diff --git a/src/asahi/lib/gen_pack.py b/src/asahi/lib/gen_pack.py
index 0396672a12d..75419942fe0 100644
--- a/src/asahi/lib/gen_pack.py
+++ b/src/asahi/lib/gen_pack.py
@@ -129,6 +129,16 @@ __gen_from_groups(uint32_t value, uint32_t group_size, uint32_t length)
 #define agx_print(fp, T, var, indent)                   \\
         AGX_ ## T ## _print(fp, &(var), indent)
 
+static inline void agx_merge_helper(uint32_t *dst, const uint32_t *src, size_t bytes)
+{
+        assert((bytes & 3) == 0);
+
+        for (unsigned i = 0; i < (bytes / 4); ++i)
+                dst[i] |= src[i];
+}
+
+#define agx_merge(packed1, packed2, type) \
+        agx_merge_helper((packed1).opaque, (packed2).opaque, AGX_##type##_LENGTH)
 """
 
 def to_alphanum(name):