[X86] Add SERIALIZE instruction.

[tianqing]

Summary

For more details about this instruction, please refer to the latest ISE document: https://software.intel.com/en-us/download/intel-architecture-instruction-set-extensions-programming-reference

[craig.topper]

LGTM

[craig.topper]

clang/lib/Headers/serializeintrin.h

18

Can you add a doxygen comment to this? We've been trying to add them to new intrinsics. There are some in some of the other intrinsic headers but not all.

[craig.topper]

LGTM

clang/docs/ClangCommandLineReference.rst

 .. option:: -mrdseed, -mno-rdseed
 
 .. option:: -mretpoline-external-thunk, -mno-retpoline-external-thunk
 
 .. option:: -mrtm, -mno-rtm
 
 .. option:: -msahf, -mno-sahf
 
+.. option:: -mserialize, -mno-serialize
+
 .. option:: -msgx, -mno-sgx
 
 .. option:: -msha, -mno-sha
 
 .. option:: -mshstk, -mno-shstk
 
 .. option:: -msse, -mno-sse
 

clang/include/clang/Basic/BuiltinsX86.def

 
 // INVPCID
 TARGET_BUILTIN(__builtin_ia32_invpcid, "vUiv*", "nc", "invpcid")
 
 // ENQCMD
 TARGET_BUILTIN(__builtin_ia32_enqcmd, "Ucv*vC*", "n", "enqcmd")
 TARGET_BUILTIN(__builtin_ia32_enqcmds, "Ucv*vC*", "n", "enqcmd")
 
+// SERIALIZE
+TARGET_BUILTIN(__builtin_ia32_serialize, "v", "n", "serialize")
+
 // MSVC
 TARGET_HEADER_BUILTIN(_BitScanForward, "UcUNi*UNi", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 TARGET_HEADER_BUILTIN(_BitScanReverse, "UcUNi*UNi", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 
 TARGET_HEADER_BUILTIN(_ReadWriteBarrier, "v", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 TARGET_HEADER_BUILTIN(_ReadBarrier,      "v", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 TARGET_HEADER_BUILTIN(_WriteBarrier,     "v", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 

clang/include/clang/Driver/Options.td

 def mrdrnd : Flag<["-"], "mrdrnd">, Group<m_x86_Features_Group>;
 def mno_rdrnd : Flag<["-"], "mno-rdrnd">, Group<m_x86_Features_Group>;
 def mrtm : Flag<["-"], "mrtm">, Group<m_x86_Features_Group>;
 def mno_rtm : Flag<["-"], "mno-rtm">, Group<m_x86_Features_Group>;
 def mrdseed : Flag<["-"], "mrdseed">, Group<m_x86_Features_Group>;
 def mno_rdseed : Flag<["-"], "mno-rdseed">, Group<m_x86_Features_Group>;
 def msahf : Flag<["-"], "msahf">, Group<m_x86_Features_Group>;
 def mno_sahf : Flag<["-"], "mno-sahf">, Group<m_x86_Features_Group>;
+def mserialize : Flag<["-"], "mserialize">, Group<m_x86_Features_Group>;
+def mno_serialize : Flag<["-"], "mno-serialize">, Group<m_x86_Features_Group>;
 def msgx : Flag<["-"], "msgx">, Group<m_x86_Features_Group>;
 def mno_sgx : Flag<["-"], "mno-sgx">, Group<m_x86_Features_Group>;
 def msha : Flag<["-"], "msha">, Group<m_x86_Features_Group>;
 def mno_sha : Flag<["-"], "mno-sha">, Group<m_x86_Features_Group>;
 def mtbm : Flag<["-"], "mtbm">, Group<m_x86_Features_Group>;
 def mno_tbm : Flag<["-"], "mno-tbm">, Group<m_x86_Features_Group>;
 def mvaes : Flag<["-"], "mvaes">, Group<m_x86_Features_Group>;
 def mno_vaes : Flag<["-"], "mno-vaes">, Group<m_x86_Features_Group>;

clang/lib/Basic/Targets/X86.h

class LLVM_LIBRARY_VISIBILITY X86TargetInfo : public TargetInfo {
   bool HasLAHFSAHF = false;
   bool HasWBNOINVD = false;
   bool HasWAITPKG = false;
   bool HasMOVDIRI = false;
   bool HasMOVDIR64B = false;
   bool HasPTWRITE = false;
   bool HasINVPCID = false;
   bool HasENQCMD = false;
+  bool HasSERIALIZE = false;
 
