[turbofan] Look at nodes instead of types for string data

We'll stop storing string data in Type objects. At the moment, we have
optimizations that read that string data in typed lowering. Instead,
look at nodes for this data.

R=bmeurer@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2406243002
Cr-Commit-Position: refs/heads/master@{#40173}

src/compiler/js-typed-lowering.cc

@@ -82,16 +82,13 @@ class JSBinopReduction final {
     if (BothInputsAre(Type::String()) ||
         ((lowering_->flags() & JSTypedLowering::kDeoptimizationEnabled) &&
          BinaryOperationHintOf(node_->op()) == BinaryOperationHint::kString)) {
-      if (left_type()->IsHeapConstant() &&
-          left_type()->AsHeapConstant()->Value()->IsString()) {
-        Handle<String> left_string =
-            Handle<String>::cast(left_type()->AsHeapConstant()->Value());
+      HeapObjectBinopMatcher m(node_);
+      if (m.left().HasValue() && m.left().Value()->IsString()) {
+        Handle<String> left_string = Handle<String>::cast(m.left().Value());
         if (left_string->length() >= ConsString::kMinLength) return true;
       }
-      if (right_type()->IsHeapConstant() &&
-          right_type()->AsHeapConstant()->Value()->IsString()) {
-        Handle<String> right_string =
-            Handle<String>::cast(right_type()->AsHeapConstant()->Value());
+      if (m.right().HasValue() && m.right().Value()->IsString()) {
+        Handle<String> right_string = Handle<String>::cast(m.right().Value());
         if (right_string->length() >= ConsString::kMinLength) return true;
       }
     }
@@ -596,21 +593,20 @@ Reduction JSTypedLowering::ReduceCreateConsString(Node* node) {
   }
 
   // Determine the {first} length.
+  HeapObjectBinopMatcher m(node);
   Node* first_length =
-      first_type->IsHeapConstant()
+      (m.left().HasValue() && m.left().Value()->IsString())
           ? jsgraph()->Constant(
-                Handle<String>::cast(first_type->AsHeapConstant()->Value())
-                    ->length())
+                Handle<String>::cast(m.left().Value())->length())
           : effect = graph()->NewNode(
                 simplified()->LoadField(AccessBuilder::ForStringLength()),
                 first, effect, control);
 
   // Determine the {second} length.
   Node* second_length =
-      second_type->IsHeapConstant()
+      (m.right().HasValue() && m.right().Value()->IsString())
           ? jsgraph()->Constant(
-                Handle<String>::cast(second_type->AsHeapConstant()->Value())
-                    ->length())
+                Handle<String>::cast(m.right().Value())->length())
           : effect = graph()->NewNode(
                 simplified()->LoadField(AccessBuilder::ForStringLength()),
                 second, effect, control);
@@ -979,12 +975,17 @@ Reduction JSTypedLowering::ReduceJSToLength(Node* node) {
 Reduction JSTypedLowering::ReduceJSToNumberInput(Node* input) {
   // Try constant-folding of JSToNumber with constant inputs.
   Type* input_type = NodeProperties::GetType(input);
-  if (input_type->IsHeapConstant()) {
-    Handle<Object> input_value = input_type->AsHeapConstant()->Value();
-    if (input_value->IsString()) {
+  if (input_type->Is(Type::String())) {
+    HeapObjectMatcher m(input);
+    if (m.HasValue() && m.Value()->IsString()) {
+      Handle<Object> input_value = m.Value();
       return Replace(jsgraph()->Constant(
           String::ToNumber(Handle<String>::cast(input_value))));
-    } else if (input_value->IsOddball()) {
+    }
+  }
+  if (input_type->IsHeapConstant()) {
+    Handle<Object> input_value = input_type->AsHeapConstant()->Value();
+    if (input_value->IsOddball()) {
       return Replace(jsgraph()->Constant(
           Oddball::ToNumber(Handle<Oddball>::cast(input_value))));
     }