src/hotspot/share/opto/mulnode.cpp

rev 52801 : Upstream/backport Shenandoah to JDK11u
* * *
[backport] 8237570: Shenandoah: cleanup uses of allocation/free threshold in static heuristics
Reviewed-by: rkennke

*** 1,7 ****
  /*
!  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 29,38 ****
--- 29,42 ----
  #include "opto/convertnode.hpp"
  #include "opto/memnode.hpp"
  #include "opto/mulnode.hpp"
  #include "opto/phaseX.hpp"
  #include "opto/subnode.hpp"
+ #include "utilities/macros.hpp"
+ #if INCLUDE_SHENANDOAHGC
+ #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
+ #endif
  
  // Portions of code courtesy of Clifford Click
  
  
  //=============================================================================
*** 472,481 ****
--- 476,494 ----
    if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
    const int mask = t2->get_con();
    Node *load = in(1);
    uint lop = load->Opcode();
  
+ #if INCLUDE_SHENANDOAHGC
+   if (UseShenandoahGC && ShenandoahBarrierC2Support::is_gc_state_load(load)) {
+     // Do not touch the load+mask, we would match the whole sequence exactly.
+     // Converting the load to LoadUB/LoadUS would mismatch and waste a register
+     // on the barrier fastpath.
+     return NULL;
+   }
+ #endif
+ 
    // Masking bits off of a Character?  Hi bits are already zero.
    if( lop == Op_LoadUS &&
        (mask & 0xFFFF0000) )     // Can we make a smaller mask?
      return new AndINode(load,phase->intcon(mask&0xFFFF));