 protected:
   /// Enumeration of all of the X86 CPUs supported by Clang.
   ///
   /// Each enumeration represents a particular CPU supported by Clang. These
   /// loosely correspond to the options passed to '-march' or '-mtune' flags.
   enum CPUKind {
     CK_Generic,

clang/lib/Basic/Targets/X86.cpp

for (const auto &Feature : Features) {
     } else if (Feature == "+pconfig") {
       HasPCONFIG = true;
     } else if (Feature == "+ptwrite") {
       HasPTWRITE = true;
     } else if (Feature == "+invpcid") {
       HasINVPCID = true;
     } else if (Feature == "+enqcmd") {
       HasENQCMD = true;
+    } else if (Feature == "+serialize") {
+      HasSERIALIZE = true;
     }
 
     X86SSEEnum Level = llvm::StringSwitch<X86SSEEnum>(Feature)
                            .Case("+avx512f", AVX512F)
                            .Case("+avx2", AVX2)
                            .Case("+avx", AVX)
                            .Case("+sse4.2", SSE42)
                            .Case("+sse4.1", SSE41)
void X86TargetInfo::getTargetDefines(const LangOptions &Opts,
   if (HasPCONFIG)
     Builder.defineMacro("__PCONFIG__");
   if (HasPTWRITE)
     Builder.defineMacro("__PTWRITE__");
   if (HasINVPCID)
     Builder.defineMacro("__INVPCID__");
   if (HasENQCMD)
     Builder.defineMacro("__ENQCMD__");
+  if (HasSERIALIZE)
+    Builder.defineMacro("__SERIALIZE__");
 
   // Each case falls through to the previous one here.
   switch (SSELevel) {
   case AVX512F:
     Builder.defineMacro("__AVX512F__");
     LLVM_FALLTHROUGH;
   case AVX2:
     Builder.defineMacro("__AVX2__");
return llvm::StringSwitch<bool>(Name)
       .Case("prefetchwt1", true)
       .Case("prfchw", true)
       .Case("ptwrite", true)
       .Case("rdpid", true)
       .Case("rdrnd", true)
       .Case("rdseed", true)
       .Case("rtm", true)
       .Case("sahf", true)
+      .Case("serialize", true)
       .Case("sgx", true)
       .Case("sha", true)
       .Case("shstk", true)
       .Case("sse", true)
       .Case("sse2", true)
       .Case("sse3", true)
       .Case("ssse3", true)
       .Case("sse4", true)
return llvm::StringSwitch<bool>(Feature)
       .Case("prfchw", HasPRFCHW)
       .Case("ptwrite", HasPTWRITE)
       .Case("rdpid", HasRDPID)
       .Case("rdrnd", HasRDRND)
       .Case("rdseed", HasRDSEED)
       .Case("retpoline-external-thunk", HasRetpolineExternalThunk)
       .Case("rtm", HasRTM)
       .Case("sahf", HasLAHFSAHF)
+      .Case("serialize", HasSERIALIZE)
       .Case("sgx", HasSGX)
       .Case("sha", HasSHA)
       .Case("shstk", HasSHSTK)
       .Case("sse", SSELevel >= SSE1)
       .Case("sse2", SSELevel >= SSE2)
       .Case("sse3", SSELevel >= SSE3)
       .Case("ssse3", SSELevel >= SSSE3)
       .Case("sse4.1", SSELevel >= SSE41)

clang/lib/Headers/CMakeLists.txt

set(files
   pkuintrin.h
   pmmintrin.h
   pconfigintrin.h
   popcntintrin.h
   prfchwintrin.h
   ptwriteintrin.h
   rdseedintrin.h
   rtmintrin.h
+  serializeintrin.h
   sgxintrin.h
   s390intrin.h
   shaintrin.h
   smmintrin.h
   stdalign.h
   stdarg.h
   stdatomic.h
   stdbool.h

clang/lib/Headers/cpuid.h

 #define bit_CLDEMOTE         0x02000000
 #define bit_MOVDIRI          0x08000000
 #define bit_MOVDIR64B        0x10000000
 #define bit_ENQCMD           0x20000000
 
 /* Features in %edx for leaf 7 sub-leaf 0 */
 #define bit_AVX5124VNNIW  0x00000004
 #define bit_AVX5124FMAPS  0x00000008
+#define bit_SERIALIZE     0x00004000
 #define bit_PCONFIG       0x00040000
 #define bit_IBT           0x00100000
 
