diff src/share/vm/opto/output.cpp @ 0:a61af66fc99e jdk7-b24

Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children 67914967a4b5
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/opto/output.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,2680 @@
+/*
+ * Copyright 1998-2007 Sun Microsystems, Inc.  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.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_output.cpp.incl"
+
+extern uint size_java_to_interp();
+extern uint reloc_java_to_interp();
+extern uint size_exception_handler();
+extern uint size_deopt_handler();
+
+#ifndef PRODUCT
+#define DEBUG_ARG(x) , x
+#else
+#define DEBUG_ARG(x)
+#endif
+
+extern int emit_exception_handler(CodeBuffer &cbuf);
+extern int emit_deopt_handler(CodeBuffer &cbuf);
+
+//------------------------------Output-----------------------------------------
+// Convert Nodes to instruction bits and pass off to the VM
+void Compile::Output() {
+  // RootNode goes
+  assert( _cfg->_broot->_nodes.size() == 0, "" );
+
+  // Initialize the space for the BufferBlob used to find and verify
+  // instruction size in MachNode::emit_size()
+  init_scratch_buffer_blob();
+
+  // Make sure I can find the Start Node
+  Block_Array& bbs = _cfg->_bbs;
+  Block *entry = _cfg->_blocks[1];
+  Block *broot = _cfg->_broot;
+
+  const StartNode *start = entry->_nodes[0]->as_Start();
+
+  // Replace StartNode with prolog
+  MachPrologNode *prolog = new (this) MachPrologNode();
+  entry->_nodes.map( 0, prolog );
+  bbs.map( prolog->_idx, entry );
+  bbs.map( start->_idx, NULL ); // start is no longer in any block
+
+  // Virtual methods need an unverified entry point
+
+  if( is_osr_compilation() ) {
+    if( PoisonOSREntry ) {
+      // TODO: Should use a ShouldNotReachHereNode...
+      _cfg->insert( broot, 0, new (this) MachBreakpointNode() );
+    }
+  } else {
+    if( _method && !_method->flags().is_static() ) {
+      // Insert unvalidated entry point
+      _cfg->insert( broot, 0, new (this) MachUEPNode() );
+    }
+
+  }
+
+
+  // Break before main entry point
+  if( (_method && _method->break_at_execute())
+#ifndef PRODUCT
+    ||(OptoBreakpoint && is_method_compilation())
+    ||(OptoBreakpointOSR && is_osr_compilation())
+    ||(OptoBreakpointC2R && !_method)
+#endif
+    ) {
+    // checking for _method means that OptoBreakpoint does not apply to
+    // runtime stubs or frame converters
+    _cfg->insert( entry, 1, new (this) MachBreakpointNode() );
+  }
+
+  // Insert epilogs before every return
+  for( uint i=0; i<_cfg->_num_blocks; i++ ) {
+    Block *b = _cfg->_blocks[i];
+    if( !b->is_connector() && b->non_connector_successor(0) == _cfg->_broot ) { // Found a program exit point?
+      Node *m = b->end();
+      if( m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt ) {
+        MachEpilogNode *epilog = new (this) MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
+        b->add_inst( epilog );
+        bbs.map(epilog->_idx, b);
+        //_regalloc->set_bad(epilog->_idx); // Already initialized this way.
+      }
+    }
+  }
+
+# ifdef ENABLE_ZAP_DEAD_LOCALS
+  if ( ZapDeadCompiledLocals )  Insert_zap_nodes();
+# endif
+
+  ScheduleAndBundle();
+
+#ifndef PRODUCT
+  if (trace_opto_output()) {
+    tty->print("\n---- After ScheduleAndBundle ----\n");
+    for (uint i = 0; i < _cfg->_num_blocks; i++) {
+      tty->print("\nBB#%03d:\n", i);
+      Block *bb = _cfg->_blocks[i];
+      for (uint j = 0; j < bb->_nodes.size(); j++) {
+        Node *n = bb->_nodes[j];
+        OptoReg::Name reg = _regalloc->get_reg_first(n);
+        tty->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
+        n->dump();
+      }
+    }
+  }
+#endif
+
+  if (failing())  return;
+
+  BuildOopMaps();
+
+  if (failing())  return;
+
+  Fill_buffer();
+}
+
+bool Compile::need_stack_bang(int frame_size_in_bytes) const {
+  // Determine if we need to generate a stack overflow check.
+  // Do it if the method is not a stub function and
+  // has java calls or has frame size > vm_page_size/8.
+  return (stub_function() == NULL &&
+          (has_java_calls() || frame_size_in_bytes > os::vm_page_size()>>3));
+}
+
+bool Compile::need_register_stack_bang() const {
+  // Determine if we need to generate a register stack overflow check.
+  // This is only used on architectures which have split register
+  // and memory stacks (ie. IA64).
+  // Bang if the method is not a stub function and has java calls
+  return (stub_function() == NULL && has_java_calls());
+}
+
+# ifdef ENABLE_ZAP_DEAD_LOCALS
+
+
+// In order to catch compiler oop-map bugs, we have implemented
+// a debugging mode called ZapDeadCompilerLocals.
+// This mode causes the compiler to insert a call to a runtime routine,
+// "zap_dead_locals", right before each place in compiled code
+// that could potentially be a gc-point (i.e., a safepoint or oop map point).
+// The runtime routine checks that locations mapped as oops are really
+// oops, that locations mapped as values do not look like oops,
+// and that locations mapped as dead are not used later
+// (by zapping them to an invalid address).
+
+int Compile::_CompiledZap_count = 0;
+
+void Compile::Insert_zap_nodes() {
+  bool skip = false;
+
+
+  // Dink with static counts because code code without the extra
+  // runtime calls is MUCH faster for debugging purposes
+
+       if ( CompileZapFirst  ==  0  ) ; // nothing special
+  else if ( CompileZapFirst  >  CompiledZap_count() )  skip = true;
+  else if ( CompileZapFirst  == CompiledZap_count() )
+    warning("starting zap compilation after skipping");
+
+       if ( CompileZapLast  ==  -1  ) ; // nothing special
+  else if ( CompileZapLast  <   CompiledZap_count() )  skip = true;
+  else if ( CompileZapLast  ==  CompiledZap_count() )
+    warning("about to compile last zap");
+
+  ++_CompiledZap_count; // counts skipped zaps, too
+
+  if ( skip )  return;
+
+
+  if ( _method == NULL )
+    return; // no safepoints/oopmaps emitted for calls in stubs,so we don't care
+
+  // Insert call to zap runtime stub before every node with an oop map
+  for( uint i=0; i<_cfg->_num_blocks; i++ ) {
+    Block *b = _cfg->_blocks[i];
+    for ( uint j = 0;  j < b->_nodes.size();  ++j ) {
+      Node *n = b->_nodes[j];
+
+      // Determining if we should insert a zap-a-lot node in output.
+      // We do that for all nodes that has oopmap info, except for calls
+      // to allocation.  Calls to allocation passes in the old top-of-eden pointer
+      // and expect the C code to reset it.  Hence, there can be no safepoints between
+      // the inlined-allocation and the call to new_Java, etc.
+      // We also cannot zap monitor calls, as they must hold the microlock
+      // during the call to Zap, which also wants to grab the microlock.
+      bool insert = n->is_MachSafePoint() && (n->as_MachSafePoint()->oop_map() != NULL);
+      if ( insert ) { // it is MachSafePoint
+        if ( !n->is_MachCall() ) {
+          insert = false;
+        } else if ( n->is_MachCall() ) {
+          MachCallNode* call = n->as_MachCall();
+          if (call->entry_point() == OptoRuntime::new_instance_Java() ||
+              call->entry_point() == OptoRuntime::new_array_Java() ||
+              call->entry_point() == OptoRuntime::multianewarray2_Java() ||
+              call->entry_point() == OptoRuntime::multianewarray3_Java() ||
+              call->entry_point() == OptoRuntime::multianewarray4_Java() ||
+              call->entry_point() == OptoRuntime::multianewarray5_Java() ||
+              call->entry_point() == OptoRuntime::slow_arraycopy_Java() ||
+              call->entry_point() == OptoRuntime::complete_monitor_locking_Java()
+              ) {
+            insert = false;
+          }
+        }
+        if (insert) {
+          Node *zap = call_zap_node(n->as_MachSafePoint(), i);
+          b->_nodes.insert( j, zap );
+          _cfg->_bbs.map( zap->_idx, b );
+          ++j;
+        }
+      }
+    }
+  }
+}
+
+
+Node* Compile::call_zap_node(MachSafePointNode* node_to_check, int block_no) {
+  const TypeFunc *tf = OptoRuntime::zap_dead_locals_Type();
+  CallStaticJavaNode* ideal_node =
+    new (this, tf->domain()->cnt()) CallStaticJavaNode( tf,
+         OptoRuntime::zap_dead_locals_stub(_method->flags().is_native()),
+                            "call zap dead locals stub", 0, TypePtr::BOTTOM);
+  // We need to copy the OopMap from the site we're zapping at.
+  // We have to make a copy, because the zap site might not be
+  // a call site, and zap_dead is a call site.
+  OopMap* clone = node_to_check->oop_map()->deep_copy();
+
+  // Add the cloned OopMap to the zap node
+  ideal_node->set_oop_map(clone);
+  return _matcher->match_sfpt(ideal_node);
+}
+
+//------------------------------is_node_getting_a_safepoint--------------------
+bool Compile::is_node_getting_a_safepoint( Node* n) {
+  // This code duplicates the logic prior to the call of add_safepoint
+  // below in this file.
+  if( n->is_MachSafePoint() ) return true;
+  return false;
+}
+
+# endif // ENABLE_ZAP_DEAD_LOCALS
+
+//------------------------------compute_loop_first_inst_sizes------------------
+// Compute the size of first NumberOfLoopInstrToAlign instructions at head
+// of a loop. When aligning a loop we need to provide enough instructions
+// in cpu's fetch buffer to feed decoders. The loop alignment could be
+// avoided if we have enough instructions in fetch buffer at the head of a loop.
+// By default, the size is set to 999999 by Block's constructor so that
+// a loop will be aligned if the size is not reset here.
+//
+// Note: Mach instructions could contain several HW instructions
+// so the size is estimated only.
+//
+void Compile::compute_loop_first_inst_sizes() {
+  // The next condition is used to gate the loop alignment optimization.
+  // Don't aligned a loop if there are enough instructions at the head of a loop
+  // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
+  // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
+  // equal to 11 bytes which is the largest address NOP instruction.
+  if( MaxLoopPad < OptoLoopAlignment-1 ) {
+    uint last_block = _cfg->_num_blocks-1;
+    for( uint i=1; i <= last_block; i++ ) {
+      Block *b = _cfg->_blocks[i];
+      // Check the first loop's block which requires an alignment.
+      if( b->head()->is_Loop() &&
+          b->code_alignment() > (uint)relocInfo::addr_unit() ) {
+        uint sum_size = 0;
+        uint inst_cnt = NumberOfLoopInstrToAlign;
+        inst_cnt = b->compute_first_inst_size(sum_size, inst_cnt,
+                                              _regalloc);
+        // Check the next fallthrough block if first loop's block does not have
+        // enough instructions.
+        if( inst_cnt > 0 && i < last_block ) {
+          // First, check if the first loop's block contains whole loop.
+          // LoopNode::LoopBackControl == 2.
+          Block *bx = _cfg->_bbs[b->pred(2)->_idx];
+          // Skip connector blocks (with limit in case of irreducible loops).
+          int search_limit = 16;
+          while( bx->is_connector() && search_limit-- > 0) {
+            bx = _cfg->_bbs[bx->pred(1)->_idx];
+          }
+          if( bx != b ) { // loop body is in several blocks.
