diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index 702b182c579..62c2314fece 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -212,6 +212,14 @@ dst_reg::dst_reg(src_reg reg)
    this->fixed_hw_reg = reg.fixed_hw_reg;
 }
 
+bool
+dst_reg::is_null() const
+{
+   return file == HW_REG &&
+          fixed_hw_reg.file == BRW_ARCHITECTURE_REGISTER_FILE &&
+          fixed_hw_reg.nr == BRW_ARF_NULL;
+}
+
 bool
 vec4_instruction::is_send_from_grf()
 {
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h
index 5e5ef036a66..159a5bdfbbb 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_vec4.h
@@ -194,6 +194,8 @@ public:
 
    explicit dst_reg(src_reg reg);
 
+   bool is_null() const;
+
    int writemask; /**< Bitfield of WRITEMASK_[XYZW] */
 
    src_reg *reladdr;