diff --git a/clang/lib/Basic/Targets/X86.cpp b/clang/lib/Basic/Targets/X86.cpp
--- a/clang/lib/Basic/Targets/X86.cpp
+++ b/clang/lib/Basic/Targets/X86.cpp
@@ -110,342 +110,12 @@
     setFeatureEnabledImpl(Features, "sse2", true);
 
   using namespace llvm::X86;
-  const enum CPUKind Kind = parseArchX86(CPU);
 
-  // Enable X87 for all X86 processors but Lakemont.
-  if (Kind != CK_Lakemont)
-    setFeatureEnabledImpl(Features, "x87", true);
+  SmallVector<StringRef, 16> CPUFeatures;
+  getFeaturesForCPU(CPU, CPUFeatures);
+  for (auto &F : CPUFeatures)
+    setFeatureEnabledImpl(Features, F, true);
 
-  // Enable cmpxchg8 for i586 and greater CPUs. Include generic for backwards
-  // compatibility.
-  if (Kind >= CK_i586 || Kind == CK_None)
-    setFeatureEnabledImpl(Features, "cx8", true);
-
-  switch (Kind) {
-  case CK_None:
-  case CK_i386:
-  case CK_i486:
-  case CK_i586:
-  case CK_Pentium:
-  case CK_PentiumPro:
-  case CK_i686:
-  case CK_Lakemont:
-    break;
-
-  case CK_Cooperlake:
-    // CPX inherits all CLX features plus AVX512BF16
-    setFeatureEnabledImpl(Features, "avx512bf16", true);
-    LLVM_FALLTHROUGH;
-  case CK_Cascadelake:
-    // CLX inherits all SKX features plus AVX512VNNI
-    setFeatureEnabledImpl(Features, "avx512vnni", true);
-    LLVM_FALLTHROUGH;
-  case CK_SkylakeServer:
-    setFeatureEnabledImpl(Features, "avx512f", true);
-    setFeatureEnabledImpl(Features, "avx512cd", true);
-    setFeatureEnabledImpl(Features, "avx512dq", true);
-    setFeatureEnabledImpl(Features, "avx512bw", true);
-    setFeatureEnabledImpl(Features, "avx512vl", true);
-    setFeatureEnabledImpl(Features, "clwb", true);
-    setFeatureEnabledImpl(Features, "pku", true);
-    // SkylakeServer cores inherits all SKL features, except SGX
-    goto SkylakeCommon;
-
-  case CK_Tigerlake:
-    setFeatureEnabledImpl(Features, "avx512vp2intersect", true);
-    setFeatureEnabledImpl(Features, "movdiri", true);
-    setFeatureEnabledImpl(Features, "movdir64b", true);
-    setFeatureEnabledImpl(Features, "shstk", true);
-    // Tigerlake cores inherits IcelakeClient, except pconfig and wbnoinvd
-    goto IcelakeCommon;
-
-  case CK_IcelakeServer:
-    setFeatureEnabledImpl(Features, "pconfig", true);
-    setFeatureEnabledImpl(Features, "wbnoinvd", true);
-    LLVM_FALLTHROUGH;
-  case CK_IcelakeClient:
-IcelakeCommon:
-    setFeatureEnabledImpl(Features, "vaes", true);
-    setFeatureEnabledImpl(Features, "gfni", true);
-    setFeatureEnabledImpl(Features, "vpclmulqdq", true);
-    setFeatureEnabledImpl(Features, "avx512bitalg", true);
-    setFeatureEnabledImpl(Features, "avx512vbmi2", true);
-    setFeatureEnabledImpl(Features, "avx512vnni", true);
-    setFeatureEnabledImpl(Features, "avx512vpopcntdq", true);
-    setFeatureEnabledImpl(Features, "rdpid", true);
-    setFeatureEnabledImpl(Features, "clwb", true);
-    LLVM_FALLTHROUGH;
-  case CK_Cannonlake:
-    setFeatureEnabledImpl(Features, "avx512f", true);
-    setFeatureEnabledImpl(Features, "avx512cd", true);
-    setFeatureEnabledImpl(Features, "avx512dq", true);
-    setFeatureEnabledImpl(Features, "avx512bw", true);
-    setFeatureEnabledImpl(Features, "avx512vl", true);
-    setFeatureEnabledImpl(Features, "avx512ifma", true);
-    setFeatureEnabledImpl(Features, "avx512vbmi", true);
-    setFeatureEnabledImpl(Features, "pku", true);
-    setFeatureEnabledImpl(Features, "sha", true);
-    LLVM_FALLTHROUGH;
-  case CK_SkylakeClient:
-    setFeatureEnabledImpl(Features, "sgx", true);
-    // SkylakeServer cores inherits all SKL features, except SGX
-SkylakeCommon:
-    setFeatureEnabledImpl(Features, "xsavec", true);
-    setFeatureEnabledImpl(Features, "xsaves", true);
-    setFeatureEnabledImpl(Features, "clflushopt", true);
-    setFeatureEnabledImpl(Features, "aes", true);
-    LLVM_FALLTHROUGH;
-  case CK_Broadwell:
-    setFeatureEnabledImpl(Features, "rdseed", true);
-    setFeatureEnabledImpl(Features, "adx", true);
-    setFeatureEnabledImpl(Features, "prfchw", true);
-    LLVM_FALLTHROUGH;
-  case CK_Haswell:
-    setFeatureEnabledImpl(Features, "avx2", true);
-    setFeatureEnabledImpl(Features, "lzcnt", true);
-    setFeatureEnabledImpl(Features, "bmi", true);
-    setFeatureEnabledImpl(Features, "bmi2", true);
-    setFeatureEnabledImpl(Features, "fma", true);
-    setFeatureEnabledImpl(Features, "invpcid", true);
-    setFeatureEnabledImpl(Features, "movbe", true);
-    LLVM_FALLTHROUGH;
-  case CK_IvyBridge:
-    setFeatureEnabledImpl(Features, "rdrnd", true);
-    setFeatureEnabledImpl(Features, "f16c", true);
-    setFeatureEnabledImpl(Features, "fsgsbase", true);
-    LLVM_FALLTHROUGH;
-  case CK_SandyBridge:
-    setFeatureEnabledImpl(Features, "avx", true);
-    setFeatureEnabledImpl(Features, "xsave", true);
-    setFeatureEnabledImpl(Features, "xsaveopt", true);
-    LLVM_FALLTHROUGH;
-  case CK_Westmere:
-    setFeatureEnabledImpl(Features, "pclmul", true);
-    LLVM_FALLTHROUGH;
-  case CK_Nehalem:
-    setFeatureEnabledImpl(Features, "sse4.2", true);
-    setFeatureEnabledImpl(Features, "popcnt", true);
-    LLVM_FALLTHROUGH;
-  case CK_Penryn:
-    setFeatureEnabledImpl(Features, "sse4.1", true);
-    LLVM_FALLTHROUGH;
-  case CK_Core2:
-    setFeatureEnabledImpl(Features, "ssse3", true);
-    setFeatureEnabledImpl(Features, "sahf", true);
-    LLVM_FALLTHROUGH;
-  case CK_Nocona:
-    setFeatureEnabledImpl(Features, "cx16", true);
-    LLVM_FALLTHROUGH;
-  case CK_Yonah:
-  case CK_Prescott:
-    setFeatureEnabledImpl(Features, "sse3", true);
-    LLVM_FALLTHROUGH;
-  case CK_PentiumM:
-  case CK_Pentium4:
-  case CK_x86_64:
-    setFeatureEnabledImpl(Features, "sse2", true);
-    LLVM_FALLTHROUGH;
-  case CK_Pentium3:
-  case CK_C3_2:
-    setFeatureEnabledImpl(Features, "sse", true);
-    LLVM_FALLTHROUGH;
-  case CK_Pentium2:
-    setFeatureEnabledImpl(Features, "fxsr", true);
-    LLVM_FALLTHROUGH;
-  case CK_PentiumMMX:
-  case CK_K6:
-  case CK_WinChipC6:
-    setFeatureEnabledImpl(Features, "mmx", true);
-    break;
-
-  case CK_Tremont:
-    setFeatureEnabledImpl(Features, "clwb", true);
-    setFeatureEnabledImpl(Features, "gfni", true);
-    LLVM_FALLTHROUGH;
-  case CK_GoldmontPlus:
-    setFeatureEnabledImpl(Features, "ptwrite", true);
-    setFeatureEnabledImpl(Features, "rdpid", true);
-    setFeatureEnabledImpl(Features, "sgx", true);
-    LLVM_FALLTHROUGH;
-  case CK_Goldmont:
-    setFeatureEnabledImpl(Features, "sha", true);
-    setFeatureEnabledImpl(Features, "rdseed", true);
-    setFeatureEnabledImpl(Features, "xsave", true);
-    setFeatureEnabledImpl(Features, "xsaveopt", true);
-    setFeatureEnabledImpl(Features, "xsavec", true);
-    setFeatureEnabledImpl(Features, "xsaves", true);
-    setFeatureEnabledImpl(Features, "clflushopt", true);
-    setFeatureEnabledImpl(Features, "fsgsbase", true);
-    setFeatureEnabledImpl(Features, "aes", true);
-    LLVM_FALLTHROUGH;
-  case CK_Silvermont:
-    setFeatureEnabledImpl(Features, "rdrnd", true);
-    setFeatureEnabledImpl(Features, "pclmul", true);
-    setFeatureEnabledImpl(Features, "sse4.2", true);
