[turbofan] Remove some dead code from the EffectControlLinearizer.

src/compiler/effect-control-linearizer.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/effect-control-linearizer.h"
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
@@ skipping 322 matching lines @@
     // the effect uses to the effect input.
     return RemoveRegionNode(node);
   }
 
   // Special treatment for checkpoint nodes.
   if (node->opcode() == IrOpcode::kCheckpoint) {
     // Unlink the check point; effect uses will be updated to the incoming
     // effect that is passed. The frame state is preserved for lowering.
     DCHECK_EQ(RegionObservability::kObservable, region_observability_);
     *frame_state = NodeProperties::GetFrameStateInput(node, 0);
-    node->TrimInputCount(0);
     return;
   }
 
   if (node->opcode() == IrOpcode::kIfSuccess) {
     // We always schedule IfSuccess with its call, so skip it here.
     DCHECK_EQ(IrOpcode::kCall, node->InputAt(0)->opcode());
     // The IfSuccess node should not belong to an exceptional call node
     // because such IfSuccess nodes should only start a basic block (and
     // basic block start nodes are not handled in the ProcessNode method).
     DCHECK(!NodeProperties::IsExceptionalCall(node->InputAt(0)));
@@ skipping 444 matching lines @@
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckBounds(Node* node, Node* frame_state,
                                           Node* effect, Node* control) {
   Node* index = node->InputAt(0);
   Node* limit = node->InputAt(1);
 
   Node* check = graph()->NewNode(machine()->Uint32LessThan(), index, limit);
   control = effect = graph()->NewNode(common()->DeoptimizeUnless(), check,
                                       frame_state, effect, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(index, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckNumber(Node* node, Node* frame_state,
                                           Node* effect, Node* control) {
   Node* value = node->InputAt(0);
 
   Node* check0 = ObjectIsSmi(value);
   Node* branch0 =
@@ skipping 10 matching lines @@
                          value, efalse0, if_false0);
     Node* check1 = graph()->NewNode(machine()->WordEqual(), value_map,
                                     jsgraph()->HeapNumberMapConstant());
     if_false0 = efalse0 = graph()->NewNode(common()->DeoptimizeUnless(), check1,
                                            frame_state, efalse0, if_false0);
   }
 
   control = graph()->NewNode(common()->Merge(2), if_true0, if_false0);
   effect = graph()->NewNode(common()->EffectPhi(2), etrue0, efalse0, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckIf(Node* node, Node* frame_state,
                                       Node* effect, Node* control) {
   Node* value = node->InputAt(0);
 
   control = effect = graph()->NewNode(common()->DeoptimizeUnless(), value,
                                       frame_state, effect, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckTaggedPointer(Node* node, Node* frame_state,
                                                  Node* effect, Node* control) {
   Node* value = node->InputAt(0);
 
   Node* check = ObjectIsSmi(value);
   control = effect = graph()->NewNode(common()->DeoptimizeIf(), check,
                                       frame_state, effect, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckTaggedSigned(Node* node, Node* frame_state,
                                                 Node* effect, Node* control) {
   Node* value = node->InputAt(0);
 
   Node* check = ObjectIsSmi(value);
   control = effect = graph()->NewNode(common()->DeoptimizeUnless(), check,
                                       frame_state, effect, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckedInt32Add(Node* node, Node* frame_state,
                                               Node* effect, Node* control) {
   Node* lhs = node->InputAt(0);
   Node* rhs = node->InputAt(1);
 
   Node* value =
       graph()->NewNode(machine()->Int32AddWithOverflow(), lhs, rhs, control);
 
   Node* check = graph()->NewNode(common()->Projection(1), value, control);
   control = effect = graph()->NewNode(common()->DeoptimizeIf(), check,
                                       frame_state, effect, control);
 
   value = graph()->NewNode(common()->Projection(0), value, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckedInt32Sub(Node* node, Node* frame_state,
                                               Node* effect, Node* control) {
   Node* lhs = node->InputAt(0);
   Node* rhs = node->InputAt(1);
 
   Node* value =
       graph()->NewNode(machine()->Int32SubWithOverflow(), lhs, rhs, control);
 
   Node* check = graph()->NewNode(common()->Projection(1), value, control);
   control = effect = graph()->NewNode(common()->DeoptimizeIf(), check,
                                       frame_state, effect, control);
 
   value = graph()->NewNode(common()->Projection(0), value, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckedInt32Div(Node* node, Node* frame_state,
                                               Node* effect, Node* control) {
   Node* zero = jsgraph()->Int32Constant(0);
   Node* minusone = jsgraph()->Int32Constant(-1);
   Node* minint = jsgraph()->Int32Constant(std::numeric_limits<int32_t>::min());
 
@@ skipping 59 matching lines @@
       graph()->NewNode(common()->Phi(MachineRepresentation::kWord32, 2), vtrue0,
                        vfalse0, control);
 
   // Check if the remainder is non-zero.
   Node* check =
       graph()->NewNode(machine()->Word32Equal(), lhs,
                        graph()->NewNode(machine()->Int32Mul(), rhs, value));
   control = effect = graph()->NewNode(common()->DeoptimizeUnless(), check,
                                       frame_state, effect, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckedInt32Mod(Node* node, Node* frame_state,
                                               Node* effect, Node* control) {
   Node* zero = jsgraph()->Int32Constant(0);
   Node* minusone = jsgraph()->Int32Constant(-1);
   Node* minint = jsgraph()->Int32Constant(std::numeric_limits<int32_t>::min());
 
