diff --git a/clang/include/clang/Basic/BuiltinsPPC.def b/clang/include/clang/Basic/BuiltinsPPC.def
--- a/clang/include/clang/Basic/BuiltinsPPC.def
+++ b/clang/include/clang/Basic/BuiltinsPPC.def
@@ -306,6 +306,10 @@
 BUILTIN(__builtin_altivec_vclrlb, "V16cV16cUi", "")
 BUILTIN(__builtin_altivec_vclrrb, "V16cV16cUi", "")
 
+// P10 Vector Count Leading / Trailing Zeroes under bit Mask built-ins.
+BUILTIN(__builtin_altivec_vclzdm, "V2ULLiV2ULLiV2ULLi", "")
+BUILTIN(__builtin_altivec_vctzdm, "V2ULLiV2ULLiV2ULLi", "")
+
 // VSX built-ins.
 
 BUILTIN(__builtin_vsx_lxvd2x, "V2divC*", "")
@@ -485,6 +489,8 @@
 BUILTIN(__builtin_bpermd, "SLLiSLLiSLLi", "")
 BUILTIN(__builtin_pdepd, "ULLiULLiULLi", "")
 BUILTIN(__builtin_pextd, "ULLiULLiULLi", "")
+BUILTIN(__builtin_cntlzdm, "ULLiULLiULLi", "")
+BUILTIN(__builtin_cnttzdm, "ULLiULLiULLi", "")
 
 // Vector int128 (un)pack
 BUILTIN(__builtin_unpack_vector_int128, "ULLiV1LLLii", "")
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
@@ -16830,6 +16830,21 @@
   return __builtin_altivec_vclrrb((vector signed char)__a, __n);
 #endif
 }
+
+/* vec_cntlzm */
+
+static __inline__ vector unsigned long long __ATTRS_o_ai
+vec_cntlzm(vector unsigned long long __a, vector unsigned long long __b) {
+  return __builtin_altivec_vclzdm(__a, __b);
+}
+
+/* vec_cnttzm */
+
+static __inline__ vector unsigned long long __ATTRS_o_ai
+vec_cnttzm(vector unsigned long long __a, vector unsigned long long __b) {
+  return __builtin_altivec_vctzdm(__a, __b);
+}
+
 #endif /* __POWER10_VECTOR__ */
 
 #undef __ATTRS_o_ai
diff --git a/clang/test/CodeGen/builtins-ppc-p10.c b/clang/test/CodeGen/builtins-ppc-p10.c
--- a/clang/test/CodeGen/builtins-ppc-p10.c
+++ b/clang/test/CodeGen/builtins-ppc-p10.c
@@ -13,3 +13,13 @@
   // CHECK: @llvm.ppc.pextd
   return __builtin_pextd(ulla, ullb);
 }
+
+unsigned long long test_cntlzdm(void) {
+  // CHECK: @llvm.ppc.cntlzdm
+  return __builtin_cntlzdm(ulla, ullb);
+}
+
+unsigned long long test_cnttzdm(void) {
+  // CHECK: @llvm.ppc.cnttzdm
+  return __builtin_cnttzdm(ulla, ullb);
+}
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
@@ -79,3 +79,15 @@
   // CHECK-LE-NEXT: ret <16 x i8>
   return vec_clrr(vuca, uia);
 }
+
+vector unsigned long long test_vclzdm(void) {
+  // CHECK: @llvm.ppc.altivec.vclzdm(<2 x i64>
+  // CHECK-NEXT: ret <2 x i64>
+  return vec_cntlzm(vulla, vullb);
+}
+
+vector unsigned long long test_vctzdm(void) {
+  // CHECK: @llvm.ppc.altivec.vctzdm(<2 x i64>
+  // CHECK-NEXT: ret <2 x i64>
+  return vec_cnttzm(vulla, vullb);
+}
diff --git a/llvm/include/llvm/IR/IntrinsicsPowerPC.td b/llvm/include/llvm/IR/IntrinsicsPowerPC.td
--- a/llvm/include/llvm/IR/IntrinsicsPowerPC.td
+++ b/llvm/include/llvm/IR/IntrinsicsPowerPC.td
@@ -68,6 +68,14 @@
       : GCCBuiltin<"__builtin_pextd">,
         Intrinsic <[llvm_i64_ty], [llvm_i64_ty, llvm_i64_ty], [IntrNoMem]>;
 
