src/cpu/s390/vm/macroAssembler_s390.cpp

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

*** 2664,2673 ****
--- 2664,2699 ----
      add2reg(Z_R1, -offset, Z_SP);    // Do not destroy Z_SP!!!
      z_tm(0, Z_R1, mask_stackbang);  // Just banging.
    }
  }
  
+ void MacroAssembler::reserved_stack_check(Register return_pc) {
+   // Test if reserved zone needs to be enabled.
+   Label no_reserved_zone_enabling;
+   assert(return_pc == Z_R14, "Return pc must be in R14 before z_br() to StackOverflow stub.");
+   BLOCK_COMMENT("reserved_stack_check {");
+ 
+   z_clg(Z_SP, Address(Z_thread, JavaThread::reserved_stack_activation_offset()));
+   z_brl(no_reserved_zone_enabling);
+ 
+   // Enable reserved zone again, throw stack overflow exception.
+   save_return_pc();
+   push_frame_abi160(0);
+   call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::enable_stack_reserved_zone), Z_thread);
+   pop_frame();
+   restore_return_pc();
+ 
+   load_const_optimized(Z_R1, StubRoutines::throw_delayed_StackOverflowError_entry());
+   // Don't use call() or z_basr(), they will invalidate Z_R14 which contains the return pc.
+   z_br(Z_R1);
+ 
+   should_not_reach_here();
+ 
+   bind(no_reserved_zone_enabling);
+   BLOCK_COMMENT("} reserved_stack_check");
+ }
+ 
  // Defines obj, preserves var_size_in_bytes, okay for t2 == var_size_in_bytes.
  void MacroAssembler::tlab_allocate(Register obj,
                                     Register var_size_in_bytes,
                                     int con_size_in_bytes,
                                     Register t1,