[turbofan]: More optimizations to add and subtract operations on x64

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 567b1c920f00ff86273dec94e4e4fb6ea5356330..9acdcc84cf38e70458cace12b8b871717f7719fa 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -154,6 +154,22 @@ bool InstructionSelector::IsNextInAssemblyOrder(const BasicBlock* block) const {
 }
 
 
+bool InstructionSelector::ValueOwnedBy(Node* owner, Node* value) const {

[titzer, 2014/11/20 12:39:24]

Maybe we can move this to a more generic location like NodeProperties?
Also, a test.

[danno, 2014/11/20 13:43:07]

As discussed, the new patch set uses IsLive rather than this, so I removed it
completely.

+  Node::Uses uses = value->uses();
+  bool found_use = false;
+  for (Node::Uses::iterator current = uses.begin(); current != uses.end();

[titzer, 2014/11/20 12:39:24]

You can use a C++ foreach here now!

+       ++current) {
+    Node* use = *current;
+    if (use == owner) {
+      found_use = true;
+    } else if (!NodeProperties::IsEffectEdge(current.edge())) {
+      return false;
+    }
+  }
+  return found_use;
+}
+
+
 bool InstructionSelector::CanCover(Node* user, Node* node) const {
   return node->OwnedBy(user) &&
          schedule()->block(node) == schedule()->block(user);