Mesa (glsl-to-tgsi): glsl_to_tgsi: use swizzle_for_size for src reg in conditional moves

[Bryan Cain]

Module: Mesa
Branch: glsl-to-tgsi
Commit: 4e09dfa44dc1942742c55f82cf37b6910d8a2db2
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=4e09dfa44dc1942742c55f82cf37b6910d8a2db2

Author: Bryan Cain <bryancain3 at gmail.com>
Date:   Thu Jun 23 19:35:36 2011 -0500

glsl_to_tgsi: use swizzle_for_size for src reg in conditional moves

This prevents the copy propagation pass from being confused by undefined
channels and thus missing optimization opportunities.

---

 src/mesa/state_tracker/st_glsl_to_tgsi.cpp |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index abeb44a..6d76686 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -1882,10 +1882,13 @@ glsl_to_tgsi_visitor::visit(ir_assignment *ir)
       st_src_reg condition = this->result;
 
       for (i = 0; i < type_size(ir->lhs->type); i++) {
+         st_src_reg l_src = st_src_reg(l);
+         l_src.swizzle = swizzle_for_size(ir->lhs->type->vector_elements);
+         
          if (switch_order) {
-            emit(ir, TGSI_OPCODE_CMP, l, condition, st_src_reg(l), r);
+            emit(ir, TGSI_OPCODE_CMP, l, condition, l_src, r);
          } else {
-            emit(ir, TGSI_OPCODE_CMP, l, condition, r, st_src_reg(l));
+            emit(ir, TGSI_OPCODE_CMP, l, condition, r, l_src);
          }
 
          l.index++;