[Mesa-dev] [PATCH 01/14] i965: Don't copy propagate sat MOVs into LOAD_PAYLOAD

[Kristian Høgsberg]

The LOAD_PAYLOAD opcode can't saturate its sources, so skip
saturating MOVs.  The register coalescing after lower_load_payload()
will clean up the extra MOVs.

Signed-off-by: Kristian Høgsberg <krh at bitplanet.net>
---
 src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
index e1989cb..87ea9c2 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
@@ -454,8 +454,12 @@ fs_visitor::try_constant_propagate(fs_inst *inst, acp_entry *entry)
       val.effective_width = inst->src[i].effective_width;
 
       switch (inst->opcode) {
-      case BRW_OPCODE_MOV:
       case SHADER_OPCODE_LOAD_PAYLOAD:
+         /* LOAD_PAYLOAD can't sat its sources. */
+         if (entry->saturate)
+            break;
+         /* Otherwise, fall through */
+      case BRW_OPCODE_MOV:
          inst->src[i] = val;
          progress = true;
          break;
-- 
2.1.0