Revert "Initial implementation of on-stack replacement (OSR)."

runtime/vm/intermediate_language.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/intermediate_language.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
@@ skipping 220 matching lines @@
 
 const Object& Value::BoundConstant() const {
   ASSERT(BindsToConstant());
   ConstantInstr* constant = definition()->AsConstant();
   ASSERT(constant != NULL);
   return constant->value();
 }
 
 
 GraphEntryInstr::GraphEntryInstr(const ParsedFunction& parsed_function,
-                                 TargetEntryInstr* normal_entry,
-                                 intptr_t osr_id)
+                                 TargetEntryInstr* normal_entry)
     : BlockEntryInstr(0, CatchClauseNode::kInvalidTryIndex),
       parsed_function_(parsed_function),
       normal_entry_(normal_entry),
       catch_entries_(),
       initial_definitions_(),
-      osr_id_(osr_id),
       spill_slot_count_(0),
       fixed_slot_count_(0) {
 }
 
 
 ConstantInstr* GraphEntryInstr::constant_null() {
   ASSERT(initial_definitions_.length() > 0);
   for (intptr_t i = 0; i < initial_definitions_.length(); ++i) {
     ConstantInstr* defn = initial_definitions_[i]->AsConstant();
     if (defn != NULL && defn->value().IsNull()) return defn;
@@ skipping 516 matching lines @@
                                          variable_count,
                                          fixed_parameter_count);
   }
 
   // 6. Assign postorder number and add the block entry to the list.
   set_postorder_number(postorder->length());
   postorder->Add(this);
 }
 
 
-bool BlockEntryInstr::PruneUnreachable(FlowGraphBuilder* builder,
-                                       GraphEntryInstr* graph_entry,
-                                       intptr_t osr_id,
-                                       BitVector* block_marks) {
-  // Search for the instruction with the OSR id.  Use a depth first search
-  // because basic blocks have not been discovered yet.  Prune unreachable
-  // blocks by replacing the normal entry with a jump to the block
-  // containing the OSR entry point.
-
-  // Do not visit blocks more than once.
-  if (block_marks->Contains(block_id())) return false;
-  block_marks->Add(block_id());
-
-  // Search this block for the OSR id.
-  Instruction* instr = this;
-  for (ForwardInstructionIterator it(this); !it.Done(); it.Advance()) {
-    instr = it.Current();
-    if (instr->GetDeoptId() == osr_id) {
-      // Sanity check that we found a stack check instruction.
-      ASSERT(instr->IsCheckStackOverflow());
-      // Loop stack check checks are always in join blocks so that they can
-      // be the target of a goto.
-      ASSERT(IsJoinEntry());
-      // The instruction should be the first instruction in the block so
-      // we can simply jump to the beginning of the block.
-      ASSERT(instr->previous() == this);
-
-      GotoInstr* goto_join = new GotoInstr(AsJoinEntry());
-      goto_join->deopt_id_ = deopt_id_;
-      graph_entry->normal_entry()->LinkTo(goto_join);
-      return true;
-    }
-  }
-
-  // Recursively search the successors.
-  for (intptr_t i = instr->SuccessorCount() - 1; i >= 0; --i) {
-    if (instr->SuccessorAt(i)->PruneUnreachable(builder,
-                                                graph_entry,
-                                                osr_id,
-                                                block_marks)) {
-      return true;
-    }
-  }
-  return false;
-}
-
-
 bool BlockEntryInstr::Dominates(BlockEntryInstr* other) const {
   // TODO(fschneider): Make this faster by e.g. storing dominators for each
   // block while computing the dominator tree.
   ASSERT(other != NULL);
   BlockEntryInstr* current = other;
   while (current != NULL && current != this) {
     current = current->dominator();
   }
   return current == this;
 }
@@ skipping 1700 matching lines @@
     default:
       UNREACHABLE();
   }
   return kPowRuntimeEntry;
 }
 
 
 #undef __
 
 }  // namespace dart