 /* Features in %eax for leaf 7 sub-leaf 1 */
 #define bit_AVX512BF16    0x00000020
 
 /* Features in %eax for leaf 13 sub-leaf 1 */
 #define bit_XSAVEOPT    0x00000001

clang/lib/Headers/immintrin.h

#if !defined(_MSC_VER) || __has_feature(modules) || \
   (defined(__AVX512VL__) && defined(__AVX512VP2INTERSECT__))
 #include <avx512vlvp2intersectintrin.h>
 #endif
 
 #if !defined(_MSC_VER) || __has_feature(modules) || defined(__ENQCMD__)
 #include <enqcmdintrin.h>
 #endif
 
+#if !defined(_MSC_VER) || __has_feature(modules) || defined(__SERIALIZE__)
+#include <serializeintrin.h>
+#endif
+
 #if defined(_MSC_VER) && __has_extension(gnu_asm)
 /* Define the default attributes for these intrinsics */
 #define __DEFAULT_FN_ATTRS __attribute__((__always_inline__, __nodebug__))
 #ifdef __cplusplus
 extern "C" {
 #endif
 /*----------------------------------------------------------------------------*\
 |* Interlocked Exchange HLE

clang/lib/Headers/serializeintrin.h

+/*===--------------- serializeintrin.h - serialize intrinsics --------------===
+ *
+ * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+ * See https://llvm.org/LICENSE.txt for license information.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+#ifndef __IMMINTRIN_H
+#error "Never use <serializeintrin.h> directly; include <immintrin.h> instead."
+#endif
+
+#ifndef __SERIALIZEINTRIN_H
+#define __SERIALIZEINTRIN_H
+
+/// Serialize instruction fetch and execution.
+///
+/// \headerfile <x86intrin.h>
+///
+/// This intrinsic corresponds to the <c> SERIALIZE </c> instruction.
+///
+static __inline__ void
+__attribute__((__always_inline__, __nodebug__, __target__("serialize")))
+_serialize (void)
+{
+  __builtin_ia32_serialize ();
+}
+
+#endif /* __SERIALIZEINTRIN_H */

clang/test/CodeGen/x86-serialize-intrin.c

+// RUN: %clang_cc1 %s -ffreestanding -triple x86_64-unknown-unknown -target-feature +serialize -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 %s -ffreestanding -triple i386-unknown-unknown -target-feature +serialize -emit-llvm -o - | FileCheck %s
+
+#include <immintrin.h>
+
+void test_serialize(void)
+{
+// CHECK-LABEL: test_serialize
+// CHECK: call void @llvm.x86.serialize()
+  _serialize();
+}

clang/test/Driver/x86-target-features.c

 // RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mno-enqcmd %s -### -o %t.o 2>&1 | FileCheck --check-prefix=NO-ENQCMD %s
 // ENQCMD: "-target-feature" "+enqcmd"
 // NO-ENQCMD: "-target-feature" "-enqcmd"
 
 // RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mvzeroupper %s -### -o %t.o 2>&1 | FileCheck --check-prefix=VZEROUPPER %s
 // RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mno-vzeroupper %s -### -o %t.o 2>&1 | FileCheck --check-prefix=NO-VZEROUPPER %s
 // VZEROUPPER: "-target-feature" "+vzeroupper"
 // NO-VZEROUPPER: "-target-feature" "-vzeroupper"
+
+// RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mserialize %s -### -o %t.o 2>&1 | FileCheck -check-prefix=SERIALIZE %s
+// RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mno-serialize %s -### -o %t.o 2>&1 | FileCheck -check-prefix=NO-SERIALIZE %s
+// SERIALIZE: "-target-feature" "+serialize"
+// NO-SERIALIZE: "-target-feature" "-serialize"

clang/test/Preprocessor/x86_target_features.c

 
 // RUN: %clang -target i386-unknown-unknown -march=atom -menqcmd -x c -E -dM -o - %s | FileCheck -match-full-lines --check-prefix=ENQCMD %s
 
 // ENQCMD: #define __ENQCMD__ 1
 
 // RUN: %clang -target i386-unknown-unknown -march=atom -mno-enqcmd -x c -E -dM -o - %s | FileCheck -match-full-lines --check-prefix=NOENQCMD %s
 
