src/hotspot/cpu/arm/templateInterpreterGenerator_arm.cpp

rev 49916 : 8201786: Modularize interpreter GC barriers: leftovers for ARM32
Reviewed-by: enevill

*** 850,885 ****
  //
  // (*) - AArch64 only
  //
  
  address TemplateInterpreterGenerator::generate_Reference_get_entry(void) {
- #if INCLUDE_ALL_GCS
-   if (UseG1GC) {
      // Code: _aload_0, _getfield, _areturn
      // parameter size = 1
      //
      // The code that gets generated by this routine is split into 2 parts:
!     //    1. The "intrinsified" code for G1 (or any SATB based GC),
      //    2. The slow path - which is an expansion of the regular method entry.
      //
      // Notes:-
!     // * In the G1 code we do not check whether we need to block for
!     //   a safepoint. If G1 is enabled then we must execute the specialized
!     //   code for Reference.get (except when the Reference object is null)
!     //   so that we can log the value in the referent field with an SATB
!     //   update buffer.
!     //   If the code for the getfield template is modified so that the
!     //   G1 pre-barrier code is executed when the current method is
!     //   Reference.get() then going through the normal method entry
!     //   will be fine.
!     // * The G1 code can, however, check the receiver object (the instance
!     //   of java.lang.Reference) and jump to the slow path if null. If the
!     //   Reference object is null then we obviously cannot fetch the referent
!     //   and so we don't need to call the G1 pre-barrier. Thus we can use the
!     //   regular method entry code to generate the NPE.
!     //
!     // This code is based on generate_accessor_enty.
      //
      // Rmethod: Method*
      // Rthread: thread
      // Rsender_sp: sender sp, must be preserved for slow path, set SP to it on fast path
      // Rparams: parameters
--- 850,871 ----
  //
  // (*) - AArch64 only
  //
  
  address TemplateInterpreterGenerator::generate_Reference_get_entry(void) {
    // Code: _aload_0, _getfield, _areturn
    // parameter size = 1
    //
    // The code that gets generated by this routine is split into 2 parts:
!   //    1. The "intrinsified" code performing an ON_WEAK_OOP_REF load,
    //    2. The slow path - which is an expansion of the regular method entry.
    //
    // Notes:-
!   // * An intrinsic is always executed, where an ON_WEAK_OOP_REF load is performed.
!   // * We may jump to the slow path iff the receiver is null. If the
!   //   Reference object is null then we no longer perform an ON_WEAK_OOP_REF load
!   //   Thus we can use the regular method entry code to generate the NPE.
    //
    // Rmethod: Method*
    // Rthread: thread
    // Rsender_sp: sender sp, must be preserved for slow path, set SP to it on fast path
    // Rparams: parameters
*** 896,933 ****
      // Check if local 0 != NULL
      // If the receiver is null then it is OK to jump to the slow path.
      __ ldr(Rthis, Address(Rparams));
      __ cbz(Rthis, slow_path);
  
-     // Generate the G1 pre-barrier code to log the value of
-     // the referent field in an SATB buffer.
- 
-     // Load the value of the referent field.
-     __ load_heap_oop(R0, Address(Rthis, referent_offset));
- 
      // Preserve LR
      __ mov(Rret_addr, LR);
  
!     __ g1_write_barrier_pre(noreg,   // store_addr
!                             noreg,   // new_val
!                             R0,      // pre_val
!                             Rtemp,   // tmp1
!                             R1_tmp); // tmp2
  
      // _areturn
      __ mov(SP, Rsender_sp);
      __ ret(Rret_addr);
  
      // generate a vanilla interpreter entry as the slow path
      __ bind(slow_path);
      __ jump_to_entry(Interpreter::entry_for_kind(Interpreter::zerolocals));
      return entry;
-   }
- #endif // INCLUDE_ALL_GCS
- 
-   // If G1 is not enabled then attempt to go through the normal entry point
-   return NULL;
  }
  
  // Not supported
  address TemplateInterpreterGenerator::generate_CRC32_update_entry() { return NULL; }
  address TemplateInterpreterGenerator::generate_CRC32_updateBytes_entry(AbstractInterpreter::MethodKind kind) { return NULL; }
--- 882,906 ----
    // Check if local 0 != NULL
    // If the receiver is null then it is OK to jump to the slow path.
    __ ldr(Rthis, Address(Rparams));
    __ cbz(Rthis, slow_path);
  
    // Preserve LR
    __ mov(Rret_addr, LR);
  
!   // Load the value of the referent field.
!   const Address field_address(Rthis, referent_offset);
!   __ load_heap_oop(R0, field_address, R0, Rtemp, R1_tmp);
  
    // _areturn
    __ mov(SP, Rsender_sp);
    __ ret(Rret_addr);
  
    // generate a vanilla interpreter entry as the slow path
    __ bind(slow_path);
    __ jump_to_entry(Interpreter::entry_for_kind(Interpreter::zerolocals));
    return entry;
  }
  
  // Not supported
  address TemplateInterpreterGenerator::generate_CRC32_update_entry() { return NULL; }
  address TemplateInterpreterGenerator::generate_CRC32_updateBytes_entry(AbstractInterpreter::MethodKind kind) { return NULL; }