--- a/hotspot/src/share/vm/opto/compile.cpp	Wed Jul 22 15:48:51 2009 -0700
+++ b/hotspot/src/share/vm/opto/compile.cpp	Thu Jul 23 14:53:56 2009 -0700
@@ -441,6 +441,8 @@
                   _orig_pc_slot_offset_in_bytes(0),
                   _node_bundling_limit(0),
                   _node_bundling_base(NULL),
+                  _java_calls(0),
+                  _inner_loops(0),
 #ifndef PRODUCT
                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
                   _printer(IdealGraphPrinter::printer()),
@@ -711,6 +713,8 @@
     _code_buffer("Compile::Fill_buffer"),
     _node_bundling_limit(0),
     _node_bundling_base(NULL),
+    _java_calls(0),
+    _inner_loops(0),
 #ifndef PRODUCT
     _trace_opto_output(TraceOptoOutput),
     _printer(NULL),
@@ -1851,22 +1855,26 @@
   int  _float_count;            // count float ops requiring 24-bit precision
   int  _double_count;           // count double ops requiring more precision
   int  _java_call_count;        // count non-inlined 'java' calls
+  int  _inner_loop_count;       // count loops which need alignment
   VectorSet _visited;           // Visitation flags
   Node_List _tests;             // Set of IfNodes & PCTableNodes
 
   Final_Reshape_Counts() :
-    _call_count(0), _float_count(0), _double_count(0), _java_call_count(0),
+    _call_count(0), _float_count(0), _double_count(0),
+    _java_call_count(0), _inner_loop_count(0),
     _visited( Thread::current()->resource_area() ) { }
 
   void inc_call_count  () { _call_count  ++; }
   void inc_float_count () { _float_count ++; }
   void inc_double_count() { _double_count++; }
   void inc_java_call_count() { _java_call_count++; }
+  void inc_inner_loop_count() { _inner_loop_count++; }
 
   int  get_call_count  () const { return _call_count  ; }
   int  get_float_count () const { return _float_count ; }
   int  get_double_count() const { return _double_count; }
   int  get_java_call_count() const { return _java_call_count; }
+  int  get_inner_loop_count() const { return _inner_loop_count; }
 };
 
 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
@@ -1878,7 +1886,7 @@
 
 //------------------------------final_graph_reshaping_impl----------------------
 // Implement items 1-5 from final_graph_reshaping below.
-static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
+static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc ) {
 
   if ( n->outcnt() == 0 ) return; // dead node
   uint nop = n->Opcode();
@@ -1920,13 +1928,13 @@
   case Op_CmpF:
   case Op_CmpF3:
   // case Op_ConvL2F: // longs are split into 32-bit halves
-    fpu.inc_float_count();
+    frc.inc_float_count();
     break;
 
   case Op_ConvF2D:
   case Op_ConvD2F:
-    fpu.inc_float_count();
-    fpu.inc_double_count();
+    frc.inc_float_count();
+    frc.inc_double_count();
     break;
 
   // Count all double operations that may use FPU
@@ -1943,7 +1951,7 @@
   case Op_ConD:
   case Op_CmpD:
   case Op_CmpD3:
-    fpu.inc_double_count();
+    frc.inc_double_count();
     break;
   case Op_Opaque1:              // Remove Opaque Nodes before matching
   case Op_Opaque2:              // Remove Opaque Nodes before matching
@@ -1952,7 +1960,7 @@
   case Op_CallStaticJava:
   case Op_CallJava:
   case Op_CallDynamicJava:
-    fpu.inc_java_call_count(); // Count java call site;
+    frc.inc_java_call_count(); // Count java call site;
   case Op_CallRuntime:
   case Op_CallLeaf:
   case Op_CallLeafNoFP: {
@@ -1963,7 +1971,7 @@
     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
-      fpu.inc_call_count();   // Count the call site
+      frc.inc_call_count();   // Count the call site
     } else {                  // See if uncommon argument is shared
       Node *n = call->in(TypeFunc::Parms);
       int nop = n->Opcode();
@@ -1984,11 +1992,11 @@
   case Op_StoreD:
   case Op_LoadD:
   case Op_LoadD_unaligned:
-    fpu.inc_double_count();
+    frc.inc_double_count();
     goto handle_mem;
   case Op_StoreF:
   case Op_LoadF:
-    fpu.inc_float_count();
+    frc.inc_float_count();
     goto handle_mem;
 
