gallium/tgsi: Move interpolation info from tgsi_declaration to a separate token.

Move Interpolate, Centroid and CylindricalWrap from tgsi_declaration
to a separate token -- they only make sense for FS inputs and we need
room for other flags in the top-level declaration token.

src/gallium/auxiliary/draw/draw_pipe_aaline.c

@@ -237,12 +237,13 @@ aa_transform_inst(struct tgsi_transform_context *ctx,
       decl = tgsi_default_full_declaration();
       decl.Declaration.File = TGSI_FILE_INPUT;
       /* XXX this could be linear... */
-      decl.Declaration.Interpolate = TGSI_INTERPOLATE_PERSPECTIVE;
+      decl.Declaration.Interpolate = 1;
       decl.Declaration.Semantic = 1;
       decl.Semantic.Name = TGSI_SEMANTIC_GENERIC;
       decl.Semantic.Index = aactx->maxGeneric + 1;
       decl.Range.First = 
       decl.Range.Last = aactx->maxInput + 1;
+      decl.Interp.Interpolate = TGSI_INTERPOLATE_PERSPECTIVE;
       ctx->emit_declaration(ctx, &decl);
 
       /* declare new sampler */

src/gallium/auxiliary/draw/draw_pipe_aapoint.c

@@ -201,12 +201,13 @@ aa_transform_inst(struct tgsi_transform_context *ctx,
       decl = tgsi_default_full_declaration();
       decl.Declaration.File = TGSI_FILE_INPUT;
       /* XXX this could be linear... */
-      decl.Declaration.Interpolate = TGSI_INTERPOLATE_PERSPECTIVE;
+      decl.Declaration.Interpolate = 1;
       decl.Declaration.Semantic = 1;
       decl.Semantic.Name = TGSI_SEMANTIC_GENERIC;
       decl.Semantic.Index = aactx->maxGeneric + 1;
       decl.Range.First = 
       decl.Range.Last = texInput;
+      decl.Interp.Interpolate = TGSI_INTERPOLATE_PERSPECTIVE;
       ctx->emit_declaration(ctx, &decl);
 
       /* declare new temp regs */

src/gallium/auxiliary/draw/draw_pipe_pstipple.c

@@ -234,12 +234,13 @@ pstip_transform_inst(struct tgsi_transform_context *ctx,
          /* declare new position input reg */
          decl = tgsi_default_full_declaration();
          decl.Declaration.File = TGSI_FILE_INPUT;
-         decl.Declaration.Interpolate = TGSI_INTERPOLATE_LINEAR; /* XXX? */
+         decl.Declaration.Interpolate = 1;
          decl.Declaration.Semantic = 1;
          decl.Semantic.Name = TGSI_SEMANTIC_POSITION;
          decl.Semantic.Index = 0;
          decl.Range.First = 
             decl.Range.Last = wincoordInput;
+         decl.Interp.Interpolate = TGSI_INTERPOLATE_LINEAR; /* XXX? */
          ctx->emit_declaration(ctx, &decl);
       }
 

src/gallium/auxiliary/tgsi/tgsi_build.c

@@ -104,12 +104,10 @@ tgsi_default_declaration( void )
    declaration.NrTokens = 1;
    declaration.File = TGSI_FILE_NULL;
    declaration.UsageMask = TGSI_WRITEMASK_XYZW;
-   declaration.Interpolate = TGSI_INTERPOLATE_CONSTANT;
+   declaration.Interpolate = 0;
    declaration.Dimension = 0;
    declaration.Semantic = 0;
-   declaration.Centroid = 0;
    declaration.Invariant = 0;
-   declaration.CylindricalWrap = 0;
 
    return declaration;
 }
@@ -121,9 +119,7 @@ tgsi_build_declaration(
    unsigned interpolate,
    unsigned dimension,
    unsigned semantic,
-   unsigned centroid,
    unsigned invariant,
-   unsigned cylindrical_wrap,
    struct tgsi_header *header )
 {
    struct tgsi_declaration declaration;
@@ -137,9 +133,7 @@ tgsi_build_declaration(
    declaration.Interpolate = interpolate;
    declaration.Dimension = dimension;
    declaration.Semantic = semantic;
-   declaration.Centroid = centroid;
    declaration.Invariant = invariant;
-   declaration.CylindricalWrap = cylindrical_wrap;
 
    header_bodysize_grow( header );
 
