Index: lib/Target/X86/X86InstrAVX512.td
===================================================================
--- lib/Target/X86/X86InstrAVX512.td
+++ lib/Target/X86/X86InstrAVX512.td
@@ -4193,8 +4193,24 @@
                               VTInfo.info256>, EVEX_V256;
 }
 
+multiclass avx512_vperm_bw<bits<8> opc, string OpcodeStr,
+                              Predicate prd, SDNode OpNode,
+                              AVX512VLVectorVTInfo _> {
+  let Predicates = [prd] in
+  defm Z:    avx512_var_shift<opc, OpcodeStr, OpNode, _.info512>,
+              EVEX_V512 ;
+  let Predicates = [HasVLX, prd] in {
+  defm Z256: avx512_var_shift<opc, OpcodeStr, OpNode, _.info256>,
+              EVEX_V256 ;
+  defm Z128: avx512_var_shift<opc, OpcodeStr, OpNode, _.info128>,
+              EVEX_V128 ;
+  }
+}
 
-defm VPERM  : avx512_var_shift_w<0x8D, "vpermw", X86VPermv>;
+defm VPERMW  : avx512_vperm_bw<0x8D, "vpermw", HasBWI, X86VPermv,
+                                  avx512vl_i16_info>, VEX_W;
+defm VPERMB  : avx512_vperm_bw<0x8D, "vpermb", HasVBMI, X86VPermv,
+                                  avx512vl_i8_info>;
 
