[turbofan] Call frequencies for JSCallFunction and JSCallConstruct.

src/compiler/js-inlining-heuristic.cc

Index: src/compiler/js-inlining-heuristic.cc
diff --git a/src/compiler/js-inlining-heuristic.cc b/src/compiler/js-inlining-heuristic.cc
index 26c9b1d33ef082ad947f95bb8cb25679d17bbf9f..a526cf5f9c2c3b6d5617a422cc9e40aade58a261 100644
--- a/src/compiler/js-inlining-heuristic.cc
+++ b/src/compiler/js-inlining-heuristic.cc
@@ -123,22 +123,12 @@ Reduction JSInliningHeuristic::Reduce(Node* node) {
 
   // Gather feedback on how often this call site has been hit before.
   if (node->opcode() == IrOpcode::kJSCallFunction) {
-    CallFunctionParameters p = CallFunctionParametersOf(node->op());
-    if (p.feedback().IsValid()) {
-      CallICNexus nexus(p.feedback().vector(), p.feedback().slot());
-      candidate.calls = nexus.ExtractCallCount();
-    }
+    CallFunctionParameters const p = CallFunctionParametersOf(node->op());
+    candidate.frequency = p.frequency();
   } else {
     DCHECK_EQ(IrOpcode::kJSCallConstruct, node->opcode());
-    CallConstructParameters p = CallConstructParametersOf(node->op());
-    if (p.feedback().IsValid()) {
-      int const extra_index =
-          p.feedback().vector()->GetIndex(p.feedback().slot()) + 1;
-      Object* feedback_extra = p.feedback().vector()->get(extra_index);
-      if (feedback_extra->IsSmi()) {
-        candidate.calls = Smi::cast(feedback_extra)->value();
-      }
-    }
+    CallConstructParameters const p = CallConstructParametersOf(node->op());
+    candidate.frequency = p.frequency();
   }
 
   // Handling of special inlining modes right away:
@@ -280,17 +270,20 @@ Reduction JSInliningHeuristic::InlineCandidate(Candidate const& candidate) {
 
 bool JSInliningHeuristic::CandidateCompare::operator()(
     const Candidate& left, const Candidate& right) const {
-  if (left.calls != right.calls) {
-    return left.calls > right.calls;
+  if (left.frequency > right.frequency) {
+    return true;
+  } else if (left.frequency < right.frequency) {
+    return false;
+  } else {
+    return left.node < right.node;

[Jarin, 2016/09/12 13:10:01]

Could we compare on node->id(), so that we do not depend on the whim of the zone
allocator (and on undefined behaviour).

[Benedikt Meurer, 2016/09/13 17:45:07]

Done.

   }
-  return left.node < right.node;
 }
 
 void JSInliningHeuristic::PrintCandidates() {
   PrintF("Candidates for inlining (size=%zu):\n", candidates_.size());
   for (const Candidate& candidate : candidates_) {
-    PrintF("  #%d:%s, calls:%d\n", candidate.node->id(),
-           candidate.node->op()->mnemonic(), candidate.calls);
+    PrintF("  #%d:%s, frequency:%g\n", candidate.node->id(),
+           candidate.node->op()->mnemonic(), candidate.frequency);
     for (int i = 0; i < candidate.num_functions; ++i) {
       Handle<JSFunction> function = candidate.functions[i];
       PrintF("  - size[source]:%d, size[ast]:%d, name: %s\n",