[Turbofan] Only weaken types for Phi nodes.

src/compiler/typer.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/flags.h"
 #include "src/bootstrapper.h"
 #include "src/compiler/graph-reducer.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/node.h"
 #include "src/compiler/node-properties.h"
@@ skipping 347 matching lines @@
 #undef DECLARE_METHOD
 
   static Type* JSUnaryNotTyper(Type*, Typer*);
   static Type* JSLoadPropertyTyper(Type*, Type*, Typer*);
   static Type* JSCallFunctionTyper(Type*, Typer*);
 
   Reduction UpdateBounds(Node* node, Bounds current) {
     if (NodeProperties::IsTyped(node)) {
       // Widen the bounds of a previously typed node.
       Bounds previous = NodeProperties::GetBounds(node);
-      // Speed up termination in the presence of range types:
-      current.upper = Weaken(current.upper, previous.upper);
-      current.lower = Weaken(current.lower, previous.lower);
+      if (node->opcode() == IrOpcode::kPhi) {
+        // Speed up termination in the presence of range types:
+        current.upper = Weaken(current.upper, previous.upper);
+        current.lower = Weaken(current.lower, previous.lower);
+      }
 
       // Types should not get less precise.
       DCHECK(previous.lower->Is(current.lower));
       DCHECK(previous.upper->Is(current.upper));
 
       NodeProperties::SetBounds(node, current);
       if (!(previous.Narrows(current) && current.Narrows(previous))) {
         // If something changed, revisit all uses.
         return Changed(node);
       }
@@ skipping 921 matching lines @@
 // the fixpoint calculation in case there appears to be a loop
 // in the graph. In the current implementation, we are
 // increasing the limits to the closest power of two.
 Type* Typer::Visitor::Weaken(Type* current_type, Type* previous_type) {
   // If the types have nothing to do with integers, return the types.
   if (!current_type->Maybe(typer_->integer) ||
       !previous_type->Maybe(typer_->integer)) {
     return current_type;
   }
 
-  Type* previous_number =
-      Type::Intersect(previous_type, typer_->integer, zone());
-  Type* current_number = Type::Intersect(current_type, typer_->integer, zone());
-  if (!current_number->IsRange() || !previous_number->IsRange()) {
+  Type::RangeType* previous =
+      Type::Intersect(previous_type, typer_->integer, zone())->GetRange();
+  Type::RangeType* current =
+      Type::Intersect(current_type, typer_->integer, zone())->GetRange();
+  if (current == nullptr || previous == nullptr) {
     return current_type;
   }
 
-  Type::RangeType* previous = previous_number->AsRange();
-  Type::RangeType* current = current_number->AsRange();
-
   double current_min = current->Min();
   double new_min = current_min;
   // Find the closest lower entry in the list of allowed
   // minima (or negative infinity if there is no such entry).
   if (current_min != previous->Min()) {
     new_min = typer_->integer->AsRange()->Min();
     for (const auto val : typer_->weaken_min_limits_) {
       if (val <= current_min) {
         new_min = val;
         break;
@@ skipping 891 matching lines @@
       TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
     }
   }
   return Type::Constant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8