[turbofan] Simplify {IfException} discovery during inlining.

This unifies the search for a potential {IfException} projection with
the existing predicate on {NodeProperties} used by the rest of the
system. Also contains a related drive-by change to graph builders. This
is in preparation of eliding {IfSuccess} projections when possible.

R=jarin@chromium.org

Change-Id: I8ba0ae9e9fdb69a77bce01578200ceea434535f7
Reviewed-on: https://chromium-review.googlesource.com/448039Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43540}

src/compiler/ast-graph-builder.cc

@@ -2931,7 +2931,7 @@ Node* AstGraphBuilder::MakeNode(const Operator* op, int value_input_count,
     result = graph()->NewNode(op, input_count_with_deps, buffer, incomplete);
     if (!environment()->IsMarkedAsUnreachable()) {
       // Update the current control dependency for control-producing nodes.
-      if (NodeProperties::IsControl(result)) {
+      if (result->op()->ControlOutputCount() > 0) {
         environment_->UpdateControlDependency(result);
       }
       // Update the current effect dependency for effect-producing nodes.

src/compiler/bytecode-graph-builder.cc

@@ -2310,7 +2310,7 @@ Node* BytecodeGraphBuilder::MakeNode(const Operator* op, int value_input_count,
     }
     result = graph()->NewNode(op, input_count_with_deps, buffer, incomplete);
     // Update the current control dependency for control-producing nodes.
-    if (NodeProperties::IsControl(result)) {
+    if (result->op()->ControlOutputCount() > 0) {
       environment()->UpdateControlDependency(result);
     }
     // Update the current effect dependency for effect-producing nodes.

src/compiler/js-inlining.cc

@@ -513,20 +513,11 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
     }
   }
 
-  // Find the IfException node, if any.
+  // Calls surrounded by a local try-block are only inlined if the appropriate
+  // flag is active. We also discover the {IfException} projection this way.
   Node* exception_target = nullptr;
-  for (Edge edge : node->use_edges()) {
-    if (NodeProperties::IsControlEdge(edge) &&
-        edge.from()->opcode() == IrOpcode::kIfException) {
-      DCHECK_NULL(exception_target);
-      exception_target = edge.from();
-    }
-  }
-
-  NodeVector uncaught_subcalls(local_zone_);
-
-  if (exception_target != nullptr) {
-    if (!FLAG_inline_into_try) {
+  if (NodeProperties::IsExceptionalCall(node, &exception_target) &&
+      !FLAG_inline_into_try) {
     TRACE(
         "Try block surrounds #%d:%s and --no-inline-into-try active, so not "
         "inlining %s into %s.\n",
@@ -534,14 +525,6 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
         shared_info->DebugName()->ToCString().get(),
         info_->shared_info()->DebugName()->ToCString().get());
     return NoChange();
-    } else {
-      TRACE(
-          "Inlining %s into %s regardless of surrounding try-block to catcher "
-          "#%d:%s\n",
-          shared_info->DebugName()->ToCString().get(),
-          info_->shared_info()->DebugName()->ToCString().get(),
-          exception_target->id(), exception_target->op()->mnemonic());
-    }
   }
 
   ParseInfo parse_info(shared_info);
@@ -570,9 +553,9 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
   // After this point, we've made a decision to inline this function.
   // We shall not bailout from inlining if we got here.
 
-  TRACE("Inlining %s into %s\n",
-        shared_info->DebugName()->ToCString().get(),
-        info_->shared_info()->DebugName()->ToCString().get());
+  TRACE("Inlining %s into %s%s\n", shared_info->DebugName()->ToCString().get(),
+        info_->shared_info()->DebugName()->ToCString().get(),
+        (exception_target != nullptr) ? " (inside try-block)" : "");
 
   // Determine the targets feedback vector and its context.
   Node* context;
@@ -595,6 +578,7 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
     end = graph()->end();
   }
 
+  NodeVector uncaught_subcalls(local_zone_);
   if (exception_target != nullptr) {
     // Find all uncaught 'calls' in the inlinee.
     AllNodes inlined_nodes(local_zone_, end, graph());

src/compiler/node-properties.cc

@@ -126,11 +126,14 @@ bool NodeProperties::IsControlEdge(Edge edge) {
 
 
 // static
-bool NodeProperties::IsExceptionalCall(Node* node) {
+bool NodeProperties::IsExceptionalCall(Node* node, Node** out_exception) {
   if (node->op()->HasProperty(Operator::kNoThrow)) return false;
   for (Edge const edge : node->use_edges()) {
     if (!NodeProperties::IsControlEdge(edge)) continue;
-    if (edge.from()->opcode() == IrOpcode::kIfException) return true;
+    if (edge.from()->opcode() == IrOpcode::kIfException) {
+      if (out_exception != nullptr) *out_exception = edge.from();
+      return true;
+    }
   }
   return false;
 }

src/compiler/node-properties.h

@@ -75,8 +75,9 @@ class V8_EXPORT_PRIVATE NodeProperties final {
   }
 
   // Determines whether exceptions thrown by the given node are handled locally
-  // within the graph (i.e. an IfException projection is present).
-  static bool IsExceptionalCall(Node* node);
+  // within the graph (i.e. an IfException projection is present). Optionally
+  // the present IfException projection is returned via {out_exception}.
+  static bool IsExceptionalCall(Node* node, Node** out_exception = nullptr);
 
   // ---------------------------------------------------------------------------
   // Miscellaneous mutators.