+            Block *nb = NULL;
+            while( inst_cnt > 0 && i < last_block && nb != bx &&
+                  !_cfg->_blocks[i+1]->head()->is_Loop() ) {
+              i++;
+              nb = _cfg->_blocks[i];
+              inst_cnt  = nb->compute_first_inst_size(sum_size, inst_cnt,
+                                                      _regalloc);
+            } // while( inst_cnt > 0 && i < last_block  )
+          } // if( bx != b )
+        } // if( inst_cnt > 0 && i < last_block )
+        b->set_first_inst_size(sum_size);
+      } // f( b->head()->is_Loop() )
+    } // for( i <= last_block )
+  } // if( MaxLoopPad < OptoLoopAlignment-1 )
+}
+
+//----------------------Shorten_branches---------------------------------------
+// The architecture description provides short branch variants for some long
+// branch instructions. Replace eligible long branches with short branches.
+void Compile::Shorten_branches(Label *labels, int& code_size, int& reloc_size, int& stub_size, int& const_size) {
+
+  // fill in the nop array for bundling computations
+  MachNode *_nop_list[Bundle::_nop_count];
+  Bundle::initialize_nops(_nop_list, this);
+
+  // ------------------
+  // Compute size of each block, method size, and relocation information size
+  uint *jmp_end    = NEW_RESOURCE_ARRAY(uint,_cfg->_num_blocks);
+  uint *blk_starts = NEW_RESOURCE_ARRAY(uint,_cfg->_num_blocks+1);
+  DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,_cfg->_num_blocks); )
+  blk_starts[0]    = 0;
+
+  // Initialize the sizes to 0
+  code_size  = 0;          // Size in bytes of generated code
+  stub_size  = 0;          // Size in bytes of all stub entries
+  // Size in bytes of all relocation entries, including those in local stubs.
+  // Start with 2-bytes of reloc info for the unvalidated entry point
+  reloc_size = 1;          // Number of relocation entries
+  const_size = 0;          // size of fp constants in words
+
+  // Make three passes.  The first computes pessimistic blk_starts,
+  // relative jmp_end, reloc_size and const_size information.
+  // The second performs short branch substitution using the pessimistic
+  // sizing. The third inserts nops where needed.
+
+  Node *nj; // tmp
+
+  // Step one, perform a pessimistic sizing pass.
+  uint i;
+  uint min_offset_from_last_call = 1;  // init to a positive value
+  uint nop_size = (new (this) MachNopNode())->size(_regalloc);
+  for( i=0; i<_cfg->_num_blocks; i++ ) { // For all blocks
+    Block *b = _cfg->_blocks[i];
+
+    // Sum all instruction sizes to compute block size
+    uint last_inst = b->_nodes.size();
+    uint blk_size = 0;
+    for( uint j = 0; j<last_inst; j++ ) {
+      nj = b->_nodes[j];
+      uint inst_size = nj->size(_regalloc);
+      blk_size += inst_size;
+      // Handle machine instruction nodes
+      if( nj->is_Mach() ) {
+        MachNode *mach = nj->as_Mach();
+        blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
+        reloc_size += mach->reloc();
+        const_size += mach->const_size();
+        if( mach->is_MachCall() ) {
+          MachCallNode *mcall = mach->as_MachCall();
+          // This destination address is NOT PC-relative
+
+          mcall->method_set((intptr_t)mcall->entry_point());
+
+          if( mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method ) {
+            stub_size  += size_java_to_interp();
+            reloc_size += reloc_java_to_interp();
+          }
+        } else if (mach->is_MachSafePoint()) {
+          // If call/safepoint are adjacent, account for possible
+          // nop to disambiguate the two safepoints.
+          if (min_offset_from_last_call == 0) {
+            blk_size += nop_size;
+          }
+        }
+      }
+      min_offset_from_last_call += inst_size;
+      // Remember end of call offset
+      if (nj->is_MachCall() && nj->as_MachCall()->is_safepoint_node()) {
+        min_offset_from_last_call = 0;
+      }
+    }
+
+    // During short branch replacement, we store the relative (to blk_starts)
+    // end of jump in jmp_end, rather than the absolute end of jump.  This
+    // is so that we do not need to recompute sizes of all nodes when we compute
+    // correct blk_starts in our next sizing pass.
+    jmp_end[i] = blk_size;
+    DEBUG_ONLY( jmp_target[i] = 0; )
+
+    // When the next block starts a loop, we may insert pad NOP
+    // instructions.  Since we cannot know our future alignment,
+    // assume the worst.
+    if( i<_cfg->_num_blocks-1 ) {
+      Block *nb = _cfg->_blocks[i+1];
+      int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
+      if( max_loop_pad > 0 ) {
+        assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
+        blk_size += max_loop_pad;
+      }
+    }
+
+    // Save block size; update total method size
+    blk_starts[i+1] = blk_starts[i]+blk_size;
+  }
+
+  // Step two, replace eligible long jumps.
+
+  // Note: this will only get the long branches within short branch
+  //   range. Another pass might detect more branches that became
+  //   candidates because the shortening in the first pass exposed
+  //   more opportunities. Unfortunately, this would require
+  //   recomputing the starting and ending positions for the blocks
+  for( i=0; i<_cfg->_num_blocks; i++ ) {
+    Block *b = _cfg->_blocks[i];
+
+    int j;
+    // Find the branch; ignore trailing NOPs.
+    for( j = b->_nodes.size()-1; j>=0; j-- ) {
+      nj = b->_nodes[j];
+      if( !nj->is_Mach() || nj->as_Mach()->ideal_Opcode() != Op_Con )
+        break;
+    }
+
+    if (j >= 0) {
+      if( nj->is_Mach() && nj->as_Mach()->may_be_short_branch() ) {
+        MachNode *mach = nj->as_Mach();
+        // This requires the TRUE branch target be in succs[0]
+        uint bnum = b->non_connector_successor(0)->_pre_order;
+        uintptr_t target = blk_starts[bnum];
+        if( mach->is_pc_relative() ) {
+          int offset = target-(blk_starts[i] + jmp_end[i]);
+          if (_matcher->is_short_branch_offset(offset)) {
+            // We've got a winner.  Replace this branch.
+            MachNode *replacement = mach->short_branch_version(this);
+            b->_nodes.map(j, replacement);
+
+            // Update the jmp_end size to save time in our
+            // next pass.
+            jmp_end[i] -= (mach->size(_regalloc) - replacement->size(_regalloc));
+            DEBUG_ONLY( jmp_target[i] = bnum; );
+          }
+        } else {
+#ifndef PRODUCT
+          mach->dump(3);
+#endif
+          Unimplemented();
+        }
+      }
+    }
+  }
+
+  // Compute the size of first NumberOfLoopInstrToAlign instructions at head
+  // of a loop. It is used to determine the padding for loop alignment.
+  compute_loop_first_inst_sizes();
+
+  // Step 3, compute the offsets of all the labels
+  uint last_call_adr = max_uint;
+  for( i=0; i<_cfg->_num_blocks; i++ ) { // For all blocks
+    // copy the offset of the beginning to the corresponding label
+    assert(labels[i].is_unused(), "cannot patch at this point");
+    labels[i].bind_loc(blk_starts[i], CodeBuffer::SECT_INSTS);
+
+    // insert padding for any instructions that need it
+    Block *b = _cfg->_blocks[i];
+    uint last_inst = b->_nodes.size();
+    uint adr = blk_starts[i];
+    for( uint j = 0; j<last_inst; j++ ) {
+      nj = b->_nodes[j];
+      if( nj->is_Mach() ) {
+        int padding = nj->as_Mach()->compute_padding(adr);
+        // If call/safepoint are adjacent insert a nop (5010568)
+        if (padding == 0 && nj->is_MachSafePoint() && !nj->is_MachCall() &&
+            adr == last_call_adr ) {
+          padding = nop_size;
+        }
+        if(padding > 0) {
+          assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
+          int nops_cnt = padding / nop_size;
+          MachNode *nop = new (this) MachNopNode(nops_cnt);
+          b->_nodes.insert(j++, nop);
+          _cfg->_bbs.map( nop->_idx, b );
+          adr += padding;
+          last_inst++;
+        }
+      }
+      adr += nj->size(_regalloc);
+
+      // Remember end of call offset
+      if (nj->is_MachCall() && nj->as_MachCall()->is_safepoint_node()) {
+        last_call_adr = adr;
+      }
+    }
+
+    if ( i != _cfg->_num_blocks-1) {
+      // Get the size of the block
+      uint blk_size = adr - blk_starts[i];
+
+      // When the next block starts a loop, we may insert pad NOP
+      // instructions.
+      Block *nb = _cfg->_blocks[i+1];
+      int current_offset = blk_starts[i] + blk_size;
+      current_offset += nb->alignment_padding(current_offset);
+      // Save block size; update total method size
+      blk_starts[i+1] = current_offset;
+    }
+  }
+
+#ifdef ASSERT
+  for( i=0; i<_cfg->_num_blocks; i++ ) { // For all blocks
+    if( jmp_target[i] != 0 ) {
+      int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_end[i]);
+      if (!_matcher->is_short_branch_offset(offset)) {
+        tty->print_cr("target (%d) - jmp_end(%d) = offset (%d), jmp_block B%d, target_block B%d", blk_starts[jmp_target[i]], blk_starts[i] + jmp_end[i], offset, i, jmp_target[i]);
+      }
+      assert(_matcher->is_short_branch_offset(offset), "Displacement too large for short jmp");
+    }
+  }
+#endif
+
+  // ------------------
+  // Compute size for code buffer
+  code_size   = blk_starts[i-1] + jmp_end[i-1];
+
+  // Relocation records
+  reloc_size += 1;              // Relo entry for exception handler
+
+  // Adjust reloc_size to number of record of relocation info
+  // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
+  // a relocation index.
+  // The CodeBuffer will expand the locs array if this estimate is too low.
+  reloc_size   *= 10 / sizeof(relocInfo);
+
+  // Adjust const_size to number of bytes
+  const_size   *= 2*jintSize; // both float and double take two words per entry
+
+}
+
+//------------------------------FillLocArray-----------------------------------
+// Create a bit of debug info and append it to the array.  The mapping is from
+// Java local or expression stack to constant, register or stack-slot.  For
+// doubles, insert 2 mappings and return 1 (to tell the caller that the next
+// entry has been taken care of and caller should skip it).
+static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
+  // This should never have accepted Bad before
+  assert(OptoReg::is_valid(regnum), "location must be valid");
+  return (OptoReg::is_reg(regnum))
+    ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
+    : new LocationValue(Location::new_stk_loc(l_type,  ra->reg2offset(regnum)));
+}
+
+void Compile::FillLocArray( int idx, Node *local, GrowableArray<ScopeValue*> *array ) {
+  assert( local, "use _top instead of null" );
+  if (array->length() != idx) {
+    assert(array->length() == idx + 1, "Unexpected array count");
+    // Old functionality:
+    //   return
+    // New functionality:
+    //   Assert if the local is not top. In product mode let the new node
+    //   override the old entry.
+    assert(local == top(), "LocArray collision");
+    if (local == top()) {
+      return;
+    }
+    array->pop();
+  }
+  const Type *t = local->bottom_type();
+
+  // Grab the register number for the local
+  OptoReg::Name regnum = _regalloc->get_reg_first(local);
+  if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
+    // Record the double as two float registers.
+    // The register mask for such a value always specifies two adjacent
+    // float registers, with the lower register number even.
+    // Normally, the allocation of high and low words to these registers
+    // is irrelevant, because nearly all operations on register pairs
+    // (e.g., StoreD) treat them as a single unit.
+    // Here, we assume in addition that the words in these two registers
+    // stored "naturally" (by operations like StoreD and double stores
+    // within the interpreter) such that the lower-numbered register
+    // is written to the lower memory address.  This may seem like
+    // a machine dependency, but it is not--it is a requirement on
+    // the author of the <arch>.ad file to ensure that, for every
+    // even/odd double-register pair to which a double may be allocated,
+    // the word in the even single-register is stored to the first
+    // memory word.  (Note that register numbers are completely
+    // arbitrary, and are not tied to any machine-level encodings.)
+#ifdef _LP64
+    if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
+      array->append(new ConstantIntValue(0));
+      array->append(new_loc_value( _regalloc, regnum, Location::dbl ));
+    } else if ( t->base() == Type::Long ) {
+      array->append(new ConstantIntValue(0));
+      array->append(new_loc_value( _regalloc, regnum, Location::lng ));
+    } else if ( t->base() == Type::RawPtr ) {
+      // jsr/ret return address which must be restored into a the full
+      // width 64-bit stack slot.
