[turbofan] Unify Math.floor / Math.ceil optimization.

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 22 matching lines @@
     case Runtime::kInlineIsFunction:
       return ReduceInlineIsInstanceType(node, JS_FUNCTION_TYPE);
     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::kInlineMathFloor:
+      return ReduceInlineMathFloor(node);
     case Runtime::kInlineValueOf:
       return ReduceInlineValueOf(node);
     default:
       break;
   }
   return NoChange();
 }
 
 
 Reduction JSIntrinsicLowering::ReduceInlineDeoptimizeNow(Node* node) {
@@ skipping 102 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::ReduceInlineMathFloor(Node* node) {
+  if (!machine()->HasFloat64RoundDown()) return NoChange();
+  return Change(node, machine()->Float64RoundDown());
+}
+
+
 Reduction JSIntrinsicLowering::ReduceInlineValueOf(Node* node) {
   // if (%_IsSmi(value)) {
   //   return value;
   // } else if (%_GetInstanceType(%_GetMap(value)) == JS_VALUE_TYPE) {
   //   return %_GetValue(value);
   // } else {
   //   return value;
   // }
   const Operator* const merge_op = common()->Merge(2);
   const Operator* const ephi_op = common()->EffectPhi(2);
@@ skipping 80 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSIntrinsicLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8