 // NOENQCMD-NOT: #define __ENQCMD__ 1
+
+// RUN: %clang -target i386-unknown-unknown -march=atom -mserialize -x c -E -dM -o - %s | FileCheck -match-full-lines --check-prefix=SERIALIZE %s
+
+// SERIALIZE: #define __SERIALIZE__ 1
+
+// RUN: %clang -target i386-unknown-unknown -march=atom -mno-serialize -x c -E -dM -o - %s | FileCheck -match-full-lines --check-prefix=NOSERIALIZE %s
+
+// NOSERIALIZE-NOT: #define __SERIALIZE__ 1

llvm/include/llvm/IR/IntrinsicsX86.td

 // ENQCMD - Enqueue Stores Instructions
 
 let TargetPrefix = "x86" in {
   def int_x86_enqcmd : GCCBuiltin<"__builtin_ia32_enqcmd">,
               Intrinsic<[llvm_i8_ty], [llvm_ptr_ty, llvm_ptr_ty], []>;
   def int_x86_enqcmds : GCCBuiltin<"__builtin_ia32_enqcmds">,
               Intrinsic<[llvm_i8_ty], [llvm_ptr_ty, llvm_ptr_ty], []>;
 }
+
+//===----------------------------------------------------------------------===//
+// SERIALIZE - Serialize instruction fetch and execution
+
+let TargetPrefix = "x86" in {
+  def int_x86_serialize : GCCBuiltin<"__builtin_ia32_serialize">,
+              Intrinsic<[], [], []>;
+}

llvm/lib/Support/Host.cpp

#endif
   Features["avx512bitalg"]    = HasLeaf7 && ((ECX >> 12) & 1) && HasAVX512Save;
   Features["avx512vpopcntdq"] = HasLeaf7 && ((ECX >> 14) & 1) && HasAVX512Save;
   Features["rdpid"]           = HasLeaf7 && ((ECX >> 22) & 1);
   Features["cldemote"]        = HasLeaf7 && ((ECX >> 25) & 1);
   Features["movdiri"]         = HasLeaf7 && ((ECX >> 27) & 1);
   Features["movdir64b"]       = HasLeaf7 && ((ECX >> 28) & 1);
   Features["enqcmd"]          = HasLeaf7 && ((ECX >> 29) & 1);
 
+  Features["serialize"]       = HasLeaf7 && ((EDX >> 14) & 1);
   // There are two CPUID leafs which information associated with the pconfig
   // instruction:
   // EAX=0x7, ECX=0x0 indicates the availability of the instruction (via the 18th
   // bit of EDX), while the EAX=0x1b leaf returns information on the
   // availability of specific pconfig leafs.
   // The target feature here only refers to the the first of these two.
   // Users might need to check for the availability of specific pconfig
   // leaves using cpuid, since that information is ignored while

llvm/lib/Target/X86/X86.td

 def FeatureWBNOINVD    : SubtargetFeature<"wbnoinvd", "HasWBNOINVD", "true",
                                       "Write Back No Invalidate">;
 def FeatureRDPID : SubtargetFeature<"rdpid", "HasRDPID", "true",
                                     "Support RDPID instructions">;
 def FeatureWAITPKG  : SubtargetFeature<"waitpkg", "HasWAITPKG", "true",
                                       "Wait and pause enhancements">;
 def FeatureENQCMD : SubtargetFeature<"enqcmd", "HasENQCMD", "true",
                                      "Has ENQCMD instructions">;
+def FeatureSERIALIZE : SubtargetFeature<"serialize", "HasSERIALIZE", "true",
+                                        "Has serialize instruction">;
 // On some processors, instructions that implicitly take two memory operands are
 // slow. In practice, this means that CALL, PUSH, and POP with memory operands
 // should be avoided in favor of a MOV + register CALL/PUSH/POP.
 def FeatureSlowTwoMemOps : SubtargetFeature<"slow-two-mem-ops",
                                      "SlowTwoMemOps", "true",
                                      "Two memory operand instructions are slow">;
 def FeatureLEAUsesAG : SubtargetFeature<"lea-uses-ag", "LEAUsesAG", "true",
                                    "LEA instruction needs inputs at AG stage">;

