--- a/src/cpu/sparc/vm/vm_version_sparc.cpp	Fri Nov 23 11:40:17 2012 +0100
+++ b/src/cpu/sparc/vm/vm_version_sparc.cpp	Fri Nov 23 11:50:27 2012 +0100
@@ -96,6 +96,7 @@
   UseSSE = 0; // Only on x86 and x64
 
   _supports_cx8 = has_v9();
+  _supports_atomic_getset4 = true; // swap instruction
 
   if (is_niagara()) {
     // Indirect branch is the same cost as direct
@@ -116,6 +117,7 @@
     // 32-bit oops don't make sense for the 64-bit VM on sparc
     // since the 32-bit VM has the same registers and smaller objects.
     Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
+    Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
 #endif // _LP64
 #ifdef COMPILER2
     // Indirect branch is the same cost as direct
@@ -338,7 +340,11 @@
 
 unsigned int VM_Version::calc_parallel_worker_threads() {
   unsigned int result;
-  if (is_niagara_plus()) {
+  if (is_M_series()) {
+    // for now, use same gc thread calculation for M-series as for niagara-plus
+    // in future, we may want to tweak parameters for nof_parallel_worker_thread
+    result = nof_parallel_worker_threads(5, 16, 8);
+  } else if (is_niagara_plus()) {
     result = nof_parallel_worker_threads(5, 16, 8);
   } else {
     result = nof_parallel_worker_threads(5, 8, 8);