i965/fs: Propagate conditional modifiers from not instructions to compare instructionscmod-propagation-work

No changes.

1 files changed, 14 insertions, 0 deletions

diff --git a/src/intel/compiler/brw_fs_cmod_propagation.cpp b/src/intel/compiler/brw_fs_cmod_propagation.cpp
index b07da8f03a4..4268265e8b9 100644
--- a/src/intel/compiler/brw_fs_cmod_propagation.cpp
+++ b/src/intel/compiler/brw_fs_cmod_propagation.cpp
@@ -157,6 +157,20 @@ cmod_propagate_not(const gen_device_info *devinfo, bblock_t *block,
          break;
       }
 
+      /* Elide a bunch of the usual checks here.  Compares can always do
+       * conditional modifiers, and the instruction will always already have a
+       * conditional modifier set.
+       */
+      if (scan_inst->opcode == BRW_OPCODE_CMP &&
+          scan_inst->src[1].is_zero() &&
+          scan_inst->src[0].equals(inst->src[0]) &&
+          !scan_inst->is_partial_write() &&
+          scan_inst->exec_size == inst->exec_size &&
+          scan_inst->conditional_mod == cond) {
+         inst->remove(block);
+         return true;
+      }
+
       if (scan_inst->flags_written())
          break;