diff --git a/clang/lib/Headers/altivec.h b/clang/lib/Headers/altivec.h
--- a/clang/lib/Headers/altivec.h
+++ b/clang/lib/Headers/altivec.h
@@ -16597,6 +16597,58 @@
 }
 #endif
 
+/* vec_xst_trunc */
+
+#if defined(__POWER10_VECTOR__) && defined(__VSX__)
+static inline __ATTRS_o_ai void vec_xst_trunc(vector signed __int128 __vec,
+                                              signed long long __offset,
+                                              signed char *__ptr) {
+  *(__ptr + __offset) = (signed char)__vec[0];
+}
+
+static inline __ATTRS_o_ai void vec_xst_trunc(vector unsigned __int128 __vec,
+                                              signed long long __offset,
+                                              unsigned char *__ptr) {
+  *(__ptr + __offset) = (unsigned char)__vec[0];
+}
+
+static inline __ATTRS_o_ai void vec_xst_trunc(vector signed __int128 __vec,
+                                              signed long long __offset,
+                                              signed short *__ptr) {
+  *(__ptr + __offset) = (signed short)__vec[0];
+}
+
+static inline __ATTRS_o_ai void vec_xst_trunc(vector unsigned __int128 __vec,
+                                              signed long long __offset,
+                                              unsigned short *__ptr) {
+  *(__ptr + __offset) = (unsigned short)__vec[0];
+}
+
+static inline __ATTRS_o_ai void vec_xst_trunc(vector signed __int128 __vec,
+                                              signed long long __offset,
+                                              signed int *__ptr) {
+  *(__ptr + __offset) = (signed int)__vec[0];
+}
+
+static inline __ATTRS_o_ai void vec_xst_trunc(vector unsigned __int128 __vec,
+                                              signed long long __offset,
+                                              unsigned int *__ptr) {
+  *(__ptr + __offset) = (unsigned int)__vec[0];
+}
+
+static inline __ATTRS_o_ai void vec_xst_trunc(vector signed __int128 __vec,
+                                              signed long long __offset,
+                                              signed long long *__ptr) {
+  *(__ptr + __offset) = (signed long long)__vec[0];
+}
+
+static inline __ATTRS_o_ai void vec_xst_trunc(vector unsigned __int128 __vec,
+                                              signed long long __offset,
+                                              unsigned long long *__ptr) {
+  *(__ptr + __offset) = (unsigned long long)__vec[0];
+}
+#endif
+
 /* vec_xst_be */
 
 #ifdef __LITTLE_ENDIAN__
diff --git a/clang/test/CodeGen/builtins-ppc-p10vector.c b/clang/test/CodeGen/builtins-ppc-p10vector.c
--- a/clang/test/CodeGen/builtins-ppc-p10vector.c
+++ b/clang/test/CodeGen/builtins-ppc-p10vector.c
@@ -10,7 +10,18 @@
 vector unsigned short vusa;
 vector unsigned int vuia;
 vector unsigned long long vulla, vullb;
+
+signed char sca;
+unsigned char uca;
+signed short ssa;
