[runtime] Remove the unused weird %Likely and %Unlikely intrinsics.

These intrinsics are completely unused and there doesn't seem to an
actual use case for it in the future.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1418663011

Cr-Commit-Position: refs/heads/master@{#31828}

src/compiler/js-intrinsic-lowering.cc

@@ -63,8 +63,6 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceIsSmi(node);
     case Runtime::kInlineJSValueGetValue:
       return ReduceJSValueGetValue(node);
-    case Runtime::kInlineLikely:
-      return ReduceUnLikely(node, BranchHint::kTrue);
     case Runtime::kInlineMapGetInstanceType:
       return ReduceMapGetInstanceType(node);
     case Runtime::kInlineMathClz32:
@@ -83,8 +81,6 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceSeqStringGetChar(node, String::TWO_BYTE_ENCODING);
     case Runtime::kInlineTwoByteSeqStringSetChar:
       return ReduceSeqStringSetChar(node, String::TWO_BYTE_ENCODING);
-    case Runtime::kInlineUnlikely:
-      return ReduceUnLikely(node, BranchHint::kFalse);
     case Runtime::kInlineValueOf:
       return ReduceValueOf(node);
     case Runtime::kInlineIsMinusZero:
@@ -341,29 +337,6 @@ Reduction JSIntrinsicLowering::ReduceStringGetLength(Node* node) {
 }
 
 
-Reduction JSIntrinsicLowering::ReduceUnLikely(Node* node, BranchHint hint) {
-  std::stack<Node*> nodes_to_visit;
-  nodes_to_visit.push(node);
-  while (!nodes_to_visit.empty()) {
-    Node* current = nodes_to_visit.top();
-    nodes_to_visit.pop();
-    for (Node* use : current->uses()) {
-      if (use->opcode() == IrOpcode::kJSToBoolean) {
-        // We have to "look through" ToBoolean calls.
-        nodes_to_visit.push(use);
-      } else if (use->opcode() == IrOpcode::kBranch) {
-        // Actually set the hint on any branch using the intrinsic node.
-        NodeProperties::ChangeOp(use, common()->Branch(hint));
-      }
-    }
-  }
-  // Apart from adding hints to branchs nodes, this is the identity function.
-  Node* value = NodeProperties::GetValueInput(node, 0);
-  ReplaceWithValue(node, value);
-  return Changed(value);
-}
-
-
 Reduction JSIntrinsicLowering::ReduceValueOf(Node* node) {
   // if (%_IsSmi(value)) {
   //   return value;

src/compiler/js-intrinsic-lowering.h

@@ -55,7 +55,6 @@ class JSIntrinsicLowering final : public AdvancedReducer {
   Reduction ReduceSeqStringGetChar(Node* node, String::Encoding encoding);
   Reduction ReduceSeqStringSetChar(Node* node, String::Encoding encoding);
   Reduction ReduceStringGetLength(Node* node);
-  Reduction ReduceUnLikely(Node* node, BranchHint hint);
   Reduction ReduceValueOf(Node* node);
   Reduction ReduceFixedArrayGet(Node* node);
   Reduction ReduceFixedArraySet(Node* node);

src/crankshaft/hydrogen.cc

@@ -12743,17 +12743,6 @@ void HOptimizedGraphBuilder::GenerateMathSqrt(CallRuntime* call) {
 }
 
 
-void HOptimizedGraphBuilder::GenerateLikely(CallRuntime* call) {
-  DCHECK(call->arguments()->length() == 1);
-  Visit(call->arguments()->at(0));
-}
-
-
-void HOptimizedGraphBuilder::GenerateUnlikely(CallRuntime* call) {
-  return GenerateLikely(call);
-}
-
-
 void HOptimizedGraphBuilder::GenerateHasInPrototypeChain(CallRuntime* call) {
   DCHECK_EQ(2, call->arguments()->length());
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));

src/crankshaft/hydrogen.h

@@ -2235,8 +2235,6 @@ class HOptimizedGraphBuilder : public HGraphBuilder, public AstVisitor {
   F(RegExpConstructResult)             \
   F(NumberToString)                    \
   F(DebugIsActive)                     \
-  F(Likely)                            \
-  F(Unlikely)                          \
   F(HasInPrototypeChain)               \
   /* Typed Arrays */                   \
   F(TypedArrayInitialize)              \