@@ -194,6 +188,36 @@ tgsi_build_declaration_dimension(unsigned index_2d,
    return dd;
 }
 
+static struct tgsi_declaration_interp
+tgsi_default_declaration_interp( void )
+{
+   struct tgsi_declaration_interp di;
+
+   di.Interpolate = TGSI_INTERPOLATE_CONSTANT;
+   di.Centroid = 0;
+   di.CylindricalWrap = 0;
+
+   return di;
+}
+
+static struct tgsi_declaration_interp
+tgsi_build_declaration_interp(unsigned interpolate,
+                              unsigned centroid,
+                              unsigned cylindrical_wrap,
+                              struct tgsi_declaration *declaration,
+                              struct tgsi_header *header)
+{
+   struct tgsi_declaration_interp di;
+
+   di.Interpolate = interpolate;
+   di.Centroid = centroid;
+   di.CylindricalWrap = cylindrical_wrap;
+
+   declaration_grow(declaration, header);
+
+   return di;
+}
+
 static struct tgsi_declaration_semantic
 tgsi_default_declaration_semantic( void )
 {
@@ -298,6 +322,7 @@ tgsi_default_full_declaration( void )
    full_declaration.Declaration  = tgsi_default_declaration();
    full_declaration.Range = tgsi_default_declaration_range();
    full_declaration.Semantic = tgsi_default_declaration_semantic();
+   full_declaration.Interp = tgsi_default_declaration_interp();
    full_declaration.ImmediateData.u = NULL;
    full_declaration.Resource = tgsi_default_declaration_resource();
    full_declaration.SamplerView = tgsi_default_declaration_sampler_view();
@@ -327,9 +352,7 @@ tgsi_build_full_declaration(
       full_decl->Declaration.Interpolate,
       full_decl->Declaration.Dimension,
       full_decl->Declaration.Semantic,
-      full_decl->Declaration.Centroid,
       full_decl->Declaration.Invariant,
-      full_decl->Declaration.CylindricalWrap,
       header );
 
    if (maxsize <= size)
@@ -357,6 +380,22 @@ tgsi_build_full_declaration(
                                              header);
    }
 
+   if (full_decl->Declaration.Interpolate) {
+      struct tgsi_declaration_interp *di;
+
+      if (maxsize <= size) {
+         return 0;
+      }
+      di = (struct tgsi_declaration_interp *)&tokens[size];
+      size++;
+
+      *di = tgsi_build_declaration_interp(full_decl->Interp.Interpolate,
+                                          full_decl->Interp.Centroid,
+                                          full_decl->Interp.CylindricalWrap,
+                                          declaration,
+                                          header);
+   }
+
    if( full_decl->Declaration.Semantic ) {
       struct tgsi_declaration_semantic *ds;
 

src/gallium/auxiliary/tgsi/tgsi_dump.c

@@ -306,36 +306,39 @@ iter_declaration(
       }
    }
 
-   if (iter->processor.Processor == TGSI_PROCESSOR_FRAGMENT &&
-       decl->Declaration.File == TGSI_FILE_INPUT)
-   {
-      TXT( ", " );
-      ENM( decl->Declaration.Interpolate, tgsi_interpolate_names );
-   }
+   if (decl->Declaration.Interpolate) {
+      if (iter->processor.Processor == TGSI_PROCESSOR_FRAGMENT &&
+          decl->Declaration.File == TGSI_FILE_INPUT)
+      {
+         TXT( ", " );
+         ENM( decl->Interp.Interpolate, tgsi_interpolate_names );
+      }
 
-   if (decl->Declaration.Centroid) {
-      TXT( ", CENTROID" );
+      if (decl->Interp.Centroid) {
+         TXT( ", CENTROID" );
+      }
+
+      if (decl->Interp.CylindricalWrap) {
+         TXT(", CYLWRAP_");
+         if (decl->Interp.CylindricalWrap & TGSI_CYLINDRICAL_WRAP_X) {
+            CHR('X');
+         }
+         if (decl->Interp.CylindricalWrap & TGSI_CYLINDRICAL_WRAP_Y) {
+            CHR('Y');
+         }
+         if (decl->Interp.CylindricalWrap & TGSI_CYLINDRICAL_WRAP_Z) {
+            CHR('Z');
+         }
+         if (decl->Interp.CylindricalWrap & TGSI_CYLINDRICAL_WRAP_W) {
+            CHR('W');
+         }
+      }
    }
 