-    setFeatureEnabledImpl(Features, "popcnt", true);
-    setFeatureEnabledImpl(Features, "prfchw", true);
-    LLVM_FALLTHROUGH;
-  case CK_Bonnell:
-    setFeatureEnabledImpl(Features, "movbe", true);
-    setFeatureEnabledImpl(Features, "ssse3", true);
-    setFeatureEnabledImpl(Features, "fxsr", true);
-    setFeatureEnabledImpl(Features, "cx16", true);
-    setFeatureEnabledImpl(Features, "sahf", true);
-    setFeatureEnabledImpl(Features, "mmx", true);
-    break;
-
-  case CK_KNM:
-    // TODO: Add avx5124fmaps/avx5124vnniw.
-    setFeatureEnabledImpl(Features, "avx512vpopcntdq", true);
-    LLVM_FALLTHROUGH;
-  case CK_KNL:
-    setFeatureEnabledImpl(Features, "avx512f", true);
-    setFeatureEnabledImpl(Features, "avx512cd", true);
-    setFeatureEnabledImpl(Features, "avx512er", true);
-    setFeatureEnabledImpl(Features, "avx512pf", true);
-    setFeatureEnabledImpl(Features, "prfchw", true);
-    setFeatureEnabledImpl(Features, "prefetchwt1", true);
-    setFeatureEnabledImpl(Features, "fxsr", true);
-    setFeatureEnabledImpl(Features, "rdseed", true);
-    setFeatureEnabledImpl(Features, "adx", true);
-    setFeatureEnabledImpl(Features, "lzcnt", true);
-    setFeatureEnabledImpl(Features, "popcnt", true);
-    setFeatureEnabledImpl(Features, "bmi", true);
-    setFeatureEnabledImpl(Features, "bmi2", true);
-    setFeatureEnabledImpl(Features, "fma", true);
-    setFeatureEnabledImpl(Features, "rdrnd", true);
-    setFeatureEnabledImpl(Features, "f16c", true);
-    setFeatureEnabledImpl(Features, "fsgsbase", true);
-    setFeatureEnabledImpl(Features, "aes", true);
-    setFeatureEnabledImpl(Features, "pclmul", true);
-    setFeatureEnabledImpl(Features, "cx16", true);
-    setFeatureEnabledImpl(Features, "xsaveopt", true);
-    setFeatureEnabledImpl(Features, "xsave", true);
-    setFeatureEnabledImpl(Features, "movbe", true);
-    setFeatureEnabledImpl(Features, "sahf", true);
-    setFeatureEnabledImpl(Features, "mmx", true);
-    break;
-
-  case CK_K6_2:
-  case CK_K6_3:
-  case CK_WinChip2:
-  case CK_C3:
-    setFeatureEnabledImpl(Features, "3dnow", true);
-    break;
-
-  case CK_AMDFAM10:
-    setFeatureEnabledImpl(Features, "sse4a", true);
-    setFeatureEnabledImpl(Features, "lzcnt", true);
-    setFeatureEnabledImpl(Features, "popcnt", true);
-    setFeatureEnabledImpl(Features, "sahf", true);
-    setFeatureEnabledImpl(Features, "prfchw", true);
-    setFeatureEnabledImpl(Features, "cx16", true);
-    LLVM_FALLTHROUGH;
-  case CK_K8SSE3:
-    setFeatureEnabledImpl(Features, "sse3", true);
-    LLVM_FALLTHROUGH;
-  case CK_K8:
-    setFeatureEnabledImpl(Features, "sse2", true);
-    LLVM_FALLTHROUGH;
-  case CK_AthlonXP:
-    setFeatureEnabledImpl(Features, "sse", true);
-    setFeatureEnabledImpl(Features, "fxsr", true);
-    LLVM_FALLTHROUGH;
-  case CK_Athlon:
-  case CK_Geode:
-    setFeatureEnabledImpl(Features, "3dnowa", true);
-    break;
-
-  case CK_BTVER2:
-    setFeatureEnabledImpl(Features, "avx", true);
-    setFeatureEnabledImpl(Features, "aes", true);
-    setFeatureEnabledImpl(Features, "pclmul", true);
-    setFeatureEnabledImpl(Features, "bmi", true);
-    setFeatureEnabledImpl(Features, "f16c", true);
-    setFeatureEnabledImpl(Features, "xsaveopt", true);
-    setFeatureEnabledImpl(Features, "xsave", true);
-    setFeatureEnabledImpl(Features, "movbe", true);
-    LLVM_FALLTHROUGH;
-  case CK_BTVER1:
-    setFeatureEnabledImpl(Features, "ssse3", true);
-    setFeatureEnabledImpl(Features, "sse4a", true);
-    setFeatureEnabledImpl(Features, "lzcnt", true);
-    setFeatureEnabledImpl(Features, "popcnt", true);
-    setFeatureEnabledImpl(Features, "prfchw", true);
-    setFeatureEnabledImpl(Features, "cx16", true);
-    setFeatureEnabledImpl(Features, "fxsr", true);
-    setFeatureEnabledImpl(Features, "sahf", true);
-    setFeatureEnabledImpl(Features, "mmx", true);
-    break;
-
-  case CK_ZNVER2:
-    setFeatureEnabledImpl(Features, "clwb", true);
-    setFeatureEnabledImpl(Features, "rdpid", true);
-    setFeatureEnabledImpl(Features, "wbnoinvd", true);
-    LLVM_FALLTHROUGH;
-  case CK_ZNVER1:
-    setFeatureEnabledImpl(Features, "adx", true);
-    setFeatureEnabledImpl(Features, "aes", true);
-    setFeatureEnabledImpl(Features, "avx2", true);
-    setFeatureEnabledImpl(Features, "bmi", true);
-    setFeatureEnabledImpl(Features, "bmi2", true);
-    setFeatureEnabledImpl(Features, "clflushopt", true);
-    setFeatureEnabledImpl(Features, "clzero", true);
-    setFeatureEnabledImpl(Features, "cx16", true);
-    setFeatureEnabledImpl(Features, "f16c", true);
-    setFeatureEnabledImpl(Features, "fma", true);
-    setFeatureEnabledImpl(Features, "fsgsbase", true);
-    setFeatureEnabledImpl(Features, "fxsr", true);
-    setFeatureEnabledImpl(Features, "lzcnt", true);
-    setFeatureEnabledImpl(Features, "mmx", true);
-    setFeatureEnabledImpl(Features, "mwaitx", true);
-    setFeatureEnabledImpl(Features, "movbe", true);
-    setFeatureEnabledImpl(Features, "pclmul", true);
-    setFeatureEnabledImpl(Features, "popcnt", true);
-    setFeatureEnabledImpl(Features, "prfchw", true);
-    setFeatureEnabledImpl(Features, "rdrnd", true);
-    setFeatureEnabledImpl(Features, "rdseed", true);
-    setFeatureEnabledImpl(Features, "sahf", true);
-    setFeatureEnabledImpl(Features, "sha", true);
-    setFeatureEnabledImpl(Features, "sse4a", true);
-    setFeatureEnabledImpl(Features, "xsave", true);
-    setFeatureEnabledImpl(Features, "xsavec", true);
-    setFeatureEnabledImpl(Features, "xsaveopt", true);
-    setFeatureEnabledImpl(Features, "xsaves", true);
-    break;
-
-  case CK_BDVER4:
-    setFeatureEnabledImpl(Features, "avx2", true);
-    setFeatureEnabledImpl(Features, "bmi2", true);
-    setFeatureEnabledImpl(Features, "movbe", true);
-    setFeatureEnabledImpl(Features, "rdrnd", true);
-    setFeatureEnabledImpl(Features, "mwaitx", true);
-    LLVM_FALLTHROUGH;
-  case CK_BDVER3:
-    setFeatureEnabledImpl(Features, "fsgsbase", true);
-    setFeatureEnabledImpl(Features, "xsaveopt", true);
-    LLVM_FALLTHROUGH;
-  case CK_BDVER2:
-    setFeatureEnabledImpl(Features, "bmi", true);
-    setFeatureEnabledImpl(Features, "fma", true);
-    setFeatureEnabledImpl(Features, "f16c", true);
-    setFeatureEnabledImpl(Features, "tbm", true);
-    LLVM_FALLTHROUGH;
-  case CK_BDVER1:
-    // xop implies avx, sse4a and fma4.
-    setFeatureEnabledImpl(Features, "xop", true);
-    setFeatureEnabledImpl(Features, "lwp", true);
-    setFeatureEnabledImpl(Features, "lzcnt", true);
-    setFeatureEnabledImpl(Features, "aes", true);
-    setFeatureEnabledImpl(Features, "pclmul", true);
-    setFeatureEnabledImpl(Features, "prfchw", true);
-    setFeatureEnabledImpl(Features, "cx16", true);
-    setFeatureEnabledImpl(Features, "fxsr", true);
-    setFeatureEnabledImpl(Features, "xsave", true);
-    setFeatureEnabledImpl(Features, "sahf", true);
-    setFeatureEnabledImpl(Features, "mmx", true);
-    break;
-  }
   if (!TargetInfo::initFeatureMap(Features, Diags, CPU, FeaturesVec))
     return false;
 