+      array->append(new_loc_value( _regalloc, regnum, Location::lng ));
+    }
+#else //_LP64
+#ifdef SPARC
+    if (t->base() == Type::Long && OptoReg::is_reg(regnum)) {
+      // For SPARC we have to swap high and low words for
+      // long values stored in a single-register (g0-g7).
+      array->append(new_loc_value( _regalloc,              regnum   , Location::normal ));
+      array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
+    } else
+#endif //SPARC
+    if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
+      // Repack the double/long as two jints.
+      // The convention the interpreter uses is that the second local
+      // holds the first raw word of the native double representation.
+      // This is actually reasonable, since locals and stack arrays
+      // grow downwards in all implementations.
+      // (If, on some machine, the interpreter's Java locals or stack
+      // were to grow upwards, the embedded doubles would be word-swapped.)
+      array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
+      array->append(new_loc_value( _regalloc,              regnum   , Location::normal ));
+    }
+#endif //_LP64
+    else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
+               OptoReg::is_reg(regnum) ) {
+      array->append(new_loc_value( _regalloc, regnum, Matcher::float_in_double
+                                   ? Location::float_in_dbl : Location::normal ));
+    } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
+      array->append(new_loc_value( _regalloc, regnum, Matcher::int_in_long
+                                   ? Location::int_in_long : Location::normal ));
+    } else {
+      array->append(new_loc_value( _regalloc, regnum, _regalloc->is_oop(local) ? Location::oop : Location::normal ));
+    }
+    return;
+  }
+
+  // No register.  It must be constant data.
+  switch (t->base()) {
+  case Type::Half:              // Second half of a double
+    ShouldNotReachHere();       // Caller should skip 2nd halves
+    break;
+  case Type::AnyPtr:
+    array->append(new ConstantOopWriteValue(NULL));
+    break;
+  case Type::AryPtr:
+  case Type::InstPtr:
+  case Type::KlassPtr:          // fall through
+    array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->encoding()));
+    break;
+  case Type::Int:
+    array->append(new ConstantIntValue(t->is_int()->get_con()));
+    break;
+  case Type::RawPtr:
+    // A return address (T_ADDRESS).
+    assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
+#ifdef _LP64
+    // Must be restored to the full-width 64-bit stack slot.
+    array->append(new ConstantLongValue(t->is_ptr()->get_con()));
+#else
+    array->append(new ConstantIntValue(t->is_ptr()->get_con()));
+#endif
+    break;
+  case Type::FloatCon: {
+    float f = t->is_float_constant()->getf();
+    array->append(new ConstantIntValue(jint_cast(f)));
+    break;
+  }
+  case Type::DoubleCon: {
+    jdouble d = t->is_double_constant()->getd();
+#ifdef _LP64
+    array->append(new ConstantIntValue(0));
+    array->append(new ConstantDoubleValue(d));
+#else
+    // Repack the double as two jints.
+    // The convention the interpreter uses is that the second local
+    // holds the first raw word of the native double representation.
+    // This is actually reasonable, since locals and stack arrays
+    // grow downwards in all implementations.
+    // (If, on some machine, the interpreter's Java locals or stack
+    // were to grow upwards, the embedded doubles would be word-swapped.)
+    jint   *dp = (jint*)&d;
+    array->append(new ConstantIntValue(dp[1]));
+    array->append(new ConstantIntValue(dp[0]));
+#endif
+    break;
+  }
+  case Type::Long: {
+    jlong d = t->is_long()->get_con();
+#ifdef _LP64
+    array->append(new ConstantIntValue(0));
+    array->append(new ConstantLongValue(d));
+#else
+    // Repack the long as two jints.
+    // The convention the interpreter uses is that the second local
+    // holds the first raw word of the native double representation.
+    // This is actually reasonable, since locals and stack arrays
+    // grow downwards in all implementations.
+    // (If, on some machine, the interpreter's Java locals or stack
+    // were to grow upwards, the embedded doubles would be word-swapped.)
+    jint *dp = (jint*)&d;
+    array->append(new ConstantIntValue(dp[1]));
+    array->append(new ConstantIntValue(dp[0]));
+#endif
+    break;
+  }
+  case Type::Top:               // Add an illegal value here
+    array->append(new LocationValue(Location()));
+    break;
+  default:
+    ShouldNotReachHere();
+    break;
+  }
+}
+
+// Determine if this node starts a bundle
+bool Compile::starts_bundle(const Node *n) const {
+  return (_node_bundling_limit > n->_idx &&
+          _node_bundling_base[n->_idx].starts_bundle());
+}
+
+//--------------------------Process_OopMap_Node--------------------------------
+void Compile::Process_OopMap_Node(MachNode *mach, int current_offset) {
+
+  // Handle special safepoint nodes for synchronization
+  MachSafePointNode *sfn   = mach->as_MachSafePoint();
+  MachCallNode      *mcall;
+
+#ifdef ENABLE_ZAP_DEAD_LOCALS
+  assert( is_node_getting_a_safepoint(mach),  "logic does not match; false negative");
+#endif
+
+  int safepoint_pc_offset = current_offset;
+
+  // Add the safepoint in the DebugInfoRecorder
+  if( !mach->is_MachCall() ) {
+    mcall = NULL;
+    debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
+  } else {
+    mcall = mach->as_MachCall();
+    safepoint_pc_offset += mcall->ret_addr_offset();
+    debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
+  }
+
+  // Loop over the JVMState list to add scope information
+  // Do not skip safepoints with a NULL method, they need monitor info
+  JVMState* youngest_jvms = sfn->jvms();
+  int max_depth = youngest_jvms->depth();
+
+  // Visit scopes from oldest to youngest.
+  for (int depth = 1; depth <= max_depth; depth++) {
+    JVMState* jvms = youngest_jvms->of_depth(depth);
+    int idx;
+    ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
+    // Safepoints that do not have method() set only provide oop-map and monitor info
+    // to support GC; these do not support deoptimization.
+    int num_locs = (method == NULL) ? 0 : jvms->loc_size();
+    int num_exps = (method == NULL) ? 0 : jvms->stk_size();
+    int num_mon  = jvms->nof_monitors();
+    assert(method == NULL || jvms->bci() < 0 || num_locs == method->max_locals(),
+           "JVMS local count must match that of the method");
+
+    // Add Local and Expression Stack Information
+
+    // Insert locals into the locarray
+    GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
+    for( idx = 0; idx < num_locs; idx++ ) {
+      FillLocArray( idx, sfn->local(jvms, idx), locarray );
+    }
+
+    // Insert expression stack entries into the exparray
+    GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
+    for( idx = 0; idx < num_exps; idx++ ) {
+      FillLocArray( idx,  sfn->stack(jvms, idx), exparray );
+    }
+
+    // Add in mappings of the monitors
+    assert( !method ||
+            !method->is_synchronized() ||
+            method->is_native() ||
+            num_mon > 0 ||
+            !GenerateSynchronizationCode,
+            "monitors must always exist for synchronized methods");
+
+    // Build the growable array of ScopeValues for exp stack
+    GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
+
+    // Loop over monitors and insert into array
+    for(idx = 0; idx < num_mon; idx++) {
+      // Grab the node that defines this monitor
+      Node* box_node;
+      Node* obj_node;
+      box_node = sfn->monitor_box(jvms, idx);
+      obj_node = sfn->monitor_obj(jvms, idx);
+
+      // Create ScopeValue for object
+      ScopeValue *scval = NULL;
+      if( !obj_node->is_Con() ) {
+        OptoReg::Name obj_reg = _regalloc->get_reg_first(obj_node);
+        scval = new_loc_value( _regalloc, obj_reg, Location::oop );
+      } else {
+        scval = new ConstantOopWriteValue(obj_node->bottom_type()->is_instptr()->const_oop()->encoding());
+      }
+
+      OptoReg::Name box_reg = BoxLockNode::stack_slot(box_node);
+      monarray->append(new MonitorValue(scval, Location::new_stk_loc(Location::normal,_regalloc->reg2offset(box_reg))));
+    }
+
+    // Build first class objects to pass to scope
+    DebugToken *locvals = debug_info()->create_scope_values(locarray);
+    DebugToken *expvals = debug_info()->create_scope_values(exparray);
+    DebugToken *monvals = debug_info()->create_monitor_values(monarray);
+
+    // Make method available for all Safepoints
+    ciMethod* scope_method = method ? method : _method;
+    // Describe the scope here
+    assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
+    debug_info()->describe_scope(safepoint_pc_offset,scope_method,jvms->bci(),locvals,expvals,monvals);
+  } // End jvms loop
+
+  // Mark the end of the scope set.
+  debug_info()->end_safepoint(safepoint_pc_offset);
+}
+
+
+
+// A simplified version of Process_OopMap_Node, to handle non-safepoints.
+class NonSafepointEmitter {
+  Compile*  C;
+  JVMState* _pending_jvms;
+  int       _pending_offset;
+
+  void emit_non_safepoint();
+
+ public:
+  NonSafepointEmitter(Compile* compile) {
+    this->C = compile;
+    _pending_jvms = NULL;
+    _pending_offset = 0;
+  }
+
+  void observe_instruction(Node* n, int pc_offset) {
+    if (!C->debug_info()->recording_non_safepoints())  return;
+
+    Node_Notes* nn = C->node_notes_at(n->_idx);
+    if (nn == NULL || nn->jvms() == NULL)  return;
+    if (_pending_jvms != NULL &&
+        _pending_jvms->same_calls_as(nn->jvms())) {
+      // Repeated JVMS?  Stretch it up here.
+      _pending_offset = pc_offset;
+    } else {
+      if (_pending_jvms != NULL &&
+          _pending_offset < pc_offset) {
+        emit_non_safepoint();
+      }
+      _pending_jvms = NULL;
+      if (pc_offset > C->debug_info()->last_pc_offset()) {
+        // This is the only way _pending_jvms can become non-NULL:
+        _pending_jvms = nn->jvms();
+        _pending_offset = pc_offset;
+      }
+    }
+  }
+
+  // Stay out of the way of real safepoints:
+  void observe_safepoint(JVMState* jvms, int pc_offset) {
+    if (_pending_jvms != NULL &&
+        !_pending_jvms->same_calls_as(jvms) &&
+        _pending_offset < pc_offset) {
+      emit_non_safepoint();
+    }
+    _pending_jvms = NULL;
+  }
+
+  void flush_at_end() {
+    if (_pending_jvms != NULL) {
+      emit_non_safepoint();
+    }
+    _pending_jvms = NULL;
+  }
+};
+
+void NonSafepointEmitter::emit_non_safepoint() {
+  JVMState* youngest_jvms = _pending_jvms;
+  int       pc_offset     = _pending_offset;
+
+  // Clear it now:
+  _pending_jvms = NULL;
+
+  DebugInformationRecorder* debug_info = C->debug_info();
+  assert(debug_info->recording_non_safepoints(), "sanity");
+
+  debug_info->add_non_safepoint(pc_offset);
+  int max_depth = youngest_jvms->depth();
+
+  // Visit scopes from oldest to youngest.
+  for (int depth = 1; depth <= max_depth; depth++) {
+    JVMState* jvms = youngest_jvms->of_depth(depth);
+    ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
+    debug_info->describe_scope(pc_offset, method, jvms->bci());
+  }
+
+  // Mark the end of the scope set.
+  debug_info->end_non_safepoint(pc_offset);
+}
+
+
+
+// helper for Fill_buffer bailout logic
+static void turn_off_compiler(Compile* C) {
+  if (CodeCache::unallocated_capacity() >= CodeCacheMinimumFreeSpace*10) {
+    // Do not turn off compilation if a single giant method has
+    // blown the code cache size.