src/runtime/runtime-internal.cc

@@ -371,18 +371,6 @@ RUNTIME_FUNCTION(Runtime_IncrementStatsCounter) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_Likely) {
-  DCHECK(args.length() == 1);
-  return args[0];
-}
-
-
-RUNTIME_FUNCTION(Runtime_Unlikely) {
-  DCHECK(args.length() == 1);
-  return args[0];
-}
-
-
 RUNTIME_FUNCTION(Runtime_HarmonyToString) {
   // TODO(caitp): Delete this runtime method when removing --harmony-tostring
   return isolate->heap()->ToBoolean(FLAG_harmony_tostring);

src/runtime/runtime.h

@@ -349,8 +349,6 @@ namespace internal {
   F(CallSiteIsConstructorRT, 1, 1)            \
   F(IS_VAR, 1, 1)                             \
   F(IncrementStatsCounter, 1, 1)              \
-  F(Likely, 1, 1)                             \
-  F(Unlikely, 1, 1)                           \
   F(HarmonyToString, 0, 1)                    \
   F(GetTypeFeedbackVector, 1, 1)              \
   F(GetCallerJSFunction, 0, 1)                \

test/unittests/compiler/js-intrinsic-lowering-unittest.cc

@@ -301,30 +301,6 @@ TEST_F(JSIntrinsicLoweringTest, InlineJSValueGetValue) {
 }
 
 
-// -----------------------------------------------------------------------------
-// %_Likely
-
-TEST_F(JSIntrinsicLoweringTest, Likely) {
-  Node* const input = Parameter(0);
-  Node* const context = Parameter(1);
-  Node* const effect = graph()->start();
-  Node* const control = graph()->start();
-  Node* const likely =
-      graph()->NewNode(javascript()->CallRuntime(Runtime::kInlineLikely, 1),
-                       input, context, effect, control);
-  Node* const to_boolean =
-      graph()->NewNode(javascript()->ToBoolean(), likely, context, effect);
-  Diamond d(graph(), common(), to_boolean);
-  graph()->SetEnd(graph()->NewNode(common()->End(1), d.merge));
-
-  ASSERT_EQ(BranchHint::kNone, BranchHintOf(d.branch->op()));
-  Reduction const r = Reduce(likely);
-  ASSERT_TRUE(r.Changed());
-  EXPECT_THAT(r.replacement(), input);
-  ASSERT_EQ(BranchHint::kTrue, BranchHintOf(d.branch->op()));
-}
-
-
 // -----------------------------------------------------------------------------
 // %_MathFloor
 
@@ -395,30 +371,6 @@ TEST_F(JSIntrinsicLoweringTest, InlineMathClz32) {
 }
 
 
-// -----------------------------------------------------------------------------
-// %_Unlikely
-
-TEST_F(JSIntrinsicLoweringTest, Unlikely) {
-  Node* const input = Parameter(0);
-  Node* const context = Parameter(1);
-  Node* const effect = graph()->start();
-  Node* const control = graph()->start();
-  Node* const unlikely =
-      graph()->NewNode(javascript()->CallRuntime(Runtime::kInlineUnlikely, 1),
-                       input, context, effect, control);
-  Node* const to_boolean =
-      graph()->NewNode(javascript()->ToBoolean(), unlikely, context, effect);
-  Diamond d(graph(), common(), to_boolean);
-  graph()->SetEnd(graph()->NewNode(common()->End(1), d.merge));
-
-  ASSERT_EQ(BranchHint::kNone, BranchHintOf(d.branch->op()));
-  Reduction const r = Reduce(unlikely);
-  ASSERT_TRUE(r.Changed());
-  EXPECT_THAT(r.replacement(), input);
-  ASSERT_EQ(BranchHint::kFalse, BranchHintOf(d.branch->op()));
-}
-
-
 // -----------------------------------------------------------------------------
 // %_ValueOf