src/hotspot/share/opto/loopopts.cpp

*** 38,47 ****
--- 38,48 ----
  #include "opto/mulnode.hpp"
  #include "opto/movenode.hpp"
  #include "opto/opaquenode.hpp"
  #include "opto/rootnode.hpp"
  #include "opto/subnode.hpp"
+ #include "opto/valuetypenode.hpp"
  #include "utilities/macros.hpp"
  #if INCLUDE_ZGC
  #include "gc/z/c2/zBarrierSetC2.hpp"
  #endif
  
*** 61,70 ****
--- 62,77 ----
    if (n->Opcode() == Op_CastII && n->as_CastII()->has_range_check() &&
        region->is_CountedLoop() && n->in(1) == region->as_CountedLoop()->phi()) {
      return NULL;
    }
  
+   // Value types should not be split through Phis because they cannot be merged
+   // through Phi nodes but each value input needs to be merged individually.
+   if (n->is_ValueType()) {
+     return NULL;
+   }
+ 
    int wins = 0;
    assert(!n->is_CFG(), "");
    assert(region->is_Region(), "");
  
    const Type* type = n->bottom_type();
*** 1447,1456 ****
--- 1454,1469 ----
      }
    }
  
    try_move_store_after_loop(n);
  
+   // Remove multiple allocations of the same value type
+   if (n->is_ValueType() && EliminateAllocations) {
+     n->as_ValueType()->remove_redundant_allocations(&_igvn, this);
+     return; // n is now dead
+   }
+ 
    // Check for Opaque2's who's loop has disappeared - who's input is in the
    // same loop nest as their output.  Remove 'em, they are no longer useful.
    if( n_op == Op_Opaque2 &&
        n->in(1) != NULL &&
        get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) {