@@ -1531,7 +1201,7 @@
 
 static llvm::X86::ProcessorFeatures getFeature(StringRef Name) {
   return llvm::StringSwitch<llvm::X86::ProcessorFeatures>(Name)
-#define X86_FEATURE_COMPAT(ENUM, STR) .Case(STR, llvm::X86::ENUM)
+#define X86_FEATURE_COMPAT(ENUM, STR) .Case(STR, llvm::X86::FEATURE_##ENUM)
 #include "llvm/Support/X86TargetParser.def"
       ;
   // Note, this function should only be used after ensuring the value is
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -11688,7 +11688,7 @@
   for (const StringRef &FeatureStr : FeatureStrs) {
     unsigned Feature =
         StringSwitch<unsigned>(FeatureStr)
-#define X86_FEATURE_COMPAT(ENUM, STR) .Case(STR, llvm::X86::ENUM)
+#define X86_FEATURE_COMPAT(ENUM, STR) .Case(STR, llvm::X86::FEATURE_##ENUM)
 #include "llvm/Support/X86TargetParser.def"
         ;
     FeaturesMask |= (1ULL << Feature);
diff --git a/llvm/include/llvm/Support/X86TargetParser.h b/llvm/include/llvm/Support/X86TargetParser.h
--- a/llvm/include/llvm/Support/X86TargetParser.h
+++ b/llvm/include/llvm/Support/X86TargetParser.h
@@ -53,8 +53,7 @@
 // This should be kept in sync with libcc/compiler-rt as it should be used
 // by clang as a proxy for what's in libgcc/compiler-rt.
 enum ProcessorFeatures {
-#define X86_FEATURE(ENUM) \
-  ENUM,
+#define X86_FEATURE(ENUM, STRING) FEATURE_##ENUM,
 #include "llvm/Support/X86TargetParser.def"
   CPU_FEATURE_MAX
 };
@@ -132,8 +131,12 @@
 void fillValidCPUArchList(SmallVectorImpl<StringRef> &Values,
                           bool ArchIs32Bit);
 
+/// Get the key feature prioritizing target multiversioning.
 ProcessorFeatures getKeyFeature(CPUKind Kind);
 
+/// Fill in the features that \p CPU supports into \p Features.
+void getFeaturesForCPU(StringRef CPU, SmallVectorImpl<StringRef> &Features);
+
 } // namespace X86
 } // namespace llvm
 
diff --git a/llvm/include/llvm/Support/X86TargetParser.def b/llvm/include/llvm/Support/X86TargetParser.def
--- a/llvm/include/llvm/Support/X86TargetParser.def
+++ b/llvm/include/llvm/Support/X86TargetParser.def
@@ -125,56 +125,97 @@
 
 // This macro is used for cpu types present in compiler-rt/libgcc.
 #ifndef X86_FEATURE_COMPAT
-#define X86_FEATURE_COMPAT(ENUM, STR) X86_FEATURE(ENUM)
+#define X86_FEATURE_COMPAT(ENUM, STR) X86_FEATURE(ENUM, STR)
 #endif
 
 #ifndef X86_FEATURE
-#define X86_FEATURE(ENUM)
+#define X86_FEATURE(ENUM, STR)
 #endif
 