    if (decl->Declaration.Invariant) {
       TXT( ", INVARIANT" );
    }
 
-   if (decl->Declaration.CylindricalWrap) {
-      TXT(", CYLWRAP_");
-      if (decl->Declaration.CylindricalWrap & TGSI_CYLINDRICAL_WRAP_X) {
-         CHR('X');
-      }
-      if (decl->Declaration.CylindricalWrap & TGSI_CYLINDRICAL_WRAP_Y) {
-         CHR('Y');
-      }
-      if (decl->Declaration.CylindricalWrap & TGSI_CYLINDRICAL_WRAP_Z) {
-         CHR('Z');
-      }
-      if (decl->Declaration.CylindricalWrap & TGSI_CYLINDRICAL_WRAP_W) {
-         CHR('W');
-      }
-   }
 
    if (decl->Declaration.File == TGSI_FILE_IMMEDIATE_ARRAY) {
       unsigned i;

src/gallium/auxiliary/tgsi/tgsi_exec.c

@@ -2371,7 +2371,7 @@ exec_declaration(struct tgsi_exec_machine *mach,
             eval_coef_func eval;
             uint i, j;
 
-            switch (decl->Declaration.Interpolate) {
+            switch (decl->Interp.Interpolate) {
             case TGSI_INTERPOLATE_CONSTANT:
                eval = eval_constant_coef;
                break;

src/gallium/auxiliary/tgsi/tgsi_parse.c

@@ -113,6 +113,10 @@ tgsi_parse_token(
          next_token(ctx, &decl->Dim);
       }
 
+      if( decl->Declaration.Interpolate ) {
+         next_token( ctx, &decl->Interp );
+      }
+
       if( decl->Declaration.Semantic ) {
          next_token( ctx, &decl->Semantic );
       }

src/gallium/auxiliary/tgsi/tgsi_parse.h

@@ -67,6 +67,7 @@ struct tgsi_full_declaration
    struct tgsi_declaration Declaration;
    struct tgsi_declaration_range Range;
    struct tgsi_declaration_dimension Dim;
+   struct tgsi_declaration_interp Interp;
    struct tgsi_declaration_semantic Semantic;
    struct tgsi_immediate_array_data ImmediateData;
    struct tgsi_declaration_resource Resource;

src/gallium/auxiliary/tgsi/tgsi_ppc.c

@@ -1170,7 +1170,7 @@ emit_declaration(
       for( i = first; i <= last; i++ ) {
          for( j = 0; j < NUM_CHANNELS; j++ ) {
             if( mask & (1 << j) ) {
-               switch( decl->Declaration.Interpolate ) {
+               switch( decl->Interp.Interpolate ) {
                case TGSI_INTERPOLATE_CONSTANT:
                   emit_coef_a0( func, 0, i, j );
                   emit_inputs( func, 0, i, j );

src/gallium/auxiliary/tgsi/tgsi_scan.c

@@ -157,9 +157,9 @@ tgsi_scan_shader(const struct tgsi_token *tokens,
                if (file == TGSI_FILE_INPUT) {
                   info->input_semantic_name[reg] = (ubyte)fulldecl->Semantic.Name;
                   info->input_semantic_index[reg] = (ubyte)fulldecl->Semantic.Index;
-                  info->input_interpolate[reg] = (ubyte)fulldecl->Declaration.Interpolate;
-                  info->input_centroid[reg] = (ubyte)fulldecl->Declaration.Centroid;
-                  info->input_cylindrical_wrap[reg] = (ubyte)fulldecl->Declaration.CylindricalWrap;
+                  info->input_interpolate[reg] = (ubyte)fulldecl->Interp.Interpolate;
+                  info->input_centroid[reg] = (ubyte)fulldecl->Interp.Centroid;
+                  info->input_cylindrical_wrap[reg] = (ubyte)fulldecl->Interp.CylindricalWrap;
                   info->num_inputs++;
 
