[clang] Add clang atomic control options and attribute (PR #114841)

[Yaxun Liu via cfe-commits]

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@@ -1101,6 +1107,187 @@ inline void FPOptions::applyChanges(FPOptionsOverride FPO) {
   *this = FPO.applyOverrides(*this);
 }
 
+// The three atomic code-generation options.
+// The canonical (positive) names are:
+//   "remote_memory", "fine_grained_memory", and "ignore_denormal_mode".
+// In attribute or command-line parsing, a token prefixed with "no_" inverts its
+// value.
+enum class AtomicOptionKind {
+  RemoteMemory,       // true means remote memory is enabled.
+  FineGrainedMemory,  // true means fine-grained memory is enabled.
+  IgnoreDenormalMode, // true means ignore floating-point denormals.
+  LANGOPT_ATOMIC_OPTION_LAST
+};
+
+struct AtomicOptions {
+  // Bitfields for each option.
+  unsigned remote_memory : 1;
+  unsigned fine_grained_memory : 1;
+  unsigned ignore_denormal_mode : 1;
+
+  AtomicOptions()
+      : remote_memory(0), fine_grained_memory(0), ignore_denormal_mode(0) {}
+
+  bool getOption(AtomicOptionKind Kind) const {
+    switch (Kind) {
+    case AtomicOptionKind::RemoteMemory:
+      return remote_memory;
+    case AtomicOptionKind::FineGrainedMemory:
+      return fine_grained_memory;
+    case AtomicOptionKind::IgnoreDenormalMode:
+      return ignore_denormal_mode;
+    default:
+      llvm_unreachable("Invalid AtomicOptionKind");
+    }
+  }
+
+  void setOption(AtomicOptionKind Kind, bool Value) {
+    switch (Kind) {
+    case AtomicOptionKind::RemoteMemory:
+      remote_memory = Value;
+      break;
+    case AtomicOptionKind::FineGrainedMemory:
+      fine_grained_memory = Value;
+      break;
+    case AtomicOptionKind::IgnoreDenormalMode:
+      ignore_denormal_mode = Value;
+      break;
+    default:
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yxsamliu wrote:

will do

https://github.com/llvm/llvm-project/pull/114841