-X86_FEATURE_COMPAT(FEATURE_CMOV,            "cmov")
-X86_FEATURE_COMPAT(FEATURE_MMX,             "mmx")
-X86_FEATURE_COMPAT(FEATURE_POPCNT,          "popcnt")
-X86_FEATURE_COMPAT(FEATURE_SSE,             "sse")
-X86_FEATURE_COMPAT(FEATURE_SSE2,            "sse2")
-X86_FEATURE_COMPAT(FEATURE_SSE3,            "sse3")
-X86_FEATURE_COMPAT(FEATURE_SSSE3,           "ssse3")
-X86_FEATURE_COMPAT(FEATURE_SSE4_1,          "sse4.1")
-X86_FEATURE_COMPAT(FEATURE_SSE4_2,          "sse4.2")
-X86_FEATURE_COMPAT(FEATURE_AVX,             "avx")
-X86_FEATURE_COMPAT(FEATURE_AVX2,            "avx2")
-X86_FEATURE_COMPAT(FEATURE_SSE4_A,          "sse4a")
-X86_FEATURE_COMPAT(FEATURE_FMA4,            "fma4")
-X86_FEATURE_COMPAT(FEATURE_XOP,             "xop")
-X86_FEATURE_COMPAT(FEATURE_FMA,             "fma")
-X86_FEATURE_COMPAT(FEATURE_AVX512F,         "avx512f")
-X86_FEATURE_COMPAT(FEATURE_BMI,             "bmi")
-X86_FEATURE_COMPAT(FEATURE_BMI2,            "bmi2")
-X86_FEATURE_COMPAT(FEATURE_AES,             "aes")
-X86_FEATURE_COMPAT(FEATURE_PCLMUL,          "pclmul")
-X86_FEATURE_COMPAT(FEATURE_AVX512VL,        "avx512vl")
-X86_FEATURE_COMPAT(FEATURE_AVX512BW,        "avx512bw")
-X86_FEATURE_COMPAT(FEATURE_AVX512DQ,        "avx512dq")
-X86_FEATURE_COMPAT(FEATURE_AVX512CD,        "avx512cd")
-X86_FEATURE_COMPAT(FEATURE_AVX512ER,        "avx512er")
-X86_FEATURE_COMPAT(FEATURE_AVX512PF,        "avx512pf")
-X86_FEATURE_COMPAT(FEATURE_AVX512VBMI,      "avx512vbmi")
-X86_FEATURE_COMPAT(FEATURE_AVX512IFMA,      "avx512ifma")
-X86_FEATURE_COMPAT(FEATURE_AVX5124VNNIW,    "avx5124vnniw")
-X86_FEATURE_COMPAT(FEATURE_AVX5124FMAPS,    "avx5124fmaps")
-X86_FEATURE_COMPAT(FEATURE_AVX512VPOPCNTDQ, "avx512vpopcntdq")
-X86_FEATURE_COMPAT(FEATURE_AVX512VBMI2,     "avx512vbmi2")
-X86_FEATURE_COMPAT(FEATURE_GFNI,            "gfni")
-X86_FEATURE_COMPAT(FEATURE_VPCLMULQDQ,      "vpclmulqdq")
-X86_FEATURE_COMPAT(FEATURE_AVX512VNNI,      "avx512vnni")
-X86_FEATURE_COMPAT(FEATURE_AVX512BITALG,    "avx512bitalg")
-X86_FEATURE_COMPAT(FEATURE_AVX512BF16,      "avx512bf16")
-X86_FEATURE_COMPAT(FEATURE_AVX512VP2INTERSECT, "avx512vp2intersect")
+X86_FEATURE_COMPAT(CMOV,            "cmov")
+X86_FEATURE_COMPAT(MMX,             "mmx")
+X86_FEATURE_COMPAT(POPCNT,          "popcnt")
+X86_FEATURE_COMPAT(SSE,             "sse")
+X86_FEATURE_COMPAT(SSE2,            "sse2")
+X86_FEATURE_COMPAT(SSE3,            "sse3")
+X86_FEATURE_COMPAT(SSSE3,           "ssse3")
+X86_FEATURE_COMPAT(SSE4_1,          "sse4.1")
+X86_FEATURE_COMPAT(SSE4_2,          "sse4.2")
+X86_FEATURE_COMPAT(AVX,             "avx")
+X86_FEATURE_COMPAT(AVX2,            "avx2")
+X86_FEATURE_COMPAT(SSE4_A,          "sse4a")
+X86_FEATURE_COMPAT(FMA4,            "fma4")
+X86_FEATURE_COMPAT(XOP,             "xop")
+X86_FEATURE_COMPAT(FMA,             "fma")
+X86_FEATURE_COMPAT(AVX512F,         "avx512f")
+X86_FEATURE_COMPAT(BMI,             "bmi")
+X86_FEATURE_COMPAT(BMI2,            "bmi2")
+X86_FEATURE_COMPAT(AES,             "aes")
+X86_FEATURE_COMPAT(PCLMUL,          "pclmul")
+X86_FEATURE_COMPAT(AVX512VL,        "avx512vl")
+X86_FEATURE_COMPAT(AVX512BW,        "avx512bw")
+X86_FEATURE_COMPAT(AVX512DQ,        "avx512dq")
+X86_FEATURE_COMPAT(AVX512CD,        "avx512cd")
+X86_FEATURE_COMPAT(AVX512ER,        "avx512er")
+X86_FEATURE_COMPAT(AVX512PF,        "avx512pf")
+X86_FEATURE_COMPAT(AVX512VBMI,      "avx512vbmi")
+X86_FEATURE_COMPAT(AVX512IFMA,      "avx512ifma")
+X86_FEATURE_COMPAT(AVX5124VNNIW,    "avx5124vnniw")
+X86_FEATURE_COMPAT(AVX5124FMAPS,    "avx5124fmaps")
+X86_FEATURE_COMPAT(AVX512VPOPCNTDQ, "avx512vpopcntdq")
+X86_FEATURE_COMPAT(AVX512VBMI2,     "avx512vbmi2")
+X86_FEATURE_COMPAT(GFNI,            "gfni")
+X86_FEATURE_COMPAT(VPCLMULQDQ,      "vpclmulqdq")
+X86_FEATURE_COMPAT(AVX512VNNI,      "avx512vnni")
+X86_FEATURE_COMPAT(AVX512BITALG,    "avx512bitalg")
+X86_FEATURE_COMPAT(AVX512BF16,      "avx512bf16")
+X86_FEATURE_COMPAT(AVX512VP2INTERSECT, "avx512vp2intersect")
 // Features below here are not in libgcc/compiler-rt.
-X86_FEATURE       (FEATURE_MOVBE)
-X86_FEATURE       (FEATURE_ADX)
-X86_FEATURE       (FEATURE_EM64T)
-X86_FEATURE       (FEATURE_CLFLUSHOPT)
-X86_FEATURE       (FEATURE_SHA)
+X86_FEATURE       (3DNOW,           "3dnow")
+X86_FEATURE       (3DNOWA,          "3dnowa")
+X86_FEATURE       (ADX,             "adx")
+X86_FEATURE       (CLDEMOTE,        "cldemote")
+X86_FEATURE       (CLFLUSHOPT,      "clflushopt")
+X86_FEATURE       (CLWB,            "clwb")
+X86_FEATURE       (CLZERO,          "clzero")
+X86_FEATURE       (CMPXCHG16B,      "cx16")
+X86_FEATURE       (CMPXCHG8B,       "cx8")
+X86_FEATURE       (EM64T,           nullptr)
+X86_FEATURE       (ENQCMD,          "enqcmd")
+X86_FEATURE       (F16C,            "f16c")
+X86_FEATURE       (FSGSBASE,        "fsgsbase")
+X86_FEATURE       (FXSR,            "fxsr")
+X86_FEATURE       (INVPCID,         "invpcid")
+X86_FEATURE       (LWP,             "lwp")
+X86_FEATURE       (LZCNT,           "lzcnt")
+X86_FEATURE       (MOVBE,           "movbe")
+X86_FEATURE       (MOVDIR64B,       "movdir64b")
+X86_FEATURE       (MOVDIRI,         "movdiri")
+X86_FEATURE       (MWAITX,          "mwaitx")
+X86_FEATURE       (PCONFIG,         "pconfig")
+X86_FEATURE       (PKU,             "pku")
+X86_FEATURE       (PREFETCHWT1,     "prefetchwt1")
+X86_FEATURE       (PRFCHW,          "prfchw")
+X86_FEATURE       (PTWRITE,         "ptwrite")
+X86_FEATURE       (RDPID,           "rdpid")
+X86_FEATURE       (RDRND,           "rdrnd")
+X86_FEATURE       (RDSEED,          "rdseed")
+X86_FEATURE       (RTM,             "rtm")
+X86_FEATURE       (SAHF,            "sahf")
+X86_FEATURE       (SERIALIZE,       "serialize")
+X86_FEATURE       (SGX,             "sgx")
+X86_FEATURE       (SHA,             "sha")
+X86_FEATURE       (SHSTK,           "shstk")
+X86_FEATURE       (SSE4A,           "sse4a")
+X86_FEATURE       (TBM,             "tbm")
+X86_FEATURE       (TSXLDTRK,        "tsxldtrk")
+X86_FEATURE       (VAES,            "vaes")
+X86_FEATURE       (WAITPKG,         "waitpkg")
+X86_FEATURE       (WBNOINVD,        "wbnoinvd")
+X86_FEATURE       (X87,             "x87")
+X86_FEATURE       (XSAVE,           "xsave")
+X86_FEATURE       (XSAVEC,          "xsavec")
+X86_FEATURE       (XSAVEOPT,        "xsaveopt")
+X86_FEATURE       (XSAVES,          "xsaves")
 #undef X86_FEATURE_COMPAT
 #undef X86_FEATURE
diff --git a/llvm/lib/Support/X86TargetParser.cpp b/llvm/lib/Support/X86TargetParser.cpp
--- a/llvm/lib/Support/X86TargetParser.cpp
+++ b/llvm/lib/Support/X86TargetParser.cpp
@@ -19,134 +19,339 @@
 