+unsigned short usa;
+signed int sia;
 unsigned int uia;
+signed long long slla;
+unsigned long long ulla;
+
+vector unsigned __int128 vui128a;
+vector signed __int128 vsi128a;
 
 vector unsigned long long test_vpdepd(void) {
   // CHECK: @llvm.ppc.altivec.vpdepd(<2 x i64>
@@ -91,3 +102,59 @@
   // CHECK-NEXT: ret i32
   return vec_test_lsbb_all_zeros(vuca);
 }
+
+void test_vec_xst_trunc_sc(vector signed __int128 __a, signed long long __b,
+                           signed char *__c) {
+  // CHECK-BE: store i8 %{{.+}}, i8* %{{.+}}, align 1
+  // CHECK-LE: store i8 %{{.+}}, i8* %{{.+}}, align 1
+  vec_xst_trunc(__a, __b, __c);
+}
+
+void test_vec_xst_trunc_uc(vector unsigned __int128 __a, signed long long __b,
+                           unsigned char *__c) {
+  // CHECK-BE: store i8 %{{.+}}, i8* %{{.+}}, align 1
+  // CHECK-LE: store i8 %{{.+}}, i8* %{{.+}}, align 1
+  vec_xst_trunc(__a, __b, __c);
+}
+
+void test_vec_xst_trunc_ss(vector signed __int128 __a, signed long long __b,
+                           signed short *__c) {
+  // CHECK-BE: store i16 %{{.+}}, i16* %{{.+}}, align 2
+  // CHECK-LE: store i16 %{{.+}}, i16* %{{.+}}, align 2
+  vec_xst_trunc(__a, __b, __c);
+}
+
+void test_vec_xst_trunc_us(vector unsigned __int128 __a, signed long long __b,
+                           unsigned short *__c) {
+  // CHECK-BE: store i16 %{{.+}}, i16* %{{.+}}, align 2
+  // CHECK-LE: store i16 %{{.+}}, i16* %{{.+}}, align 2
+  vec_xst_trunc(__a, __b, __c);
+}
+
+void test_vec_xst_trunc_si(vector signed __int128 __a, signed long long __b,
+                           signed int *__c) {
+  // CHECK-BE: store i32 %{{.+}}, i32* %{{.+}}, align 4
+  // CHECK-LE: store i32 %{{.+}}, i32* %{{.+}}, align 4
+  vec_xst_trunc(__a, __b, __c);
+}
+
+void test_vec_xst_trunc_ui(vector unsigned __int128 __a, signed long long __b,
+                           unsigned int *__c) {
+  // CHECK-BE: store i32 %{{.+}}, i32* %{{.+}}, align 4
+  // CHECK-LE: store i32 %{{.+}}, i32* %{{.+}}, align 4
+  vec_xst_trunc(__a, __b, __c);
+}
+
+void test_vec_xst_trunc_sll(vector signed __int128 __a, signed long long __b,
+                            signed long long *__c) {
+  // CHECK-BE: store i64 %{{.+}}, i64* %{{.+}}, align 8
+  // CHECK-LE: store i64 %{{.+}}, i64* %{{.+}}, align 8
+  vec_xst_trunc(__a, __b, __c);
+}
+
+void test_vec_xst_trunc_ull(vector unsigned __int128 __a, signed long long __b,
+                            unsigned long long *__c) {
+  // CHECK-BE: store i64 %{{.+}}, i64* %{{.+}}, align 8
+  // CHECK-LE: store i64 %{{.+}}, i64* %{{.+}}, align 8
+  vec_xst_trunc(__a, __b, __c);
+}
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
@@ -228,6 +228,14 @@
 def PrefixInstrs : Predicate<"PPCSubTarget->hasPrefixInstrs()">;
 def IsISA3_1 : Predicate<"PPCSubTarget->isISA3_1()">;
 
+let mayLoad = 0, mayStore = 1, Predicates = [IsISA3_1] in {
+  // The XFormMemOp flag is set on the instruction format.
