src/hotspot/cpu/x86/stubGenerator_x86_64.cpp

*** 2783,2792 ****
--- 2783,2835 ----
      __ ret(0);
  
      return start;
    }
  
+   address generate_data_cache_writeback() {
+     bool optimized = VM_Version::supports_clflushopt();
+     bool no_evict = VM_Version::supports_clwb();
+ 
+     const Register src        = c_rarg0;  // source address
+ 
+     __ align(CodeEntryAlignment);
+ 
+     StubCodeMark mark(this, "StubRoutines", "_data_cache_writeback");
+ 
+     address start = __ pc();
+     __ enter();
+     const Address line(src, 0);
+     __ cache_wb(line);
+     __ leave();
+     __ ret(0);
+ 
+     return start;    
+   }
+ 
+   address generate_data_cache_writeback_sync() {
+     const Register is_pre    = c_rarg0;  // pre or post sync
+ 
+     __ align(CodeEntryAlignment);
+ 
+     StubCodeMark mark(this, "StubRoutines", "_data_cache_writeback_sync");
+ 
+     // pre wbsync is a no-op
+     // post wbsync translates to an sfence
+ 
+     Label skip;
+     address start = __ pc();
+     __ enter();
+     __ cmpl(is_pre, 0);
+     __ jcc(Assembler::notEqual, skip); 
+     __ cache_wbsync(false);
+     __ bind(skip);
+     __ leave();
+     __ ret(0);
+ 
+     return start;
+   }
+ 
    void generate_arraycopy_stubs() {
      address entry;
      address entry_jbyte_arraycopy;
      address entry_jshort_arraycopy;
      address entry_jint_arraycopy;
*** 5775,5784 ****
--- 5818,5831 ----
      StubRoutines::x86::_double_sign_flip = generate_fp_mask("double_sign_flip", 0x8000000000000000);
  
      // support for verify_oop (must happen after universe_init)
      StubRoutines::_verify_oop_subroutine_entry = generate_verify_oop();
  
+     // data cache line writeback
+     StubRoutines::_data_cache_writeback = generate_data_cache_writeback();
+     StubRoutines::_data_cache_writeback_sync = generate_data_cache_writeback_sync();
+     
      // arraycopy stubs used by compilers
      generate_arraycopy_stubs();
  
      // don't bother generating these AES intrinsic stubs unless global flag is set
      if (UseAESIntrinsics) {