src/cpu/s390/vm/s390.ad

rev 12487 : 8172049: [s390] Implement "JEP 270: Reserved Stack Areas for Critical Sections".
Reviewed-by: mdoerr

@@ -907,41 +907,39 @@
   __ verify_thread();
 
   // If this does safepoint polling, then do it here.
   bool need_polling = do_polling() && C->is_method_compilation();
 
-  // Touch the polling page.
-  // Part 1: get the page's address.
-  if (need_polling) {
-    AddressLiteral pp(os::get_polling_page());
-    __ load_const_optimized(Z_R1_scratch, pp);
-  }
-
   // Pop frame, restore return_pc, and all stuff needed by interpreter.
-  // Pop frame by add insted of load (a penny saved is a penny got :-).
+  // Pop frame by add instead of load (a penny saved is a penny got :-).
   int frame_size_in_bytes = Assembler::align((C->frame_slots() << LogBytesPerInt), frame::alignment_in_bytes);
   int retPC_offset        = frame_size_in_bytes + _z_abi16(return_pc);
   if (Displacement::is_validDisp(retPC_offset)) {
     __ z_lg(Z_R14, retPC_offset, Z_SP);
     __ add2reg(Z_SP, frame_size_in_bytes);
   } else {
     __ add2reg(Z_SP, frame_size_in_bytes);
     __ restore_return_pc();
   }
 
-  // Touch the polling page,
-  // part 2: touch the page now.
+  if (StackReservedPages > 0 && C->has_reserved_stack_access()) {
+    __ reserved_stack_check(Z_R14);
+  }
+
+  // Touch the polling page.
   if (need_polling) {
+    AddressLiteral pp(os::get_polling_page());
+    __ load_const_optimized(Z_R1_scratch, pp);
     // We need to mark the code position where the load from the safepoint
     // polling page was emitted as relocInfo::poll_return_type here.
     __ relocate(relocInfo::poll_return_type);
     __ load_from_polling_page(Z_R1_scratch);
   }
 }
 
 uint MachEpilogNode::size(PhaseRegAlloc *ra_) const {
-  // variable size. determine dynamically.
+  // Variable size. determine dynamically.
   return MachNode::size(ra_);
 }
 
 int MachEpilogNode::reloc() const {
   // Return number of relocatable values contained in this instruction.