+  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, []>;
+}
+
 let Predicates = [PrefixInstrs] in {
   let Interpretation64Bit = 1, isCodeGenOnly = 1 in {
     defm PADDI8 :
@@ -590,3 +598,14 @@
   def : Pat<(i32 (int_ppc_vsx_xvtlsbb v16i8:$XB, 0)),
             (EXTRACT_SUBREG (XVTLSBB (COPY_TO_REGCLASS $XB, VSRC)), sub_eq)>;
 }
+
+let AddedComplexity = 400, Predicates = [IsISA3_1] in {
+  def : Pat<(truncstorei8 (i32 (vector_extract v16i8:$rS, 0)), xoaddr:$src),
+            (STXVRBX (COPY_TO_REGCLASS $rS, VSRC), xoaddr:$src)>;
+  def : Pat<(truncstorei16 (i32 (vector_extract v8i16:$rS, 0)), xoaddr:$src),
+            (STXVRHX (COPY_TO_REGCLASS $rS, VSRC), xoaddr:$src)>;
+  def : Pat<(store (i32 (vector_extract v4i32:$rS, 0)), xoaddr:$src),
+            (STXVRWX (COPY_TO_REGCLASS $rS, VSRC), xoaddr:$src)>;
+  def : Pat<(store (i64 (vector_extract v2i64:$rS, 0)), xoaddr:$src),
+            (STXVRDX (COPY_TO_REGCLASS $rS, VSRC), xoaddr:$src)>;
+}
diff --git a/llvm/test/CodeGen/PowerPC/p10-vsx-builtins.ll b/llvm/test/CodeGen/PowerPC/p10-vsx-builtins.ll
--- a/llvm/test/CodeGen/PowerPC/p10-vsx-builtins.ll
+++ b/llvm/test/CodeGen/PowerPC/p10-vsx-builtins.ll
@@ -33,3 +33,113 @@
   %0 = tail call i32 @llvm.ppc.vsx.xvtlsbb(<16 x i8> %vuca, i1 0)
   ret i32 %0
 }
+
+define void @vec_xst_trunc_sc(<1 x i128> %__vec, i64 %__offset, i8* nocapture %__ptr) {
+; CHECK-LABEL: vec_xst_trunc_sc:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    stxvrbx v2, r6, r5
+; CHECK-NEXT:    blr
+entry:
+  %0 = bitcast <1 x i128> %__vec to <16 x i8>
+  %conv = extractelement <16 x i8> %0, i32 0
+  %add.ptr = getelementptr inbounds i8, i8* %__ptr, i64 %__offset
+  store i8 %conv, i8* %add.ptr, align 1
+  ret void
+}
+
+define void @vec_xst_trunc_uc(<1 x i128> %__vec, i64 %__offset, i8* nocapture %__ptr) {
+; CHECK-LABEL: vec_xst_trunc_uc:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    stxvrbx v2, r6, r5
+; CHECK-NEXT:    blr
+entry:
+  %0 = bitcast <1 x i128> %__vec to <16 x i8>
+  %conv = extractelement <16 x i8> %0, i32 0
+  %add.ptr = getelementptr inbounds i8, i8* %__ptr, i64 %__offset
+  store i8 %conv, i8* %add.ptr, align 1
+  ret void
+}
+
+define void @vec_xst_trunc_ss(<1 x i128> %__vec, i64 %__offset, i16* nocapture %__ptr) {
+; CHECK-LABEL: vec_xst_trunc_ss:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    sldi r3, r5, 1
+; CHECK-NEXT:    stxvrhx v2, r6, r3
+; CHECK-NEXT:    blr
+entry:
+  %0 = bitcast <1 x i128> %__vec to <8 x i16>
+  %conv = extractelement <8 x i16> %0, i32 0
+  %add.ptr = getelementptr inbounds i16, i16* %__ptr, i64 %__offset
+  store i16 %conv, i16* %add.ptr, align 2
+  ret void
+}
+
+define void @vec_xst_trunc_us(<1 x i128> %__vec, i64 %__offset, i16* nocapture %__ptr) {
+; CHECK-LABEL: vec_xst_trunc_us:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    sldi r3, r5, 1
+; CHECK-NEXT:    stxvrhx v2, r6, r3
+; CHECK-NEXT:    blr
+entry:
+  %0 = bitcast <1 x i128> %__vec to <8 x i16>
+  %conv = extractelement <8 x i16> %0, i32 0
