draw: don't pretend have_clipdist is per-vertex

This is just for code cleanup, conceptually the have_clipdist really
isn't per-vertex state, so don't put it there (just dependent on the
shader). Even though there wasn't really any overhead associated with
this, we shouldn't store random shader information in the vertex header.

Reviewed-by: Brian Paul <brianp@vmware.com
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>

src/gallium/auxiliary/draw/draw_cliptest_tmp.h

@@ -137,7 +137,6 @@ static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
                if (have_cd && num_written_clipdistance) {
                   float clipdist;
                   i = plane_idx - 6;
-                  out->have_clipdist = 1;
                   /* first four clip distance in first vector etc. */
                   if (i < 4)
                      clipdist = out->data[cd[0]][i];

src/gallium/auxiliary/draw/draw_llvm.c

@@ -826,7 +826,7 @@ store_aos(struct gallivm_state *gallivm,
  * struct vertex_header {
  *    unsigned clipmask:DRAW_TOTAL_CLIP_PLANES;
  *    unsigned edgeflag:1;
- *    unsigned have_clipdist:1;
+ *    unsigned pad:1;
  *    unsigned vertex_id:16;
  *    [...]
  * }
@@ -838,7 +838,7 @@ store_aos(struct gallivm_state *gallivm,
  * {
  *   return (x >> 16) |              // vertex_id
  *          ((x & 0x3fff) << 18) |   // clipmask
- *          ((x & 0x4000) << 3) |    // have_clipdist
+ *          ((x & 0x4000) << 3) |    // pad
  *          ((x & 0x8000) << 1);     // edgeflag
  * }
  */
@@ -850,19 +850,23 @@ adjust_mask(struct gallivm_state *gallivm,
    LLVMBuilderRef builder = gallivm->builder;
    LLVMValueRef vertex_id;
    LLVMValueRef clipmask;
-   LLVMValueRef have_clipdist;
+   LLVMValueRef pad;
    LLVMValueRef edgeflag;
 
    vertex_id = LLVMBuildLShr(builder, mask, lp_build_const_int32(gallivm, 16), "");
    clipmask  = LLVMBuildAnd(builder, mask, lp_build_const_int32(gallivm, 0x3fff), "");
    clipmask  = LLVMBuildShl(builder, clipmask, lp_build_const_int32(gallivm, 18), "");
-   have_clipdist = LLVMBuildAnd(builder, mask, lp_build_const_int32(gallivm, 0x4000), "");
-   have_clipdist = LLVMBuildShl(builder, have_clipdist, lp_build_const_int32(gallivm, 3), "");
+   if (0) {
+      pad = LLVMBuildAnd(builder, mask, lp_build_const_int32(gallivm, 0x4000), "");
+      pad = LLVMBuildShl(builder, pad, lp_build_const_int32(gallivm, 3), "");
+   }
    edgeflag = LLVMBuildAnd(builder, mask, lp_build_const_int32(gallivm, 0x8000), "");
    edgeflag = LLVMBuildShl(builder, edgeflag, lp_build_const_int32(gallivm, 1), "");
 
