[turbofan] Turn Math.clz32 into an inlinable builtin.

src/compiler/js-intrinsic-lowering.cc

 // Copyright 2015 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-intrinsic-lowering.h"
 
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 24 matching lines @@
     case Runtime::kInlineJSValueGetValue:
       return ReduceInlineJSValueGetValue(node);
     case Runtime::kInlineConstructDouble:
       return ReduceInlineConstructDouble(node);
     case Runtime::kInlineDoubleLo:
       return ReduceInlineDoubleLo(node);
     case Runtime::kInlineDoubleHi:
       return ReduceInlineDoubleHi(node);
     case Runtime::kInlineIsRegExp:
       return ReduceInlineIsInstanceType(node, JS_REGEXP_TYPE);
+    case Runtime::kInlineMathClz32:
+      return ReduceInlineMathClz32(node);
     case Runtime::kInlineMathFloor:
       return ReduceInlineMathFloor(node);
     case Runtime::kInlineMathSqrt:
       return ReduceInlineMathSqrt(node);
     case Runtime::kInlineStringGetLength:
       return ReduceInlineStringGetLength(node);
     case Runtime::kInlineValueOf:
       return ReduceInlineValueOf(node);
     default:
       break;
@@ skipping 117 matching lines @@
 
   // Replace all effect uses of {node} with the {ephi}.
   Node* ephi = graph()->NewNode(common()->EffectPhi(2), etrue, efalse, merge);
   NodeProperties::ReplaceWithValue(node, node, ephi);
 
   // Turn the {node} into a Phi.
   return Change(node, common()->Phi(type, 2), vtrue, vfalse, merge);
 }
 
 
+Reduction JSIntrinsicLowering::ReduceInlineMathClz32(Node* node) {
+  return Change(node, machine()->Word32Clz());
+}
+
+
 Reduction JSIntrinsicLowering::ReduceInlineMathFloor(Node* node) {
   if (!machine()->HasFloat64RoundDown()) return NoChange();
   return Change(node, machine()->Float64RoundDown());
 }
 
 
 Reduction JSIntrinsicLowering::ReduceInlineMathSqrt(Node* node) {
   return Change(node, machine()->Float64Sqrt());
 }
 
@@ skipping 101 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSIntrinsicLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8