+  // Count Leading / Trailing Zeroes under bit Mask Builtins.
+  def int_ppc_cntlzdm
+      : GCCBuiltin<"__builtin_cntlzdm">,
+        Intrinsic <[llvm_i64_ty], [llvm_i64_ty, llvm_i64_ty], [IntrNoMem]>;
+  def int_ppc_cnttzdm
+      : GCCBuiltin<"__builtin_cnttzdm">,
+        Intrinsic <[llvm_i64_ty], [llvm_i64_ty, llvm_i64_ty], [IntrNoMem]>;
+
   def int_ppc_truncf128_round_to_odd
       : GCCBuiltin<"__builtin_truncf128_round_to_odd">,
         Intrinsic <[llvm_double_ty], [llvm_f128_ty], [IntrNoMem]>;
@@ -673,6 +681,14 @@
               Intrinsic<[llvm_v1i128_ty],
                         [llvm_v1i128_ty, llvm_v1i128_ty, llvm_v1i128_ty],
                         [IntrNoMem]>;
+
+  // P10 Vector Count Leading / Trailing Zeroes under bit Mask Builtins.
+  def int_ppc_altivec_vclzdm : GCCBuiltin<"__builtin_altivec_vclzdm">,
+              Intrinsic<[llvm_v2i64_ty], [llvm_v2i64_ty, llvm_v2i64_ty],
+                        [IntrNoMem]>;
+  def int_ppc_altivec_vctzdm : GCCBuiltin<"__builtin_altivec_vctzdm">,
+              Intrinsic<[llvm_v2i64_ty], [llvm_v2i64_ty, llvm_v2i64_ty],
+                        [IntrNoMem]>;
 }
 
 def int_ppc_altivec_vsl   : PowerPC_Vec_WWW_Intrinsic<"vsl">;
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
@@ -532,6 +532,22 @@
    def PEXTD : XForm_6<31, 188, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
                        "pextd $rA, $rS, $rB", IIC_IntGeneral,
                        [(set i64:$rA, (int_ppc_pextd i64:$rS, i64:$rB))]>;
+   def VCLZDM : VXForm_1<1924, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vB),
+                         "vclzdm $vD, $vA, $vB", IIC_VecGeneral,
+                         [(set v2i64:$vD,
+                         (int_ppc_altivec_vclzdm v2i64:$vA, v2i64:$vB))]>;
+   def VCTZDM : VXForm_1<1988, (outs vrrc:$vD), (ins vrrc:$vA, vrrc:$vB),
+                         "vctzdm $vD, $vA, $vB", IIC_VecGeneral,
+                         [(set v2i64:$vD,
+                         (int_ppc_altivec_vctzdm v2i64:$vA, v2i64:$vB))]>;
+   def CNTLZDM : XForm_6<31, 59, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
+                         "cntlzdm $rA, $rS, $rB", IIC_IntGeneral,
+                         [(set i64:$rA,
+                         (int_ppc_cntlzdm i64:$rS, i64:$rB))]>;
+   def CNTTZDM : XForm_6<31, 571, (outs g8rc:$rA), (ins g8rc:$rS, g8rc:$rB),
+                         "cnttzdm $rA, $rS, $rB", IIC_IntGeneral,
+                         [(set i64:$rA,
+                         (int_ppc_cnttzdm i64:$rS, i64:$rB))]>;
    def XXGENPCVBM :
      XForm_XT6_IMM5_VB5<60, 916, (outs vsrc:$XT), (ins vrrc:$VRB, s5imm:$IMM),
                         "xxgenpcvbm $XT, $VRB, $IMM", IIC_VecGeneral, []>;
diff --git a/llvm/test/CodeGen/PowerPC/p10-bit-manip-ops.ll b/llvm/test/CodeGen/PowerPC/p10-bit-manip-ops.ll
--- a/llvm/test/CodeGen/PowerPC/p10-bit-manip-ops.ll
+++ b/llvm/test/CodeGen/PowerPC/p10-bit-manip-ops.ll
@@ -9,6 +9,10 @@
 declare <2 x i64> @llvm.ppc.altivec.vpextd(<2 x i64>, <2 x i64>)
 declare i64 @llvm.ppc.pdepd(i64, i64)
 declare i64 @llvm.ppc.pextd(i64, i64)
+declare <2 x i64> @llvm.ppc.altivec.vclzdm(<2 x i64>, <2 x i64>)
+declare <2 x i64> @llvm.ppc.altivec.vctzdm(<2 x i64>, <2 x i64>)
+declare i64 @llvm.ppc.cntlzdm(i64, i64)
+declare i64 @llvm.ppc.cnttzdm(i64, i64)
 
