i965/nir: Switch on shader stage in nir_lower_outputs().

VS, GS, and FS continue doing the same thing they did before.  We can
simplify the FS code a bit because it is always scalar.

Compute shaders now assert that there are no outputs instead of doing
a loop over 0 outputs.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>

diff --git a/src/mesa/drivers/dri/i965/brw_nir.c b/src/mesa/drivers/dri/i965/brw_nir.c
index af9d0414d512bb326326ffbb90d2dcc1b1904b71..1b4dace84fbdf5f25eeca99bce9c54f71d1ad310 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_nir.c
+++ b/src/mesa/drivers/dri/i965/brw_nir.c
@@ -112,11 +112,27 @@ brw_nir_lower_inputs(nir_shader *nir, bool is_scalar)
 static void
 brw_nir_lower_outputs(nir_shader *nir, bool is_scalar)
 {
-   if (is_scalar) {
-      nir_assign_var_locations(&nir->outputs, &nir->num_outputs, type_size_scalar);
-   } else {
-      nir_foreach_variable(var, &nir->outputs)
-         var->data.driver_location = var->data.location;
+   switch (nir->stage) {
+   case MESA_SHADER_VERTEX:
+   case MESA_SHADER_GEOMETRY:
+      if (is_scalar) {
+         nir_assign_var_locations(&nir->outputs, &nir->num_outputs,
+                                  type_size_scalar);
+      } else {
+         nir_foreach_variable(var, &nir->outputs)
+            var->data.driver_location = var->data.location;
+      }
+      break;
+   case MESA_SHADER_FRAGMENT:
+      nir_assign_var_locations(&nir->outputs, &nir->num_outputs,
+                               type_size_scalar);
+      break;
+   case MESA_SHADER_COMPUTE:
+      /* Compute shaders have no outputs. */
+      assert(exec_list_is_empty(&nir->outputs));
+      break;
+   default:
+      unreachable("unsupported shader stage");
    }
 }