+    C->record_failure("excessive request to CodeCache");
+  } else {
+    UseInterpreter            = true;
+    UseCompiler               = false;
+    AlwaysCompileLoopMethods  = false;
+    C->record_failure("CodeCache is full");
+    warning("CodeCache is full. Compiling has been disabled");
+  }
+}
+
+
+//------------------------------Fill_buffer------------------------------------
+void Compile::Fill_buffer() {
+
+  // Set the initially allocated size
+  int  code_req   = initial_code_capacity;
+  int  locs_req   = initial_locs_capacity;
+  int  stub_req   = TraceJumps ? initial_stub_capacity * 10 : initial_stub_capacity;
+  int  const_req  = initial_const_capacity;
+  bool labels_not_set = true;
+
+  int  pad_req    = NativeCall::instruction_size;
+  // The extra spacing after the code is necessary on some platforms.
+  // Sometimes we need to patch in a jump after the last instruction,
+  // if the nmethod has been deoptimized.  (See 4932387, 4894843.)
+
+  uint i;
+  // Compute the byte offset where we can store the deopt pc.
+  if (fixed_slots() != 0) {
+    _orig_pc_slot_offset_in_bytes = _regalloc->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
+  }
+
+  // Compute prolog code size
+  _method_size = 0;
+  _frame_slots = OptoReg::reg2stack(_matcher->_old_SP)+_regalloc->_framesize;
+#ifdef IA64
+  if (save_argument_registers()) {
+    // 4815101: this is a stub with implicit and unknown precision fp args.
+    // The usual spill mechanism can only generate stfd's in this case, which
+    // doesn't work if the fp reg to spill contains a single-precision denorm.
+    // Instead, we hack around the normal spill mechanism using stfspill's and
+    // ldffill's in the MachProlog and MachEpilog emit methods.  We allocate
+    // space here for the fp arg regs (f8-f15) we're going to thusly spill.
+    //
+    // If we ever implement 16-byte 'registers' == stack slots, we can
+    // get rid of this hack and have SpillCopy generate stfspill/ldffill
+    // instead of stfd/stfs/ldfd/ldfs.
+    _frame_slots += 8*(16/BytesPerInt);
+  }
+#endif
+  assert( _frame_slots >= 0 && _frame_slots < 1000000, "sanity check" );
+
+  // Create an array of unused labels, one for each basic block
+  Label *blk_labels = NEW_RESOURCE_ARRAY(Label, _cfg->_num_blocks+1);
+
+  for( i=0; i <= _cfg->_num_blocks; i++ ) {
+    blk_labels[i].init();
+  }
+
+  // If this machine supports different size branch offsets, then pre-compute
+  // the length of the blocks
+  if( _matcher->is_short_branch_offset(0) ) {
+    Shorten_branches(blk_labels, code_req, locs_req, stub_req, const_req);
+    labels_not_set = false;
+  }
+
+  // nmethod and CodeBuffer count stubs & constants as part of method's code.
+  int exception_handler_req = size_exception_handler();
+  int deopt_handler_req = size_deopt_handler();
+  exception_handler_req += MAX_stubs_size; // add marginal slop for handler
+  deopt_handler_req += MAX_stubs_size; // add marginal slop for handler
+  stub_req += MAX_stubs_size;   // ensure per-stub margin
+  code_req += MAX_inst_size;    // ensure per-instruction margin
+  if (StressCodeBuffers)
+    code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10;  // force expansion
+  int total_req = code_req + pad_req + stub_req + exception_handler_req + deopt_handler_req + const_req;
+  CodeBuffer* cb = code_buffer();
+  cb->initialize(total_req, locs_req);
+
+  // Have we run out of code space?
+  if (cb->blob() == NULL) {
+    turn_off_compiler(this);
+    return;
+  }
+  // Configure the code buffer.
+  cb->initialize_consts_size(const_req);
+  cb->initialize_stubs_size(stub_req);
+  cb->initialize_oop_recorder(env()->oop_recorder());
+
+  // fill in the nop array for bundling computations
+  MachNode *_nop_list[Bundle::_nop_count];
+  Bundle::initialize_nops(_nop_list, this);
+
+  // Create oopmap set.
+  _oop_map_set = new OopMapSet();
+
+  // !!!!! This preserves old handling of oopmaps for now
+  debug_info()->set_oopmaps(_oop_map_set);
+
+  // Count and start of implicit null check instructions
+  uint inct_cnt = 0;
+  uint *inct_starts = NEW_RESOURCE_ARRAY(uint, _cfg->_num_blocks+1);
+
+  // Count and start of calls
+  uint *call_returns = NEW_RESOURCE_ARRAY(uint, _cfg->_num_blocks+1);
+
+  uint  return_offset = 0;
+  MachNode *nop = new (this) MachNopNode();
+
+  int previous_offset = 0;
+  int current_offset  = 0;
+  int last_call_offset = -1;
+
+  // Create an array of unused labels, one for each basic block, if printing is enabled
+#ifndef PRODUCT
+  int *node_offsets      = NULL;
+  uint  node_offset_limit = unique();
+
+
+  if ( print_assembly() )
+    node_offsets         = NEW_RESOURCE_ARRAY(int, node_offset_limit);
+#endif
+
+  NonSafepointEmitter non_safepoints(this);  // emit non-safepoints lazily
+
+  // ------------------
+  // Now fill in the code buffer
+  Node *delay_slot = NULL;
+
+  for( i=0; i < _cfg->_num_blocks; i++ ) {
+    Block *b = _cfg->_blocks[i];
+
+    Node *head = b->head();
+
+    // If this block needs to start aligned (i.e, can be reached other
+    // than by falling-thru from the previous block), then force the
+    // start of a new bundle.
+    if( Pipeline::requires_bundling() && starts_bundle(head) )
+      cb->flush_bundle(true);
+
+    // Define the label at the beginning of the basic block
+    if( labels_not_set )
+      MacroAssembler(cb).bind( blk_labels[b->_pre_order] );
+
+    else
+      assert( blk_labels[b->_pre_order].loc_pos() == cb->code_size(),
+              "label position does not match code offset" );
+
+    uint last_inst = b->_nodes.size();
+
+    // Emit block normally, except for last instruction.
+    // Emit means "dump code bits into code buffer".
+    for( uint j = 0; j<last_inst; j++ ) {
+
+      // Get the node
+      Node* n = b->_nodes[j];
+
+      // See if delay slots are supported
+      if (valid_bundle_info(n) &&
+          node_bundling(n)->used_in_unconditional_delay()) {
+        assert(delay_slot == NULL, "no use of delay slot node");
+        assert(n->size(_regalloc) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
+
+        delay_slot = n;
+        continue;
+      }
+
+      // If this starts a new instruction group, then flush the current one
+      // (but allow split bundles)
+      if( Pipeline::requires_bundling() && starts_bundle(n) )
+        cb->flush_bundle(false);
+
+      // The following logic is duplicated in the code ifdeffed for
+      // ENABLE_ZAP_DEAD_LOCALS which apppears above in this file.  It
+      // should be factored out.  Or maybe dispersed to the nodes?
+
+      // Special handling for SafePoint/Call Nodes
+      bool is_mcall = false;
+      if( n->is_Mach() ) {
+        MachNode *mach = n->as_Mach();
+        is_mcall = n->is_MachCall();
+        bool is_sfn = n->is_MachSafePoint();
+
+        // If this requires all previous instructions be flushed, then do so
+        if( is_sfn || is_mcall || mach->alignment_required() != 1) {
+          cb->flush_bundle(true);
+          current_offset = cb->code_size();
+        }
+
+        // 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.
+        if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset ) {
+          padding = nop_size;
+        }
+        assert( labels_not_set || padding == 0, "instruction should already be aligned")
+
+        if(padding > 0) {
+          assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
+          int nops_cnt = padding / nop_size;
+          MachNode *nop = new (this) MachNopNode(nops_cnt);
+          b->_nodes.insert(j++, nop);
+          last_inst++;
+          _cfg->_bbs.map( nop->_idx, b );
+          nop->emit(*cb, _regalloc);
+          cb->flush_bundle(true);
+          current_offset = cb->code_size();
+        }
+
+        // Remember the start of the last call in a basic block
+        if (is_mcall) {
+          MachCallNode *mcall = mach->as_MachCall();
+
+          // This destination address is NOT PC-relative
+          mcall->method_set((intptr_t)mcall->entry_point());
+
+          // Save the return address
+          call_returns[b->_pre_order] = current_offset + mcall->ret_addr_offset();
+
+          if (!mcall->is_safepoint_node()) {
+            is_mcall = false;
+            is_sfn = false;
+          }
+        }
+
+        // sfn will be valid whenever mcall is valid now because of inheritance
+        if( is_sfn || is_mcall ) {
+
+          // Handle special safepoint nodes for synchronization
+          if( !is_mcall ) {
+            MachSafePointNode *sfn = mach->as_MachSafePoint();
+            // !!!!! Stubs only need an oopmap right now, so bail out
+            if( sfn->jvms()->method() == NULL) {
+              // Write the oopmap directly to the code blob??!!
+#             ifdef ENABLE_ZAP_DEAD_LOCALS
+              assert( !is_node_getting_a_safepoint(sfn),  "logic does not match; false positive");
+#             endif
+              continue;
+            }
+          } // End synchronization
+
+          non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
+                                           current_offset);
+          Process_OopMap_Node(mach, current_offset);
+        } // End if safepoint
+
+        // If this is a null check, then add the start of the previous instruction to the list
+        else if( mach->is_MachNullCheck() ) {
+          inct_starts[inct_cnt++] = previous_offset;
+        }
+
+        // If this is a branch, then fill in the label with the target BB's label
+        else if ( mach->is_Branch() ) {
+
+          if ( mach->ideal_Opcode() == Op_Jump ) {
+            for (uint h = 0; h < b->_num_succs; h++ ) {
+              Block* succs_block = b->_succs[h];
+              for (uint j = 1; j < succs_block->num_preds(); j++) {
+                Node* jpn = succs_block->pred(j);
+                if ( jpn->is_JumpProj() && jpn->in(0) == mach ) {
+                  uint block_num = succs_block->non_connector()->_pre_order;
+                  Label *blkLabel = &blk_labels[block_num];
+                  mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
+                }
+              }
+            }
+          } else {
+            // For Branchs
+            // This requires the TRUE branch target be in succs[0]
+            uint block_num = b->non_connector_successor(0)->_pre_order;
+            mach->label_set( blk_labels[block_num], block_num );
+          }
+        }
+
+#ifdef ASSERT
+        // Check that oop-store preceeds the card-mark
+        else if( mach->ideal_Opcode() == Op_StoreCM ) {
+          uint storeCM_idx = j;
+          Node *oop_store = mach->in(mach->_cnt);  // First precedence edge
+          assert( oop_store != NULL, "storeCM expects a precedence edge");
+          uint i4;
+          for( i4 = 0; i4 < last_inst; ++i4 ) {
+            if( b->_nodes[i4] == oop_store ) break;
+          }
+          // Note: This test can provide a false failure if other precedence
+          // edges have been added to the storeCMNode.
+          assert( i4 == last_inst || i4 < storeCM_idx, "CM card-mark executes before oop-store");
+        }
+#endif
+
+        else if( !n->is_Proj() ) {
+          // Remember the begining of the previous instruction, in case
+          // it's followed by a flag-kill and a null-check.  Happens on
+          // Intel all the time, with add-to-memory kind of opcodes.
+          previous_offset = current_offset;
+        }
+      }
+
+      // Verify that there is sufficient space remaining
+      cb->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
+      if (cb->blob() == NULL) {
+        turn_off_compiler(this);
+        return;
+      }
+
+      // Save the offset for the listing
+#ifndef PRODUCT
+      if( node_offsets && n->_idx < node_offset_limit )
+        node_offsets[n->_idx] = cb->code_size();
+#endif
+
+      // "Normal" instruction case
+      n->emit(*cb, _regalloc);
+      current_offset  = cb->code_size();
+      non_safepoints.observe_instruction(n, current_offset);
+
+      // mcall is last "call" that can be a safepoint
+      // record it so we can see if a poll will directly follow it
+      // in which case we'll need a pad to make the PcDesc sites unique
+      // see  5010568. This can be slightly inaccurate but conservative
+      // in the case that return address is not actually at current_offset.