 namespace {
 
+/// Container class for CPU features.
+/// This is a constexpr reimplementation of a subset of std::bitset. It would be
+/// nice to use std::bitset directly, but it doesn't support constant
+/// initialization.
+class FeatureBitset {
+  static constexpr unsigned NUM_FEATURE_WORDS =
+      (X86::CPU_FEATURE_MAX + 31) / 32;
+
+  // This cannot be a std::array, operator[] is not constexpr until C++17.
+  uint32_t Bits[NUM_FEATURE_WORDS] = {};
+
+public:
+  constexpr FeatureBitset() = default;
+  constexpr FeatureBitset(std::initializer_list<unsigned> Init) {
+    for (auto I : Init)
+      set(I);
+  }
+
+  constexpr FeatureBitset &set(unsigned I) {
+    uint32_t NewBits = Bits[I / 32] | (uint32_t(1) << (I % 32));
+    Bits[I / 32] = NewBits;
+    return *this;
+  }
+
+  constexpr bool operator[](unsigned I) const {
+    uint32_t Mask = uint32_t(1) << (I % 32);
+    return (Bits[I / 32] & Mask) != 0;
+  }
+
+  constexpr FeatureBitset operator&(const FeatureBitset &RHS) const {
+    FeatureBitset Result;
+    for (unsigned I = 0, E = array_lengthof(Bits); I != E; ++I)
+      Result.Bits[I] = Bits[I] & RHS.Bits[I];
+    return Result;
+  }
+
+  constexpr FeatureBitset operator|(const FeatureBitset &RHS) const {
+    FeatureBitset Result;
+    for (unsigned I = 0, E = array_lengthof(Bits); I != E; ++I)
+      Result.Bits[I] = Bits[I] | RHS.Bits[I];
+    return Result;
+  }
+
+  constexpr FeatureBitset operator~() const {
+    FeatureBitset Result;
+    for (unsigned I = 0, E = array_lengthof(Bits); I != E; ++I)
+      Result.Bits[I] = ~Bits[I];
+    return Result;
+  }
+};
+
 struct ProcInfo {
   StringLiteral Name;
   X86::CPUKind Kind;
   unsigned KeyFeature;
-  bool Is64Bit;
+  FeatureBitset Features;
 };
 
 } // end anonymous namespace
 
-#define PROC_64_BIT true
-#define PROC_32_BIT false
+#define X86_FEATURE(ENUM, STRING)                                              \
+  static constexpr FeatureBitset Feature##ENUM = {X86::FEATURE_##ENUM};
+#include "llvm/Support/X86TargetParser.def"
+
+// Pentium with MMX.
+static constexpr FeatureBitset FeaturesPentiumMMX =
+    FeatureX87 | FeatureCMPXCHG8B | FeatureMMX;
+
+// Pentium 2 and 3.
+static constexpr FeatureBitset FeaturesPentium2 =
+    FeatureX87 | FeatureCMPXCHG8B | FeatureMMX | FeatureFXSR;
+static constexpr FeatureBitset FeaturesPentium3 = FeaturesPentium2 | FeatureSSE;
+
+// Pentium 4 CPUs
+static constexpr FeatureBitset FeaturesPentium4 =
+    FeaturesPentium3 | FeatureSSE2;
+static constexpr FeatureBitset FeaturesPrescott =
+    FeaturesPentium4 | FeatureSSE3;
+static constexpr FeatureBitset FeaturesNocona =
+    FeaturesPrescott | FeatureEM64T | FeatureCMPXCHG16B;
+
+// Basic 64-bit capable CPU.
+static constexpr FeatureBitset FeaturesX86_64 = FeaturesPentium4 | FeatureEM64T;
+
+// Intel Core CPUs
+static constexpr FeatureBitset FeaturesCore2 =
+    FeaturesNocona | FeatureSAHF | FeatureSSSE3;
+static constexpr FeatureBitset FeaturesPenryn = FeaturesCore2 | FeatureSSE4_1;
+static constexpr FeatureBitset FeaturesNehalem =
+    FeaturesPenryn | FeaturePOPCNT | FeatureSSE4_2;
+static constexpr FeatureBitset FeaturesWestmere =
+    FeaturesNehalem | FeaturePCLMUL;
+static constexpr FeatureBitset FeaturesSandyBridge =
+    FeaturesWestmere | FeatureAVX | FeatureXSAVE | FeatureXSAVEOPT;
+static constexpr FeatureBitset FeaturesIvyBridge =
+    FeaturesSandyBridge | FeatureF16C | FeatureFSGSBASE | FeatureRDRND;
+static constexpr FeatureBitset FeaturesHaswell =
+    FeaturesIvyBridge | FeatureAVX2 | FeatureBMI | FeatureBMI2 | FeatureFMA |
+    FeatureINVPCID | FeatureLZCNT | FeatureMOVBE;
+static constexpr FeatureBitset FeaturesBroadwell =
+    FeaturesHaswell | FeatureADX | FeaturePRFCHW | FeatureRDSEED;
+
+// Intel Knights Landing and Knights Mill
+// Knights Landing has feature parity with Broadwell.
+static constexpr FeatureBitset FeaturesKNL =
+    FeaturesBroadwell | FeatureAES | FeatureAVX512F | FeatureAVX512CD |
+    FeatureAVX512ER | FeatureAVX512PF | FeaturePREFETCHWT1;
+static constexpr FeatureBitset FeaturesKNM =
+    FeaturesKNL | FeatureAVX512VPOPCNTDQ;
+
+// Intel Skylake processors.
+static constexpr FeatureBitset FeaturesSkylakeClient =
+    FeaturesBroadwell | FeatureAES | FeatureCLFLUSHOPT | FeatureXSAVEC |
+    FeatureXSAVES | FeatureSGX;
+// SkylakeServer inherits all SkylakeClient features except SGX.
+// FIXME: That doesn't match gcc.
+static constexpr FeatureBitset FeaturesSkylakeServer =
+    (FeaturesSkylakeClient & ~FeatureSGX) | FeatureAVX512F | FeatureAVX512CD |
+    FeatureAVX512DQ | FeatureAVX512BW | FeatureAVX512VL | FeatureCLWB |
+    FeaturePKU;
+static constexpr FeatureBitset FeaturesCascadeLake =
+    FeaturesSkylakeServer | FeatureAVX512VNNI;
+static constexpr FeatureBitset FeaturesCooperLake =
+    FeaturesCascadeLake | FeatureAVX512BF16;
+
+// Intel 10nm processors.
+static constexpr FeatureBitset FeaturesCannonlake =
+    FeaturesSkylakeClient | FeatureAVX512F | FeatureAVX512CD | FeatureAVX512DQ |
+    FeatureAVX512BW | FeatureAVX512VL | FeatureAVX512IFMA | FeatureAVX512VBMI |
+    FeaturePKU | FeatureSHA;
+static constexpr FeatureBitset FeaturesICLClient =
+    FeaturesCannonlake | FeatureAVX512BITALG | FeatureAVX512VBMI2 |
+    FeatureAVX512VNNI | FeatureAVX512VPOPCNTDQ | FeatureCLWB | FeatureGFNI |
+    FeatureRDPID | FeatureVAES | FeatureVPCLMULQDQ;
+static constexpr FeatureBitset FeaturesICLServer =
+    FeaturesICLClient | FeaturePCONFIG | FeatureWBNOINVD;
+static constexpr FeatureBitset FeaturesTigerlake =
+    FeaturesICLClient | FeatureAVX512VP2INTERSECT | FeatureMOVDIR64B |
+    FeatureMOVDIRI | FeatureSHSTK;
+
+// Intel Atom processors.
+// Bonnell has feature parity with Core2 and adds MOVBE.
+static constexpr FeatureBitset FeaturesBonnell = FeaturesCore2 | FeatureMOVBE;
+// Silvermont has parity with Westmere and Bonnell plus PRFCHW and RDRND.
+static constexpr FeatureBitset FeaturesSilvermont =
+    FeaturesBonnell | FeaturesWestmere | FeaturePRFCHW | FeatureRDRND;
+static constexpr FeatureBitset FeaturesGoldmont =
+    FeaturesSilvermont | FeatureAES | FeatureCLFLUSHOPT | FeatureFSGSBASE |
+    FeatureRDSEED | FeatureSHA | FeatureXSAVE | FeatureXSAVEC |
+    FeatureXSAVEOPT | FeatureXSAVES;
+static constexpr FeatureBitset FeaturesGoldmontPlus =
+    FeaturesGoldmont | FeaturePTWRITE | FeatureRDPID | FeatureSGX;
+static constexpr FeatureBitset FeaturesTremont =
+    FeaturesGoldmontPlus | FeatureCLWB | FeatureGFNI;
+
+// Geode Processor.
+static constexpr FeatureBitset FeaturesGeode =
+    FeatureX87 | FeatureCMPXCHG8B | FeatureMMX | Feature3DNOW | Feature3DNOWA;
+
+// K6 processor.
+static constexpr FeatureBitset FeaturesK6 =
+    FeatureX87 | FeatureCMPXCHG8B | FeatureMMX;
+
+// K7 and K8 architecture processors.
+static constexpr FeatureBitset FeaturesAthlon =
+    FeatureX87 | FeatureCMPXCHG8B | FeatureMMX | Feature3DNOW | Feature3DNOWA;
+static constexpr FeatureBitset FeaturesAthlonXP =
+    FeaturesAthlon | FeatureFXSR | FeatureSSE;
+static constexpr FeatureBitset FeaturesK8 =
+    FeaturesAthlonXP | FeatureSSE2 | FeatureEM64T;
+static constexpr FeatureBitset FeaturesK8SSE3 = FeaturesK8 | FeatureSSE3;
+static constexpr FeatureBitset FeaturesAMDFAM10 =
+    FeaturesK8SSE3 | FeatureCMPXCHG16B | FeatureLZCNT | FeaturePOPCNT |
+    FeaturePRFCHW | FeatureSAHF | FeatureSSE4A;
+
+// Bobcat architecture processors.
+static constexpr FeatureBitset FeaturesBTVER1 =
+    FeatureX87 | FeatureCMPXCHG8B | FeatureCMPXCHG16B | FeatureEM64T |
+    FeatureFXSR | FeatureLZCNT | FeatureMMX | FeaturePOPCNT | FeaturePRFCHW |
+    FeatureSSE | FeatureSSE2 | FeatureSSE3 | FeatureSSSE3 | FeatureSSE4A |
+    FeatureSAHF;
+static constexpr FeatureBitset FeaturesBTVER2 =
+    FeaturesBTVER1 | FeatureAES | FeatureAVX | FeatureBMI | FeatureF16C |
+    FeatureMOVBE | FeaturePCLMUL | FeatureXSAVE | FeatureXSAVEOPT;
+
+// AMD Bulldozer architecture processors.
+static constexpr FeatureBitset FeaturesBDVER1 =
+    FeatureX87 | FeatureAES | FeatureAVX | FeatureCMPXCHG8B |
+    FeatureCMPXCHG16B | FeatureEM64T | FeatureFMA4 | FeatureFXSR |
+    FeatureLZCNT | FeatureLWP | FeatureLZCNT | FeatureMMX | FeaturePCLMUL |
+    FeaturePOPCNT | FeaturePRFCHW | FeatureSAHF | FeatureSSE | FeatureSSE2 |
+    FeatureSSE3 | FeatureSSSE3 | FeatureSSE4_1 | FeatureSSE4_2 | FeatureSSE4A |
+    FeatureXOP | FeatureXSAVE;
+static constexpr FeatureBitset FeaturesBDVER2 =
+    FeaturesBDVER1 | FeatureBMI | FeatureFMA | FeatureF16C | FeatureTBM;
+static constexpr FeatureBitset FeaturesBDVER3 =
+    FeaturesBDVER2 | FeatureFSGSBASE | FeatureXSAVEOPT;
+static constexpr FeatureBitset FeaturesBDVER4 =
+    FeaturesBDVER3 | FeatureAVX2 | FeatureBMI2 | FeatureMOVBE | FeatureMWAITX |
+    FeatureRDRND;
+
+// AMD Zen architecture processors.
+static constexpr FeatureBitset FeaturesZNVER1 =
+    FeatureX87 | FeatureADX | FeatureAES | FeatureAVX | FeatureAVX2 |
+    FeatureBMI | FeatureBMI2 | FeatureCLFLUSHOPT | FeatureCLZERO |
+    FeatureCMPXCHG8B | FeatureCMPXCHG16B | FeatureEM64T | FeatureF16C |
+    FeatureFMA | FeatureFSGSBASE | FeatureFXSR | FeatureLZCNT | FeatureLWP |
+    FeatureLZCNT | FeatureMOVBE | FeatureMMX | FeatureMWAITX | FeaturePCLMUL |
+    FeaturePOPCNT | FeaturePRFCHW | FeatureRDRND | FeatureRDSEED | FeatureSAHF |
+    FeatureSHA | FeatureSSE | FeatureSSE2 | FeatureSSE3 | FeatureSSSE3 |
+    FeatureSSE4_1 | FeatureSSE4_2 | FeatureSSE4A | FeatureXSAVE |
+    FeatureXSAVEC | FeatureXSAVEOPT | FeatureXSAVES;
+static constexpr FeatureBitset FeaturesZNVER2 =
+    FeaturesZNVER1 | FeatureCLWB | FeatureRDPID | FeatureWBNOINVD;
 