    mask = LLVMBuildOr(builder, vertex_id, clipmask, "");
-   mask = LLVMBuildOr(builder, mask, have_clipdist, "");
+   if (0) {
+      mask = LLVMBuildOr(builder, mask, pad, "");
+   }
    mask = LLVMBuildOr(builder, mask, edgeflag, "");
 #endif
    return mask;
@@ -876,8 +880,7 @@ store_aos_array(struct gallivm_state *gallivm,
                 LLVMValueRef* aos,
                 int attrib,
                 int num_outputs,
-                LLVMValueRef clipmask,
-                boolean have_clipdist)
+                LLVMValueRef clipmask)
 {
    LLVMBuilderRef builder = gallivm->builder;
    LLVMValueRef attr_index = lp_build_const_int32(gallivm, attrib);
@@ -908,10 +911,8 @@ store_aos_array(struct gallivm_state *gallivm,
        * code here.  See struct vertex_header in draw_private.h.
        */
       assert(DRAW_TOTAL_CLIP_PLANES==14);
-      /* initialize vertex id:16 = 0xffff, have_clipdist:1 = 0, edgeflag:1 = 1 */
+      /* initialize vertex id:16 = 0xffff, pad:1 = 0, edgeflag:1 = 1 */
       vertex_id_pad_edgeflag = (0xffff << 16) | (1 << DRAW_TOTAL_CLIP_PLANES);
-      if (have_clipdist)
-         vertex_id_pad_edgeflag |= 1 << (DRAW_TOTAL_CLIP_PLANES+1);
       val = lp_build_const_int_vec(gallivm, lp_int_type(soa_type), vertex_id_pad_edgeflag);
       /* OR with the clipmask */
       cliptmp = LLVMBuildOr(builder, val, clipmask, "");
@@ -998,7 +999,7 @@ convert_to_aos(struct gallivm_state *gallivm,
                       aos,
                       attrib,
                       num_outputs,
-                      clipmask, have_clipdist);
+                      clipmask);
    }
 #if DEBUG_STORE
    lp_build_printf(gallivm, "   # storing end\n");

src/gallium/auxiliary/draw/draw_pipe_clip.c

@@ -59,6 +59,7 @@ struct clip_stage {
    struct draw_stage stage;      /**< base class */
 
    unsigned pos_attr;
+   boolean have_clipdist;
 
    /* List of the attributes to be constant interpolated. */
    uint num_const_attribs;
@@ -145,7 +146,7 @@ static void interp(const struct clip_stage *clip,
     */
    dst->clipmask = 0;
    dst->edgeflag = 0;        /* will get overwritten later */
-   dst->have_clipdist = in->have_clipdist;
+   dst->pad = 0;
    dst->vertex_id = UNDEFINED_VERTEX_ID;
 
    /* Interpolate the clip-space coords.
@@ -350,7 +351,7 @@ static inline float getclipdist(const struct clip_stage *clipper,
       plane = clipper->plane[plane_idx];
       dp = dot4(vert->pre_clip_pos, plane);
    }
-   else if (vert->have_clipdist) {
+   else if (clipper->have_clipdist) {
       /* pick the correct clipdistance element from the output vectors */
       int _idx = plane_idx - 6;
       int cdi = _idx >= 4;
@@ -782,7 +783,7 @@ find_interp(const struct draw_fragment_shader *fs, int *indexed_interp,
 static void 
 clip_init_state(struct draw_stage *stage)
 {
-   struct clip_stage *clipper = clip_stage( stage );
+   struct clip_stage *clipper = clip_stage(stage);
    const struct draw_context *draw = stage->draw;
    const struct draw_fragment_shader *fs = draw->fs.fragment_shader;
    const struct tgsi_shader_info *info = draw_get_shader_info(draw);
@@ -790,6 +791,7 @@ clip_init_state(struct draw_stage *stage)
    int indexed_interp[2];
 
    clipper->pos_attr = draw_current_shader_position_output(draw);
+   clipper->have_clipdist = draw_current_shader_num_written_clipdistances(draw) > 0;
 
    /* We need to know for each attribute what kind of interpolation is
     * done on it (flat, smooth or noperspective).  But the information

src/gallium/auxiliary/draw/draw_private.h

@@ -86,7 +86,7 @@ struct draw_vertex_buffer {
 struct vertex_header {
    unsigned clipmask:DRAW_TOTAL_CLIP_PLANES;
    unsigned edgeflag:1;
-   unsigned have_clipdist:1;
+   unsigned pad:1;
    unsigned vertex_id:16;
 
    float clip[4];

src/gallium/auxiliary/draw/draw_pt_post_vs.c

@@ -58,7 +58,7 @@ initialize_vertex_header(struct vertex_header *header)
 {
    header->clipmask = 0;
    header->edgeflag = 1;
-   header->have_clipdist = 0;
+   header->pad = 0;
    header->vertex_id = UNDEFINED_VERTEX_ID;
 }