+      // This is a small price to pay.
+
+      if (is_mcall) {
+        last_call_offset = current_offset;
+      }
+
+      // See if this instruction has a delay slot
+      if ( valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
+        assert(delay_slot != NULL, "expecting delay slot node");
+
+        // Back up 1 instruction
+        cb->set_code_end(
+          cb->code_end()-Pipeline::instr_unit_size());
+
+        // Save the offset for the listing
+#ifndef PRODUCT
+        if( node_offsets && delay_slot->_idx < node_offset_limit )
+          node_offsets[delay_slot->_idx] = cb->code_size();
+#endif
+
+        // Support a SafePoint in the delay slot
+        if( delay_slot->is_MachSafePoint() ) {
+          MachNode *mach = delay_slot->as_Mach();
+          // !!!!! Stubs only need an oopmap right now, so bail out
+          if( !mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == NULL ) {
+            // Write the oopmap directly to the code blob??!!
+#           ifdef ENABLE_ZAP_DEAD_LOCALS
+            assert( !is_node_getting_a_safepoint(mach),  "logic does not match; false positive");
+#           endif
+            delay_slot = NULL;
+            continue;
+          }
+
+          int adjusted_offset = current_offset - Pipeline::instr_unit_size();
+          non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
+                                           adjusted_offset);
+          // Generate an OopMap entry
+          Process_OopMap_Node(mach, adjusted_offset);
+        }
+
+        // Insert the delay slot instruction
+        delay_slot->emit(*cb, _regalloc);
+
+        // Don't reuse it
+        delay_slot = NULL;
+      }
+
+    } // End for all instructions in block
+
+    // If the next block _starts_ a loop, pad this block out to align
+    // the loop start a little. Helps prevent pipe stalls at loop starts
+    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);
+      if( padding > 0 ) {
+        MachNode *nop = new (this) MachNopNode(padding / nop_size);
+        b->_nodes.insert( b->_nodes.size(), nop );
+        _cfg->_bbs.map( nop->_idx, b );
+        nop->emit(*cb, _regalloc);
+        current_offset = cb->code_size();
+      }
+    }
+
+  } // End of for all blocks
+
+  non_safepoints.flush_at_end();
+
+  // Offset too large?
+  if (failing())  return;
+
+  // Define a pseudo-label at the end of the code
+  MacroAssembler(cb).bind( blk_labels[_cfg->_num_blocks] );
+
+  // Compute the size of the first block
+  _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
+
+  assert(cb->code_size() < 500000, "method is unreasonably large");
+
+  // ------------------
+
+#ifndef PRODUCT
+  // Information on the size of the method, without the extraneous code
+  Scheduling::increment_method_size(cb->code_size());
+#endif
+
+  // ------------------
+  // Fill in exception table entries.
+  FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
+
+  // Only java methods have exception handlers and deopt handlers
+  if (_method) {
+    // Emit the exception handler code.
+    _code_offsets.set_value(CodeOffsets::Exceptions, emit_exception_handler(*cb));
+    // Emit the deopt handler code.
+    _code_offsets.set_value(CodeOffsets::Deopt, emit_deopt_handler(*cb));
+  }
+
+  // One last check for failed CodeBuffer::expand:
+  if (cb->blob() == NULL) {
+    turn_off_compiler(this);
+    return;
+  }
+
+#ifndef PRODUCT
+  // Dump the assembly code, including basic-block numbers
+  if (print_assembly()) {
+    ttyLocker ttyl;  // keep the following output all in one block
+    if (!VMThread::should_terminate()) {  // test this under the tty lock
+      // This output goes directly to the tty, not the compiler log.
+      // To enable tools to match it up with the compilation activity,
+      // be sure to tag this tty output with the compile ID.
+      if (xtty != NULL) {
+        xtty->head("opto_assembly compile_id='%d'%s", compile_id(),
+                   is_osr_compilation()    ? " compile_kind='osr'" :
+                   "");
+      }
+      if (method() != NULL) {
+        method()->print_oop();
+        print_codes();
+      }
+      dump_asm(node_offsets, node_offset_limit);
+      if (xtty != NULL) {
+        xtty->tail("opto_assembly");
+      }
+    }
+  }
+#endif
+
+}
+
+void Compile::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
+  _inc_table.set_size(cnt);
+
+  uint inct_cnt = 0;
+  for( uint i=0; i<_cfg->_num_blocks; i++ ) {
+    Block *b = _cfg->_blocks[i];
+    Node *n = NULL;
+    int j;
+
+    // Find the branch; ignore trailing NOPs.
+    for( j = b->_nodes.size()-1; j>=0; j-- ) {
+      n = b->_nodes[j];
+      if( !n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con )
+        break;
+    }
+
+    // If we didn't find anything, continue
+    if( j < 0 ) continue;
+
+    // Compute ExceptionHandlerTable subtable entry and add it
+    // (skip empty blocks)
+    if( n->is_Catch() ) {
+
+      // Get the offset of the return from the call
+      uint call_return = call_returns[b->_pre_order];
+#ifdef ASSERT
+      assert( call_return > 0, "no call seen for this basic block" );
+      while( b->_nodes[--j]->Opcode() == Op_MachProj ) ;
+      assert( b->_nodes[j]->is_Call(), "CatchProj must follow call" );
+#endif
+      // last instruction is a CatchNode, find it's CatchProjNodes
+      int nof_succs = b->_num_succs;
+      // allocate space
+      GrowableArray<intptr_t> handler_bcis(nof_succs);
+      GrowableArray<intptr_t> handler_pcos(nof_succs);
+      // iterate through all successors
+      for (int j = 0; j < nof_succs; j++) {
+        Block* s = b->_succs[j];
+        bool found_p = false;
+        for( uint k = 1; k < s->num_preds(); k++ ) {
+          Node *pk = s->pred(k);
+          if( pk->is_CatchProj() && pk->in(0) == n ) {
+            const CatchProjNode* p = pk->as_CatchProj();
+            found_p = true;
+            // add the corresponding handler bci & pco information
+            if( p->_con != CatchProjNode::fall_through_index ) {
+              // p leads to an exception handler (and is not fall through)
+              assert(s == _cfg->_blocks[s->_pre_order],"bad numbering");
+              // no duplicates, please
+              if( !handler_bcis.contains(p->handler_bci()) ) {
+                uint block_num = s->non_connector()->_pre_order;
+                handler_bcis.append(p->handler_bci());
+                handler_pcos.append(blk_labels[block_num].loc_pos());
+              }
+            }
+          }
+        }
+        assert(found_p, "no matching predecessor found");
+        // Note:  Due to empty block removal, one block may have
+        // several CatchProj inputs, from the same Catch.
+      }
+
+      // Set the offset of the return from the call
+      _handler_table.add_subtable(call_return, &handler_bcis, NULL, &handler_pcos);
+      continue;
+    }
+
+    // Handle implicit null exception table updates
+    if( n->is_MachNullCheck() ) {
+      uint block_num = b->non_connector_successor(0)->_pre_order;
+      _inc_table.append( inct_starts[inct_cnt++], blk_labels[block_num].loc_pos() );
+      continue;
+    }
+  } // End of for all blocks fill in exception table entries
+}
+
+// Static Variables
+#ifndef PRODUCT
+uint Scheduling::_total_nop_size = 0;
+uint Scheduling::_total_method_size = 0;
+uint Scheduling::_total_branches = 0;
+uint Scheduling::_total_unconditional_delays = 0;
+uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
+#endif
+
+// Initializer for class Scheduling
+
+Scheduling::Scheduling(Arena *arena, Compile &compile)
+  : _arena(arena),
+    _cfg(compile.cfg()),
+    _bbs(compile.cfg()->_bbs),
+    _regalloc(compile.regalloc()),
+    _reg_node(arena),
+    _bundle_instr_count(0),
+    _bundle_cycle_number(0),
+    _scheduled(arena),
+    _available(arena),
+    _next_node(NULL),
+    _bundle_use(0, 0, resource_count, &_bundle_use_elements[0]),
+    _pinch_free_list(arena)
+#ifndef PRODUCT
+  , _branches(0)
+  , _unconditional_delays(0)
+#endif
+{
+  // Create a MachNopNode
+  _nop = new (&compile) MachNopNode();
+
+  // Now that the nops are in the array, save the count
+  // (but allow entries for the nops)
+  _node_bundling_limit = compile.unique();
+  uint node_max = _regalloc->node_regs_max_index();
+
+  compile.set_node_bundling_limit(_node_bundling_limit);
+
+  // This one is persistant within the Compile class
+  _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
+
+  // Allocate space for fixed-size arrays
+  _node_latency    = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
+  _uses            = NEW_ARENA_ARRAY(arena, short,          node_max);
+  _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
+
+  // Clear the arrays
+  memset(_node_bundling_base, 0, node_max * sizeof(Bundle));
+  memset(_node_latency,       0, node_max * sizeof(unsigned short));
+  memset(_uses,               0, node_max * sizeof(short));
+  memset(_current_latency,    0, node_max * sizeof(unsigned short));
+
+  // Clear the bundling information
+  memcpy(_bundle_use_elements,
+    Pipeline_Use::elaborated_elements,
+    sizeof(Pipeline_Use::elaborated_elements));
+
+  // Get the last node
+  Block *bb = _cfg->_blocks[_cfg->_blocks.size()-1];
+
+  _next_node = bb->_nodes[bb->_nodes.size()-1];
+}
+
+#ifndef PRODUCT
+// Scheduling destructor
+Scheduling::~Scheduling() {
+  _total_branches             += _branches;
+  _total_unconditional_delays += _unconditional_delays;
+}
+#endif
+
+// Step ahead "i" cycles
+void Scheduling::step(uint i) {
+
+  Bundle *bundle = node_bundling(_next_node);
+  bundle->set_starts_bundle();
+
+  // Update the bundle record, but leave the flags information alone
+  if (_bundle_instr_count > 0) {
+    bundle->set_instr_count(_bundle_instr_count);
+    bundle->set_resources_used(_bundle_use.resourcesUsed());
+  }
+
+  // Update the state information
+  _bundle_instr_count = 0;
+  _bundle_cycle_number += i;
+  _bundle_use.step(i);
+}
+
+void Scheduling::step_and_clear() {
+  Bundle *bundle = node_bundling(_next_node);
+  bundle->set_starts_bundle();
+
+  // Update the bundle record
+  if (_bundle_instr_count > 0) {
+    bundle->set_instr_count(_bundle_instr_count);
+    bundle->set_resources_used(_bundle_use.resourcesUsed());
+
+    _bundle_cycle_number += 1;
+  }
+
+  // Clear the bundling information
+  _bundle_instr_count = 0;
+  _bundle_use.reset();
+
+  memcpy(_bundle_use_elements,
+    Pipeline_Use::elaborated_elements,
+    sizeof(Pipeline_Use::elaborated_elements));
+}
+
+//------------------------------ScheduleAndBundle------------------------------
+// Perform instruction scheduling and bundling over the sequence of
+// instructions in backwards order.
+void Compile::ScheduleAndBundle() {
+
+  // Don't optimize this if it isn't a method
+  if (!_method)
+    return;
+
+  // Don't optimize this if scheduling is disabled
+  if (!do_scheduling())
+    return;
+
+  NOT_PRODUCT( TracePhase t2("isched", &_t_instrSched, TimeCompiler); )
+
+  // Create a data structure for all the scheduling information
+  Scheduling scheduling(Thread::current()->resource_area(), *this);
+
+  // Walk backwards over each basic block, computing the needed alignment
+  // Walk over all the basic blocks
+  scheduling.DoScheduling();
+}
+
+//------------------------------ComputeLocalLatenciesForward-------------------
+// Compute the latency of all the instructions.  This is fairly simple,
+// because we already have a legal ordering.  Walk over the instructions
+// from first to last, and compute the latency of the instruction based
+// on the latency of the preceeding instruction(s).
