Index: llvm/lib/Target/Sparc/SparcInstrAliases.td
===================================================================
--- llvm/lib/Target/Sparc/SparcInstrAliases.td
+++ llvm/lib/Target/Sparc/SparcInstrAliases.td
@@ -492,6 +492,7 @@
 
 def : MnemonicAlias<"stuha", "stha">;
 def : MnemonicAlias<"stsha", "stha">;
+def : MnemonicAlias<"stw", "st">, Requires<[HasV9]>;
 
 def : MnemonicAlias<"lduw", "ld">, Requires<[HasV9]>;
 def : MnemonicAlias<"lduwa", "lda">, Requires<[HasV9]>;
Index: llvm/lib/Target/Sparc/SparcInstrInfo.td
===================================================================
--- llvm/lib/Target/Sparc/SparcInstrInfo.td
+++ llvm/lib/Target/Sparc/SparcInstrInfo.td
@@ -1623,6 +1623,17 @@
 }
 }
 
+// Section A.42 - Prefetch Data
+let Predicates = [HasV9] in {
+  def PREFETCHr : F3_1<3, 0b101101,
+                   (outs), (ins MEMrr:$addr, shift_imm5:$rd),
+                   "prefetch [$addr], $rd", []>;
+  def PREFETCHi : F3_2<3, 0b101101,
+                   (outs), (ins MEMri:$addr, shift_imm5:$rd),
+                   "prefetch [$addr], $rd", []>;
+}
+
+
 
 // Section A.43 - Read Privileged Register Instructions
 let Predicates = [HasV9] in {
Index: llvm/test/MC/Sparc/sparcv9-instructions.s
===================================================================
--- llvm/test/MC/Sparc/sparcv9-instructions.s
+++ llvm/test/MC/Sparc/sparcv9-instructions.s
@@ -298,3 +298,16 @@
         ! V8-NEXT: rd %pc, %o7
         ! V9: rd %pc, %o7               ! encoding: [0x9f,0x41,0x40,0x00]
         rd %pc, %o7
+
+        ! V9: st %o1, [%o0]             ! encoding: [0xd2,0x22,0x00,0x00]
+        stw %o1, [%o0]
+
+        ! V8:      error: instruction requires a CPU feature not currently enabled
+        ! V8-NEXT: prefetch  [ %i1 + 0xf80 ], 1
+        ! V9: prefetch  [%i1+3968], 1  ! encoding: [0xc3,0x6e,0x6f,0x80]
+        prefetch  [ %i1 + 0xf80 ], 1
+
+        ! V8:      error: instruction requires a CPU feature not currently enabled
+        ! V8-NEXT: prefetch  [ %i1 + %i2 ], 1
+        ! V9: prefetch  [%i1+%i2], 1  ! encoding: [0xc3,0x6e,0x40,0x1a]
+        prefetch  [ %i1 + %i2 ], 1