[turbofan] Recognize fast path for Number.parseInt.

src/compiler/js-builtin-reducer.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/compiler/js-builtin-reducer.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/simplified-operator.h"
 #include "src/objects-inl.h"
@@ skipping 503 matching lines @@
   JSCallReduction r(node);
   if (r.InputsMatchOne(Type::PlainPrimitive())) {
     // Math.trunc(a:plain-primitive) -> NumberTrunc(ToNumber(a))
     Node* input = ToNumber(r.GetJSCallInput(0));
     Node* value = graph()->NewNode(simplified()->NumberTrunc(), input);
     return Replace(value);
   }
   return NoChange();
 }
 
+// ES6 section 20.1.2.13 Number.parseInt ( string, radix )
+Reduction JSBuiltinReducer::ReduceNumberParseInt(Node* node) {
+  JSCallReduction r(node);
+  if (r.InputsMatchOne(type_cache_.kSafeInteger) ||
+      r.InputsMatchTwo(type_cache_.kSafeInteger,
+                       type_cache_.kZeroOrUndefined) ||
+      r.InputsMatchTwo(type_cache_.kSafeInteger, type_cache_.kTenOrUndefined)) {
+    // Number.parseInt(a:safe-integer) -> NumberToInt32(a)
+    // Number.parseInt(a:safe-integer,b:#0\/undefined) -> NumberToInt32(a)
+    // Number.parseInt(a:safe-integer,b:#10\/undefined) -> NumberToInt32(a)
+    Node* input = r.GetJSCallInput(0);
+    Node* value = graph()->NewNode(simplified()->NumberToInt32(), input);
+    return Replace(value);
+  }
+  return NoChange();
+}
+
 // ES6 section 21.1.2.1 String.fromCharCode ( ...codeUnits )
 Reduction JSBuiltinReducer::ReduceStringFromCharCode(Node* node) {
   JSCallReduction r(node);
   if (r.InputsMatchOne(Type::PlainPrimitive())) {
     // String.fromCharCode(a:plain-primitive) -> StringFromCharCode(a)
     Node* input = ToNumber(r.GetJSCallInput(0));
     Node* value = graph()->NewNode(simplified()->StringFromCharCode(), input);
     return Replace(value);
   }
   return NoChange();
@@ skipping 98 matching lines @@
       break;
     case kMathTan:
       reduction = ReduceMathTan(node);
       break;
     case kMathTanh:
       reduction = ReduceMathTanh(node);
       break;
     case kMathTrunc:
       reduction = ReduceMathTrunc(node);
       break;
+    case kNumberParseInt:
+      reduction = ReduceNumberParseInt(node);
+      break;
     case kStringFromCharCode:
       reduction = ReduceStringFromCharCode(node);
       break;
     default:
       break;
   }
 
   // Replace builtin call assuming replacement nodes are pure values that don't
   // produce an effect. Replaces {node} with {reduction} and relaxes effects.
   if (reduction.Changed()) ReplaceWithValue(node, reduction.replacement());
@@ skipping 25 matching lines @@
 }
 
 
 SimplifiedOperatorBuilder* JSBuiltinReducer::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8