[Hexagon] NFC: Reduce the amount of version-specific code

There is a lot of redundant code that needs to be modified when new
Hexagon versions are added. Reduce the amount of this redundancy.

- compute ELF flags and attributes based on version feature names;
- simplify EnableHVX option handling by using arch features instead of
  arch version enums;
- simplify completeHVXFeatures() by using features;
- delete several unused or redundant functions and constants:
  isCPUValid, getCpu, getHexagonCPUSuffix;
- do not set HexagonArchVersion in initializeSubtargetDependencies,
  it is set in ParseSubtargetFeatures;

Signed-off-by: Alexey Karyakin <[email protected]>

Author: quic-akaryaki

clang/lib/Basic/Targets/Hexagon.cpp

@@ -18,6 +18,19 @@
 using namespace clang;
 using namespace clang::targets;
 
+namespace {
+
+constexpr llvm::StringLiteral CpuValsTextArray[] = {
+    "hexagonv5",  "hexagonv55",  "hexagonv60",  "hexagonv62", "hexagonv65",
+    "hexagonv66", "hexagonv67",  "hexagonv67t", "hexagonv68", "hexagonv69",
+    "hexagonv71", "hexagonv71t", "hexagonv73",  "hexagonv75", "hexagonv79",
+};
+
+} // namespace
+
+const llvm::ArrayRef<llvm::StringLiteral>
+    HexagonTargetInfo::CpuValsText(CpuValsTextArray);
+
 void HexagonTargetInfo::getTargetDefines(const LangOptions &Opts,
                                          MacroBuilder &Builder) const {
   Builder.defineMacro("__qdsp6__", "1");
@@ -239,22 +252,6 @@ bool HexagonTargetInfo::hasFeature(StringRef Feature) const {
       .Default(false);
 }
 
-struct CPUSuffix {
-  llvm::StringLiteral Name;
-  llvm::StringLiteral Suffix;
-};
-
-static constexpr CPUSuffix Suffixes[] = {
-    {{"hexagonv5"}, {"5"}},   {{"hexagonv55"}, {"55"}},
-    {{"hexagonv60"}, {"60"}}, {{"hexagonv62"}, {"62"}},
-    {{"hexagonv65"}, {"65"}}, {{"hexagonv66"}, {"66"}},
-    {{"hexagonv67"}, {"67"}}, {{"hexagonv67t"}, {"67t"}},
-    {{"hexagonv68"}, {"68"}}, {{"hexagonv69"}, {"69"}},
-    {{"hexagonv71"}, {"71"}}, {{"hexagonv71t"}, {"71t"}},
-    {{"hexagonv73"}, {"73"}}, {{"hexagonv75"}, {"75"}},
-    {{"hexagonv79"}, {"79"}},
-};
-
 std::optional<unsigned> HexagonTargetInfo::getHexagonCPURev(StringRef Name) {
   StringRef Arch = Name;
   Arch.consume_front("hexagonv");
@@ -267,18 +264,10 @@ std::optional<unsigned> HexagonTargetInfo::getHexagonCPURev(StringRef Name) {
   return std::nullopt;
 }
 
-const char *HexagonTargetInfo::getHexagonCPUSuffix(StringRef Name) {
-  const CPUSuffix *Item = llvm::find_if(
-      Suffixes, [Name](const CPUSuffix &S) { return S.Name == Name; });
-  if (Item == std::end(Suffixes))
-    return nullptr;
-  return Item->Suffix.data();
-}
-
 void HexagonTargetInfo::fillValidCPUList(
     SmallVectorImpl<StringRef> &Values) const {
-  for (const CPUSuffix &Suffix : Suffixes)
-    Values.push_back(Suffix.Name);
+  for (const llvm::StringLiteral &I : CpuValsText)
+    Values.push_back(I);
 }
 
 llvm::SmallVector<Builtin::InfosShard>

clang/lib/Basic/Targets/Hexagon.h

@@ -25,6 +25,7 @@ namespace targets {
 // Hexagon abstract base class
 class LLVM_LIBRARY_VISIBILITY HexagonTargetInfo : public TargetInfo {
 
+  static const llvm::ArrayRef<llvm::StringLiteral> CpuValsText;
   static const char *const GCCRegNames[];
   static const TargetInfo::GCCRegAlias GCCRegAliases[];
   std::string CPU;
@@ -115,11 +116,11 @@ class LLVM_LIBRARY_VISIBILITY HexagonTargetInfo : public TargetInfo {
 
   std::string_view getClobbers() const override { return ""; }
 
-  static const char *getHexagonCPUSuffix(StringRef Name);
   static std::optional<unsigned> getHexagonCPURev(StringRef Name);
 
   bool isValidCPUName(StringRef Name) const override {
-    return getHexagonCPUSuffix(Name);
+    return std::any_of(std::begin(CpuValsText), std::end(CpuValsText),
+                       [Name](StringRef V) { return V == Name; });
   }
 
   void fillValidCPUList(SmallVectorImpl<StringRef> &Values) const override;

llvm/lib/Target/Hexagon/HexagonDepArch.h

@@ -32,26 +32,6 @@ enum class ArchEnum {
   V79
 };
 
