[NFC][AArch64] Get default features directly from ArchInfo and CpuInfo objects

This updates the AArch64's Target Parser and its uses to capture
information about default features directly from ArchInfo and CpuInfo
objects, instead of relying on an API function to access them
indirectly.

Reviewed By: tmatheson

Differential Revision: https://reviews.llvm.org/D142540

Author: pratlucas

clang/lib/Basic/Targets/AArch64.cpp

@@ -692,10 +692,8 @@ void AArch64TargetInfo::setFeatureEnabled(llvm::StringMap<bool> &Features,
       Features[OtherArch->getSubArch()] = Enabled;
 
   // Set any features implied by the architecture
-  uint64_t Extensions =
-      llvm::AArch64::getDefaultExtensions("generic", *ArchInfo);
   std::vector<StringRef> CPUFeats;
-  if (llvm::AArch64::getExtensionFeatures(Extensions, CPUFeats)) {
+  if (llvm::AArch64::getExtensionFeatures(ArchInfo->DefaultExts, CPUFeats)) {
     for (auto F : CPUFeats) {
       assert(F[0] == '+' && "Expected + in target feature!");
       Features[F.drop_front(1)] = true;
@@ -951,7 +949,7 @@ bool AArch64TargetInfo::initFeatureMap(
   // Parse the CPU and add any implied features.
   std::optional<llvm::AArch64::CpuInfo> CpuInfo = llvm::AArch64::parseCpu(CPU);
   if (CpuInfo) {
-    uint64_t Exts = llvm::AArch64::getDefaultExtensions(CPU, CpuInfo->Arch);
+    uint64_t Exts = CpuInfo->getImpliedExtensions();
     std::vector<StringRef> CPUFeats;
     llvm::AArch64::getExtensionFeatures(Exts, CPUFeats);
     for (auto F : CPUFeats) {

clang/lib/Driver/ToolChains/Arch/AArch64.cpp

@@ -140,7 +140,7 @@ static bool DecodeAArch64Mcpu(const Driver &D, StringRef Mcpu, StringRef &CPU,
 
     Features.push_back(ArchInfo->ArchFeature);
 
-    uint64_t Extension = llvm::AArch64::getDefaultExtensions(CPU, *ArchInfo);
+    uint64_t Extension = CpuInfo->getImpliedExtensions();
     if (!llvm::AArch64::getExtensionFeatures(Extension, Features))
       return false;
   }

llvm/include/llvm/TargetParser/AArch64TargetParser.h

@@ -334,6 +334,10 @@ struct CpuInfo {
   const ArchInfo &Arch;
   uint64_t DefaultExtensions; // Default extensions for this CPU. These will be
                               // ORd with the architecture defaults.
+
+  uint64_t getImpliedExtensions() const {
+    return DefaultExtensions | Arch.DefaultExts;
+  }
 };
 
 inline constexpr CpuInfo CpuInfos[] = {
@@ -509,7 +513,6 @@ StringRef getArchExtFeature(StringRef ArchExt);
 StringRef resolveCPUAlias(StringRef CPU);
 
 // Information by Name
-uint64_t getDefaultExtensions(StringRef CPU, const ArchInfo &AI);
 void getFeatureOption(StringRef Name, std::string &Feature);
 std::optional<ArchInfo> getArchForCpu(StringRef CPU);
 

llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

@@ -6891,8 +6891,7 @@ bool AArch64AsmParser::parseDirectiveArch(SMLoc L) {
   // Get the architecture and extension features.
   std::vector<StringRef> AArch64Features;
   AArch64Features.push_back(ArchInfo->ArchFeature);
-  AArch64::getExtensionFeatures(
-      AArch64::getDefaultExtensions("generic", *ArchInfo), AArch64Features);
+  AArch64::getExtensionFeatures(ArchInfo->DefaultExts, AArch64Features);
 
   MCSubtargetInfo &STI = copySTI();
   std::vector<std::string> ArchFeatures(AArch64Features.begin(), AArch64Features.end());

llvm/lib/TargetParser/AArch64TargetParser.cpp

@@ -25,19 +25,6 @@ static unsigned checkArchVersion(llvm::StringRef Arch) {
   return 0;
 }
 
-uint64_t AArch64::getDefaultExtensions(StringRef CPU,
-                                       const AArch64::ArchInfo &AI) {
-  if (CPU == "generic")
-    return AI.DefaultExts;
-
-  // Note: this now takes cpu aliases into account
-  std::optional<CpuInfo> Cpu = parseCpu(CPU);
-  if (!Cpu)
-    return AI.DefaultExts;
-
-  return Cpu->Arch.DefaultExts | Cpu->DefaultExtensions;
-}
-
 void AArch64::getFeatureOption(StringRef Name, std::string &Feature) {
   for (const auto &E : llvm::AArch64::Extensions) {
     if (Name == E.Name) {

llvm/unittests/TargetParser/TargetParserTest.cpp

@@ -966,11 +966,9 @@ TEST_P(AArch64CPUTestFixture, testAArch64CPU) {
   EXPECT_TRUE(Cpu);
   EXPECT_EQ(params.ExpectedArch, Cpu->Arch.Name);
 
-  uint64_t default_extensions =
-      AArch64::getDefaultExtensions(params.CPUName, Cpu->Arch);
   EXPECT_PRED_FORMAT2(
       AssertSameExtensionFlags<ARM::ISAKind::AARCH64>(params.CPUName),
-      params.ExpectedFlags, default_extensions);
+      params.ExpectedFlags, Cpu->getImpliedExtensions());
 }
 
 INSTANTIATE_TEST_SUITE_P(
@@ -1472,7 +1470,7 @@ bool testAArch64Extension(StringRef CPUName, StringRef ArchExt) {
   if (!Extension)
     return false;
   std::optional<AArch64::CpuInfo> CpuInfo = AArch64::parseCpu(CPUName);
-  return (CpuInfo->Arch.DefaultExts | CpuInfo->DefaultExtensions) & Extension->ID;
+  return CpuInfo->getImpliedExtensions() & Extension->ID;
 }
 
 bool testAArch64Extension(const AArch64::ArchInfo &AI, StringRef ArchExt) {