tgsi: add Stream{X,Y,Z,W} fields to tgsi_declaration_semantic

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.

Reviewed-by: Marek Olšák <[email protected]>

4 files changed, 81 insertions, 3 deletions

diff --git a/src/gallium/auxiliary/tgsi/tgsi_build.c b/src/gallium/auxiliary/tgsi/tgsi_build.c
index d525c8ff34e..773f8926cb2 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_build.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_build.c
@@ -239,7 +239,10 @@ tgsi_default_declaration_semantic( void )
 
    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;
 }
@@ -248,6 +251,10 @@ 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 )
 {
@@ -258,7 +265,10 @@ tgsi_build_declaration_semantic(
 
    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 );
 
@@ -461,6 +471,10 @@ tgsi_build_full_declaration(
       *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 );
    }
diff --git a/src/gallium/auxiliary/tgsi/tgsi_dump.c b/src/gallium/auxiliary/tgsi/tgsi_dump.c
index 614bcb2ef3c..f74aad167fa 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_dump.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_dump.c
@@ -360,6 +360,19 @@ iter_declaration(
          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) {
diff --git a/src/gallium/auxiliary/tgsi/tgsi_text.c b/src/gallium/auxiliary/tgsi/tgsi_text.c
index be808425199..1b4f5940460 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_text.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_text.c
@@ -1546,6 +1546,54 @@ static boolean parse_declaration( struct translate_ctx *ctx )
 
    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;
 
diff --git a/src/gallium/include/pipe/p_shader_tokens.h b/src/gallium/include/pipe/p_shader_tokens.h
index 4a259db9f0d..ee59df0c393 100644
--- a/src/gallium/include/pipe/p_shader_tokens.h
+++ b/src/gallium/include/pipe/p_shader_tokens.h
@@ -207,7 +207,10 @@ 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 {