diff --git a/lib/Target/R600/AMDGPUCallingConv.td b/lib/Target/R600/AMDGPUCallingConv.td
index 65cdb24..5f8ad8c 100644
--- a/lib/Target/R600/AMDGPUCallingConv.td
+++ b/lib/Target/R600/AMDGPUCallingConv.td
@@ -20,7 +20,7 @@
   CCIfInReg<CCIfType<[f32, i32] , CCAssignToReg<[
     SGPR0, SGPR1, SGPR2, SGPR3, SGPR4, SGPR5, SGPR6, SGPR7,
     SGPR8, SGPR9, SGPR10, SGPR11, SGPR12, SGPR13, SGPR14, SGPR15,
-    SGPR16
+    SGPR16, SGPR17, SGPR18, SGPR19, SGPR20, SGPR21
   ]>>>,
 
   CCIfInReg<CCIfType<[i64] , CCAssignToRegWithShadow<