                   if (procType == TGSI_PROCESSOR_FRAGMENT &&

src/gallium/auxiliary/tgsi/tgsi_text.c

@@ -1225,7 +1225,8 @@ static boolean parse_declaration( struct translate_ctx *ctx )
          if (str_match_no_case( &cur, tgsi_interpolate_names[i] )) {
             if (is_digit_alpha_underscore( cur ))
                continue;
-            decl.Declaration.Interpolate = i;
+            decl.Declaration.Interpolate = 1;
+            decl.Interp.Interpolate = i;
 
             ctx->cur = cur;
             break;

src/gallium/auxiliary/tgsi/tgsi_ureg.c

@@ -46,6 +46,7 @@ union tgsi_any_token {
    struct tgsi_declaration decl;
    struct tgsi_declaration_range decl_range;
    struct tgsi_declaration_dimension decl_dim;
+   struct tgsi_declaration_interp decl_interp;
    struct tgsi_declaration_semantic decl_semantic;
    struct tgsi_declaration_sampler_view decl_sampler_view;
    struct tgsi_immediate imm;
@@ -1229,25 +1230,28 @@ emit_decl_fs(struct ureg_program *ureg,
              unsigned cylindrical_wrap,
              unsigned centroid)
 {
-   union tgsi_any_token *out = get_tokens(ureg, DOMAIN_DECL, 3);
+   union tgsi_any_token *out = get_tokens(ureg, DOMAIN_DECL, 4);
 
    out[0].value = 0;
    out[0].decl.Type = TGSI_TOKEN_TYPE_DECLARATION;
-   out[0].decl.NrTokens = 3;
+   out[0].decl.NrTokens = 4;
    out[0].decl.File = file;
    out[0].decl.UsageMask = TGSI_WRITEMASK_XYZW; /* FIXME! */
-   out[0].decl.Interpolate = interpolate;
+   out[0].decl.Interpolate = 1;
    out[0].decl.Semantic = 1;
-   out[0].decl.CylindricalWrap = cylindrical_wrap;
-   out[0].decl.Centroid = centroid;
 
    out[1].value = 0;
    out[1].decl_range.First = index;
    out[1].decl_range.Last = index;
 
    out[2].value = 0;
-   out[2].decl_semantic.Name = semantic_name;
-   out[2].decl_semantic.Index = semantic_index;
+   out[2].decl_interp.Interpolate = interpolate;
+   out[2].decl_interp.CylindricalWrap = cylindrical_wrap;
+   out[2].decl_interp.Centroid = centroid;
+
+   out[3].value = 0;
+   out[3].decl_semantic.Name = semantic_name;
+   out[3].decl_semantic.Index = semantic_index;
 }
 
 
@@ -1263,7 +1267,6 @@ static void emit_decl_range( struct ureg_program *ureg,
    out[0].decl.NrTokens = 2;
    out[0].decl.File = file;
    out[0].decl.UsageMask = TGSI_WRITEMASK_XYZW;
-   out[0].decl.Interpolate = TGSI_INTERPOLATE_CONSTANT;
    out[0].decl.Semantic = 0;
 
    out[1].value = 0;
@@ -1285,7 +1288,6 @@ emit_decl_range2D(struct ureg_program *ureg,
    out[0].decl.NrTokens = 3;
    out[0].decl.File = file;
    out[0].decl.UsageMask = TGSI_WRITEMASK_XYZW;
-   out[0].decl.Interpolate = TGSI_INTERPOLATE_CONSTANT;
    out[0].decl.Dimension = 1;
 
    out[1].value = 0;
@@ -1312,7 +1314,6 @@ emit_decl_sampler_view(struct ureg_program *ureg,
    out[0].decl.NrTokens = 3;
    out[0].decl.File = TGSI_FILE_SAMPLER_VIEW;
    out[0].decl.UsageMask = 0xf;
-   out[0].decl.Interpolate = TGSI_INTERPOLATE_CONSTANT;
 
    out[1].value = 0;
    out[1].decl_range.First = index;

src/gallium/auxiliary/util/u_pstipple.c

@@ -298,12 +298,13 @@ pstip_transform_inst(struct tgsi_transform_context *ctx,
          /* declare new position input reg */
          decl = tgsi_default_full_declaration();
          decl.Declaration.File = TGSI_FILE_INPUT;
-         decl.Declaration.Interpolate = TGSI_INTERPOLATE_LINEAR;
+         decl.Declaration.Interpolate = 1;
          decl.Declaration.Semantic = 1;
          decl.Semantic.Name = TGSI_SEMANTIC_POSITION;
          decl.Semantic.Index = 0;
          decl.Range.First = 
             decl.Range.Last = wincoordInput;
+         decl.Interp.Interpolate = TGSI_INTERPOLATE_LINEAR;
          ctx->emit_declaration(ctx, &decl);
       }
 

src/gallium/docs/source/tgsi.rst

@@ -1559,19 +1559,11 @@ of TGSI_FILE.
 UsageMask field specifies which of the register components can be accessed
 and is one of TGSI_WRITEMASK.
 
