-// Truncations of 32-bit registers to memory.
-defm STC : StoreRXPair<"stc", 0x42, 0xE372, truncstorei8, GR32, 1>;
-defm STH : StoreRXPair<"sth", 0x40, 0xE370, truncstorei16, GR32, 2>;
-def STHRL : StoreRILPC<"sthrl", 0xC47, aligned_truncstorei16, GR32>;
+// Truncations of 32-bit registers to 8-bit memory. STCMux expands to
+// STC, STCY or STCH, depending on the choice of register.
+def STCMux : StoreRXYPseudo<truncstorei8, GRX32, 1>,
+ Requires<[FeatureHighWord]>;
+defm STC : StoreRXPair<"stc", 0x42, 0xE372, truncstorei8, GR32, 1>;
+def STCH : StoreRXY<"stch", 0xE3C3, truncstorei8, GRH32, 1>,
+ Requires<[FeatureHighWord]>;
+
+// Truncations of 32-bit registers to 16-bit memory. STHMux expands to
+// STH, STHY or STHH, depending on the choice of register.
+def STHMux : StoreRXYPseudo<truncstorei16, GRX32, 1>,
+ Requires<[FeatureHighWord]>;
+defm STH : StoreRXPair<"sth", 0x40, 0xE370, truncstorei16, GR32, 2>;
+def STHH : StoreRXY<"sthh", 0xE3C7, truncstorei16, GRH32, 2>,
+ Requires<[FeatureHighWord]>;
+def STHRL : StoreRILPC<"sthrl", 0xC47, aligned_truncstorei16, GR32>;