+void Scheduling::ComputeLocalLatenciesForward(const Block *bb) {
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output())
+    tty->print("# -> ComputeLocalLatenciesForward\n");
+#endif
+
+  // Walk over all the schedulable instructions
+  for( uint j=_bb_start; j < _bb_end; j++ ) {
+
+    // This is a kludge, forcing all latency calculations to start at 1.
+    // Used to allow latency 0 to force an instruction to the beginning
+    // of the bb
+    uint latency = 1;
+    Node *use = bb->_nodes[j];
+    uint nlen = use->len();
+
+    // Walk over all the inputs
+    for ( uint k=0; k < nlen; k++ ) {
+      Node *def = use->in(k);
+      if (!def)
+        continue;
+
+      uint l = _node_latency[def->_idx] + use->latency(k);
+      if (latency < l)
+        latency = l;
+    }
+
+    _node_latency[use->_idx] = latency;
+
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output()) {
+      tty->print("# latency %4d: ", latency);
+      use->dump();
+    }
+#endif
+  }
+
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output())
+    tty->print("# <- ComputeLocalLatenciesForward\n");
+#endif
+
+} // end ComputeLocalLatenciesForward
+
+// See if this node fits into the present instruction bundle
+bool Scheduling::NodeFitsInBundle(Node *n) {
+  uint n_idx = n->_idx;
+
+  // If this is the unconditional delay instruction, then it fits
+  if (n == _unconditional_delay_slot) {
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output())
+      tty->print("#     NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
+#endif
+    return (true);
+  }
+
+  // If the node cannot be scheduled this cycle, skip it
+  if (_current_latency[n_idx] > _bundle_cycle_number) {
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output())
+      tty->print("#     NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
+        n->_idx, _current_latency[n_idx], _bundle_cycle_number);
+#endif
+    return (false);
+  }
+
+  const Pipeline *node_pipeline = n->pipeline();
+
+  uint instruction_count = node_pipeline->instructionCount();
+  if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
+    instruction_count = 0;
+  else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
+    instruction_count++;
+
+  if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output())
+      tty->print("#     NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
+        n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
+#endif
+    return (false);
+  }
+
+  // Don't allow non-machine nodes to be handled this way
+  if (!n->is_Mach() && instruction_count == 0)
+    return (false);
+
+  // See if there is any overlap
+  uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
+
+  if (delay > 0) {
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output())
+      tty->print("#     NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
+#endif
+    return false;
+  }
+
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output())
+    tty->print("#     NodeFitsInBundle [%4d]:  TRUE\n", n_idx);
+#endif
+
+  return true;
+}
+
+Node * Scheduling::ChooseNodeToBundle() {
+  uint siz = _available.size();
+
+  if (siz == 0) {
+
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output())
+      tty->print("#   ChooseNodeToBundle: NULL\n");
+#endif
+    return (NULL);
+  }
+
+  // Fast path, if only 1 instruction in the bundle
+  if (siz == 1) {
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output()) {
+      tty->print("#   ChooseNodeToBundle (only 1): ");
+      _available[0]->dump();
+    }
+#endif
+    return (_available[0]);
+  }
+
+  // Don't bother, if the bundle is already full
+  if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
+    for ( uint i = 0; i < siz; i++ ) {
+      Node *n = _available[i];
+
+      // Skip projections, we'll handle them another way
+      if (n->is_Proj())
+        continue;
+
+      // This presupposed that instructions are inserted into the
+      // available list in a legality order; i.e. instructions that
+      // must be inserted first are at the head of the list
+      if (NodeFitsInBundle(n)) {
+#ifndef PRODUCT
+        if (_cfg->C->trace_opto_output()) {
+          tty->print("#   ChooseNodeToBundle: ");
+          n->dump();
+        }
+#endif
+        return (n);
+      }
+    }
+  }
+
+  // Nothing fits in this bundle, choose the highest priority
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output()) {
+    tty->print("#   ChooseNodeToBundle: ");
+    _available[0]->dump();
+  }
+#endif
+
+  return _available[0];
+}
+
+//------------------------------AddNodeToAvailableList-------------------------
+void Scheduling::AddNodeToAvailableList(Node *n) {
+  assert( !n->is_Proj(), "projections never directly made available" );
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output()) {
+    tty->print("#   AddNodeToAvailableList: ");
+    n->dump();
+  }
+#endif
+
+  int latency = _current_latency[n->_idx];
+
+  // Insert in latency order (insertion sort)
+  uint i;
+  for ( i=0; i < _available.size(); i++ )
+    if (_current_latency[_available[i]->_idx] > latency)
+      break;
+
+  // Special Check for compares following branches
+  if( n->is_Mach() && _scheduled.size() > 0 ) {
+    int op = n->as_Mach()->ideal_Opcode();
+    Node *last = _scheduled[0];
+    if( last->is_MachIf() && last->in(1) == n &&
+        ( op == Op_CmpI ||
+          op == Op_CmpU ||
+          op == Op_CmpP ||
+          op == Op_CmpF ||
+          op == Op_CmpD ||
+          op == Op_CmpL ) ) {
+
+      // Recalculate position, moving to front of same latency
+      for ( i=0 ; i < _available.size(); i++ )
+        if (_current_latency[_available[i]->_idx] >= latency)
+          break;
+    }
+  }
+
+  // Insert the node in the available list
+  _available.insert(i, n);
+
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output())
+    dump_available();
+#endif
+}
+
+//------------------------------DecrementUseCounts-----------------------------
+void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
+  for ( uint i=0; i < n->len(); i++ ) {
+    Node *def = n->in(i);
+    if (!def) continue;
+    if( def->is_Proj() )        // If this is a machine projection, then
+      def = def->in(0);         // propagate usage thru to the base instruction
+
+    if( _bbs[def->_idx] != bb ) // Ignore if not block-local
+      continue;
+
+    // Compute the latency
+    uint l = _bundle_cycle_number + n->latency(i);
+    if (_current_latency[def->_idx] < l)
+      _current_latency[def->_idx] = l;
+
+    // If this does not have uses then schedule it
+    if ((--_uses[def->_idx]) == 0)
+      AddNodeToAvailableList(def);
+  }
+}
+
+//------------------------------AddNodeToBundle--------------------------------
+void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output()) {
+    tty->print("#   AddNodeToBundle: ");
+    n->dump();
+  }
+#endif
+
+  // Remove this from the available list
+  uint i;
+  for (i = 0; i < _available.size(); i++)
+    if (_available[i] == n)
+      break;
+  assert(i < _available.size(), "entry in _available list not found");
+  _available.remove(i);
+
+  // See if this fits in the current bundle
+  const Pipeline *node_pipeline = n->pipeline();
+  const Pipeline_Use& node_usage = node_pipeline->resourceUse();
+
+  // Check for instructions to be placed in the delay slot. We
+  // do this before we actually schedule the current instruction,
+  // because the delay slot follows the current instruction.
+  if (Pipeline::_branch_has_delay_slot &&
+      node_pipeline->hasBranchDelay() &&
+      !_unconditional_delay_slot) {
+
+    uint siz = _available.size();
+
+    // Conditional branches can support an instruction that
+    // is unconditionally executed and not dependant by the
+    // branch, OR a conditionally executed instruction if
+    // the branch is taken.  In practice, this means that
+    // the first instruction at the branch target is
+    // copied to the delay slot, and the branch goes to
+    // the instruction after that at the branch target
+    if ( n->is_Mach() && n->is_Branch() ) {
+
+      assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
+      assert( !n->is_Catch(),         "should not look for delay slot for Catch" );
+
+#ifndef PRODUCT
+      _branches++;
+#endif
+
+      // At least 1 instruction is on the available list
+      // that is not dependant on the branch
+      for (uint i = 0; i < siz; i++) {
+        Node *d = _available[i];
+        const Pipeline *avail_pipeline = d->pipeline();
+
+        // Don't allow safepoints in the branch shadow, that will
+        // cause a number of difficulties
+        if ( avail_pipeline->instructionCount() == 1 &&
+            !avail_pipeline->hasMultipleBundles() &&
+            !avail_pipeline->hasBranchDelay() &&
+            Pipeline::instr_has_unit_size() &&
+            d->size(_regalloc) == Pipeline::instr_unit_size() &&
+            NodeFitsInBundle(d) &&
+            !node_bundling(d)->used_in_delay()) {
+
+          if (d->is_Mach() && !d->is_MachSafePoint()) {
+            // A node that fits in the delay slot was found, so we need to
+            // set the appropriate bits in the bundle pipeline information so
+            // that it correctly indicates resource usage.  Later, when we
+            // attempt to add this instruction to the bundle, we will skip
+            // setting the resource usage.
+            _unconditional_delay_slot = d;
+            node_bundling(n)->set_use_unconditional_delay();
+            node_bundling(d)->set_used_in_unconditional_delay();
+            _bundle_use.add_usage(avail_pipeline->resourceUse());
+            _current_latency[d->_idx] = _bundle_cycle_number;
+            _next_node = d;
+            ++_bundle_instr_count;
+#ifndef PRODUCT
+            _unconditional_delays++;
+#endif
+            break;
+          }
+        }
+      }
+    }
+
+    // No delay slot, add a nop to the usage
+    if (!_unconditional_delay_slot) {
+      // See if adding an instruction in the delay slot will overflow
+      // the bundle.
+      if (!NodeFitsInBundle(_nop)) {
+#ifndef PRODUCT
+        if (_cfg->C->trace_opto_output())
+          tty->print("#  *** STEP(1 instruction for delay slot) ***\n");
+#endif
+        step(1);
+      }
+
+      _bundle_use.add_usage(_nop->pipeline()->resourceUse());
+      _next_node = _nop;
+      ++_bundle_instr_count;
+    }
+
+    // See if the instruction in the delay slot requires a
+    // step of the bundles
+    if (!NodeFitsInBundle(n)) {
+#ifndef PRODUCT
+        if (_cfg->C->trace_opto_output())
+          tty->print("#  *** STEP(branch won't fit) ***\n");
+#endif
+        // Update the state information
+        _bundle_instr_count = 0;
+        _bundle_cycle_number += 1;
+        _bundle_use.step(1);
+    }
+  }
+
+  // Get the number of instructions
+  uint instruction_count = node_pipeline->instructionCount();
+  if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
+    instruction_count = 0;
+
+  // Compute the latency information
+  uint delay = 0;
+
+  if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
+    int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
+    if (relative_latency < 0)
+      relative_latency = 0;
+
+    delay = _bundle_use.full_latency(relative_latency, node_usage);
+
+    // Does not fit in this bundle, start a new one
+    if (delay > 0) {
+      step(delay);
+
+#ifndef PRODUCT
+      if (_cfg->C->trace_opto_output())
+        tty->print("#  *** STEP(%d) ***\n", delay);
+#endif
+    }
+  }
+
+  // If this was placed in the delay slot, ignore it
+  if (n != _unconditional_delay_slot) {
+
+    if (delay == 0) {
+      if (node_pipeline->hasMultipleBundles()) {
+#ifndef PRODUCT
+        if (_cfg->C->trace_opto_output())
+          tty->print("#  *** STEP(multiple instructions) ***\n");
+#endif
+        step(1);
+      }
+
+      else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
+#ifndef PRODUCT
+        if (_cfg->C->trace_opto_output())
+          tty->print("#  *** STEP(%d >= %d instructions) ***\n",
+            instruction_count + _bundle_instr_count,
+            Pipeline::_max_instrs_per_cycle);
+#endif
+        step(1);
+      }
+    }
+
+    if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
+      _bundle_instr_count++;
+
+    // Set the node's latency
+    _current_latency[n->_idx] = _bundle_cycle_number;
+
+    // Now merge the functional unit information
+    if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
+      _bundle_use.add_usage(node_usage);
+
+    // Increment the number of instructions in this bundle
+    _bundle_instr_count += instruction_count;
+
+    // Remember this node for later
+    if (n->is_Mach())
+      _next_node = n;
+  }
+
+  // It's possible to have a BoxLock in the graph and in the _bbs mapping but
+  // not in the bb->_nodes array.  This happens for debug-info-only BoxLocks.
