1 files changed, 30 insertions, 1 deletions
diff --git a/llvm/utils/TableGen/Basic/RuntimeLibcallsEmitter.cpp b/llvm/utils/TableGen/Basic/RuntimeLibcallsEmitter.cpp
index 10f0213..fd8ddb1 100644
--- a/llvm/utils/TableGen/Basic/RuntimeLibcallsEmitter.cpp
+++ b/llvm/utils/TableGen/Basic/RuntimeLibcallsEmitter.cpp
@@ -588,7 +588,12 @@ void RuntimeLibcallEmitter::emitSystemRuntimeLibrarySetCalls(
     PredicateSorter.insert(
         PredicateWithCC()); // No predicate or CC override first.
 
+    constexpr unsigned BitsPerStorageElt = 64;
     DenseMap<PredicateWithCC, LibcallsWithCC> Pred2Funcs;
+
+    SmallVector<uint64_t, 32> BitsetValues(
+        divideCeil(RuntimeLibcallImplDefList.size(), BitsPerStorageElt));
+
     for (const Record *Elt : *Elements) {
       const RuntimeLibcallImpl *LibCallImpl = getRuntimeLibcallImpl(Elt);
       if (!LibCallImpl) {
@@ -597,16 +602,24 @@ void RuntimeLibcallEmitter::emitSystemRuntimeLibrarySetCalls(
         continue;
       }
 
+      size_t BitIdx = LibCallImpl->getEnumVal();
+      uint64_t BitmaskVal = uint64_t(1) << (BitIdx % BitsPerStorageElt);
+      size_t BitsetIdx = BitIdx / BitsPerStorageElt;
+
       auto It = Func2Preds.find(LibCallImpl);
       if (It == Func2Preds.end()) {
+        BitsetValues[BitsetIdx] |= BitmaskVal;
         Pred2Funcs[PredicateWithCC()].LibcallImpls.push_back(LibCallImpl);
         continue;
       }
 
       for (const Record *Pred : It->second.first) {
         const Record *CC = It->second.second;
-        PredicateWithCC Key(Pred, CC);
+        AvailabilityPredicate SubsetPredicate(Pred);
+        if (SubsetPredicate.isAlwaysAvailable())
+          BitsetValues[BitsetIdx] |= BitmaskVal;
 
+        PredicateWithCC Key(Pred, CC);
         auto &Entry = Pred2Funcs[Key];
         Entry.LibcallImpls.push_back(LibCallImpl);
         Entry.CallingConv = It->second.second;
@@ -614,6 +627,22 @@ void RuntimeLibcallEmitter::emitSystemRuntimeLibrarySetCalls(
       }
     }
 
+    OS << "    static constexpr LibcallImplBitset SystemAvailableImpls({\n"
+       << indent(6);
+
+    ListSeparator LS;
+    unsigned EntryCount = 0;
+    for (uint64_t Bits : BitsetValues) {
+      if (EntryCount++ == 4) {
+        EntryCount = 1;
+        OS << ",\n" << indent(6);
+      } else
+        OS << LS;
+      OS << format_hex(Bits, 16);
+    }
+    OS << "\n    });\n"
+          "    AvailableLibcallImpls = SystemAvailableImpls;\n\n";
+
     SmallVector<PredicateWithCC, 0> SortedPredicates =
         PredicateSorter.takeVector();