Extend JSBuiltinReducer to cover Math.sqrt as well.

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/graph-inl.h"
 #include "src/compiler/js-builtin-reducer.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/types.h"
 
@@ skipping 77 matching lines @@
     DCHECK_LT(index, GetJSCallArity());
     // Skip first (i.e. callee) and second (i.e. receiver) operand.
     return NodeProperties::GetValueInput(node_, index + 2);
   }
 
  private:
   Node* node_;
 };
 
 
+// ECMA-262, section 15.8.2.17.
+Reduction JSBuiltinReducer::ReduceMathSqrt(Node* node) {
+  JSCallReduction r(node);
+  if (r.InputsMatchOne(Type::Number())) {
+    // Math.sqrt(a:number) -> Float64Sqrt(a)
+    Node* value = graph()->NewNode(machine()->Float64Sqrt(), r.left());
+    return Replace(value);
+  }
+  return NoChange();
+}
+
+
 // ECMA-262, section 15.8.2.11.
 Reduction JSBuiltinReducer::ReduceMathMax(Node* node) {
   JSCallReduction r(node);
   if (r.InputsMatchZero()) {
     // Math.max() -> -Infinity
     return Replace(jsgraph()->Constant(-V8_INFINITY));
   }
   if (r.InputsMatchOne(Type::Number())) {
     // Math.max(a:number) -> a
     return Replace(r.left());
@@ skipping 30 matching lines @@
   return NoChange();
 }
 
 
 Reduction JSBuiltinReducer::Reduce(Node* node) {
   JSCallReduction r(node);
 
   // Dispatch according to the BuiltinFunctionId if present.
   if (!r.HasBuiltinFunctionId()) return NoChange();
   switch (r.GetBuiltinFunctionId()) {
+    case kMathSqrt:
+      return ReplaceWithPureReduction(node, ReduceMathSqrt(node));
     case kMathMax:
       return ReplaceWithPureReduction(node, ReduceMathMax(node));
     case kMathImul:
       return ReplaceWithPureReduction(node, ReduceMathImul(node));
     default:
       break;
   }
   return NoChange();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8