6892658: C2 should optimize some stringbuilder patterns

Reviewed-by: kvn, twisti

hotspot/src/share/vm/opto/graphKit.hpp

@@ -279,6 +279,34 @@ class GraphKit : public Phase {
   }
   Node* basic_plus_adr(Node* base, Node* ptr, Node* offset);
 
+
+  // Some convenient shortcuts for common nodes
+  Node* IfTrue(IfNode* iff)                   { return _gvn.transform(new (C,1) IfTrueNode(iff));      }
+  Node* IfFalse(IfNode* iff)                  { return _gvn.transform(new (C,1) IfFalseNode(iff));     }
+
+  Node* AddI(Node* l, Node* r)                { return _gvn.transform(new (C,3) AddINode(l, r));       }
+  Node* SubI(Node* l, Node* r)                { return _gvn.transform(new (C,3) SubINode(l, r));       }
+  Node* MulI(Node* l, Node* r)                { return _gvn.transform(new (C,3) MulINode(l, r));       }
+  Node* DivI(Node* ctl, Node* l, Node* r)     { return _gvn.transform(new (C,3) DivINode(ctl, l, r));  }
+
+  Node* AndI(Node* l, Node* r)                { return _gvn.transform(new (C,3) AndINode(l, r));       }
+  Node* OrI(Node* l, Node* r)                 { return _gvn.transform(new (C,3) OrINode(l, r));        }
+  Node* XorI(Node* l, Node* r)                { return _gvn.transform(new (C,3) XorINode(l, r));       }
+
+  Node* MaxI(Node* l, Node* r)                { return _gvn.transform(new (C,3) MaxINode(l, r));       }
+  Node* MinI(Node* l, Node* r)                { return _gvn.transform(new (C,3) MinINode(l, r));       }
+
+  Node* LShiftI(Node* l, Node* r)             { return _gvn.transform(new (C,3) LShiftINode(l, r));    }
+  Node* RShiftI(Node* l, Node* r)             { return _gvn.transform(new (C,3) RShiftINode(l, r));    }
+  Node* URShiftI(Node* l, Node* r)            { return _gvn.transform(new (C,3) URShiftINode(l, r));   }
+
+  Node* CmpI(Node* l, Node* r)                { return _gvn.transform(new (C,3) CmpINode(l, r));       }
+  Node* CmpL(Node* l, Node* r)                { return _gvn.transform(new (C,3) CmpLNode(l, r));       }
+  Node* CmpP(Node* l, Node* r)                { return _gvn.transform(new (C,3) CmpPNode(l, r));       }
+  Node* Bool(Node* cmp, BoolTest::mask relop) { return _gvn.transform(new (C,2) BoolNode(cmp, relop)); }
+
+  Node* AddP(Node* b, Node* a, Node* o)       { return _gvn.transform(new (C,4) AddPNode(b, a, o));    }
+
   // Convert between int and long, and size_t.
   // (See macros ConvI2X, etc., in type.hpp for ConvI2X, etc.)
   Node* ConvI2L(Node* offset);
@@ -400,7 +428,7 @@ class GraphKit : public Phase {
   void set_all_memory(Node* newmem);
 
   // Create a memory projection from the call, then set_all_memory.
-  void set_all_memory_call(Node* call);
+  void set_all_memory_call(Node* call, bool separate_io_proj = false);
 
   // Create a LoadNode, reading from the parser's memory state.
   // (Note:  require_atomic_access is useful only with T_LONG.)
@@ -543,12 +571,12 @@ class GraphKit : public Phase {
   // Transform the call, and update the basics: control, i_o, memory.
   // (The next step is usually to call set_results_for_java_call.)
   void set_edges_for_java_call(CallJavaNode* call,
-                               bool must_throw = false);
+                               bool must_throw = false, bool separate_io_proj = false);
 
   // Finish up a java call that was started by set_edges_for_java_call.
   // Call add_exception on any throw arising from the call.
   // Return the call result (transformed).
-  Node* set_results_for_java_call(CallJavaNode* call);
+  Node* set_results_for_java_call(CallJavaNode* call, bool separate_io_proj = false);
 
   // Similar to set_edges_for_java_call, but simplified for runtime calls.
   void  set_predefined_output_for_runtime_call(Node* call) {
@@ -559,6 +587,11 @@ class GraphKit : public Phase {
                                                const TypePtr* hook_mem);
   Node* set_predefined_input_for_runtime_call(SafePointNode* call);
 
+  // Replace the call with the current state of the kit.  Requires
+  // that the call was generated with separate io_projs so that
+  // exceptional control flow can be handled properly.
+  void replace_call(CallNode* call, Node* result);
+
   // helper functions for statistics
   void increment_counter(address counter_addr);   // increment a debug counter
   void increment_counter(Node*   counter_addr);   // increment a debug counter