+  %add.ptr = getelementptr inbounds i16, i16* %__ptr, i64 %__offset
+  store i16 %conv, i16* %add.ptr, align 2
+  ret void
+}
+
+define void @vec_xst_trunc_si(<1 x i128> %__vec, i64 %__offset, i32* nocapture %__ptr) {
+; CHECK-LABEL: vec_xst_trunc_si:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    sldi r3, r5, 2
+; CHECK-NEXT:    stxvrwx v2, r6, r3
+; CHECK-NEXT:    blr
+entry:
+  %0 = bitcast <1 x i128> %__vec to <4 x i32>
+  %conv = extractelement <4 x i32> %0, i32 0
+  %add.ptr = getelementptr inbounds i32, i32* %__ptr, i64 %__offset
+  store i32 %conv, i32* %add.ptr, align 4
+  ret void
+}
+
+define void @vec_xst_trunc_ui(<1 x i128> %__vec, i64 %__offset, i32* nocapture %__ptr) {
+; CHECK-LABEL: vec_xst_trunc_ui:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    sldi r3, r5, 2
+; CHECK-NEXT:    stxvrwx v2, r6, r3
+; CHECK-NEXT:    blr
+entry:
+  %0 = bitcast <1 x i128> %__vec to <4 x i32>
+  %conv = extractelement <4 x i32> %0, i32 0
+  %add.ptr = getelementptr inbounds i32, i32* %__ptr, i64 %__offset
+  store i32 %conv, i32* %add.ptr, align 4
+  ret void
+}
+
+define void @vec_xst_trunc_sll(<1 x i128> %__vec, i64 %__offset, i64* nocapture %__ptr)  {
+; CHECK-LABEL: vec_xst_trunc_sll:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    sldi r3, r5, 3
+; CHECK-NEXT:    stxvrdx v2, r6, r3
+; CHECK-NEXT:    blr
+entry:
+  %0 = bitcast <1 x i128> %__vec to <2 x i64>
+  %conv = extractelement <2 x i64> %0, i32 0
+  %add.ptr = getelementptr inbounds i64, i64* %__ptr, i64 %__offset
+  store i64 %conv, i64* %add.ptr, align 8
+  ret void
+}
+
+define void @vec_xst_trunc_ull(<1 x i128> %__vec, i64 %__offset, i64* nocapture %__ptr)  {
+; CHECK-LABEL: vec_xst_trunc_ull:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    sldi r3, r5, 3
+; CHECK-NEXT:    stxvrdx v2, r6, r3
+; CHECK-NEXT:    blr
+entry:
+  %0 = bitcast <1 x i128> %__vec to <2 x i64>
+  %conv = extractelement <2 x i64> %0, i32 0
+  %add.ptr = getelementptr inbounds i64, i64* %__ptr, i64 %__offset
+  store i64 %conv, i64* %add.ptr, align 8
+  ret void
+}
diff --git a/llvm/test/MC/Disassembler/PowerPC/p10insts.txt b/llvm/test/MC/Disassembler/PowerPC/p10insts.txt
--- a/llvm/test/MC/Disassembler/PowerPC/p10insts.txt
+++ b/llvm/test/MC/Disassembler/PowerPC/p10insts.txt
@@ -31,5 +31,17 @@
 # CHECK: vclrrb 1, 4, 3
 0x10 0x24 0x19 0xcd
 
+# 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
+
 # CHECK: xvtlsbb 1, 7
 0xf0 0x82 0x3f 0x6c
diff --git a/llvm/test/MC/PowerPC/p10.s b/llvm/test/MC/PowerPC/p10.s
--- a/llvm/test/MC/PowerPC/p10.s
+++ b/llvm/test/MC/PowerPC/p10.s
@@ -33,6 +33,18 @@
 # CHECK-BE: vclrrb 1, 4, 3                        # encoding: [0x10,0x24,0x19,0xcd]
 # CHECK-LE: vclrrb 1, 4, 3                        # encoding: [0xcd,0x19,0x24,0x10]
             vclrrb 1, 4, 3
+# 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
 # CHECK-BE: xvtlsbb 1, 7                          # encoding: [0xf0,0x82,0x3f,0x6c]
 # CHECK-LE: xvtlsbb 1, 7                          # encoding: [0x6c,0x3f,0x82,0xf0]
             xvtlsbb 1, 7