[SystemZ] Add sign-extending high-word loads (LBH and LHH)

llvm-svn: 191740
diff --git a/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp b/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp
index 798fa33..a1c0c36 100644
--- a/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZInstrInfo.cpp
@@ -806,6 +806,14 @@
     splitMove(MI, SystemZ::STD);
     return true;
 
+  case SystemZ::LBMux:
+    expandRXYPseudo(MI, SystemZ::LB, SystemZ::LBH);
+    return true;
+
+  case SystemZ::LHMux:
+    expandRXYPseudo(MI, SystemZ::LH, SystemZ::LHH);
+    return true;
+
   case SystemZ::LMux:
     expandRXYPseudo(MI, SystemZ::L, SystemZ::LFH);
     return true;