   case Op_StoreB:
@@ -2325,6 +2333,12 @@
       n->subsume_by(btp);
     }
     break;
+  case Op_Loop:
+  case Op_CountedLoop:
+    if (n->as_Loop()->is_inner_loop()) {
+      frc.inc_inner_loop_count();
+    }
+    break;
   default:
     assert( !n->is_Call(), "" );
     assert( !n->is_Mem(), "" );
@@ -2333,17 +2347,17 @@
 
   // Collect CFG split points
   if (n->is_MultiBranch())
-    fpu._tests.push(n);
+    frc._tests.push(n);
 }
 
 //------------------------------final_graph_reshaping_walk---------------------
 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
 // requires that the walk visits a node's inputs before visiting the node.
-static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &fpu ) {
+static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
   ResourceArea *area = Thread::current()->resource_area();
   Unique_Node_List sfpt(area);
 
-  fpu._visited.set(root->_idx); // first, mark node as visited
+  frc._visited.set(root->_idx); // first, mark node as visited
   uint cnt = root->req();
   Node *n = root;
   uint  i = 0;
@@ -2352,7 +2366,7 @@
       // Place all non-visited non-null inputs onto stack
       Node* m = n->in(i);
       ++i;
-      if (m != NULL && !fpu._visited.test_set(m->_idx)) {
+      if (m != NULL && !frc._visited.test_set(m->_idx)) {
         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
           sfpt.push(m);
         cnt = m->req();
@@ -2362,7 +2376,7 @@
       }
     } else {
       // Now do post-visit work
-      final_graph_reshaping_impl( n, fpu );
+      final_graph_reshaping_impl( n, frc );
       if (nstack.is_empty())
         break;             // finished
       n = nstack.node();   // Get node from stack
@@ -2443,16 +2457,16 @@
     return true;
   }
 
-  Final_Reshape_Counts fpu;
+  Final_Reshape_Counts frc;
 
   // Visit everybody reachable!
   // Allocate stack of size C->unique()/2 to avoid frequent realloc
   Node_Stack nstack(unique() >> 1);
-  final_graph_reshaping_walk(nstack, root(), fpu);
+  final_graph_reshaping_walk(nstack, root(), frc);
 
   // Check for unreachable (from below) code (i.e., infinite loops).
-  for( uint i = 0; i < fpu._tests.size(); i++ ) {
-    MultiBranchNode *n = fpu._tests[i]->as_MultiBranch();
+  for( uint i = 0; i < frc._tests.size(); i++ ) {
+    MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
     // Get number of CFG targets.
     // Note that PCTables include exception targets after calls.
     uint required_outcnt = n->required_outcnt();
@@ -2498,7 +2512,7 @@
     // Check that I actually visited all kids.  Unreached kids
     // must be infinite loops.
     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
-      if (!fpu._visited.test(n->fast_out(j)->_idx)) {
+      if (!frc._visited.test(n->fast_out(j)->_idx)) {
         record_method_not_compilable("infinite loop");
         return true;            // Found unvisited kid; must be unreach
       }
@@ -2507,13 +2521,14 @@
   // If original bytecodes contained a mixture of floats and doubles
   // check if the optimizer has made it homogenous, item (3).
   if( Use24BitFPMode && Use24BitFP &&
-      fpu.get_float_count() > 32 &&
-      fpu.get_double_count() == 0 &&
-      (10 * fpu.get_call_count() < fpu.get_float_count()) ) {
+      frc.get_float_count() > 32 &&
+      frc.get_double_count() == 0 &&
+      (10 * frc.get_call_count() < frc.get_float_count()) ) {
     set_24_bit_selection_and_mode( false,  true );
   }
 
