From cf1ebf36625ce8ffa713822768acfa59153440fc Mon Sep 17 00:00:00 2001
From: leszeks <leszeks@chromium.org>
Date: Thu, 3 Nov 2016 03:21:05 -0700
Subject: [PATCH] [ignition/turbo] Remove stack check from inlined functions

This removes the first stack check in inlined functions in the bytecode
graph builder, to match the behaviour of the AST graph builder.

I measure a ~1% statistically significant (p < 0.01) improvement on
Mandreel with --ignition-staging --turbo (on my x64 machine, YMMV).

Review-Url: https://codereview.chromium.org/2392333002
Cr-Commit-Position: refs/heads/master@{#40715}
---
 src/compiler/bytecode-graph-builder.cc | 16 +++++++++++-----
 src/compiler/bytecode-graph-builder.h  |  4 ++--
 src/compiler/js-inlining.cc            |  2 +-
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/compiler/bytecode-graph-builder.cc b/src/compiler/bytecode-graph-builder.cc
index b00bcec339..ab7db8079b 100644
--- a/src/compiler/bytecode-graph-builder.cc
+++ b/src/compiler/bytecode-graph-builder.cc
@@ -569,7 +569,7 @@ VectorSlotPair BytecodeGraphBuilder::CreateVectorSlotPair(int slot_id) {
   return VectorSlotPair(feedback_vector(), slot);
 }
 
-bool BytecodeGraphBuilder::CreateGraph() {
+bool BytecodeGraphBuilder::CreateGraph(bool stack_check) {
   // Set up the basic structure of the graph. Outputs for {Start} are the formal
   // parameters (including the receiver) plus new target, number of arguments,
   // context and closure.
@@ -581,7 +581,7 @@ bool BytecodeGraphBuilder::CreateGraph() {
                   GetFunctionContext());
   set_environment(&env);
 
-  VisitBytecodes();
+  VisitBytecodes(stack_check);
 
   // Finish the basic structure of the graph.
   DCHECK_NE(0u, exit_controls_.size());
@@ -641,7 +641,7 @@ void BytecodeGraphBuilder::ClearNonLiveSlotsInFrameStates() {
   }
 }
 
-void BytecodeGraphBuilder::VisitBytecodes() {
+void BytecodeGraphBuilder::VisitBytecodes(bool stack_check) {
   BytecodeBranchAnalysis analysis(bytecode_array(), local_zone());
   BytecodeLoopAnalysis loop_analysis(bytecode_array(), &analysis, local_zone());
   analysis.Analyze();
@@ -655,7 +655,7 @@ void BytecodeGraphBuilder::VisitBytecodes() {
       bytecode_array()->source_position_table());
 
   BuildOSRNormalEntryPoint();
-  while (!iterator.done()) {
+  for (; !iterator.done(); iterator.Advance()) {
     int current_offset = iterator.current_offset();
     UpdateCurrentSourcePosition(&source_position_iterator, current_offset);
     EnterAndExitExceptionHandlers(current_offset);
@@ -664,6 +664,13 @@ void BytecodeGraphBuilder::VisitBytecodes() {
       BuildLoopHeaderEnvironment(current_offset);
       BuildOSRLoopEntryPoint(current_offset);
 
+      // Skip the first stack check if stack_check is false
+      if (!stack_check &&
+          iterator.current_bytecode() == interpreter::Bytecode::kStackCheck) {
+        stack_check = true;
+        continue;
+      }
+
       switch (iterator.current_bytecode()) {
 #define BYTECODE_CASE(name, ...)       \
   case interpreter::Bytecode::k##name: \
@@ -673,7 +680,6 @@ void BytecodeGraphBuilder::VisitBytecodes() {
 #undef BYTECODE_CODE
       }
     }
-    iterator.Advance();
   }
 
   set_branch_analysis(nullptr);
diff --git a/src/compiler/bytecode-graph-builder.h b/src/compiler/bytecode-graph-builder.h
index 65e5042d9d..d2feb93a20 100644
--- a/src/compiler/bytecode-graph-builder.h
+++ b/src/compiler/bytecode-graph-builder.h
@@ -33,12 +33,12 @@ class BytecodeGraphBuilder {
                        SourcePositionTable* source_positions);
 
   // Creates a graph by visiting bytecodes.
-  bool CreateGraph();
+  bool CreateGraph(bool stack_check = true);
 
  private:
   class Environment;
 
-  void VisitBytecodes();
+  void VisitBytecodes(bool stack_check);
 
   // Get or create the node that represents the outer function closure.
   Node* GetFunctionClosure();
diff --git a/src/compiler/js-inlining.cc b/src/compiler/js-inlining.cc
index 1a49e2f4c6..8ab07c5fa6 100644
--- a/src/compiler/js-inlining.cc
+++ b/src/compiler/js-inlining.cc
@@ -531,7 +531,7 @@ Reduction JSInliner::ReduceJSCall(Node* node, Handle<JSFunction> function) {
     Graph::SubgraphScope scope(graph());
     BytecodeGraphBuilder graph_builder(&zone, &info, jsgraph(),
                                        call.frequency(), nullptr);
-    graph_builder.CreateGraph();
+    graph_builder.CreateGraph(false);
 
     // Extract the inlinee start/end nodes.
     start = graph()->start();