 static constexpr ProcInfo Processors[] = {
+  // Empty processor. Include X87 and CMPXCHG8 for backwards compatibility.
+  { {""}, CK_None, ~0U, FeatureX87 | FeatureCMPXCHG8B },
   // i386-generation processors.
-  { {"i386"}, CK_i386, ~0U, PROC_32_BIT },
+  { {"i386"}, CK_i386, ~0U, FeatureX87 },
   // i486-generation processors.
-  { {"i486"}, CK_i486, ~0U, PROC_32_BIT },
-  { {"winchip-c6"}, CK_WinChipC6, ~0U, PROC_32_BIT },
-  { {"winchip2"}, CK_WinChip2, ~0U, PROC_32_BIT },
-  { {"c3"}, CK_C3, ~0U, PROC_32_BIT },
+  { {"i486"}, CK_i486, ~0U, FeatureX87 },
+  { {"winchip-c6"}, CK_WinChipC6, ~0U, FeaturesPentiumMMX },
+  { {"winchip2"}, CK_WinChip2, ~0U, FeaturesPentiumMMX | Feature3DNOW },
+  { {"c3"}, CK_C3, ~0U, FeaturesPentiumMMX | Feature3DNOW },
   // i586-generation processors, P5 microarchitecture based.
-  { {"i586"}, CK_i586, ~0U, PROC_32_BIT },
-  { {"pentium"}, CK_Pentium, ~0U, PROC_32_BIT },
-  { {"pentium-mmx"}, CK_PentiumMMX, ~0U, PROC_32_BIT },
-  { {"pentiumpro"}, CK_PentiumPro, ~0U, PROC_32_BIT },
+  { {"i586"}, CK_i586, ~0U, FeatureX87 | FeatureCMPXCHG8B },
+  { {"pentium"}, CK_Pentium, ~0U, FeatureX87 | FeatureCMPXCHG8B },
+  { {"pentium-mmx"}, CK_PentiumMMX, ~0U, FeaturesPentiumMMX },
   // i686-generation processors, P6 / Pentium M microarchitecture based.
-  { {"i686"}, CK_i686, ~0U, PROC_32_BIT },
-  { {"pentium2"}, CK_Pentium2, ~0U, PROC_32_BIT },
-  { {"pentium3"}, CK_Pentium3, ~0U, PROC_32_BIT },
-  { {"pentium3m"}, CK_Pentium3, ~0U, PROC_32_BIT },
-  { {"pentium-m"}, CK_PentiumM, ~0U, PROC_32_BIT },
-  { {"c3-2"}, CK_C3_2, ~0U, PROC_32_BIT },
-  { {"yonah"}, CK_Yonah, ~0U, PROC_32_BIT },
+  { {"pentiumpro"}, CK_PentiumPro, ~0U, FeatureX87 | FeatureCMPXCHG8B },
+  { {"i686"}, CK_i686, ~0U, FeatureX87 | FeatureCMPXCHG8B },
+  { {"pentium2"}, CK_Pentium2, ~0U, FeaturesPentium2 },
+  { {"pentium3"}, CK_Pentium3, ~0U, FeaturesPentium3 },
+  { {"pentium3m"}, CK_Pentium3, ~0U, FeaturesPentium3 },
+  { {"pentium-m"}, CK_PentiumM, ~0U, FeaturesPentium4 },
+  { {"c3-2"}, CK_C3_2, ~0U, FeaturesPentium3 },
+  { {"yonah"}, CK_Yonah, ~0U, FeaturesPrescott },
   // Netburst microarchitecture based processors.
-  { {"pentium4"}, CK_Pentium4, ~0U, PROC_32_BIT },
-  { {"pentium4m"}, CK_Pentium4, ~0U, PROC_32_BIT },
-  { {"prescott"}, CK_Prescott, ~0U, PROC_32_BIT },
-  { {"nocona"}, CK_Nocona, ~0U, PROC_64_BIT },
+  { {"pentium4"}, CK_Pentium4, ~0U, FeaturesPentium4 },
+  { {"pentium4m"}, CK_Pentium4, ~0U, FeaturesPentium4 },
+  { {"prescott"}, CK_Prescott, ~0U, FeaturesPrescott },
+  { {"nocona"}, CK_Nocona, ~0U, FeaturesNocona },
   // Core microarchitecture based processors.
-  { {"core2"}, CK_Core2, ~0U, PROC_64_BIT },
-  { {"penryn"}, CK_Penryn, ~0U, PROC_64_BIT },
+  { {"core2"}, CK_Core2, ~0U, FeaturesCore2 },
+  { {"penryn"}, CK_Penryn, ~0U, FeaturesPenryn },
   // Atom processors
-  { {"bonnell"}, CK_Bonnell, FEATURE_SSSE3, PROC_64_BIT },
-  { {"atom"}, CK_Bonnell, FEATURE_SSSE3, PROC_64_BIT },
-  { {"silvermont"}, CK_Silvermont, FEATURE_SSE4_2, PROC_64_BIT },
-  { {"slm"}, CK_Silvermont, FEATURE_SSE4_2, PROC_64_BIT },
-  { {"goldmont"}, CK_Goldmont, FEATURE_SSE4_2, PROC_64_BIT },
-  { {"goldmont-plus"}, CK_GoldmontPlus, FEATURE_SSE4_2, PROC_64_BIT },
-  { {"tremont"}, CK_Tremont, FEATURE_SSE4_2, PROC_64_BIT },
+  { {"bonnell"}, CK_Bonnell, FEATURE_SSSE3, FeaturesBonnell },
+  { {"atom"}, CK_Bonnell, FEATURE_SSSE3, FeaturesBonnell },
+  { {"silvermont"}, CK_Silvermont, FEATURE_SSE4_2, FeaturesSilvermont },
+  { {"slm"}, CK_Silvermont, FEATURE_SSE4_2, FeaturesSilvermont },
+  { {"goldmont"}, CK_Goldmont, FEATURE_SSE4_2, FeaturesGoldmont },
+  { {"goldmont-plus"}, CK_GoldmontPlus, FEATURE_SSE4_2, FeaturesGoldmontPlus },
+  { {"tremont"}, CK_Tremont, FEATURE_SSE4_2, FeaturesTremont },
   // Nehalem microarchitecture based processors.
-  { {"nehalem"}, CK_Nehalem, FEATURE_SSE4_2, PROC_64_BIT },
-  { {"corei7"}, CK_Nehalem, FEATURE_SSE4_2, PROC_64_BIT },
+  { {"nehalem"}, CK_Nehalem, FEATURE_SSE4_2, FeaturesNehalem },
+  { {"corei7"}, CK_Nehalem, FEATURE_SSE4_2, FeaturesNehalem },
   // Westmere microarchitecture based processors.
-  { {"westmere"}, CK_Westmere, FEATURE_PCLMUL, PROC_64_BIT },
+  { {"westmere"}, CK_Westmere, FEATURE_PCLMUL, FeaturesWestmere },
   // Sandy Bridge microarchitecture based processors.
-  { {"sandybridge"}, CK_SandyBridge, FEATURE_AVX, PROC_64_BIT },
-  { {"corei7-avx"}, CK_SandyBridge, FEATURE_AVX, PROC_64_BIT },
+  { {"sandybridge"}, CK_SandyBridge, FEATURE_AVX, FeaturesSandyBridge },
+  { {"corei7-avx"}, CK_SandyBridge, FEATURE_AVX, FeaturesSandyBridge },
   // Ivy Bridge microarchitecture based processors.
-  { {"ivybridge"}, CK_IvyBridge, FEATURE_AVX, PROC_64_BIT },
-  { {"core-avx-i"}, CK_IvyBridge, FEATURE_AVX, PROC_64_BIT },
+  { {"ivybridge"}, CK_IvyBridge, FEATURE_AVX, FeaturesIvyBridge },
+  { {"core-avx-i"}, CK_IvyBridge, FEATURE_AVX, FeaturesIvyBridge },
   // Haswell microarchitecture based processors.
-  { {"haswell"}, CK_Haswell, FEATURE_AVX2, PROC_64_BIT },
-  { {"core-avx2"}, CK_Haswell, FEATURE_AVX2, PROC_64_BIT },
+  { {"haswell"}, CK_Haswell, FEATURE_AVX2, FeaturesHaswell },
+  { {"core-avx2"}, CK_Haswell, FEATURE_AVX2, FeaturesHaswell },
   // Broadwell microarchitecture based processors.
-  { {"broadwell"}, CK_Broadwell, FEATURE_AVX2, PROC_64_BIT },
+  { {"broadwell"}, CK_Broadwell, FEATURE_AVX2, FeaturesBroadwell },
   // Skylake client microarchitecture based processors.
