[Mesa-stable] [PATCH 3/4] i965/fs: Gen4-5: Setup discard masks for MRT alpha test

[Chris Forbes]

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

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
Reviewed-by: Eric Anholt <eric at anholt.net>
---
 src/mesa/drivers/dri/i965/brw_fs.cpp      | 2 +-
 src/mesa/drivers/dri/i965/brw_fs_emit.cpp | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 62dccc1..e96e5ff 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -2920,7 +2920,7 @@ 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;
       }
diff --git a/src/mesa/drivers/dri/i965/brw_fs_emit.cpp b/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
index 4225922..8b02ea9 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
@@ -107,7 +107,7 @@ fs_generator::generate_fb_write(fs_inst *inst)
    brw_set_mask_control(p, BRW_MASK_DISABLE);
    brw_set_compression_control(p, BRW_COMPRESSION_NONE);
 
-   if (fp->UsesKill) {
+   if (fp->UsesKill || c->key.alpha_test_func) {
       struct brw_reg pixel_mask;
 
       if (brw->gen >= 6)
-- 
1.8.4.2