llvm/lib/Target/X86/X86InstrInfo.td

 def HasWBNOINVD  : Predicate<"Subtarget->hasWBNOINVD()">;
 def HasRDPID     : Predicate<"Subtarget->hasRDPID()">;
 def HasWAITPKG   : Predicate<"Subtarget->hasWAITPKG()">;
 def HasINVPCID   : Predicate<"Subtarget->hasINVPCID()">;
 def HasCmpxchg8b : Predicate<"Subtarget->hasCmpxchg8b()">;
 def HasCmpxchg16b: Predicate<"Subtarget->hasCmpxchg16b()">;
 def HasPCONFIG   : Predicate<"Subtarget->hasPCONFIG()">;
 def HasENQCMD    : Predicate<"Subtarget->hasENQCMD()">;
+def HasSERIALIZE : Predicate<"Subtarget->hasSERIALIZE()">;
 def Not64BitMode : Predicate<"!Subtarget->is64Bit()">,
                              AssemblerPredicate<(all_of (not Mode64Bit)), "Not 64-bit mode">;
 def In64BitMode  : Predicate<"Subtarget->is64Bit()">,
                              AssemblerPredicate<(all_of Mode64Bit), "64-bit mode">;
 def IsLP64  : Predicate<"Subtarget->isTarget64BitLP64()">;
 def NotLP64 : Predicate<"!Subtarget->isTarget64BitLP64()">;
 def In16BitMode  : Predicate<"Subtarget->is16Bit()">,
                              AssemblerPredicate<(all_of Mode16Bit), "16-bit mode">;
let SchedRW = [WriteLoad] in {
   def CLZERO64r : I<0x01, MRM_FC, (outs), (ins), "clzero", []>,
                   TB, Requires<[HasCLZERO, In64BitMode]>;
 } // SchedRW
 
 def : InstAlias<"clzero\t{%eax|eax}", (CLZERO32r)>, Requires<[Not64BitMode]>;
 def : InstAlias<"clzero\t{%rax|rax}", (CLZERO64r)>, Requires<[In64BitMode]>;
 
 //===----------------------------------------------------------------------===//
+// SERIALIZE Instruction
+//
+def SERIALIZE : I<0x01, MRM_E8, (outs), (ins), "serialize",
+                  [(int_x86_serialize)]>, PS,
+                  Requires<[HasSERIALIZE]>;
+
+//===----------------------------------------------------------------------===//
 // Pattern fragments to auto generate TBM instructions.
 //===----------------------------------------------------------------------===//
 
 let Predicates = [HasTBM] in {
   // FIXME: patterns for the load versions are not implemented
   def : Pat<(and GR32:$src, (add GR32:$src, 1)),
             (BLCFILL32rr GR32:$src)>;
   def : Pat<(and GR64:$src, (add GR64:$src, 1)),

llvm/lib/Target/X86/X86Subtarget.h

protected:
   bool HasRDPID = false;
 
   /// Processor supports WaitPKG instructions
   bool HasWAITPKG = false;
 
   /// Processor supports PCONFIG instruction
   bool HasPCONFIG = false;
 
+  /// Processor supports SERIALIZE instruction
+  bool HasSERIALIZE = false;
+
   /// Processor has a single uop BEXTR implementation.
   bool HasFastBEXTR = false;
 
   /// Try harder to combine to horizontal vector ops if they are fast.
   bool HasFastHorizontalOps = false;
 
   /// Prefer a left/right scalar logical shifts pair over a shift+and pair.
   bool HasFastScalarShiftMasks = false;
public:
   bool hasWBNOINVD() const { return HasWBNOINVD; }
   bool hasRDPID() const { return HasRDPID; }
   bool hasWAITPKG() const { return HasWAITPKG; }
   bool hasPCONFIG() const { return HasPCONFIG; }
   bool hasSGX() const { return HasSGX; }
   bool threewayBranchProfitable() const { return ThreewayBranchProfitable; }
   bool hasINVPCID() const { return HasINVPCID; }
   bool hasENQCMD() const { return HasENQCMD; }
+  bool hasSERIALIZE() const { return HasSERIALIZE; }
   bool useRetpolineIndirectCalls() const { return UseRetpolineIndirectCalls; }
   bool useRetpolineIndirectBranches() const {
     return UseRetpolineIndirectBranches;
   }
   bool useRetpolineExternalThunk() const { return UseRetpolineExternalThunk; }
   bool preferMaskRegisters() const { return PreferMaskRegisters; }
   bool useGLMDivSqrtCosts() const { return UseGLMDivSqrtCosts; }
 