-  { {"skylake"}, CK_SkylakeClient, FEATURE_AVX2, PROC_64_BIT },
+  { {"skylake"}, CK_SkylakeClient, FEATURE_AVX2, FeaturesSkylakeClient },
   // Skylake server microarchitecture based processors.
-  { {"skylake-avx512"}, CK_SkylakeServer, FEATURE_AVX512F, PROC_64_BIT },
-  { {"skx"}, CK_SkylakeServer, FEATURE_AVX512F, PROC_64_BIT },
+  { {"skylake-avx512"}, CK_SkylakeServer, FEATURE_AVX512F, FeaturesSkylakeServer },
+  { {"skx"}, CK_SkylakeServer, FEATURE_AVX512F, FeaturesSkylakeServer },
   // Cascadelake Server microarchitecture based processors.
-  { {"cascadelake"}, CK_Cascadelake, FEATURE_AVX512VNNI, PROC_64_BIT },
+  { {"cascadelake"}, CK_Cascadelake, FEATURE_AVX512VNNI, FeaturesCascadeLake },
   // Cooperlake Server microarchitecture based processors.
-  { {"cooperlake"}, CK_Cooperlake, FEATURE_AVX512BF16, PROC_64_BIT },
+  { {"cooperlake"}, CK_Cooperlake, FEATURE_AVX512BF16, FeaturesCooperLake },
   // Cannonlake client microarchitecture based processors.
-  { {"cannonlake"}, CK_Cannonlake, FEATURE_AVX512VBMI, PROC_64_BIT },
+  { {"cannonlake"}, CK_Cannonlake, FEATURE_AVX512VBMI, FeaturesCannonlake },
   // Icelake client microarchitecture based processors.
-  { {"icelake-client"}, CK_IcelakeClient, FEATURE_AVX512VBMI2, PROC_64_BIT },
+  { {"icelake-client"}, CK_IcelakeClient, FEATURE_AVX512VBMI2, FeaturesICLClient },
   // Icelake server microarchitecture based processors.
-  { {"icelake-server"}, CK_IcelakeServer, FEATURE_AVX512VBMI2, PROC_64_BIT },
+  { {"icelake-server"}, CK_IcelakeServer, FEATURE_AVX512VBMI2, FeaturesICLServer },
   // Tigerlake microarchitecture based processors.
-  { {"tigerlake"}, CK_Tigerlake, FEATURE_AVX512VP2INTERSECT, PROC_64_BIT },
+  { {"tigerlake"}, CK_Tigerlake, FEATURE_AVX512VP2INTERSECT, FeaturesTigerlake },
   // Knights Landing processor.
-  { {"knl"}, CK_KNL, FEATURE_AVX512F, PROC_64_BIT },
+  { {"knl"}, CK_KNL, FEATURE_AVX512F, FeaturesKNL },
   // Knights Mill processor.
-  { {"knm"}, CK_KNM, FEATURE_AVX5124FMAPS, PROC_64_BIT },
+  { {"knm"}, CK_KNM, FEATURE_AVX5124FMAPS, FeaturesKNM },
   // Lakemont microarchitecture based processors.
-  { {"lakemont"}, CK_Lakemont, ~0U, PROC_32_BIT },
+  { {"lakemont"}, CK_Lakemont, ~0U, FeatureCMPXCHG8B },
   // K6 architecture processors.
-  { {"k6"}, CK_K6, ~0U, PROC_32_BIT },
-  { {"k6-2"}, CK_K6_2, ~0U, PROC_32_BIT },
-  { {"k6-3"}, CK_K6_3, ~0U, PROC_32_BIT },
+  { {"k6"}, CK_K6, ~0U, FeaturesK6 },
+  { {"k6-2"}, CK_K6_2, ~0U, FeaturesK6 | Feature3DNOW },
+  { {"k6-3"}, CK_K6_3, ~0U, FeaturesK6 | Feature3DNOW },
   // K7 architecture processors.
-  { {"athlon"}, CK_Athlon, ~0U, PROC_32_BIT },
-  { {"athlon-tbird"}, CK_Athlon, ~0U, PROC_32_BIT },
-  { {"athlon-xp"}, CK_AthlonXP, ~0U, PROC_32_BIT },
-  { {"athlon-mp"}, CK_AthlonXP, ~0U, PROC_32_BIT },
-  { {"athlon-4"}, CK_AthlonXP, ~0U, PROC_32_BIT },
+  { {"athlon"}, CK_Athlon, ~0U, FeaturesAthlon },
+  { {"athlon-tbird"}, CK_Athlon, ~0U, FeaturesAthlon },
+  { {"athlon-xp"}, CK_AthlonXP, ~0U, FeaturesAthlonXP },
+  { {"athlon-mp"}, CK_AthlonXP, ~0U, FeaturesAthlonXP },
+  { {"athlon-4"}, CK_AthlonXP, ~0U, FeaturesAthlonXP },
   // K8 architecture processors.
-  { {"k8"}, CK_K8, ~0U, PROC_64_BIT },
-  { {"athlon64"}, CK_K8, ~0U, PROC_64_BIT },
-  { {"athlon-fx"}, CK_K8, ~0U, PROC_64_BIT },
-  { {"opteron"}, CK_K8, ~0U, PROC_64_BIT },
-  { {"k8-sse3"}, CK_K8SSE3, ~0U, PROC_64_BIT },
-  { {"athlon64-sse3"}, CK_K8SSE3, ~0U, PROC_64_BIT },
-  { {"opteron-sse3"}, CK_K8SSE3, ~0U, PROC_64_BIT },
-  { {"amdfam10"}, CK_AMDFAM10, FEATURE_SSE4_A, PROC_64_BIT },
-  { {"barcelona"}, CK_AMDFAM10, FEATURE_SSE4_A, PROC_64_BIT },
+  { {"k8"}, CK_K8, ~0U, FeaturesK8 },
+  { {"athlon64"}, CK_K8, ~0U, FeaturesK8 },
+  { {"athlon-fx"}, CK_K8, ~0U, FeaturesK8 },
+  { {"opteron"}, CK_K8, ~0U, FeaturesK8 },
+  { {"k8-sse3"}, CK_K8SSE3, ~0U, FeaturesK8SSE3 },
+  { {"athlon64-sse3"}, CK_K8SSE3, ~0U, FeaturesK8SSE3 },
+  { {"opteron-sse3"}, CK_K8SSE3, ~0U, FeaturesK8SSE3 },
+  { {"amdfam10"}, CK_AMDFAM10, FEATURE_SSE4_A, FeaturesAMDFAM10 },
+  { {"barcelona"}, CK_AMDFAM10, FEATURE_SSE4_A, FeaturesAMDFAM10 },
   // Bobcat architecture processors.
-  { {"btver1"}, CK_BTVER1, FEATURE_SSE4_A, PROC_64_BIT },
-  { {"btver2"}, CK_BTVER2, FEATURE_BMI, PROC_64_BIT },
+  { {"btver1"}, CK_BTVER1, FEATURE_SSE4_A, FeaturesBTVER1 },
+  { {"btver2"}, CK_BTVER2, FEATURE_BMI, FeaturesBTVER2 },
   // Bulldozer architecture processors.
-  { {"bdver1"}, CK_BDVER1, FEATURE_XOP, PROC_64_BIT },
-  { {"bdver2"}, CK_BDVER2, FEATURE_FMA, PROC_64_BIT },
-  { {"bdver3"}, CK_BDVER3, FEATURE_FMA, PROC_64_BIT },
-  { {"bdver4"}, CK_BDVER4, FEATURE_AVX2, PROC_64_BIT },
+  { {"bdver1"}, CK_BDVER1, FEATURE_XOP, FeaturesBDVER1 },
+  { {"bdver2"}, CK_BDVER2, FEATURE_FMA, FeaturesBDVER2 },
+  { {"bdver3"}, CK_BDVER3, FEATURE_FMA, FeaturesBDVER3 },
+  { {"bdver4"}, CK_BDVER4, FEATURE_AVX2, FeaturesBDVER4 },
   // Zen architecture processors.
-  { {"znver1"}, CK_ZNVER1, FEATURE_AVX2, PROC_64_BIT },
-  { {"znver2"}, CK_ZNVER2, FEATURE_AVX2, PROC_64_BIT },
+  { {"znver1"}, CK_ZNVER1, FEATURE_AVX2, FeaturesZNVER1 },
+  { {"znver2"}, CK_ZNVER2, FEATURE_AVX2, FeaturesZNVER2 },
   // Generic 64-bit processor.
-  { {"x86-64"}, CK_x86_64, ~0U, PROC_64_BIT },
+  { {"x86-64"}, CK_x86_64, ~0U, FeaturesX86_64 },
   // Geode processors.
-  { {"geode"}, CK_Geode, ~0U, PROC_32_BIT },
+  { {"geode"}, CK_Geode, ~0U, FeaturesGeode },
 };
 
