i965/fs: Gen4-5: Setup discard masks for MRT alpha test

The same setup is required here as when the user-provided shader
explicitly uses KIL or discard.

Signed-off-by: Chris Forbes <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index c332d4cbb53..cd806c77c41 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -3228,7 +3228,7 @@ fs_visitor::run()
       /* We handle discards by keeping track of the still-live pixels in f0.1.
        * Initialize it with the dispatched pixels.
        */
-      if (fp->UsesKill) {
+      if (fp->UsesKill || c->key.alpha_test_func) {
          fs_inst *discard_init = emit(FS_OPCODE_MOV_DISPATCH_TO_FLAGS);
          discard_init->flag_subreg = 1;
       }