[AArch64][TargetParser] Move ExtensionDependencies into tablegen [NFC] (#93614)

This patch generates ExtensionDependency pairs {Earlier, Later} inferred
by the 'Implies' field of every Extension defined in tablegen. Implied
Subtarget Features that are not Extensions are skipped.

Author: labrinea

llvm/include/llvm/TargetParser/AArch64TargetParser.h

@@ -183,55 +183,8 @@ struct ExtensionDependency {
   ArchExtKind Later;
 };
 
-// clang-format off
-// Each entry here is a link in the dependency chain starting from the
-// extension that was added to the architecture first.
-inline constexpr ExtensionDependency ExtensionDependencies[] = {
-  {AEK_FP, AEK_FP16},
-  {AEK_FP, AEK_SIMD},
-  {AEK_FP, AEK_JSCVT},
-  {AEK_FP, AEK_FP8},
-  {AEK_SIMD, AEK_CRYPTO},
-  {AEK_SIMD, AEK_AES},
-  {AEK_SIMD, AEK_SHA2},
-  {AEK_SIMD, AEK_SHA3},
-  {AEK_SIMD, AEK_SM4},
-  {AEK_SIMD, AEK_RDM},
-  {AEK_SIMD, AEK_DOTPROD},
-  {AEK_SIMD, AEK_FCMA},
-  {AEK_FP16, AEK_FP16FML},
-  {AEK_FP16, AEK_SVE},
-  {AEK_BF16, AEK_SME},
-  {AEK_BF16, AEK_B16B16},
-  {AEK_SVE, AEK_SVE2},
-  {AEK_SVE, AEK_F32MM},
-  {AEK_SVE, AEK_F64MM},
-  {AEK_SVE2, AEK_SVE2P1},
-  {AEK_SVE2, AEK_SVE2BITPERM},
-  {AEK_SVE2, AEK_SVE2AES},
-  {AEK_SVE2, AEK_SVE2SHA3},
-  {AEK_SVE2, AEK_SVE2SM4},
-  {AEK_SVE2, AEK_SMEFA64},
-  {AEK_SVE2, AEK_SMEFA64},
-  {AEK_SME, AEK_SME2},
-  {AEK_SME, AEK_SMEF16F16},
-  {AEK_SME, AEK_SMEF64F64},
-  {AEK_SME, AEK_SMEI16I64},
-  {AEK_SME, AEK_SMEFA64},
-  {AEK_SME2, AEK_SME2P1},
-  {AEK_SME2, AEK_SSVE_FP8FMA},
-  {AEK_SME2, AEK_SSVE_FP8DOT2},
-  {AEK_SME2, AEK_SSVE_FP8DOT4},
-  {AEK_SME2, AEK_SMEF8F16},
-  {AEK_SME2, AEK_SMEF8F32},
-  {AEK_FP8, AEK_SMEF8F16},
-  {AEK_FP8, AEK_SMEF8F32},
-  {AEK_LSE, AEK_LSE128},
-  {AEK_PREDRES, AEK_SPECRES2},
-  {AEK_RAS, AEK_RASV2},
-  {AEK_RCPC, AEK_RCPC3},
-};
-// clang-format on
+#define EMIT_EXTENSION_DEPENDENCIES
+#include "llvm/TargetParser/AArch64TargetParserDef.inc"
 
 enum ArchProfile { AProfile = 'A', RProfile = 'R', InvalidProfile = '?' };
 

llvm/lib/TargetParser/AArch64TargetParser.cpp

@@ -181,12 +181,6 @@ void AArch64::ExtensionSet::enable(ArchExtKind E) {
         !BaseArch->is_superset(ARMV9A))
       enable(AEK_FP16FML);
 
-    // For all architectures, +crypto enables +aes and +sha2.
-    if (E == AEK_CRYPTO) {
-      enable(AEK_AES);
-      enable(AEK_SHA2);
-    }
-
     // For v8.4A+ and v9.0A+, +crypto also enables +sha3 and +sm4.
     if (E == AEK_CRYPTO && BaseArch->is_superset(ARMV8_4A)) {
       enable(AEK_SHA3);

llvm/utils/TableGen/ARMTargetDefEmitter.cpp

@@ -116,6 +116,24 @@ static void EmitARMTargetDef(RecordKeeper &RK, raw_ostream &OS) {
      << "#endif // EMIT_EXTENSIONS\n"
      << "\n";
 
+  // Emit extension dependencies
+  OS << "#ifdef EMIT_EXTENSION_DEPENDENCIES\n"
+     << "inline constexpr ExtensionDependency ExtensionDependencies[] = {\n";
+  for (const Record *Rec : SortedExtensions) {
+    auto LaterAEK = Rec->getValueAsString("ArchExtKindSpelling").upper();
+    for (const Record *I : Rec->getValueAsListOfDefs("Implies"))
+      if (auto EarlierAEK = I->getValueAsOptionalString("ArchExtKindSpelling"))
+        OS << "  {" << EarlierAEK->upper() << ", " << LaterAEK << "},\n";
+  }
+  // FIXME: Tablegen has the Subtarget Feature FeatureRCPC_IMMO which is implied
+  // by FeatureRCPC3 and in turn implies FeatureRCPC. The proper fix is to make
+  // FeatureRCPC_IMMO an Extension but that will expose it to the command line.
+  OS << "  {AEK_RCPC, AEK_RCPC3},\n";
+  OS << "};\n"
+     << "#undef EMIT_EXTENSION_DEPENDENCIES\n"
+     << "#endif // EMIT_EXTENSION_DEPENDENCIES\n"
+     << "\n";
+
   // Emit architecture information
   OS << "#ifdef EMIT_ARCHITECTURES\n";