-Interpolate field is only valid for fragment shader INPUT register files.
-It specifes the way input is being interpolated by the rasteriser and is one
-of TGSI_INTERPOLATE.
-
 If Dimension flag is set to 1, a Declaration Dimension token follows.
 
 If Semantic flag is set to 1, a Declaration Semantic token follows.
 
-CylindricalWrap bitfield is only valid for fragment shader INPUT register
-files. It specifies which register components should be subject to cylindrical
-wrapping when interpolating by the rasteriser. If TGSI_CYLINDRICAL_WRAP_X
-is set to 1, the X component should be interpolated according to cylindrical
-wrapping rules.
+If Interpolate flag is set to 1, a Declaration Interpolate token follows.
 
 If file is TGSI_FILE_RESOURCE, a Declaration Resource token follows.
 
@@ -1718,6 +1710,20 @@ is a writable stencil reference value. Only the Y component is writable.
 This allows the fragment shader to change the fragments stencilref value.
 
 
+Declaration Interpolate
+^^^^^^^^^^^^^^^^^^^^^^^
+
+This token is only valid for fragment shader INPUT declarations.
+
+The Interpolate field specifes the way input is being interpolated by
+the rasteriser and is one of TGSI_INTERPOLATE_*.
+
+The CylindricalWrap bitfield specifies which register components
+should be subject to cylindrical wrapping when interpolating by the
+rasteriser. If TGSI_CYLINDRICAL_WRAP_X is set to 1, the X component
+should be interpolated according to cylindrical wrapping rules.
+
+
 Declaration Sampler View
 ^^^^^^^^^^^^^^^^^^^^^^^^
 

src/gallium/drivers/nv50/codegen/nv50_ir_from_tgsi.cpp

@@ -805,7 +805,7 @@ bool Source::scanDeclaration(const struct tgsi_full_declaration *decl)
             info->in[i].si = si;
             if (info->type == PIPE_SHADER_FRAGMENT) {
                // translate interpolation mode
-               switch (decl->Declaration.Interpolate) {
+               switch (decl->Interp.Interpolate) {
                case TGSI_INTERPOLATE_CONSTANT:
                   info->in[i].flat = 1;
                   break;
@@ -818,7 +818,7 @@ bool Source::scanDeclaration(const struct tgsi_full_declaration *decl)
                default:
                   break;
                }
-               if (decl->Declaration.Centroid)
+               if (decl->Interp.Centroid)
                   info->in[i].centroid = 1;
             }
          }

src/gallium/drivers/r300/r300_vs_draw.c

@@ -94,11 +94,12 @@ static void emit_output(struct tgsi_transform_context *ctx,
 
     decl = tgsi_default_full_declaration();
     decl.Declaration.File = TGSI_FILE_OUTPUT;
-    decl.Declaration.Interpolate = interp;
+    decl.Declaration.Interpolate = 1;
     decl.Declaration.Semantic = TRUE;
     decl.Semantic.Name = name;
     decl.Semantic.Index = index;
     decl.Range.First = decl.Range.Last = reg;
+    decl.Interp.Interpolate = interp;
     ctx->emit_declaration(ctx, &decl);
     ++vsctx->num_outputs;
 }

