Am 30.11.2016 um 20:19 schrieb Nicolai Hähnle:
> On 30.11.2016 19:06, Roland Scheidegger wrote:
>> Am 30.11.2016 um 14:35 schrieb Nicolai Hähnle:
>>> From: Nicolai Hähnle <nicolai.haeh...@amd.com>
>>>
>>> This is for geometry shader outputs. Without it, drivers have no way of
>>> knowing which stream each output is intended for, and have to
>>> conservatively write all outputs to all streams.
>>>
>>> Separate stream numbers for each component are required due to output
>>> packing.
>> Are you sure this is true?
>> This is an area I don't know much about, but
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__www.opengl.org_wiki_Layout-5FQualifier-5F-28GLSL-29&d=DgIDaQ&c=uilaK90D4TOVoH58JNXRgQ&r=_QIjpv-UJ77xEQY8fIYoQtr5qv8wKrPJc7v7_-CYAb0&m=fVpTGTYN2KTEhU17RpFTxEULrsIfC3bdpEin0k8NIYE&s=uamnHj-9Xr12ctr0gHDfCMIMHq8DyUBtKIwHQQpjDLs&e=
>>
>> tells me "Stream
>> assignments for a geometry shader are required to be the same for all
>> members of a block, but offsets are not."
>>
>> Therefore I don't think output packing should ever happen across
>> multiple streams. I think it would be MUCH nicer if the semantic needed
>> just one stream member...
>
> There are two variants of that question, I guess.
>
> The answer to the first variant is: Yes, this is currently true.
> lower_packed_varyings will happily pack outputs from different vertex
> streams into the same vec4. This affects quite a lot of programs, e.g.
> you see it in piglit arb_gpu_shader5-xfb-streams.
>
> The second question is: Do we want it to be true? I agree that it would
> be convenient to be able to use a single Stream member. Also, isolating
> the stream0 components from the rest would lead to slightly more
> efficient shaders for us in some cases.
>
> I opted against it so far because I didn't want to think through the
> implications of changing lower_packed_varyings. The main question I have
> is: if you account for the size of the GS output in # of components,
> then it could happen that the number of output vec4s ends up being
> larger than (max # of output components) / 4. Will that be a problem
> somewhere?
I don't know if that would be a problem, but if it is I'd assume this
would be fixable (since the number of actual components ultimately
doesn't change).
Having outputs belonging to multiple streams in a single output just
seems weird...
That said, I wonder if it actually would be possible to do that with
d3d11 too.
With shader model 5 you'd have:
dcl_stream 0
dcl_output o0.xy
dcl_stream 1
dcl_output o0.zw // legal or not???
Though the shader model 4/5 rules are a bit weird for packing
inputs/outputs, I'm not even sure two dcl_output are legal for the same
reg without a dcl_stream in between them (but you can pack system values
together with ordinary inputs/outputs).
So maybe just allowing this is the right solution...
Roland
>
> Nicolai
>
>>
>> Roland
>>
>>
>>
>>> ---
>>> src/compiler/glsl/ir_print_visitor.cpp | 4 +--
>>> src/gallium/auxiliary/tgsi/tgsi_build.c | 18 +++++++++--
>>> src/gallium/auxiliary/tgsi/tgsi_dump.c | 13 ++++++++
>>> src/gallium/auxiliary/tgsi/tgsi_text.c | 48
>>> ++++++++++++++++++++++++++++++
>>> src/gallium/include/pipe/p_shader_tokens.h | 5 +++-
>>> 5 files changed, 83 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/src/compiler/glsl/ir_print_visitor.cpp
>>> b/src/compiler/glsl/ir_print_visitor.cpp
>>> index 2b77c14..d401426 100644
>>> --- a/src/compiler/glsl/ir_print_visitor.cpp
>>> +++ b/src/compiler/glsl/ir_print_visitor.cpp
>>> @@ -173,26 +173,26 @@ void ir_print_visitor::visit(ir_variable *ir)
>>> if (ir->data.location != -1)
>>> snprintf(loc, sizeof(loc), "location=%i ", ir->data.location);
>>>
>>> char component[32] = {0};
>>> if (ir->data.explicit_component)
