Mesa (master): st/glsl_to_tgsi: simpler fixup of empty writemasks

[Nicolai Hähnle]

Module: Mesa
Branch: master
Commit: f5f3cadca3809952288e3726ed5fde22090dc61d
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f5f3cadca3809952288e3726ed5fde22090dc61d

Author: Nicolai Hähnle <nicolai.haehnle at amd.com>
Date:   Fri Oct  7 12:49:36 2016 +0200

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 at folklore1984.net>
Reviewed-by: Dave Airlie <airlied at redhat.com>

---

 src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 37 ++++++++----------------------
 1 file 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;
       }