src/gallium/drivers/r600/r600_shader.c

@@ -722,8 +722,8 @@ static int tgsi_declaration(struct r600_shader_ctx *ctx)
 		ctx->shader->input[i].name = d->Semantic.Name;
 		ctx->shader->input[i].sid = d->Semantic.Index;
 		ctx->shader->input[i].spi_sid = r600_spi_sid(&ctx->shader->input[i]);
-		ctx->shader->input[i].interpolate = d->Declaration.Interpolate;
-		ctx->shader->input[i].centroid = d->Declaration.Centroid;
+		ctx->shader->input[i].interpolate = d->Interp.Interpolate;
+		ctx->shader->input[i].centroid = d->Interp.Centroid;
 		ctx->shader->input[i].gpr = ctx->file_offset[TGSI_FILE_INPUT] + d->Range.First;
 		if (ctx->type == TGSI_PROCESSOR_FRAGMENT) {
 			switch (ctx->shader->input[i].name) {
@@ -749,7 +749,7 @@ static int tgsi_declaration(struct r600_shader_ctx *ctx)
 		ctx->shader->output[i].sid = d->Semantic.Index;
 		ctx->shader->output[i].spi_sid = r600_spi_sid(&ctx->shader->output[i]);
 		ctx->shader->output[i].gpr = ctx->file_offset[TGSI_FILE_OUTPUT] + d->Range.First;
-		ctx->shader->output[i].interpolate = d->Declaration.Interpolate;
+		ctx->shader->output[i].interpolate = d->Interp.Interpolate;
 		ctx->shader->output[i].write_mask = d->Declaration.UsageMask;
 		if (ctx->type == TGSI_PROCESSOR_VERTEX) {
 			switch (d->Semantic.Name) {

src/gallium/drivers/radeonsi/radeonsi_shader.c

@@ -199,7 +199,7 @@ static void declare_input_fs(
 	LLVMValueRef attr_number = lp_build_const_int32(gallivm, input_index);
 
 	/* XXX: Handle all possible interpolation modes */
-	switch (decl->Declaration.Interpolate) {
+	switch (decl->Interp.Interpolate) {
 	case TGSI_INTERPOLATE_COLOR:
 		if (si_shader_ctx->rctx->rasterizer->flatshade)
 			intr_name = "llvm.SI.fs.interp.constant";
@@ -331,14 +331,14 @@ static void si_llvm_emit_epilogue(struct lp_build_tgsi_context * bld_base)
 			i = shader->ninput++;
 			shader->input[i].name = d->Semantic.Name;
 			shader->input[i].sid = d->Semantic.Index;
-			shader->input[i].interpolate = d->Declaration.Interpolate;
-			shader->input[i].centroid = d->Declaration.Centroid;
+			shader->input[i].interpolate = d->Interp.Interpolate;
+			shader->input[i].centroid = d->Interp.Centroid;
 			break;
 		case TGSI_FILE_OUTPUT:
 			i = shader->noutput++;
 			shader->output[i].name = d->Semantic.Name;
 			shader->output[i].sid = d->Semantic.Index;
-			shader->output[i].interpolate = d->Declaration.Interpolate;
+			shader->output[i].interpolate = d->Interp.Interpolate;
 			break;
 		}
 

src/gallium/include/pipe/p_shader_tokens.h

@@ -115,12 +115,11 @@ struct tgsi_declaration
    unsigned NrTokens    : 8;  /**< UINT */
    unsigned File        : 4;  /**< one of TGSI_FILE_x */
    unsigned UsageMask   : 4;  /**< bitmask of TGSI_WRITEMASK_x flags */
-   unsigned Interpolate : 4;  /**< one of TGSI_INTERPOLATE_x */
    unsigned Dimension   : 1;  /**< any extra dimension info? */
    unsigned Semantic    : 1;  /**< BOOL, any semantic info? */
-   unsigned Centroid    : 1;  /**< centroid sampling? */
+   unsigned Interpolate : 1;  /**< any interpolation info? */
    unsigned Invariant   : 1;  /**< invariant optimization? */
-   unsigned CylindricalWrap:4;   /**< TGSI_CYLINDRICAL_WRAP_x flags */
+   unsigned Padding     : 8;
 };
 
 struct tgsi_declaration_range
@@ -135,6 +134,14 @@ struct tgsi_declaration_dimension
    unsigned Padding:16;
 };
 
+struct tgsi_declaration_interp
+{
+   unsigned Interpolate : 4;   /**< one of TGSI_INTERPOLATE_x */
+   unsigned Centroid    : 1;   /**< centroid sampling? */
+   unsigned CylindricalWrap:4; /**< TGSI_CYLINDRICAL_WRAP_x flags */
+   unsigned Padding     : 23;
+};
+
 #define TGSI_SEMANTIC_POSITION   0
 #define TGSI_SEMANTIC_COLOR      1
 #define TGSI_SEMANTIC_BCOLOR     2  /**< back-face color */