-  set_has_java_calls(fpu.get_java_call_count() > 0);
+  set_java_calls(frc.get_java_call_count());
+  set_inner_loops(frc.get_inner_loop_count());
 
   // No infinite loops, no reason to bail out.
   return false;

--- a/hotspot/src/share/vm/opto/compile.hpp	Wed Jul 22 15:48:51 2009 -0700
+++ b/hotspot/src/share/vm/opto/compile.hpp	Thu Jul 23 14:53:56 2009 -0700
@@ -223,7 +223,8 @@
   PhaseCFG*             _cfg;                   // Results of CFG finding
   bool                  _select_24_bit_instr;   // We selected an instruction with a 24-bit result
   bool                  _in_24_bit_fp_mode;     // We are emitting instructions with 24-bit results
-  bool                  _has_java_calls;        // True if the method has java calls
+  int                   _java_calls;            // Number of java calls in the method
+  int                   _inner_loops;           // Number of inner loops in the method
   Matcher*              _matcher;               // Engine to map ideal to machine instructions
   PhaseRegAlloc*        _regalloc;              // Results of register allocation.
   int                   _frame_slots;           // Size of total frame in stack slots
@@ -505,7 +506,9 @@
   PhaseCFG*         cfg()                       { return _cfg; }
   bool              select_24_bit_instr() const { return _select_24_bit_instr; }
   bool              in_24_bit_fp_mode() const   { return _in_24_bit_fp_mode; }
-  bool              has_java_calls() const      { return _has_java_calls; }
+  bool              has_java_calls() const      { return _java_calls > 0; }
+  int               java_calls() const          { return _java_calls; }
+  int               inner_loops() const         { return _inner_loops; }
   Matcher*          matcher()                   { return _matcher; }
   PhaseRegAlloc*    regalloc()                  { return _regalloc; }
   int               frame_slots() const         { return _frame_slots; }
@@ -532,7 +535,8 @@
     _in_24_bit_fp_mode   = mode;
   }
 
-  void set_has_java_calls(bool z) { _has_java_calls = z; }
+  void  set_java_calls(int z) { _java_calls  = z; }
+  void set_inner_loops(int z) { _inner_loops = z; }
 
   // Instruction bits passed off to the VM
   int               code_size()                 { return _method_size; }

--- a/hotspot/src/share/vm/opto/output.cpp	Wed Jul 22 15:48:51 2009 -0700
+++ b/hotspot/src/share/vm/opto/output.cpp	Thu Jul 23 14:53:56 2009 -0700
@@ -50,6 +50,13 @@
   init_scratch_buffer_blob();
   if (failing())  return; // Out of memory
 
+  // The number of new nodes (mostly MachNop) is proportional to
+  // the number of java calls and inner loops which are aligned.
+  if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
+                            C->inner_loops()*(OptoLoopAlignment-1)),
+                           "out of nodes before code generation" ) ) {
+    return;
+  }
   // Make sure I can find the Start Node
   Block_Array& bbs = _cfg->_bbs;
   Block *entry = _cfg->_blocks[1];
@@ -1105,7 +1112,7 @@
   uint *call_returns = NEW_RESOURCE_ARRAY(uint, _cfg->_num_blocks+1);
 
   uint  return_offset = 0;
-  MachNode *nop = new (this) MachNopNode();
+  int nop_size = (new (this) MachNopNode())->size(_regalloc);
 
   int previous_offset = 0;
   int current_offset  = 0;
@@ -1188,7 +1195,6 @@
         }
 
         // align the instruction if necessary
-        int nop_size = nop->size(_regalloc);
         int padding = mach->compute_padding(current_offset);
         // Make sure safepoint node for polling is distinct from a call's
         // return by adding a nop if needed.
@@ -1372,7 +1378,6 @@
 
     // If the next block is the top of a loop, pad this block out to align
     // the loop top a little. Helps prevent pipe stalls at loop back branches.
-    int nop_size = (new (this) MachNopNode())->size(_regalloc);
     if( i<_cfg->_num_blocks-1 ) {
       Block *nb = _cfg->_blocks[i+1];
       uint padding = nb->alignment_padding(current_offset);