Get rid of _mesa_vert_result_to_frag_attrib().

Now that there is no difference between the enums that represent
vertex outputs and fragment inputs, there's no need for a conversion
function.  But we still need to be able to detect when a given vertex
output has no corresponding fragment input.  So it is replaced by a
new function, _mesa_varying_slot_in_fs(), which tells whether the
given varying slot exists as an FS input or not.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Tested-by: Brian Paul <brianp@vmware.com>

src/mesa/drivers/dri/i965/brw_fs.cpp

@@ -1265,16 +1265,14 @@ fs_visitor::calculate_urb_setup()
             continue;
 
 	 if (c->key.vp_outputs_written & BITFIELD64_BIT(i)) {
-	    int fp_index = _mesa_vert_result_to_frag_attrib((gl_varying_slot) i);
-
 	    /* The back color slot is skipped when the front color is
 	     * also written to.  In addition, some slots can be
 	     * written in the vertex shader and not read in the
 	     * fragment shader.  So the register number must always be
 	     * incremented, mapped or not.
 	     */
-	    if (fp_index >= 0)
-	       urb_setup[fp_index] = urb_next;
+	    if (_mesa_varying_slot_in_fs((gl_varying_slot) i))
+	       urb_setup[i] = urb_next;
             urb_next++;
 	 }
       }
@@ -3001,10 +2999,8 @@ brw_fs_precompile(struct gl_context *ctx, struct gl_shader_program *prog)
          key.proj_attrib_mask |= BITFIELD64_BIT(i);
 
       if (intel->gen < 6) {
-         int vp_index = _mesa_vert_result_to_frag_attrib((gl_varying_slot) i);
-
-         if (vp_index >= 0)
-            key.vp_outputs_written |= BITFIELD64_BIT(vp_index);
+         if (_mesa_varying_slot_in_fs((gl_varying_slot) i))
+            key.vp_outputs_written |= BITFIELD64_BIT(i);
       }
    }
 

src/mesa/drivers/dri/i965/brw_vs_constval.c

@@ -144,17 +144,14 @@ static void calc_sizes( struct tracker *t )
     * which describes the fragment program input sizes.
     */
    for (vertRes = 0; vertRes < VARYING_SLOT_MAX; vertRes++) {
-
-      /* map vertex program output index to fragment program input index */
-      GLint fragAttrib = _mesa_vert_result_to_frag_attrib(vertRes);
-      if (fragAttrib < 0)
+      if (!_mesa_varying_slot_in_fs(vertRes))
          continue;
 
       switch (get_output_size(t, vertRes)) {
-      case 4: t->size_masks[4-1] |= BITFIELD64_BIT(fragAttrib);
-      case 3: t->size_masks[3-1] |= BITFIELD64_BIT(fragAttrib);
-      case 2: t->size_masks[2-1] |= BITFIELD64_BIT(fragAttrib);
-      case 1: t->size_masks[1-1] |= BITFIELD64_BIT(fragAttrib);
+      case 4: t->size_masks[4-1] |= BITFIELD64_BIT(vertRes);
+      case 3: t->size_masks[3-1] |= BITFIELD64_BIT(vertRes);
+      case 2: t->size_masks[2-1] |= BITFIELD64_BIT(vertRes);
+      case 1: t->size_masks[1-1] |= BITFIELD64_BIT(vertRes);
 	 break;
       }
    }

src/mesa/main/mtypes.h

@@ -217,7 +217,7 @@ typedef enum
  * When this enum is updated, the following code must be updated too:
  * - vertResults (in prog_print.c's arb_output_attrib_string())
  * - fragAttribs (in prog_print.c's arb_input_attrib_string())
- * - _mesa_vert_result_to_frag_attrib()
+ * - _mesa_varying_slot_in_fs()
  * - _mesa_frag_attrib_to_vert_result()
  */
 typedef enum
@@ -288,8 +288,8 @@ typedef enum
 
 /**
  * Indexes for fragment program input attributes.  Note that
- * _mesa_vert_result_to_frag_attrib() and frag_attrib_to_vert_result() make
- * assumptions about the layout of this enum.
+ * _mesa_frag_attrib_to_vert_result() makes assumptions about the layout of
+ * this enum.
  */
 typedef enum
 {
@@ -315,26 +315,22 @@ typedef enum
 
 
 /**
- * Convert from a gl_varying_slot value for a vertex output to the
- * corresponding gl_frag_attrib.
- *
- * Varying output values which have no corresponding gl_frag_attrib
- * (VARYING_SLOT_PSIZ, VARYING_SLOT_BFC0, VARYING_SLOT_BFC1, and
- * VARYING_SLOT_EDGE) are converted to a value of -1.
+ * Determine if the given gl_varying_slot appears in the fragment shader.
  */
-static inline int
-_mesa_vert_result_to_frag_attrib(gl_varying_slot vert_result)
+static inline GLboolean
+_mesa_varying_slot_in_fs(gl_varying_slot slot)
 {
-   if (vert_result <= VARYING_SLOT_TEX7)
-      return vert_result;
-   else if (vert_result < VARYING_SLOT_CLIP_DIST0)
-      return -1;
-   else if (vert_result <= VARYING_SLOT_CLIP_DIST1)
-      return vert_result;
-   else if (vert_result < VARYING_SLOT_VAR0)
-      return -1;
-   else
-      return vert_result;
+   switch (slot) {
+   case VARYING_SLOT_PSIZ:
+   case VARYING_SLOT_BFC0:
+   case VARYING_SLOT_BFC1:
+   case VARYING_SLOT_EDGE:
+   case VARYING_SLOT_CLIP_VERTEX:
+   case VARYING_SLOT_LAYER:
+      return GL_FALSE;
+   default:
+      return GL_TRUE;
+   }
 }