Inlining monomorphic calls.

runtime/vm/flow_graph.cc

 // Copyright (c) 2012, 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/flow_graph.h"
 
 #include "vm/bit_vector.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/intermediate_language.h"
 #include "vm/longjump.h"
@@ skipping 735 matching lines @@
 // Helper to link two instructions in the graph.
 static void Link(Instruction* prev, Instruction* next) {
   ASSERT(prev != next);
   prev->set_next(next);
   next->set_previous(prev);
 }
 
 
 // Inline a flow graph at a call site.
 //
-// Assumes the callee graph was computed with BuildGraphForInlining and
-// transformed to SSA with ComputeSSAForInlining, and that the use lists have
-// been correctly computed.
+// Assumes the callee graph was computed by BuildGraph with an inlining context
+// and transformed to SSA with ComputeSSA with a correct virtual register
+// number, and that the use lists have been correctly computed.
 //
 // After inlining the caller graph will correctly have adjusted the pre/post
 // orders, the dominator tree and the use lists.
-void FlowGraph::InlineCall(StaticCallInstr* call, FlowGraph* callee_graph) {
+void FlowGraph::InlineCall(Definition* call, FlowGraph* callee_graph) {
   ASSERT(callee_graph->exits() != NULL);
   ASSERT(callee_graph->graph_entry()->SuccessorCount() == 1);
   ASSERT(callee_graph->max_virtual_register_number() >
          max_virtual_register_number());
 
   // TODO(zerny): Implement support for callee graphs with control flow.
   ASSERT(callee_graph->preorder().length() == 2);
 
   // Adjust the SSA temp index by the callee graph's index.
   current_ssa_temp_index_ = callee_graph->max_virtual_register_number();
 
+  BlockEntryInstr* caller_entry = GetBlockEntry(call);
   TargetEntryInstr* callee_entry = callee_graph->graph_entry()->normal_entry();
   ZoneGrowableArray<ReturnInstr*>* callee_exits = callee_graph->exits();
 
   // 1. Insert the callee graph into the caller graph.
-  if (callee_exits->length() == 1) {
+  if (callee_exits->length() == 0) {
+    // If no normal exits exist, inline and truncate the block after inlining.
+    Link(call->previous(), callee_entry->next());
+    caller_entry->set_last_instruction(callee_entry->last_instruction());
+  } else if (callee_exits->length() == 1) {
     ReturnInstr* exit = (*callee_exits)[0];
     // TODO(zerny): Support one exit graph containing control flow.
     ASSERT(callee_entry == GetBlockEntry(exit));
     // For just one exit, replace the uses and remove the call from the graph.
     call->ReplaceUsesWith(exit->value()->definition());
     Link(call->previous(), callee_entry->next());
     Link(exit->previous(), call->next());
   } else {
     // TODO(zerny): Support multiple exits.
     UNREACHABLE();
   }
 
   // TODO(zerny): Adjust pre/post orders.
   // TODO(zerny): Update dominator tree.
-
-  // Remove original arguments to the call.
-  for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
-    PushArgumentInstr* push = call->ArgumentAt(i);
-    push->ReplaceUsesWith(push->value()->definition());
-    push->RemoveFromGraph();
-  }
 }
 
 
 }  // namespace dart