llvmpipe: scratch some special handling of vp_index/layer

It was actually slightly buggy (missing initialization / setup not dependent
on new vs albeit I didn't see issues), but the case of non-existing attributes
is now handled by draw emit code so don't need that anymore.

Reviewed-by: Brian Paul <[email protected]>
Reviewed-by: Edward O'Callaghan <[email protected]>

4 files changed, 7 insertions, 38 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_bld_interp.h b/src/gallium/drivers/llvmpipe/lp_bld_interp.h
index 0a52642e395..9029d2a4180 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_interp.h
+++ b/src/gallium/drivers/llvmpipe/lp_bld_interp.h
@@ -63,8 +63,7 @@ enum lp_interp {
    LP_INTERP_LINEAR,
    LP_INTERP_PERSPECTIVE,
    LP_INTERP_POSITION,
-   LP_INTERP_FACING,
-   LP_INTERP_ZERO
+   LP_INTERP_FACING
 };
 
 struct lp_shader_input {
diff --git a/src/gallium/drivers/llvmpipe/lp_context.h b/src/gallium/drivers/llvmpipe/lp_context.h
index 9dcc102e758..b1cb10250bc 100644
--- a/src/gallium/drivers/llvmpipe/lp_context.h
+++ b/src/gallium/drivers/llvmpipe/lp_context.h
@@ -125,12 +125,6 @@ struct llvmpipe_context {
    /** A fake frontface output for unfilled primitives */
    uint8_t face_slot;
 
-   /** Which output slot is used for the fake vp index info */
-   uint8_t fake_vpindex_slot;
-
-   /** Which output slot is used for the fake layer info */
-   uint8_t fake_layer_slot;
-
    /** Depth format and bias settings. */
    boolean floating_point_depth;
    double mrd;   /**< minimum resolvable depth value, for polygon offset */
diff --git a/src/gallium/drivers/llvmpipe/lp_state_derived.c b/src/gallium/drivers/llvmpipe/lp_state_derived.c
index f5bcfb2b511..f1f51cf0381 100644
--- a/src/gallium/drivers/llvmpipe/lp_state_derived.c
+++ b/src/gallium/drivers/llvmpipe/lp_state_derived.c
@@ -100,27 +100,16 @@ compute_vertex_info(struct llvmpipe_context *llvmpipe)
          draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_CONSTANT, vs_index);
       /*
        * For vp index and layer, if the fs requires them but the vs doesn't
-       * provide them, store the slot - we'll later replace the data directly
-       * with zero (as required by ARB_fragment_layer_viewport). This is
-       * because draw itself just redirects them to whatever was at output 0.
-       * We'll also store the real vpindex/layer slot for setup use.
+       * provide them, draw (vbuf) will give us the required 0 (slot -1).
+       * (This means in this case we'll also use those slots in setup, which
+       * isn't necessary but they'll contain the correct (0) value.)
        */
       } else if (lpfs->info.base.input_semantic_name[i] ==
                  TGSI_SEMANTIC_VIEWPORT_INDEX) {
-         if (vs_index >= 0) {
-            llvmpipe->viewport_index_slot = vinfo->num_attribs;
-         }
-         else {
-            llvmpipe->fake_vpindex_slot = vinfo->num_attribs;
-         }
+         llvmpipe->viewport_index_slot = vinfo->num_attribs;
          draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_CONSTANT, vs_index);
       } else if (lpfs->info.base.input_semantic_name[i] == TGSI_SEMANTIC_LAYER) {
-         if (vs_index >= 0) {
-            llvmpipe->layer_slot = vinfo->num_attribs;
-         }
-         else {
-            llvmpipe->fake_layer_slot = vinfo->num_attribs;
-         }
+         llvmpipe->layer_slot = vinfo->num_attribs;
          draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_CONSTANT, vs_index);
       } else {
          /*
diff --git a/src/gallium/drivers/llvmpipe/lp_state_setup.c b/src/gallium/drivers/llvmpipe/lp_state_setup.c
index d7ba5c8ad8e..20e177f54fb 100644
--- a/src/gallium/drivers/llvmpipe/lp_state_setup.c
+++ b/src/gallium/drivers/llvmpipe/lp_state_setup.c
@@ -602,13 +602,6 @@ emit_tri_coef( struct gallivm_state *gallivm,
           */
          break;
 
-      case LP_INTERP_ZERO:
-         /*
-          * The information we get from the output is bogus, replace it
-          * with zero.
-          */
-         emit_constant_coef4(gallivm, args, slot+1, args->bld.zero);
-         break;
       case LP_INTERP_FACING:
          emit_facing_coef(gallivm, args, slot+1);
          break;
@@ -879,13 +872,7 @@ lp_make_setup_variant_key(struct llvmpipe_context *lp,
    key->pad = 0;
    memcpy(key->inputs, fs->inputs, key->num_inputs * sizeof key->inputs[0]);
    for (i = 0; i < key->num_inputs; i++) {
-      if (key->inputs[i].interp == LP_INTERP_CONSTANT) {
-         if (key->inputs[i].src_index == lp->fake_vpindex_slot ||
-             key->inputs[i].src_index == lp->fake_layer_slot) {
-            key->inputs[i].interp = LP_INTERP_ZERO;
-         }
-      }
-      else if (key->inputs[i].interp == LP_INTERP_COLOR) {
+      if (key->inputs[i].interp == LP_INTERP_COLOR) {
          if (lp->rasterizer->flatshade)
             key->inputs[i].interp = LP_INTERP_CONSTANT;
          else