diff --git a/llvm/lib/Target/PowerPC/PPCInstrPrefix.td b/llvm/lib/Target/PowerPC/PPCInstrPrefix.td
--- a/llvm/lib/Target/PowerPC/PPCInstrPrefix.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrPrefix.td
@@ -942,8 +942,26 @@
                          "vclrrb $vD, $vA, $rB", IIC_VecGeneral,
                          [(set v16i8:$vD,
                                (int_ppc_altivec_vclrrb v16i8:$vA, i32:$rB))]>;
+
+  // The XFormMemOp flag for the following 8 instructions is set on
+  // the instruction format.
+  let mayLoad = 1, mayStore = 0 in {
+    def LXVRBX : X_XT6_RA5_RB5<31, 13, "lxvrbx", vsrc, []>;
+    def LXVRHX : X_XT6_RA5_RB5<31, 45, "lxvrhx", vsrc, []>;
+    def LXVRWX : X_XT6_RA5_RB5<31, 77, "lxvrwx", vsrc, []>;
+    def LXVRDX : X_XT6_RA5_RB5<31, 109, "lxvrdx", vsrc, []>;
+  }
+
+  let mayLoad = 0, mayStore = 1 in {
+    def STXVRBX : X_XS6_RA5_RB5<31, 141, "stxvrbx", vsrc, []>;
+    def STXVRHX : X_XS6_RA5_RB5<31, 173, "stxvrhx", vsrc, []>;
+    def STXVRWX : X_XS6_RA5_RB5<31, 205, "stxvrwx", vsrc, []>;
+    def STXVRDX : X_XS6_RA5_RB5<31, 237, "stxvrdx", vsrc, []>;
+  }
 }
 
+
+
 //---------------------------- Anonymous Patterns ----------------------------//
 let Predicates = [IsISA3_1] in {
   def : Pat<(v16i8 (int_ppc_vsx_xxgenpcvbm v16i8:$VRB, imm:$IMM)),
diff --git a/llvm/test/MC/Disassembler/PowerPC/ppc64-encoding-ISA31.txt b/llvm/test/MC/Disassembler/PowerPC/ppc64-encoding-ISA31.txt
--- a/llvm/test/MC/Disassembler/PowerPC/ppc64-encoding-ISA31.txt
+++ b/llvm/test/MC/Disassembler/PowerPC/ppc64-encoding-ISA31.txt
@@ -278,3 +278,27 @@
 
 # CHECK: vinsdrx 1, 2, 3
 0x10 0x22 0x1b 0xcf
+
+# CHECK: lxvrbx 32, 1, 2
+0x7c 0x01 0x10 0x1b
+
+# CHECK: lxvrhx 33, 1, 2
+0x7c 0x21 0x10 0x5b
+
+# CHECK: lxvrdx 34, 1, 2
+0x7c 0x41 0x10 0xdb
+
+# CHECK: lxvrwx 35, 1, 2
+0x7c 0x61 0x10 0x9b
+
+# CHECK: stxvrbx 32, 3, 1
+0x7c 0x03 0x09 0x1b
+
+# CHECK: stxvrhx 33, 3, 1
+0x7c 0x23 0x09 0x5b
+
+# CHECK: stxvrwx 34, 3, 1
+0x7c 0x43 0x09 0x9b
+
+# CHECK: stxvrdx 35, 3, 1
+0x7c 0x63 0x09 0xdb
diff --git a/llvm/test/MC/PowerPC/ppc64-encoding-ISA31.s b/llvm/test/MC/PowerPC/ppc64-encoding-ISA31.s
--- a/llvm/test/MC/PowerPC/ppc64-encoding-ISA31.s
+++ b/llvm/test/MC/PowerPC/ppc64-encoding-ISA31.s
@@ -405,3 +405,27 @@
 # CHECK-BE: vinsdrx 1, 2, 3                       # encoding: [0x10,0x22,0x1b,0xcf]
 # CHECK-LE: vinsdrx 1, 2, 3                       # encoding: [0xcf,0x1b,0x22,0x10]
             vinsdrx 1, 2, 3
+# CHECK-BE: lxvrbx 32, 1, 2                       # encoding: [0x7c,0x01,0x10,0x1b]
+# CHECK-LE: lxvrbx 32, 1, 2                       # encoding: [0x1b,0x10,0x01,0x7c]
+            lxvrbx 32, 1, 2
+# CHECK-BE: lxvrhx 33, 1, 2                       # encoding: [0x7c,0x21,0x10,0x5b]
+# CHECK-LE: lxvrhx 33, 1, 2                       # encoding: [0x5b,0x10,0x21,0x7c]
+            lxvrhx 33, 1, 2
+# CHECK-BE: lxvrdx 34, 1, 2                       # encoding: [0x7c,0x41,0x10,0xdb]
+# CHECK-LE: lxvrdx 34, 1, 2                       # encoding: [0xdb,0x10,0x41,0x7c]
+            lxvrdx 34, 1, 2
+# CHECK-BE: lxvrwx 35, 1, 2                       # encoding: [0x7c,0x61,0x10,0x9b]
+# CHECK-LE: lxvrwx 35, 1, 2                       # encoding: [0x9b,0x10,0x61,0x7c]
+            lxvrwx 35, 1, 2
+# CHECK-BE: stxvrbx 32, 3, 1                      # encoding: [0x7c,0x03,0x09,0x1b]
+# CHECK-LE: stxvrbx 32, 3, 1                      # encoding: [0x1b,0x09,0x03,0x7c]
+            stxvrbx 32, 3, 1
+# CHECK-BE: stxvrhx 33, 3, 1                      # encoding: [0x7c,0x23,0x09,0x5b]
+# CHECK-LE: stxvrhx 33, 3, 1                      # encoding: [0x5b,0x09,0x23,0x7c]
+            stxvrhx 33, 3, 1
+# CHECK-BE: stxvrwx 34, 3, 1                      # encoding: [0x7c,0x43,0x09,0x9b]
+# CHECK-LE: stxvrwx 34, 3, 1                      # encoding: [0x9b,0x09,0x43,0x7c]
+            stxvrwx 34, 3, 1
+# CHECK-BE: stxvrdx 35, 3, 1                      # encoding: [0x7c,0x63,0x09,0xdb]
+# CHECK-LE: stxvrdx 35, 3, 1                      # encoding: [0xdb,0x09,0x63,0x7c]
+            stxvrdx 35, 3, 1