8267982: Set the node after peephole optimization to be removed

Reviewed-by: kvn, thartmann

Author: sunny868

src/hotspot/share/adlc/output_c.cpp

@@ -1342,6 +1342,9 @@ static void generate_peepreplace( FILE *fp, FormDict &globals, PeepMatch *pmatch
     assert( false, "ShouldNotReachHere();");
   }
 
+  for (int i = 0; i <= max_position; i++) {
+    fprintf(fp, "        inst%d->set_removed();\n", i);
+  }
   // Return the new sub-tree
   fprintf(fp, "        deleted = %d;\n", max_position+1 /*zero to one based*/);
   fprintf(fp, "        return root;  // return new root;\n");

src/hotspot/share/opto/buildOopMap.cpp

@@ -466,8 +466,11 @@ static void do_liveness(PhaseRegAlloc* regalloc, PhaseCFG* cfg, Block_List* work
           assert(def != 0, "input edge required");
           int first = regalloc->get_reg_first(def);
           int second = regalloc->get_reg_second(def);
-          if( OptoReg::is_valid(first) ) set_live_bit(tmp_live,first);
-          if( OptoReg::is_valid(second) ) set_live_bit(tmp_live,second);
+          //If peephole had removed the node,do not set live bit for it.
+          if (!(def->is_Mach() && def->as_Mach()->get_removed())) {
+            if (OptoReg::is_valid(first)) set_live_bit(tmp_live,first);
+            if (OptoReg::is_valid(second)) set_live_bit(tmp_live,second);
+          }
           // If we use the stack pointer in a cisc-alternative instruction,
           // check for use as a memory operand.  Then reconstruct the RegName
           // for this stack location, and set the appropriate bit in the

src/hotspot/share/opto/machnode.hpp

@@ -204,6 +204,9 @@ class MachOper : public ResourceObj {
 // Base type for all machine specific nodes.  All node classes generated by the
 // ADLC inherit from this class.
 class MachNode : public Node {
+private:
+  bool _removed = false;
+
 public:
   MachNode() : Node((uint)0), _barrier(0), _num_opnds(0), _opnds(NULL) {
     init_class_id(Class_Mach);
@@ -372,6 +375,8 @@ class MachNode : public Node {
 
   // Returns true if this node is a check that can be implemented with a trap.
   virtual bool is_TrapBasedCheckNode() const { return false; }
+  void set_removed() { _removed = true; }
+  bool get_removed() { return _removed; }
 
 #ifndef PRODUCT
   virtual const char *Name() const = 0; // Machine-specific name