 define <2 x i64> @test_vpdepd(<2 x i64> %a, <2 x i64> %b) {
 ; CHECK-LABEL: test_vpdepd:
@@ -49,3 +53,43 @@
   %tmp = tail call i64 @llvm.ppc.pextd(i64 %a, i64 %b)
   ret i64 %tmp
 }
+
+define <2 x i64> @test_vclzdm(<2 x i64> %a, <2 x i64> %b) {
+; CHECK-LABEL: test_vclzdm:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    vclzdm v2, v2, v3
+; CHECK-NEXT:    blr
+entry:
+  %tmp = tail call <2 x i64> @llvm.ppc.altivec.vclzdm(<2 x i64> %a, <2 x i64> %b)
+  ret <2 x i64> %tmp
+}
+
+define <2 x i64> @test_vctzdm(<2 x i64> %a, <2 x i64> %b) {
+; CHECK-LABEL: test_vctzdm:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    vctzdm v2, v2, v3
+; CHECK-NEXT:    blr
+entry:
+  %tmp = tail call <2 x i64> @llvm.ppc.altivec.vctzdm(<2 x i64> %a, <2 x i64> %b)
+  ret <2 x i64> %tmp
+}
+
+define i64 @test_cntlzdm(i64 %a, i64 %b) {
+; CHECK-LABEL: test_cntlzdm:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    cntlzdm r3, r3, r4
+; CHECK-NEXT:    blr
+entry:
+  %tmp = tail call i64 @llvm.ppc.cntlzdm(i64 %a, i64 %b)
+  ret i64 %tmp
+}
+
+define i64 @test_cnttzdm(i64 %a, i64 %b) {
+; CHECK-LABEL: test_cnttzdm:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    cnttzdm r3, r3, r4
+; CHECK-NEXT:    blr
+entry:
+  %tmp = tail call i64 @llvm.ppc.cnttzdm(i64 %a, i64 %b)
+  ret i64 %tmp
+}
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
@@ -13,6 +13,18 @@
 # CHECK: pextd 1, 2, 4
 0x7c 0x41 0x21 0x78
 
+# CHECK: vclzdm 1, 2, 3
+0x10 0x22 0x1f 0x84
+
+# CHECK: vctzdm 1, 2, 3
+0x10 0x22 0x1f 0xc4
+
+# CHECK: cntlzdm 1, 3, 2
+0x7c 0x61 0x10 0x76
+
+# CHECK: cnttzdm 1, 3, 2
+0x7c 0x61 0x14 0x76
+
 # CHECK xxgenpcvbm 0, 1, 2
 0xf0 0x02 0x0f 0x28
 
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
@@ -15,6 +15,18 @@
 # CHECK-BE: pextd 1, 2, 4                         # encoding: [0x7c,0x41,0x21,0x78]
 # CHECK-LE: pextd 1, 2, 4                         # encoding: [0x78,0x21,0x41,0x7c]
             pextd 1, 2, 4
+# CHECK-BE: vclzdm 1, 2, 3                        # encoding: [0x10,0x22,0x1f,0x84]
+# CHECK-LE: vclzdm 1, 2, 3                        # encoding: [0x84,0x1f,0x22,0x10]
+            vclzdm 1, 2, 3
+# CHECK-BE: vctzdm 1, 2, 3                        # encoding: [0x10,0x22,0x1f,0xc4]
+# CHECK-LE: vctzdm 1, 2, 3                        # encoding: [0xc4,0x1f,0x22,0x10]
+            vctzdm 1, 2, 3
+# CHECK-BE: cntlzdm 1, 3, 2                       # encoding: [0x7c,0x61,0x10,0x76]
+# CHECK-LE: cntlzdm 1, 3, 2                       # encoding: [0x76,0x10,0x61,0x7c]
+            cntlzdm 1, 3, 2
+# CHECK-BE: cnttzdm 1, 3, 2                       # encoding: [0x7c,0x61,0x14,0x76]
+# CHECK-LE: cnttzdm 1, 3, 2                       # encoding: [0x76,0x14,0x61,0x7c]
+            cnttzdm 1, 3, 2
 # CHECK-BE: xxgenpcvbm 0, 1, 2                    # encoding: [0xf0,0x02,0x0f,0x28]
 # CHECK-LE: xxgenpcvbm 0, 1, 2                    # encoding: [0x28,0x0f,0x02,0xf0]
             xxgenpcvbm 0, 1, 2