 defm VPERMD : avx512_vperm_dq_sizes<0x36, "vpermd", X86VPermv,
                                     avx512vl_i32_info>;
Index: lib/Target/X86/X86InstrInfo.td
===================================================================
--- lib/Target/X86/X86InstrInfo.td
+++ lib/Target/X86/X86InstrInfo.td
@@ -795,7 +795,8 @@
 def HasLZCNT     : Predicate<"Subtarget->hasLZCNT()">;
 def HasBMI       : Predicate<"Subtarget->hasBMI()">;
 def HasBMI2      : Predicate<"Subtarget->hasBMI2()">;
-def HasVBMI      : Predicate<"Subtarget->hasVBMI()">;
+def HasVBMI      : Predicate<"Subtarget->hasVBMI()">,
+                     AssemblerPredicate<"FeatureVBMI", "AVX-512 VBMI ISA">;
 def HasRTM       : Predicate<"Subtarget->hasRTM()">;
 def HasHLE       : Predicate<"Subtarget->hasHLE()">;
 def HasTSX       : Predicate<"Subtarget->hasRTM() || Subtarget->hasHLE()">;
Index: test/MC/X86/avx512vbmi-encoding.s
===================================================================
--- test/MC/X86/avx512vbmi-encoding.s
+++ test/MC/X86/avx512vbmi-encoding.s
@@ -0,0 +1,73 @@
+// RUN: llvm-mc -triple x86_64-unknown-unknown -mcpu=skx  --show-encoding %s | FileCheck %s
+
+         vpermb %xmm28, %xmm29, %xmm30
+//CHECK: vpermb %xmm28, %xmm29, %xmm30
+//CHECK: encoding: [0x62,0x02,0x15,0x00,0x8d,0xf4]
+
+         vpermb %xmm28, %xmm29, %xmm30 {%k7}
+//CHECK: vpermb %xmm28, %xmm29, %xmm30 {%k7}
+//CHECK: encoding: [0x62,0x02,0x15,0x07,0x8d,0xf4]
+
+         vpermb %xmm28, %xmm29, %xmm30 {%k7} {z}
+//CHECK: vpermb %xmm28, %xmm29, %xmm30 {%k7} {z}
+//CHECK: encoding: [0x62,0x02,0x15,0x87,0x8d,0xf4]
+
+         vpermb (%rcx), %xmm29, %xmm30
+//CHECK: vpermb (%rcx), %xmm29, %xmm30
+//CHECK: encoding: [0x62,0x62,0x15,0x00,0x8d,0x31]
+
+         vpermb 0x123(%rax,%r14,8), %xmm29, %xmm30
+//CHECK: vpermb 291(%rax,%r14,8), %xmm29, %xmm30
+//CHECK: encoding: [0x62,0x22,0x15,0x00,0x8d,0xb4,0xf0,0x23,0x01,0x00,0x00]
+
+         vpermb 0x7f0(%rdx), %xmm29, %xmm30
+//CHECK: vpermb 2032(%rdx), %xmm29, %xmm30
+//CHECK: encoding: [0x62,0x62,0x15,0x00,0x8d,0x72,0x7f]
+
+         vpermb 0x800(%rdx), %xmm29, %xmm30
+//CHECK: vpermb 2048(%rdx), %xmm29, %xmm30
+//CHECK: encoding: [0x62,0x62,0x15,0x00,0x8d,0xb2,0x00,0x08,0x00,0x00]
+
+         vpermb -0x800(%rdx), %xmm29, %xmm30
+//CHECK: vpermb -2048(%rdx), %xmm29, %xmm30
+//CHECK: encoding: [0x62,0x62,0x15,0x00,0x8d,0x72,0x80]
+
+         vpermb -0x810(%rdx), %xmm29, %xmm30
+//CHECK: vpermb -2064(%rdx), %xmm29, %xmm30
+//CHECK: encoding: [0x62,0x62,0x15,0x00,0x8d,0xb2,0xf0,0xf7,0xff,0xff]
+
+         vpermb %ymm28, %ymm29, %ymm30
+//CHECK: vpermb %ymm28, %ymm29, %ymm30
+//CHECK: encoding: [0x62,0x02,0x15,0x20,0x8d,0xf4]
+
+         vpermb %ymm28, %ymm29, %ymm30 {%k7}
+//CHECK: vpermb %ymm28, %ymm29, %ymm30 {%k7}
+//CHECK: encoding: [0x62,0x02,0x15,0x27,0x8d,0xf4]
+
+         vpermb %ymm28, %ymm29, %ymm30 {%k7} {z}
+//CHECK: vpermb %ymm28, %ymm29, %ymm30 {%k7} {z}
+//CHECK: encoding: [0x62,0x02,0x15,0xa7,0x8d,0xf4]
+
+         vpermb (%rcx), %ymm29, %ymm30
+//CHECK: vpermb (%rcx), %ymm29, %ymm30
+//CHECK: encoding: [0x62,0x62,0x15,0x20,0x8d,0x31]
+
+         vpermb 0x123(%rax,%r14,8), %ymm29, %ymm30
+//CHECK: vpermb 291(%rax,%r14,8), %ymm29, %ymm30
+//CHECK: encoding: [0x62,0x22,0x15,0x20,0x8d,0xb4,0xf0,0x23,0x01,0x00,0x00]
+
+         vpermb 0xfe0(%rdx), %ymm29, %ymm30
+//CHECK: vpermb 4064(%rdx), %ymm29, %ymm30
+//CHECK: encoding: [0x62,0x62,0x15,0x20,0x8d,0x72,0x7f]
+
+         vpermb 0x1000(%rdx), %ymm29, %ymm30
+//CHECK: vpermb 4096(%rdx), %ymm29, %ymm30
+//CHECK: encoding: [0x62,0x62,0x15,0x20,0x8d,0xb2,0x00,0x10,0x00,0x00]
+
+         vpermb -0x1000(%rdx), %ymm29, %ymm30
+//CHECK: vpermb -4096(%rdx), %ymm29, %ymm30
+//CHECK: encoding: [0x62,0x62,0x15,0x20,0x8d,0x72,0x80]
+
+         vpermb -0x1020(%rdx), %ymm29, %ymm30
+//CHECK: vpermb -4128(%rdx), %ymm29, %ymm30
+//CHECK: encoding: [0x62,0x62,0x15,0x20,0x8d,0xb2,0xe0,0xef,0xff,0xff]