the number of samples.

Since this is the code for imageSamples(), 0x8 seems correct to me.

>> +         ctx->shader_req_bits |= SHADER_REQ_TXQS | SHADER_REQ_INTS;
>> +         snprintf(buf, 255, "%s = %s(imageSamples(%s));\n", dsts[0],
>> get_string(INT_BITS_TO_FLOAT), srcs[0]);
>> +         EMIT_BUF_WITH_RET(ctx, buf);
>> +      }
>> +      if (inst->Dst[0].Register.WriteMask & 0x7) {
>> +         ctx->shader_req_bits |= SHADER_REQ_IMAGE_SIZE |
>> SHADER_REQ_INTS;
>> +         snprintf(buf, 255, "%s = %s(imageSize(%s));\n", dsts[0],
>> get_string(INT_BITS_TO_FLOAT), srcs[0]);
>> +         EMIT_BUF_WITH_RET(ctx, buf);
>> +      }
>>      } else if (src->Register.File == TGSI_FILE_BUFFER) {
>>         snprintf(buf, 255, "%s = %s(int(%s.length()) << 2);\n",
>> dsts[0], get_string(INT_BITS_TO_FLOAT), srcs[0]);
>>         EMIT_BUF_WITH_RET(ctx, buf);
>> @@ -3393,6 +3427,11 @@ iter_instruction(struct tgsi_iterate_context
>> *iter,
>>         if (ret)
>>            return FALSE;
>>         break;
>> +   case TGSI_OPCODE_TXQS:
>> +      ret = emit_txqs(ctx, inst, sinfo.sreg_index, srcs, dsts);
>> +      if (ret)
>> +         return FALSE;
>> +      break;
>>      case TGSI_OPCODE_I2F:
>>         snprintf(buf, 255, "%s = %s(ivec4(%s)%s);\n", dsts[0],
>> get_string(dinfo.dstconv), srcs[0], writemask);
>>         EMIT_BUF_WITH_RET(ctx, buf);
>

Reviewed-by: Erik Faye-Lund <erik.faye-lund at collabora.com>