Remove push arguments and replace constants in FlowGraph::InlineCall.

runtime/vm/flow_graph.cc

Index: runtime/vm/flow_graph.cc
diff --git a/runtime/vm/flow_graph.cc b/runtime/vm/flow_graph.cc
index 95961cb8dffc46024e77ba0c31b5faeadf032ced..5132665fb69d781556199834bc0cd4032bb3b631 100644
--- a/runtime/vm/flow_graph.cc
+++ b/runtime/vm/flow_graph.cc
@@ -784,22 +784,28 @@ void FlowGraph::ReplacePredecessor(BlockEntryInstr* old_block,
     JoinEntryInstr* join = last->SuccessorAt(sidx)->AsJoinEntry();
     ASSERT(join != NULL);
     // Find the old predecessor index.
-    intptr_t old_index = join->IndexOfPredecessor(old_block);
-    intptr_t pred_count = join->PredecessorCount();
+    const intptr_t old_index = join->IndexOfPredecessor(old_block);
+    const intptr_t pred_count = join->PredecessorCount();
     ASSERT(old_index >= 0);
     ASSERT(old_index < pred_count);
     // Find the new predecessor index while reordering the predecessors.
-    intptr_t new_id = new_block->block_id();
+    const intptr_t new_id = new_block->block_id();
     intptr_t new_index = old_index;
+    // The predecessors are sorted by block id in ascending order.  This is done
+    // in JoinEntryInstr::AddPredecessor and in InlineCall.
     if (old_block->block_id() < new_id) {
       // Search upwards, bubbling down intermediate predecessors.
       for (; new_index < pred_count - 1; ++new_index) {
+        ASSERT(join->predecessors_[new_index]->block_id() <
+               join->predecessors_[new_index + 1]->block_id());

[Kevin Millikin (Google), 2012/11/02 11:35:23]

The continuation line should be indented 4 spaces.

[zerny-google, 2012/11/02 12:37:31]

Done.

         if (join->predecessors_[new_index + 1]->block_id() > new_id) break;
         join->predecessors_[new_index] = join->predecessors_[new_index + 1];
       }
     } else {
       // Search downwards, bubbling up intermediate predecessors.
       for (; new_index > 0; --new_index) {
+        ASSERT(join->predecessors_[new_index - 1]->block_id() <

[Kevin Millikin (Google), 2012/11/02 11:35:23]

Same.

[zerny-google, 2012/11/02 12:37:31]

Done.

+               join->predecessors_[new_index]->block_id());
         if (join->predecessors_[new_index - 1]->block_id() < new_id) break;
         join->predecessors_[new_index] = join->predecessors_[new_index - 1];
       }
@@ -988,6 +994,28 @@ void FlowGraph::InlineCall(Definition* call, FlowGraph* callee_graph) {
     // TODO(zerny): Compute the dominator frontier locally.
     invalid_dominator_tree_ = true;
   }
+
+  // Remove push arguments of the call.
+  for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
+    PushArgumentInstr* push = call->ArgumentAt(i);
+    push->ReplaceUsesWith(push->value()->definition());
+    push->RemoveFromGraph();
+  }
+
+  // Replace remaining constants with uses by constants in the caller's
+  // initial definitions.
+  GrowableArray<Definition*>* defns =
+      callee_graph->graph_entry()->initial_definitions();
+  for (intptr_t i = 0; i < defns->length(); ++i) {
+    ConstantInstr* constant = (*defns)[i]->AsConstant();
+    if (constant == NULL ||

[Kevin Millikin (Google), 2012/11/02 11:35:23]

I wouldn't use continue to skip a single statement.  It seems simpler to negate
the condition and have:

if (constant != NULL &&
    ((constant->input_use_list() != NULL) ||
     (constant->env_use_list() != NULL))) {
  constant->ReplaceUsesWith(...);
}

[zerny-google, 2012/11/02 12:37:31]

That is simpler. Thanks for pointing that out.

+        ((constant->input_use_list() == NULL) &&
+         (constant->env_use_list() == NULL))) {
+      continue;
+    }
+    constant->ReplaceUsesWith(
+        AddConstantToInitialDefinitions(constant->value()));
+  }
 }