st/glsl_to_tgsi: simpler fixup of empty writemasks

Empty writemasks mean "copy everything", so we can always just use the number
of vector elements (which uses the GLSL meaning here, i.e. each double is a
single element/writemask bit).

Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Reviewed-by: Dave Airlie <airlied@redhat.com>

1 files changed, 10 insertions, 27 deletions

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index da7b83b..6a63e5c 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -2842,33 +2842,7 @@ glsl_to_tgsi_visitor::visit(ir_assignment *ir)
 
    l = get_assignment_lhs(ir->lhs, this);
 
-   /* FINISHME: This should really set to the correct maximal writemask for each
-    * FINISHME: component written (in the loops below).  This case can only
-    * FINISHME: occur for matrices, arrays, and structures.
-    */
-   if (ir->write_mask == 0) {
-      assert(!ir->lhs->type->is_scalar() && !ir->lhs->type->is_vector());
-
-      if (ir->lhs->type->is_array() || ir->lhs->type->without_array()->is_matrix()) {
-         if (ir->lhs->type->without_array()->is_64bit()) {
-            switch (ir->lhs->type->without_array()->vector_elements) {
-            case 1:
-               l.writemask = WRITEMASK_X;
-               break;
-            case 2:
-               l.writemask = WRITEMASK_XY;
-               break;
-            case 3:
-               l.writemask = WRITEMASK_XYZ;
-               break;
-            case 4:
-               l.writemask = WRITEMASK_XYZW;
-               break;
-            }
-         } else
-            l.writemask = WRITEMASK_XYZW;
-      }
-   } else {
+   {
       int swizzles[4];
       int first_enabled_chan = 0;
       int rhs_chan = 0;
@@ -2887,6 +2861,15 @@ glsl_to_tgsi_visitor::visit(ir_assignment *ir)
             assert(variable->data.location == FRAG_RESULT_STENCIL);
             l.writemask = WRITEMASK_Y;
          }
+      } else if (ir->write_mask == 0) {
+         assert(!ir->lhs->type->is_scalar() && !ir->lhs->type->is_vector());
+
+         if (ir->lhs->type->is_array() || ir->lhs->type->is_matrix()) {
+            unsigned num_elements = ir->lhs->type->without_array()->vector_elements;
+            l.writemask = u_bit_consecutive(0, num_elements);
+         } else {
+            l.writemask = WRITEMASK_XYZW;
+         }
       } else {
          l.writemask = ir->write_mask;
       }