llvm/test/CodeGen/X86/serialize-intrinsic.ll

+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+serialize | FileCheck %s --check-prefix=X86_64
+; RUN: llc < %s -mtriple=i386-unknown-unknown -mattr=+serialize | FileCheck %s --check-prefix=X86
+; RUN: llc < %s -mtriple=x86_64-linux-gnux32 -mattr=+serialize | FileCheck %s --check-prefix=X32
+
+define void @test_serialize() {
+; X86_64-LABEL: test_serialize:
+; X86_64:       # %bb.0: # %entry
+; X86_64-NEXT:    serialize
+; X86_64-NEXT:    retq
+;
+; X86-LABEL: test_serialize:
+; X86:       # %bb.0: # %entry
+; X86-NEXT:    serialize
+; X86-NEXT:    retl
+;
+; X32-LABEL: test_serialize:
+; X32:       # %bb.0: # %entry
+; X32-NEXT:    serialize
+; X32-NEXT:    retq
+entry:
+  call void @llvm.x86.serialize()
+  ret void
+}
+
+declare void @llvm.x86.serialize()

llvm/test/MC/Disassembler/X86/x86-16.txt

 # CHECK: enqcmds 7408, %cx
 0xf3,0x0f,0x38,0xf8,0x0e,0xf0,0x1c
 
 # CHECK: enqcmd (%edi), %edi
 0x67,0xf2,0x0f,0x38,0xf8,0x3f
 
 # CHECK: enqcmds (%edi), %edi
 0x67,0xf3,0x0f,0x38,0xf8,0x3f
+
+# CHECK: serialize
+0x0f 0x01 0xe8

llvm/test/MC/Disassembler/X86/x86-32.txt

 # CHECK: enqcmd 8128(%bx,%di), %ax
 0x67,0xf2,0x0f,0x38,0xf8,0x81,0xc0,0x1f
 
 # CHECK: enqcmds (%bx,%di), %di
 0x67,0xf3,0x0f,0x38,0xf8,0x39
 
 # CHECK: enqcmds 8128(%bx,%di), %ax
 0x67,0xf3,0x0f,0x38,0xf8,0x81,0xc0,0x1f
+
+# CHECK: serialize
+0x0f 0x01 0xe8

llvm/test/MC/Disassembler/X86/x86-64.txt

 # CHECK: enqcmds 8128(%rcx), %rax
 0xf3,0x0f,0x38,0xf8,0x81,0xc0,0x1f,0x00,0x00
 
 # CHECK: enqcmds -8192(%rdx), %rbx
 0xf3,0x0f,0x38,0xf8,0x9a,0x00,0xe0,0xff,0xff
 
 # CHECK: enqcmds 485498096, %rax
 0xf3,0x0f,0x38,0xf8,0x04,0x25,0xf0,0x1c,0xf0,0x1c
+
+# CHECK: serialize
+0x0f 0x01 0xe8

llvm/test/MC/X86/x86-16.s

 
 // CHECK: enqcmd (%edi), %edi
 // CHECK: encoding: [0x67,0xf2,0x0f,0x38,0xf8,0x3f]
 enqcmd  (%edi), %edi
 
 // CHECK: enqcmds (%edi), %edi
 // CHECK: encoding: [0x67,0xf3,0x0f,0x38,0xf8,0x3f]
 enqcmds (%edi), %edi
+
+// CHECK: serialize
+// CHECK: encoding: [0x0f,0x01,0xe8]
+serialize

llvm/test/MC/X86/x86-32-coverage.s

 
 // CHECK: enqcmds (%bx,%di), %di
 // CHECK: encoding: [0x67,0xf3,0x0f,0x38,0xf8,0x39]
 enqcmds (%bx,%di), %di
 
 // CHECK: enqcmds 8128(%bx,%di), %ax
 // CHECK: encoding: [0x67,0xf3,0x0f,0x38,0xf8,0x81,0xc0,0x1f]
 enqcmds 8128(%bx,%di), %ax
+
+// CHECK: serialize
+// CHECK: encoding: [0x0f,0x01,0xe8]
+serialize

llvm/test/MC/X86/x86-64.s

 
 // CHECK: enqcmds -8192(%rdx), %rbx
 // CHECK: encoding: [0xf3,0x0f,0x38,0xf8,0x9a,0x00,0xe0,0xff,0xff]
 enqcmds -8192(%rdx), %rbx
 
 // CHECK: enqcmds 485498096, %rax
 // CHECK: encoding: [0xf3,0x0f,0x38,0xf8,0x04,0x25,0xf0,0x1c,0xf0,0x1c]
 enqcmds 485498096, %rax
+
+// CHECK: serialize
+// CHECK: encoding: [0x0f,0x01,0xe8]
+serialize