+  // 'Schedule' them (basically ignore in the schedule) but do not insert them
+  // into the block.  All other scheduled nodes get put in the schedule here.
+  int op = n->Opcode();
+  if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
+      (op != Op_Node &&         // Not an unused antidepedence node and
+       // not an unallocated boxlock
+       (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
+
+    // Push any trailing projections
+    if( bb->_nodes[bb->_nodes.size()-1] != n ) {
+      for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
+        Node *foi = n->fast_out(i);
+        if( foi->is_Proj() )
+          _scheduled.push(foi);
+      }
+    }
+
+    // Put the instruction in the schedule list
+    _scheduled.push(n);
+  }
+
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output())
+    dump_available();
+#endif
+
+  // Walk all the definitions, decrementing use counts, and
+  // if a definition has a 0 use count, place it in the available list.
+  DecrementUseCounts(n,bb);
+}
+
+//------------------------------ComputeUseCount--------------------------------
+// This method sets the use count within a basic block.  We will ignore all
+// uses outside the current basic block.  As we are doing a backwards walk,
+// any node we reach that has a use count of 0 may be scheduled.  This also
+// avoids the problem of cyclic references from phi nodes, as long as phi
+// nodes are at the front of the basic block.  This method also initializes
+// the available list to the set of instructions that have no uses within this
+// basic block.
+void Scheduling::ComputeUseCount(const Block *bb) {
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output())
+    tty->print("# -> ComputeUseCount\n");
+#endif
+
+  // Clear the list of available and scheduled instructions, just in case
+  _available.clear();
+  _scheduled.clear();
+
+  // No delay slot specified
+  _unconditional_delay_slot = NULL;
+
+#ifdef ASSERT
+  for( uint i=0; i < bb->_nodes.size(); i++ )
+    assert( _uses[bb->_nodes[i]->_idx] == 0, "_use array not clean" );
+#endif
+
+  // Force the _uses count to never go to zero for unscheduable pieces
+  // of the block
+  for( uint k = 0; k < _bb_start; k++ )
+    _uses[bb->_nodes[k]->_idx] = 1;
+  for( uint l = _bb_end; l < bb->_nodes.size(); l++ )
+    _uses[bb->_nodes[l]->_idx] = 1;
+
+  // Iterate backwards over the instructions in the block.  Don't count the
+  // branch projections at end or the block header instructions.
+  for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
+    Node *n = bb->_nodes[j];
+    if( n->is_Proj() ) continue; // Projections handled another way
+
+    // Account for all uses
+    for ( uint k = 0; k < n->len(); k++ ) {
+      Node *inp = n->in(k);
+      if (!inp) continue;
+      assert(inp != n, "no cycles allowed" );
+      if( _bbs[inp->_idx] == bb ) { // Block-local use?
+        if( inp->is_Proj() )    // Skip through Proj's
+          inp = inp->in(0);
+        ++_uses[inp->_idx];     // Count 1 block-local use
+      }
+    }
+
+    // If this instruction has a 0 use count, then it is available
+    if (!_uses[n->_idx]) {
+      _current_latency[n->_idx] = _bundle_cycle_number;
+      AddNodeToAvailableList(n);
+    }
+
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output()) {
+      tty->print("#   uses: %3d: ", _uses[n->_idx]);
+      n->dump();
+    }
+#endif
+  }
+
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output())
+    tty->print("# <- ComputeUseCount\n");
+#endif
+}
+
+// This routine performs scheduling on each basic block in reverse order,
+// using instruction latencies and taking into account function unit
+// availability.
+void Scheduling::DoScheduling() {
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output())
+    tty->print("# -> DoScheduling\n");
+#endif
+
+  Block *succ_bb = NULL;
+  Block *bb;
+
+  // Walk over all the basic blocks in reverse order
+  for( int i=_cfg->_num_blocks-1; i >= 0; succ_bb = bb, i-- ) {
+    bb = _cfg->_blocks[i];
+
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output()) {
+      tty->print("#  Schedule BB#%03d (initial)\n", i);
+      for (uint j = 0; j < bb->_nodes.size(); j++)
+        bb->_nodes[j]->dump();
+    }
+#endif
+
+    // On the head node, skip processing
+    if( bb == _cfg->_broot )
+      continue;
+
+    // Skip empty, connector blocks
+    if (bb->is_connector())
+      continue;
+
+    // If the following block is not the sole successor of
+    // this one, then reset the pipeline information
+    if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
+#ifndef PRODUCT
+      if (_cfg->C->trace_opto_output()) {
+        tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
+                   _next_node->_idx, _bundle_instr_count);
+      }
+#endif
+      step_and_clear();
+    }
+
+    // Leave untouched the starting instruction, any Phis, a CreateEx node
+    // or Top.  bb->_nodes[_bb_start] is the first schedulable instruction.
+    _bb_end = bb->_nodes.size()-1;
+    for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
+      Node *n = bb->_nodes[_bb_start];
+      // Things not matched, like Phinodes and ProjNodes don't get scheduled.
+      // Also, MachIdealNodes do not get scheduled
+      if( !n->is_Mach() ) continue;     // Skip non-machine nodes
+      MachNode *mach = n->as_Mach();
+      int iop = mach->ideal_Opcode();
+      if( iop == Op_CreateEx ) continue; // CreateEx is pinned
+      if( iop == Op_Con ) continue;      // Do not schedule Top
+      if( iop == Op_Node &&     // Do not schedule PhiNodes, ProjNodes
+          mach->pipeline() == MachNode::pipeline_class() &&
+          !n->is_SpillCopy() )  // Breakpoints, Prolog, etc
+        continue;
+      break;                    // Funny loop structure to be sure...
+    }
+    // Compute last "interesting" instruction in block - last instruction we
+    // might schedule.  _bb_end points just after last schedulable inst.  We
+    // normally schedule conditional branches (despite them being forced last
+    // in the block), because they have delay slots we can fill.  Calls all
+    // have their delay slots filled in the template expansions, so we don't
+    // bother scheduling them.
+    Node *last = bb->_nodes[_bb_end];
+    if( last->is_Catch() ||
+       (last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
+      // There must be a prior call.  Skip it.
+      while( !bb->_nodes[--_bb_end]->is_Call() ) {
+        assert( bb->_nodes[_bb_end]->is_Proj(), "skipping projections after expected call" );
+      }
+    } else if( last->is_MachNullCheck() ) {
+      // Backup so the last null-checked memory instruction is
+      // outside the schedulable range. Skip over the nullcheck,
+      // projection, and the memory nodes.
+      Node *mem = last->in(1);
+      do {
+        _bb_end--;
+      } while (mem != bb->_nodes[_bb_end]);
+    } else {
+      // Set _bb_end to point after last schedulable inst.
+      _bb_end++;
+    }
+
+    assert( _bb_start <= _bb_end, "inverted block ends" );
+
+    // Compute the register antidependencies for the basic block
+    ComputeRegisterAntidependencies(bb);
+    if (_cfg->C->failing())  return;  // too many D-U pinch points
+
+    // Compute intra-bb latencies for the nodes
+    ComputeLocalLatenciesForward(bb);
+
+    // Compute the usage within the block, and set the list of all nodes
+    // in the block that have no uses within the block.
+    ComputeUseCount(bb);
+
+    // Schedule the remaining instructions in the block
+    while ( _available.size() > 0 ) {
+      Node *n = ChooseNodeToBundle();
+      AddNodeToBundle(n,bb);
+    }
+
+    assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
+#ifdef ASSERT
+    for( uint l = _bb_start; l < _bb_end; l++ ) {
+      Node *n = bb->_nodes[l];
+      uint m;
+      for( m = 0; m < _bb_end-_bb_start; m++ )
+        if( _scheduled[m] == n )
+          break;
+      assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
+    }
+#endif
+
+    // Now copy the instructions (in reverse order) back to the block
+    for ( uint k = _bb_start; k < _bb_end; k++ )
+      bb->_nodes.map(k, _scheduled[_bb_end-k-1]);
+
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output()) {
+      tty->print("#  Schedule BB#%03d (final)\n", i);
+      uint current = 0;
+      for (uint j = 0; j < bb->_nodes.size(); j++) {
+        Node *n = bb->_nodes[j];
+        if( valid_bundle_info(n) ) {
+          Bundle *bundle = node_bundling(n);
+          if (bundle->instr_count() > 0 || bundle->flags() > 0) {
+            tty->print("*** Bundle: ");
+            bundle->dump();
+          }
+          n->dump();
+        }
+      }
+    }
+#endif
+#ifdef ASSERT
+  verify_good_schedule(bb,"after block local scheduling");
+#endif
+  }
+
+#ifndef PRODUCT
+  if (_cfg->C->trace_opto_output())
+    tty->print("# <- DoScheduling\n");
+#endif
+
+  // Record final node-bundling array location
+  _regalloc->C->set_node_bundling_base(_node_bundling_base);
+
+} // end DoScheduling
+
+//------------------------------verify_good_schedule---------------------------
+// Verify that no live-range used in the block is killed in the block by a
+// wrong DEF.  This doesn't verify live-ranges that span blocks.
+
+// Check for edge existence.  Used to avoid adding redundant precedence edges.
+static bool edge_from_to( Node *from, Node *to ) {
+  for( uint i=0; i<from->len(); i++ )
+    if( from->in(i) == to )
+      return true;
+  return false;
+}
+
+#ifdef ASSERT
+//------------------------------verify_do_def----------------------------------
+void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
+  // Check for bad kills
+  if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
+    Node *prior_use = _reg_node[def];
+    if( prior_use && !edge_from_to(prior_use,n) ) {
+      tty->print("%s = ",OptoReg::as_VMReg(def)->name());
+      n->dump();
+      tty->print_cr("...");
+      prior_use->dump();
+      assert_msg(edge_from_to(prior_use,n),msg);
+    }
+    _reg_node.map(def,NULL); // Kill live USEs
+  }
+}
+
+//------------------------------verify_good_schedule---------------------------
+void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
+
+  // Zap to something reasonable for the verify code
+  _reg_node.clear();
+
+  // Walk over the block backwards.  Check to make sure each DEF doesn't
+  // kill a live value (other than the one it's supposed to).  Add each
+  // USE to the live set.
+  for( uint i = b->_nodes.size()-1; i >= _bb_start; i-- ) {
+    Node *n = b->_nodes[i];
+    int n_op = n->Opcode();
+    if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
+      // Fat-proj kills a slew of registers
+      RegMask rm = n->out_RegMask();// Make local copy
+      while( rm.is_NotEmpty() ) {
+        OptoReg::Name kill = rm.find_first_elem();
+        rm.Remove(kill);
+        verify_do_def( n, kill, msg );
+      }
+    } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
+      // Get DEF'd registers the normal way
+      verify_do_def( n, _regalloc->get_reg_first(n), msg );
+      verify_do_def( n, _regalloc->get_reg_second(n), msg );
+    }
+
+    // Now make all USEs live
+    for( uint i=1; i<n->req(); i++ ) {
+      Node *def = n->in(i);
+      assert(def != 0, "input edge required");
+      OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
+      OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
+      if( OptoReg::is_valid(reg_lo) ) {
+        assert_msg(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), msg );
+        _reg_node.map(reg_lo,n);
+      }
+      if( OptoReg::is_valid(reg_hi) ) {
+        assert_msg(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), msg );
+        _reg_node.map(reg_hi,n);
+      }
+    }
+
+  }
+
+  // Zap to something reasonable for the Antidependence code
+  _reg_node.clear();
+}
+#endif
+
+// Conditionally add precedence edges.  Avoid putting edges on Projs.
+static void add_prec_edge_from_to( Node *from, Node *to ) {
+  if( from->is_Proj() ) {       // Put precedence edge on Proj's input
+    assert( from->req() == 1 && (from->len() == 1 || from->in(1)==0), "no precedence edges on projections" );
+    from = from->in(0);
+  }
+  if( from != to &&             // No cycles (for things like LD L0,[L0+4] )
+      !edge_from_to( from, to ) ) // Avoid duplicate edge
+    from->add_prec(to);
+}
+
+//------------------------------anti_do_def------------------------------------
+void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
+  if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
+    return;
+
+  Node *pinch = _reg_node[def_reg]; // Get pinch point
+  if( !pinch || _bbs[pinch->_idx] != b || // No pinch-point yet?