>>> snprintf(component, sizeof(component), "component=%i ",
>>> ir->data.location_frac);
>>>
>>> char stream[32] = {0};
>>> if (ir->data.stream & (1u << 31)) {
>>> if (ir->data.stream & ~(1u << 31)) {
>>> - snprintf(stream, sizeof(stream), "stream(%u,%u,%u,%u)",
>>> + snprintf(stream, sizeof(stream), "stream(%u,%u,%u,%u) ",
>>> ir->data.stream & 3, (ir->data.stream >> 2) & 3,
>>> (ir->data.stream >> 4) & 3, (ir->data.stream >> 6)
>>> & 3);
>>> }
>>> } else if (ir->data.stream) {
>>> - snprintf(stream, sizeof(stream), "stream%u", ir->data.stream);
>>> + snprintf(stream, sizeof(stream), "stream%u ", ir->data.stream);
>>> }
>>>
>>> const char *const cent = (ir->data.centroid) ? "centroid " : "";
>>> const char *const samp = (ir->data.sample) ? "sample " : "";
>>> const char *const patc = (ir->data.patch) ? "patch " : "";
>>> const char *const inv = (ir->data.invariant) ? "invariant " : "";
>>> const char *const prec = (ir->data.precise) ? "precise " : "";
>>> const char *const mode[] = { "", "uniform ", "shader_storage ",
>>> "shader_shared ", "shader_in ",
>>> "shader_out ",
>>> "in ", "out ", "inout ",
>>> diff --git a/src/gallium/auxiliary/tgsi/tgsi_build.c
>>> b/src/gallium/auxiliary/tgsi/tgsi_build.c
>>> index d525c8f..773f892 100644
>>> --- a/src/gallium/auxiliary/tgsi/tgsi_build.c
>>> +++ b/src/gallium/auxiliary/tgsi/tgsi_build.c
>>> @@ -232,40 +232,50 @@ tgsi_build_declaration_interp(unsigned
>>> interpolate,
>>> return di;
>>> }
>>>
>>> static struct tgsi_declaration_semantic
>>> tgsi_default_declaration_semantic( void )
>>> {
>>> struct tgsi_declaration_semantic ds;
>>>
>>> ds.Name = TGSI_SEMANTIC_POSITION;
>>> ds.Index = 0;
>>> - ds.Padding = 0;
>>> + ds.StreamX = 0;
>>> + ds.StreamY = 0;
>>> + ds.StreamZ = 0;
>>> + ds.StreamW = 0;
>>>
>>> return ds;
>>> }
>>>
>>> static struct tgsi_declaration_semantic
>>> tgsi_build_declaration_semantic(
>>> unsigned semantic_name,
>>> unsigned semantic_index,
>>> + unsigned streamx,
>>> + unsigned streamy,
>>> + unsigned streamz,
>>> + unsigned streamw,
>>> struct tgsi_declaration *declaration,
>>> struct tgsi_header *header )
>>> {
>>> struct tgsi_declaration_semantic ds;
>>>
>>> assert( semantic_name <= TGSI_SEMANTIC_COUNT );
>>> assert( semantic_index <= 0xFFFF );
>>>
>>> ds.Name = semantic_name;
>>> ds.Index = semantic_index;
>>> - ds.Padding = 0;
>>> + ds.StreamX = streamx;
>>> + ds.StreamY = streamy;
>>> + ds.StreamZ = streamz;
>>> + ds.StreamW = streamw;
>>>
>>> declaration_grow( declaration, header );
>>>
>>> return ds;
>>> }
>>>
>>> static struct tgsi_declaration_image
>>> tgsi_default_declaration_image(void)
>>> {
>>> struct tgsi_declaration_image di;
>>> @@ -454,20 +464,24 @@ tgsi_build_full_declaration(
>>> struct tgsi_declaration_semantic *ds;
>>>
>>> if( maxsize <= size )
>>> return 0;
>>> ds = (struct tgsi_declaration_semantic *) &tokens[size];
>>> size++;
>>>
>>> *ds = tgsi_build_declaration_semantic(
>>> full_decl->Semantic.Name,
>>> full_decl->Semantic.Index,
>>> + full_decl->Semantic.StreamX,
>>> + full_decl->Semantic.StreamY,
>>> + full_decl->Semantic.StreamZ,
>>> + full_decl->Semantic.StreamW,
>>> declaration,
>>> header );
>>> }
>>>
>>> if (full_decl->Declaration.File == TGSI_FILE_IMAGE) {
>>> struct tgsi_declaration_image *di;
>>>
>>> if (maxsize <= size) {
>>> return 0;
>>> }
>>> diff --git a/src/gallium/auxiliary/tgsi/tgsi_dump.c
>>> b/src/gallium/auxiliary/tgsi/tgsi_dump.c
>>> index 614bcb2..f74aad1 100644
>>> --- a/src/gallium/auxiliary/tgsi/tgsi_dump.c
>>> +++ b/src/gallium/auxiliary/tgsi/tgsi_dump.c
>>> @@ -353,20 +353,33 @@ iter_declaration(
>>> if (decl->Declaration.Semantic) {
>>> TXT( ", " );
>>> ENM( decl->Semantic.Name, tgsi_semantic_names );
>>> if (decl->Semantic.Index != 0 ||
