8349457: [leyden] Workaround Leyden problems with -XX:-TieredCompilation

Reviewed-by: asmehra, iveresov, vlivanov

Author: shipilev

src/hotspot/share/cds/heapShared.cpp

@@ -394,6 +394,14 @@ oop HeapShared::get_archived_object(int permanent_index) {
 //   table[i] = offset of oop whose permanent index is i.
 void CachedCodeDirectoryInternal::dumptime_init_internal() {
   const int count = _dumptime_permanent_oop_count;
+  if (count == 0) {
+    // Avoid confusing CDS code with zero-sized tables, just return.
+    log_info(cds)("No permanent oops");
+    _permanent_oop_count = count;
+    _permanent_oop_offsets = nullptr;
+    return;
+  }
+
   int* table = (int*)CDSAccess::allocate_from_code_cache(count * sizeof(int));
   for (int i = 0; i < count; i++) {
     table[count] = -1;

src/hotspot/share/compiler/compilerDefinitions.cpp

@@ -334,6 +334,13 @@ void CompilerConfig::set_compilation_policy_flags() {
     }
   }
 
+  // Current Leyden implementation requires SegmentedCodeCache: the archive-backed code
+  // cache would be initialized only then. Force SegmentedCodeCache if we are loading/storing
+  // cached code. TODO: Resolve this in code cache initialization code.
+  if (!SegmentedCodeCache && (LoadCachedCode || StoreCachedCode)) {
+    FLAG_SET_ERGO(SegmentedCodeCache, true);
+  }
+
   if (CompileThresholdScaling < 0) {
     vm_exit_during_initialization("Negative value specified for CompileThresholdScaling", nullptr);
   }