+      is_def ) {    // Check for a true def (not a kill)
+    _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
+    return;
+  }
+
+  Node *kill = def;             // Rename 'def' to more descriptive 'kill'
+  debug_only( def = (Node*)0xdeadbeef; )
+
+  // After some number of kills there _may_ be a later def
+  Node *later_def = NULL;
+
+  // Finding a kill requires a real pinch-point.
+  // Check for not already having a pinch-point.
+  // Pinch points are Op_Node's.
+  if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
+    later_def = pinch;            // Must be def/kill as optimistic pinch-point
+    if ( _pinch_free_list.size() > 0) {
+      pinch = _pinch_free_list.pop();
+    } else {
+      pinch = new (_cfg->C, 1) Node(1); // Pinch point to-be
+    }
+    if (pinch->_idx >= _regalloc->node_regs_max_index()) {
+      _cfg->C->record_method_not_compilable("too many D-U pinch points");
+      return;
+    }
+    _bbs.map(pinch->_idx,b);      // Pretend it's valid in this block (lazy init)
+    _reg_node.map(def_reg,pinch); // Record pinch-point
+    //_regalloc->set_bad(pinch->_idx); // Already initialized this way.
+    if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
+      pinch->init_req(0, _cfg->C->top());     // set not NULL for the next call
+      add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
+      later_def = NULL;           // and no later def
+    }
+    pinch->set_req(0,later_def);  // Hook later def so we can find it
+  } else {                        // Else have valid pinch point
+    if( pinch->in(0) )            // If there is a later-def
+      later_def = pinch->in(0);   // Get it
+  }
+
+  // Add output-dependence edge from later def to kill
+  if( later_def )               // If there is some original def
+    add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
+
+  // See if current kill is also a use, and so is forced to be the pinch-point.
+  if( pinch->Opcode() == Op_Node ) {
+    Node *uses = kill->is_Proj() ? kill->in(0) : kill;
+    for( uint i=1; i<uses->req(); i++ ) {
+      if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
+          _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
+        // Yes, found a use/kill pinch-point
+        pinch->set_req(0,NULL);  //
+        pinch->replace_by(kill); // Move anti-dep edges up
+        pinch = kill;
+        _reg_node.map(def_reg,pinch);
+        return;
+      }
+    }
+  }
+
+  // Add edge from kill to pinch-point
+  add_prec_edge_from_to(kill,pinch);
+}
+
+//------------------------------anti_do_use------------------------------------
+void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
+  if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
+    return;
+  Node *pinch = _reg_node[use_reg]; // Get pinch point
+  // Check for no later def_reg/kill in block
+  if( pinch && _bbs[pinch->_idx] == b &&
+      // Use has to be block-local as well
+      _bbs[use->_idx] == b ) {
+    if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
+        pinch->req() == 1 ) {   // pinch not yet in block?
+      pinch->del_req(0);        // yank pointer to later-def, also set flag
+      // Insert the pinch-point in the block just after the last use
+      b->_nodes.insert(b->find_node(use)+1,pinch);
+      _bb_end++;                // Increase size scheduled region in block
+    }
+
+    add_prec_edge_from_to(pinch,use);
+  }
+}
+
+//------------------------------ComputeRegisterAntidependences-----------------
+// We insert antidependences between the reads and following write of
+// allocated registers to prevent illegal code motion. Hopefully, the
+// number of added references should be fairly small, especially as we
+// are only adding references within the current basic block.
+void Scheduling::ComputeRegisterAntidependencies(Block *b) {
+
+#ifdef ASSERT
+  verify_good_schedule(b,"before block local scheduling");
+#endif
+
+  // A valid schedule, for each register independently, is an endless cycle
+  // of: a def, then some uses (connected to the def by true dependencies),
+  // then some kills (defs with no uses), finally the cycle repeats with a new
+  // def.  The uses are allowed to float relative to each other, as are the
+  // kills.  No use is allowed to slide past a kill (or def).  This requires
+  // antidependencies between all uses of a single def and all kills that
+  // follow, up to the next def.  More edges are redundant, because later defs
+  // & kills are already serialized with true or antidependencies.  To keep
+  // the edge count down, we add a 'pinch point' node if there's more than
+  // one use or more than one kill/def.
+
+  // We add dependencies in one bottom-up pass.
+
+  // For each instruction we handle it's DEFs/KILLs, then it's USEs.
+
+  // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
+  // register.  If not, we record the DEF/KILL in _reg_node, the
+  // register-to-def mapping.  If there is a prior DEF/KILL, we insert a
+  // "pinch point", a new Node that's in the graph but not in the block.
+  // We put edges from the prior and current DEF/KILLs to the pinch point.
+  // We put the pinch point in _reg_node.  If there's already a pinch point
+  // we merely add an edge from the current DEF/KILL to the pinch point.
+
+  // After doing the DEF/KILLs, we handle USEs.  For each used register, we
+  // put an edge from the pinch point to the USE.
+
+  // To be expedient, the _reg_node array is pre-allocated for the whole
+  // compilation.  _reg_node is lazily initialized; it either contains a NULL,
+  // or a valid def/kill/pinch-point, or a leftover node from some prior
+  // block.  Leftover node from some prior block is treated like a NULL (no
+  // prior def, so no anti-dependence needed).  Valid def is distinguished by
+  // it being in the current block.
+  bool fat_proj_seen = false;
+  uint last_safept = _bb_end-1;
+  Node* end_node         = (_bb_end-1 >= _bb_start) ? b->_nodes[last_safept] : NULL;
+  Node* last_safept_node = end_node;
+  for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
+    Node *n = b->_nodes[i];
+    int is_def = n->outcnt();   // def if some uses prior to adding precedence edges
+    if( n->Opcode() == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
+      // Fat-proj kills a slew of registers
+      // This can add edges to 'n' and obscure whether or not it was a def,
+      // hence the is_def flag.
+      fat_proj_seen = true;
+      RegMask rm = n->out_RegMask();// Make local copy
+      while( rm.is_NotEmpty() ) {
+        OptoReg::Name kill = rm.find_first_elem();
+        rm.Remove(kill);
+        anti_do_def( b, n, kill, is_def );
+      }
+    } else {
+      // Get DEF'd registers the normal way
+      anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
+      anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
+    }
+
+    // Check each register used by this instruction for a following DEF/KILL
+    // that must occur afterward and requires an anti-dependence edge.
+    for( uint j=0; j<n->req(); j++ ) {
+      Node *def = n->in(j);
+      if( def ) {
+        assert( def->Opcode() != Op_MachProj || def->ideal_reg() != MachProjNode::fat_proj, "" );
+        anti_do_use( b, n, _regalloc->get_reg_first(def) );
+        anti_do_use( b, n, _regalloc->get_reg_second(def) );
+      }
+    }
+    // Do not allow defs of new derived values to float above GC
+    // points unless the base is definitely available at the GC point.
+
+    Node *m = b->_nodes[i];
+
+    // Add precedence edge from following safepoint to use of derived pointer
+    if( last_safept_node != end_node &&
+        m != last_safept_node) {
+      for (uint k = 1; k < m->req(); k++) {
+        const Type *t = m->in(k)->bottom_type();
+        if( t->isa_oop_ptr() &&
+            t->is_ptr()->offset() != 0 ) {
+          last_safept_node->add_prec( m );
+          break;
+        }
+      }
+    }
+
+    if( n->jvms() ) {           // Precedence edge from derived to safept
+      // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
+      if( b->_nodes[last_safept] != last_safept_node ) {
+        last_safept = b->find_node(last_safept_node);
+      }
+      for( uint j=last_safept; j > i; j-- ) {
+        Node *mach = b->_nodes[j];
+        if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
+          mach->add_prec( n );
+      }
+      last_safept = i;
+      last_safept_node = m;
+    }
+  }
+
+  if (fat_proj_seen) {
+    // Garbage collect pinch nodes that were not consumed.
+    // They are usually created by a fat kill MachProj for a call.
+    garbage_collect_pinch_nodes();
+  }
+}
+
+//------------------------------garbage_collect_pinch_nodes-------------------------------
+
+// Garbage collect pinch nodes for reuse by other blocks.
+//
+// The block scheduler's insertion of anti-dependence
+// edges creates many pinch nodes when the block contains
+// 2 or more Calls.  A pinch node is used to prevent a
+// combinatorial explosion of edges.  If a set of kills for a
+// register is anti-dependent on a set of uses (or defs), rather
+// than adding an edge in the graph between each pair of kill
+// and use (or def), a pinch is inserted between them:
+//
+//            use1   use2  use3
+//                \   |   /
+//                 \  |  /
+//                  pinch
+//                 /  |  \
+//                /   |   \
+//            kill1 kill2 kill3
+//
+// One pinch node is created per register killed when
+// the second call is encountered during a backwards pass
+// over the block.  Most of these pinch nodes are never
+// wired into the graph because the register is never
+// used or def'ed in the block.
+//
+void Scheduling::garbage_collect_pinch_nodes() {
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
+#endif
+    int trace_cnt = 0;
+    for (uint k = 0; k < _reg_node.Size(); k++) {
+      Node* pinch = _reg_node[k];
+      if (pinch != NULL && pinch->Opcode() == Op_Node &&
+          // no predecence input edges
+          (pinch->req() == pinch->len() || pinch->in(pinch->req()) == NULL) ) {
+        cleanup_pinch(pinch);
+        _pinch_free_list.push(pinch);
+        _reg_node.map(k, NULL);
+#ifndef PRODUCT
+        if (_cfg->C->trace_opto_output()) {
+          trace_cnt++;
+          if (trace_cnt > 40) {
+            tty->print("\n");
+            trace_cnt = 0;
+          }
+          tty->print(" %d", pinch->_idx);
+        }
+#endif
+      }
+    }
+#ifndef PRODUCT
+    if (_cfg->C->trace_opto_output()) tty->print("\n");
+#endif
+}
+
+// Clean up a pinch node for reuse.
+void Scheduling::cleanup_pinch( Node *pinch ) {
+  assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
+
+  for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
+    Node* use = pinch->last_out(i);
+    uint uses_found = 0;
+    for (uint j = use->req(); j < use->len(); j++) {
+      if (use->in(j) == pinch) {
+        use->rm_prec(j);
+        uses_found++;
+      }
+    }
+    assert(uses_found > 0, "must be a precedence edge");
+    i -= uses_found;    // we deleted 1 or more copies of this edge
+  }
+  // May have a later_def entry
+  pinch->set_req(0, NULL);
+}
+
+//------------------------------print_statistics-------------------------------
+#ifndef PRODUCT
+
+void Scheduling::dump_available() const {
+  tty->print("#Availist  ");
+  for (uint i = 0; i < _available.size(); i++)
+    tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
+  tty->cr();
+}
+
+// Print Scheduling Statistics
+void Scheduling::print_statistics() {
+  // Print the size added by nops for bundling
+  tty->print("Nops added %d bytes to total of %d bytes",
+    _total_nop_size, _total_method_size);
+  if (_total_method_size > 0)
+    tty->print(", for %.2f%%",
+      ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
+  tty->print("\n");
+
+  // Print the number of branch shadows filled
+  if (Pipeline::_branch_has_delay_slot) {
+    tty->print("Of %d branches, %d had unconditional delay slots filled",
+      _total_branches, _total_unconditional_delays);
+    if (_total_branches > 0)
+      tty->print(", for %.2f%%",
+        ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
+    tty->print("\n");
+  }
+
+  uint total_instructions = 0, total_bundles = 0;
+
+  for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
+    uint bundle_count   = _total_instructions_per_bundle[i];
+    total_instructions += bundle_count * i;
+    total_bundles      += bundle_count;
+  }
+
+  if (total_bundles > 0)
+    tty->print("Average ILP (excluding nops) is %.2f\n",
+      ((double)total_instructions) / ((double)total_bundles));
+}
+#endif