Checking for stack height equality between full codegen and hydrogen.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 40386aaaae26882cc865f7be039b93fbb627b552..e73198da3e9afcf75b003c40756ee5df1233baba 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -157,8 +157,20 @@ HPhi* HBasicBlock::AddNewPhi(int merged_index) {
 }
 
 
+HSimulate* HBasicBlock::AddNewSimulate(
+    BailoutId ast_id,
+    HSourcePosition position,
+    RemovableSimulate removable,
+    int arguments_offset) {
+  HSimulate* instr = CreateSimulate(ast_id, removable, arguments_offset);
+  AddInstruction(instr, position);
+  return instr;
+}
+
+
 HSimulate* HBasicBlock::CreateSimulate(BailoutId ast_id,
-                                       RemovableSimulate removable) {
+                                       RemovableSimulate removable,
+                                       int arguments_offset) {
   ASSERT(HasEnvironment());
   HEnvironment* environment = last_environment();
   ASSERT(ast_id.IsNone() ||
@@ -187,6 +199,10 @@ HSimulate* HBasicBlock::CreateSimulate(BailoutId ast_id,
     instr->AddAssignedValue(index, environment->Lookup(index));
   }
   environment->ClearHistory();
+#if defined(COMPARE_OPT_STACK_HEIGHT)
+  environment->VerifyStackHeight(
+      ast_id, instr->id(), arguments_offset);
+#endif
   return instr;
 }
 
@@ -256,7 +272,7 @@ void HBasicBlock::UpdateEnvironment(HEnvironment* env) {
 }
 
 
-void HBasicBlock::SetJoinId(BailoutId ast_id) {
+void HBasicBlock::SetJoinId(BailoutId ast_id, int stack_check_offset) {
   int length = predecessors_.length();
   ASSERT(length > 0);
   for (int i = 0; i < length; i++) {
@@ -268,6 +284,10 @@ void HBasicBlock::SetJoinId(BailoutId ast_id) {
             predecessor->last_environment()->closure()->shared()
               ->VerifyBailoutId(ast_id)));
     simulate->set_ast_id(ast_id);
+#if defined(COMPARE_OPT_STACK_HEIGHT)
+    predecessor->last_environment()->VerifyStackHeight(
+        ast_id, simulate->id(), stack_check_offset);
+#endif
     predecessor->last_environment()->set_ast_id(ast_id);
   }
 }
@@ -1205,10 +1225,12 @@ void HGraphBuilder::AddIncrementCounter(StatsCounter* counter) {
 
 
 void HGraphBuilder::AddSimulate(BailoutId id,
-                                RemovableSimulate removable) {
+                                RemovableSimulate removable,
+                                int arguments_offset) {
   ASSERT(current_block() != NULL);
   ASSERT(!graph()->IsInsideNoSideEffectsScope());
-  current_block()->AddNewSimulate(id, source_position(), removable);
+  current_block()->AddNewSimulate(
+      id, source_position(), removable, arguments_offset);
 }
 
 
@@ -4410,7 +4432,8 @@ void HOptimizedGraphBuilder::VisitReturnStatement(ReturnStatement* stmt) {
       CHECK_ALIVE(VisitForEffect(stmt->expression()));
       Goto(test->if_true(), state);
     } else if (context->IsEffect()) {
-      CHECK_ALIVE(VisitForEffect(stmt->expression()));
+      CHECK_ALIVE(VisitForValue(stmt->expression()));
+      Drop(1);
       Goto(function_return(), state);
     } else {
       ASSERT(context->IsValue());
@@ -7573,13 +7596,13 @@ bool HOptimizedGraphBuilder::TryInline(Handle<JSFunction> target,
     // Forward to the real test context.
     if (if_true->HasPredecessor()) {
       entry->RegisterReturnTarget(if_true, zone());
-      if_true->SetJoinId(ast_id);
+      if_true->SetJoinId(ast_id, -1);
       HBasicBlock* true_target = TestContext::cast(ast_context())->if_true();
       Goto(if_true, true_target, function_state());
     }
     if (if_false->HasPredecessor()) {
       entry->RegisterReturnTarget(if_false, zone());
-      if_false->SetJoinId(ast_id);
+      if_false->SetJoinId(ast_id, -1);
       HBasicBlock* false_target = TestContext::cast(ast_context())->if_false();
       Goto(if_false, false_target, function_state());
     }
@@ -10854,7 +10877,13 @@ void HOptimizedGraphBuilder::GenerateOneByteSeqStringSetChar(
   HValue* index = Pop();
   Add<HSeqStringSetChar>(String::ONE_BYTE_ENCODING, string,
                          index, value);
-  Add<HSimulate>(call->id(), FIXED_SIMULATE);
+  if (ast_context()->IsEffect()) {
+    Add<HSimulate>(call->id(), FIXED_SIMULATE);
+  } else {
+    Push(graph()->GetConstantUndefined());
+    Add<HSimulate>(call->id(), FIXED_SIMULATE);
+    Pop();
+  }
   return ast_context()->ReturnValue(graph()->GetConstantUndefined());
 }
 
@@ -10871,7 +10900,13 @@ void HOptimizedGraphBuilder::GenerateTwoByteSeqStringSetChar(
   HValue* index = Pop();
   Add<HSeqStringSetChar>(String::TWO_BYTE_ENCODING, string,
                          index, value);
-  Add<HSimulate>(call->id(), FIXED_SIMULATE);
+  if (ast_context()->IsEffect()) {
+    Add<HSimulate>(call->id(), FIXED_SIMULATE);
+  } else {
+    Push(graph()->GetConstantUndefined());
+    Add<HSimulate>(call->id(), FIXED_SIMULATE);
+    Pop();
+  }
   return ast_context()->ReturnValue(graph()->GetConstantUndefined());
 }
 
@@ -11474,6 +11509,29 @@ void HEnvironment::PrintToStd() {
 }
 
 
+void HEnvironment::VerifyStackHeight(
+    BailoutId ast_id,
+    int hydrogen_id,
+    int stack_height_offset) {
+#if defined(COMPARE_OPT_STACK_HEIGHT)
+  if (!ast_id.IsNone() && ast_id != BailoutId::StubEntry()) {
+    int hydrogen_height = length() - specials_count() - parameter_count();
+    int expected_stack_height =
+      closure()->shared()->GetExpectedStackHeight(ast_id) +
+      stack_height_offset;
+
+    if (expected_stack_height != hydrogen_height) {
+      V8_Fatal(__FILE__, __LINE__,
+               "Stack height mismatch.\n"
+               "Hydrogen height    = %4i,  "
+               "unoptimized height = %4i,  AST id      = %i\n",
+               hydrogen_height, expected_stack_height, ast_id.ToInt());
+    }
+  }
+#endif
+}
+
+
 void HTracer::TraceCompilation(CompilationInfo* info) {
   Tag tag(this, "compilation");
   if (info->IsOptimizing()) {