Index: llvm/trunk/lib/Target/X86/X86CallingConv.td
===================================================================
--- llvm/trunk/lib/Target/X86/X86CallingConv.td
+++ llvm/trunk/lib/Target/X86/X86CallingConv.td
@@ -770,6 +770,9 @@
 
 // This is the root argument convention for the X86-32 backend.
 def CC_X86_32 : CallingConv<[
+  // X86_INTR calling convention is valid in MCU target and should override the
+  // MCU calling convention. Thus, this should be checked before isTargetMCU().
+  CCIfCC<"CallingConv::X86_INTR", CCDelegateTo<CC_X86_32_Intr>>,
   CCIfSubtarget<"isTargetMCU()", CCDelegateTo<CC_X86_32_MCU>>,
   CCIfCC<"CallingConv::X86_FastCall", CCDelegateTo<CC_X86_32_FastCall>>,
   CCIfCC<"CallingConv::X86_VectorCall", CCDelegateTo<CC_X86_32_VectorCall>>,
@@ -777,7 +780,6 @@
   CCIfCC<"CallingConv::Fast", CCDelegateTo<CC_X86_32_FastCC>>,
   CCIfCC<"CallingConv::GHC", CCDelegateTo<CC_X86_32_GHC>>,
   CCIfCC<"CallingConv::HiPE", CCDelegateTo<CC_X86_32_HiPE>>,
-  CCIfCC<"CallingConv::X86_INTR", CCDelegateTo<CC_X86_32_Intr>>,
 
   // Otherwise, drop to normal X86-32 CC
   CCDelegateTo<CC_X86_32_C>