-inline std::optional<Hexagon::ArchEnum> getCpu(StringRef CPU) {
-  return StringSwitch<std::optional<Hexagon::ArchEnum>>(CPU)
-      .Case("generic", Hexagon::ArchEnum::V5)
-      .Case("hexagonv5", Hexagon::ArchEnum::V5)
-      .Case("hexagonv55", Hexagon::ArchEnum::V55)
-      .Case("hexagonv60", Hexagon::ArchEnum::V60)
-      .Case("hexagonv62", Hexagon::ArchEnum::V62)
-      .Case("hexagonv65", Hexagon::ArchEnum::V65)
-      .Case("hexagonv66", Hexagon::ArchEnum::V66)
-      .Case("hexagonv67", Hexagon::ArchEnum::V67)
-      .Case("hexagonv67t", Hexagon::ArchEnum::V67)
-      .Case("hexagonv68", Hexagon::ArchEnum::V68)
-      .Case("hexagonv69", Hexagon::ArchEnum::V69)
-      .Case("hexagonv71", Hexagon::ArchEnum::V71)
-      .Case("hexagonv71t", Hexagon::ArchEnum::V71)
-      .Case("hexagonv73", Hexagon::ArchEnum::V73)
-      .Case("hexagonv75", Hexagon::ArchEnum::V75)
-      .Case("hexagonv79", Hexagon::ArchEnum::V79)
-      .Default(std::nullopt);
-}
 } // namespace Hexagon
 } // namespace llvm
 

llvm/lib/Target/Hexagon/HexagonSubtarget.cpp

@@ -88,12 +88,6 @@ HexagonSubtarget::HexagonSubtarget(const Triple &TT, StringRef CPU,
 
 HexagonSubtarget &
 HexagonSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS) {
-  std::optional<Hexagon::ArchEnum> ArchVer = Hexagon::getCpu(CPUString);
-  if (ArchVer)
-    HexagonArchVersion = *ArchVer;
-  else
-    llvm_unreachable("Unrecognized Hexagon processor version");
-
   UseHVX128BOps = false;
   UseHVX64BOps = false;
   UseAudioOps = false;
@@ -163,7 +157,7 @@ HexagonSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS) {
   FeatureBitset FeatureBits = getFeatureBits();
   if (HexagonDisableDuplex)
     setFeatureBits(FeatureBits.reset(Hexagon::FeatureDuplex));
-  setFeatureBits(Hexagon_MC::completeHVXFeatures(FeatureBits));
+  SetFeatureBitsTransitively(Hexagon_MC::completeHVXFeatures(FeatureBits));
 
   return *this;
 }

llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCELFStreamer.cpp

@@ -149,57 +149,14 @@ void HexagonMCELFStreamer::HexagonMCEmitLocalCommonSymbol(MCSymbol *Symbol,
   HexagonMCEmitCommonSymbol(Symbol, Size, ByteAlignment, AccessSize);
 }
 
-static unsigned featureToArchVersion(unsigned Feature) {
-  switch (Feature) {
-  case Hexagon::ArchV5:
-    return 5;
-  case Hexagon::ArchV55:
-    return 55;
-  case Hexagon::ArchV60:
-  case Hexagon::ExtensionHVXV60:
-    return 60;
-  case Hexagon::ArchV62:
-  case Hexagon::ExtensionHVXV62:
-    return 62;
-  case Hexagon::ArchV65:
-  case Hexagon::ExtensionHVXV65:
-    return 65;
-  case Hexagon::ArchV66:
-  case Hexagon::ExtensionHVXV66:
-    return 66;
-  case Hexagon::ArchV67:
-  case Hexagon::ExtensionHVXV67:
-    return 67;
-  case Hexagon::ArchV68:
-  case Hexagon::ExtensionHVXV68:
-    return 68;
-  case Hexagon::ArchV69:
-  case Hexagon::ExtensionHVXV69:
-    return 69;
-  case Hexagon::ArchV71:
-  case Hexagon::ExtensionHVXV71:
-    return 71;
-  case Hexagon::ArchV73:
-  case Hexagon::ExtensionHVXV73:
-    return 73;
-  case Hexagon::ArchV75:
-  case Hexagon::ExtensionHVXV75:
-    return 75;
-  case Hexagon::ArchV79:
-  case Hexagon::ExtensionHVXV79:
-    return 79;
-  }
-  llvm_unreachable("Expected valid arch feature");
-  return 0;
-}
-
 void HexagonTargetStreamer::emitTargetAttributes(const MCSubtargetInfo &STI) {
   auto Features = STI.getFeatureBits();
-  unsigned Arch = featureToArchVersion(Hexagon_MC::getArchVersion(Features));
-  std::optional<unsigned> HVXArch = Hexagon_MC::getHVXVersion(Features);
+  unsigned Arch = Hexagon_MC::getArchVersionAttribute(Features).value_or(0);
+  std::optional<unsigned> HVXArch =
+      Hexagon_MC::getHVXVersionAttribute(Features);
   emitAttribute(HexagonAttrs::ARCH, Arch);
   if (HVXArch)
-    emitAttribute(HexagonAttrs::HVXARCH, featureToArchVersion(*HVXArch));
+    emitAttribute(HexagonAttrs::HVXARCH, *HVXArch);
   if (Features.test(Hexagon::ExtensionHVXIEEEFP))
     emitAttribute(HexagonAttrs::HVXIEEEFP, 1);
   if (Features.test(Hexagon::ExtensionHVXQFloat))