diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -277,6 +277,7 @@
 
 * ``__builtin_unpredictable`` (unpredictable metadata in LLVM IR), is handled by X86 Backend.
   ``X86CmovConversion`` pass now respects this builtin and does not convert CMOVs to branches.
+* Add support for the ``PBNDKB`` instruction.
 
 
 Changes to the OCaml bindings
diff --git a/llvm/lib/Target/X86/X86InstrSystem.td b/llvm/lib/Target/X86/X86InstrSystem.td
--- a/llvm/lib/Target/X86/X86InstrSystem.td
+++ b/llvm/lib/Target/X86/X86InstrSystem.td
@@ -429,7 +429,8 @@
 def WRMSRNS : I<0x01, MRM_C6, (outs), (ins), "wrmsrns", []>, PS;
 let Defs = [EAX, EDX], Uses = [ECX] in
 def RDMSR : I<0x32, RawFrm, (outs), (ins), "rdmsr", []>, TB;
-
+let Defs = [RAX, EFLAGS], Uses = [RBX, RCX], Predicates = [In64BitMode] in
+def PBNDKB : I<0x01, MRM_C7, (outs), (ins), "pbndkb", []>, PS;
 let Uses = [RSI, RDI, RCX], Predicates = [In64BitMode] in {
 def WRMSRLIST : I<0x01, MRM_C6, (outs), (ins), "wrmsrlist", []>, XS;
 def RDMSRLIST : I<0x01, MRM_C6, (outs), (ins), "rdmsrlist", []>, XD;
diff --git a/llvm/test/MC/Disassembler/X86/pbndkb.txt b/llvm/test/MC/Disassembler/X86/pbndkb.txt
new file mode 100644
--- /dev/null
+++ b/llvm/test/MC/Disassembler/X86/pbndkb.txt
@@ -0,0 +1,6 @@
+# RUN: llvm-mc --disassemble %s -triple=x86_64 | FileCheck %s
+# RUN: llvm-mc --disassemble %s -triple=x86_64 --output-asm-variant=1 | FileCheck %s
+
+# CHECK: pbndkb
+0x0f,0x01,0xc7
+
diff --git a/llvm/test/MC/X86/pbndkb.s b/llvm/test/MC/X86/pbndkb.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/MC/X86/pbndkb.s
@@ -0,0 +1,7 @@
+// RUN: llvm-mc -triple x86_64 --show-encoding %s | FileCheck %s
+// RUN: llvm-mc -triple x86_64 -x86-asm-syntax=intel -output-asm-variant=1 --show-encoding %s | FileCheck %s
+
+// CHECK: pbndkb
+// CHECK: encoding: [0x0f,0x01,0xc7]
+          pbndkb
+
diff --git a/llvm/test/MC/X86/x86_errors.s b/llvm/test/MC/X86/x86_errors.s
--- a/llvm/test/MC/X86/x86_errors.s
+++ b/llvm/test/MC/X86/x86_errors.s
@@ -187,3 +187,6 @@
 // 32: 12: error: immediate must be an integer in range [0, 15]
 // 64: 12: error: immediate must be an integer in range [0, 15]
 vpermil2pd $16, %xmm3, %xmm5, %xmm1, %xmm2
+
+// 32: error: instruction requires: 64-bit mode
+pbndkb