diff --git a/dlls/wined3d/wined3d_private.h b/dlls/wined3d/wined3d_private.h
index 05576cd967d..334724514df 100644
--- a/dlls/wined3d/wined3d_private.h
+++ b/dlls/wined3d/wined3d_private.h
@@ -4352,6 +4352,13 @@ static inline BOOL is_rasterization_disabled(const struct wined3d_shader *geomet
             && geometry_shader->u.gs.so_desc.rasterizer_stream_idx == WINED3D_NO_RASTERIZER_STREAM;
 }
 
+static inline int wined3d_bit_scan(unsigned int *x)
+{
+    int bit_offset = ffs(*x) - 1;
+    *x ^= 1u << bit_offset;
+    return bit_offset;
+}
+
 static inline DWORD wined3d_extract_bits(const DWORD *bitstream,
         unsigned int offset, unsigned int count)
 {