 X86::CPUKind llvm::X86::parseArchX86(StringRef CPU, bool Only64Bit) {
   for (const auto &P : Processors)
-    if (P.Name == CPU && (P.Is64Bit || !Only64Bit))
+    if (P.Name == CPU && (P.Features[FEATURE_EM64T] || !Only64Bit))
       return P.Kind;
 
   return CK_None;
@@ -155,7 +360,7 @@
 void llvm::X86::fillValidCPUArchList(SmallVectorImpl<StringRef> &Values,
                                      bool Only64Bit) {
   for (const auto &P : Processors)
-    if (P.Is64Bit || !Only64Bit)
+    if (!P.Name.empty() && (P.Features[FEATURE_EM64T] || !Only64Bit))
       Values.emplace_back(P.Name);
 }
 
@@ -171,3 +376,20 @@
 
   llvm_unreachable("Unable to find CPU kind!");
 }
+
+static const char *FeatureStrings[X86::CPU_FEATURE_MAX] = {
+#define X86_FEATURE(ENUM, STR) STR,
+#include "llvm/Support/X86TargetParser.def"
+};
+
+void llvm::X86::getFeaturesForCPU(StringRef CPU,
+                                  SmallVectorImpl<StringRef> &Features) {
+  auto I = llvm::find_if(Processors,
+                         [&](const ProcInfo &P) { return P.Name == CPU; });
+  assert(I != std::end(Processors) && "Processor not found!");
+
+  // Add the string version of all set bits.
+  for (unsigned i = 0; i != CPU_FEATURE_MAX; ++i)
+    if (FeatureStrings[i] && I->Features[i])
+      Features.push_back(FeatureStrings[i]);
+}