>>> decl->Semantic.Name == TGSI_SEMANTIC_TEXCOORD ||
>>> decl->Semantic.Name == TGSI_SEMANTIC_GENERIC) {
>>> CHR( '[' );
>>> UID( decl->Semantic.Index );
>>> CHR( ']' );
>>> }
>>> +
>>> + if (decl->Semantic.StreamX != 0 || decl->Semantic.StreamY != 0 ||
>>> + decl->Semantic.StreamZ != 0 || decl->Semantic.StreamW != 0) {
>>> + TXT(", STREAM(");
>>> + UID(decl->Semantic.StreamX);
>>> + TXT(", ");
>>> + UID(decl->Semantic.StreamY);
>>> + TXT(", ");
>>> + UID(decl->Semantic.StreamZ);
>>> + TXT(", ");
>>> + UID(decl->Semantic.StreamW);
>>> + CHR(')');
>>> + }
>>> }
>>>
>>> if (decl->Declaration.File == TGSI_FILE_IMAGE) {
>>> TXT(", ");
>>> ENM(decl->Image.Resource, tgsi_texture_names);
>>> TXT(", ");
>>> TXT(util_format_name(decl->Image.Format));
>>> if (decl->Image.Writable)
>>> TXT(", WR");
>>> if (decl->Image.Raw)
>>> diff --git a/src/gallium/auxiliary/tgsi/tgsi_text.c
>>> b/src/gallium/auxiliary/tgsi/tgsi_text.c
>>> index be80842..1b4f594 100644
>>> --- a/src/gallium/auxiliary/tgsi/tgsi_text.c
>>> +++ b/src/gallium/auxiliary/tgsi/tgsi_text.c
>>> @@ -1539,20 +1539,68 @@ static boolean parse_declaration( struct
>>> translate_ctx *ctx )
>>> ctx->cur = cur;
>>> break;
>>> }
>>> }
>>> }
>>> }
>>> }
>>>
>>> cur = ctx->cur;
>>> eat_opt_white( &cur );
>>> + if (*cur == ',' &&
>>> + file == TGSI_FILE_OUTPUT && ctx->processor ==
>>> PIPE_SHADER_GEOMETRY) {
>>> + cur++;
>>> + eat_opt_white(&cur);
>>> + if (str_match_nocase_whole(&cur, "STREAM")) {
>>> + uint stream[4];
>>> +
>>> + eat_opt_white(&cur);
>>> + if (*cur != '(') {
>>> + report_error(ctx, "Expected '('");
>>> + return FALSE;
>>> + }
>>> + cur++;
>>> +
>>> + for (int i = 0; i < 4; ++i) {
>>> + eat_opt_white(&cur);
>>> + if (!parse_uint(&cur, &stream[i])) {
>>> + report_error(ctx, "Expected literal integer");
>>> + return FALSE;
>>> + }
>>> +
>>> + eat_opt_white(&cur);
>>> + if (i < 3) {
>>> + if (*cur != ',') {
>>> + report_error(ctx, "Expected ','");
>>> + return FALSE;
>>> + }
>>> + cur++;
>>> + }
>>> + }
>>> +
>>> + if (*cur != ')') {
>>> + report_error(ctx, "Expected ')'");
>>> + return FALSE;
>>> + }
>>> + cur++;
>>> +
>>> + decl.Semantic.StreamX = stream[0];
>>> + decl.Semantic.StreamY = stream[1];
>>> + decl.Semantic.StreamZ = stream[2];
>>> + decl.Semantic.StreamW = stream[3];
>>> +
>>> + ctx->cur = cur;
>>> + }
>>> + }
>>> +
>>> + cur = ctx->cur;
>>> + eat_opt_white( &cur );
>>> if (*cur == ',' && !is_vs_input) {
>>> uint i;
>>>
>>> cur++;
>>> eat_opt_white( &cur );
>>> for (i = 0; i < TGSI_INTERPOLATE_COUNT; i++) {
>>> if (str_match_nocase_whole( &cur, tgsi_interpolate_names[i]
>>> )) {
>>> decl.Declaration.Interpolate = 1;
>>> decl.Interp.Interpolate = i;
>>>
>>> diff --git a/src/gallium/include/pipe/p_shader_tokens.h
>>> b/src/gallium/include/pipe/p_shader_tokens.h
>>> index 4a259db..ee59df0 100644
>>> --- a/src/gallium/include/pipe/p_shader_tokens.h
>>> +++ b/src/gallium/include/pipe/p_shader_tokens.h
>>> @@ -200,21 +200,24 @@ enum tgsi_semantic {
>>> TGSI_SEMANTIC_BASEINSTANCE,
>>> TGSI_SEMANTIC_DRAWID,
>>> TGSI_SEMANTIC_WORK_DIM, /**< opencl get_work_dim value */
>>> TGSI_SEMANTIC_COUNT, /**< number of semantic values */
>>> };
>>>
>>> struct tgsi_declaration_semantic
>>> {
>>> unsigned Name : 8; /**< one of TGSI_SEMANTIC_x */
>>> unsigned Index : 16; /**< UINT */
>>> - unsigned Padding : 8;
>>> + unsigned StreamX : 2; /**< vertex stream (for GS output) */
>>> + unsigned StreamY : 2;
>>> + unsigned StreamZ : 2;
>>> + unsigned StreamW : 2;
>>> };
>>>
>>> struct tgsi_declaration_image {
>>> unsigned Resource : 8; /**< one of TGSI_TEXTURE_ */
>>> unsigned Raw : 1;
>>> unsigned Writable : 1;
>>> unsigned Format : 10; /**< one of PIPE_FORMAT_ */
>>> unsigned Padding : 12;
>>> };
>>>
>>>
>>
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