@@ skipping 53 matching lines @@
     if_false0 = efalse0 = graph()->NewNode(common()->DeoptimizeIf(), check,
                                            frame_state, efalse0, if_false0);
   }
 
   control = graph()->NewNode(common()->Merge(2), if_true0, if_false0);
   effect = graph()->NewNode(common()->EffectPhi(2), etrue0, efalse0, control);
   Node* value =
       graph()->NewNode(common()->Phi(MachineRepresentation::kWord32, 2), vtrue0,
                        vfalse0, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckedUint32ToInt32(Node* node,
                                                    Node* frame_state,
                                                    Node* effect,
                                                    Node* control) {
   Node* value = node->InputAt(0);
   Node* max_int = jsgraph()->Int32Constant(std::numeric_limits<int32_t>::max());
   Node* is_safe =
       graph()->NewNode(machine()->Uint32LessThanOrEqual(), value, max_int);
   control = effect = graph()->NewNode(common()->DeoptimizeUnless(), is_safe,
                                       frame_state, effect, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::BuildCheckedFloat64ToInt32(Node* value,
                                                     Node* frame_state,
                                                     Node* effect,
                                                     Node* control) {
   Node* value32 = graph()->NewNode(machine()->RoundFloat64ToInt32(), value);
   Node* check_same = graph()->NewNode(
@@ skipping 29 matching lines @@
   return ValueEffectControl(value32, effect, merge);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckedFloat64ToInt32(Node* node,
                                                     Node* frame_state,
                                                     Node* effect,
                                                     Node* control) {
   Node* value = node->InputAt(0);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return BuildCheckedFloat64ToInt32(value, frame_state, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckedTaggedToInt32(Node* node,
                                                    Node* frame_state,
                                                    Node* effect,
                                                    Node* control) {
   Node* value = node->InputAt(0);
 
@@ skipping 27 matching lines @@
     if_false = state.control;
     efalse = state.effect;
     vfalse = state.value;
   }
 
   control = graph()->NewNode(common()->Merge(2), if_true, if_false);
   effect = graph()->NewNode(common()->EffectPhi(2), etrue, efalse, control);
   value = graph()->NewNode(common()->Phi(MachineRepresentation::kWord32, 2),
                            vtrue, vfalse, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::BuildCheckedHeapNumberOrOddballToFloat64(
     Node* value, Node* frame_state, Node* effect, Node* control) {
   Node* value_map = effect = graph()->NewNode(
       simplified()->LoadField(AccessBuilder::ForMap()), value, effect, control);
   Node* check_number = graph()->NewNode(machine()->WordEqual(), value_map,
                                         jsgraph()->HeapNumberMapConstant());
@@ skipping 51 matching lines @@
       value, frame_state, effect, if_false);
 
   Node* merge =
       graph()->NewNode(common()->Merge(2), if_true, number_state.control);
   Node* effect_phi = graph()->NewNode(common()->EffectPhi(2), etrue,
                                       number_state.effect, merge);
   Node* result =
       graph()->NewNode(common()->Phi(MachineRepresentation::kFloat64, 2), vtrue,
                        number_state.value, merge);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(result, effect_phi, merge);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerTruncateTaggedToWord32(Node* node, Node* effect,
                                                      Node* control) {
   Node* value = node->InputAt(0);
 
   Node* check = ObjectIsSmi(value);
   Node* branch =
@@ skipping 340 matching lines @@
   // with allow-return-hole, we cannot do anything, so just deoptimize
   // in case of the hole NaN (similar to Crankshaft).
   Node* value = node->InputAt(0);
   Node* check = graph()->NewNode(
       machine()->Word32Equal(),
       graph()->NewNode(machine()->Float64ExtractHighWord32(), value),
       jsgraph()->Int32Constant(kHoleNanUpper32));
   control = effect = graph()->NewNode(common()->DeoptimizeIf(), check,
                                       frame_state, effect, control);
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckTaggedHole(Node* node, Node* frame_state,
                                               Node* effect, Node* control) {
   CheckTaggedHoleMode mode = CheckTaggedHoleModeOf(node->op());
   Node* value = node->InputAt(0);
   Node* check = graph()->NewNode(machine()->WordEqual(), value,
                                  jsgraph()->TheHoleConstant());
   switch (mode) {
     case CheckTaggedHoleMode::kConvertHoleToUndefined:
       value = graph()->NewNode(
           common()->Select(MachineRepresentation::kTagged, BranchHint::kFalse),
           check, jsgraph()->UndefinedConstant(), value);
       break;
     case CheckTaggedHoleMode::kNeverReturnHole:
       control = effect = graph()->NewNode(common()->DeoptimizeIf(), check,
                                           frame_state, effect, control);
       break;
   }
 
-  // Make sure the lowered node does not appear in any use lists.
-  node->TrimInputCount(0);
-
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::AllocateHeapNumberWithValue(Node* value, Node* effect,
                                                      Node* control) {
   Node* result = effect = graph()->NewNode(
       simplified()->Allocate(NOT_TENURED),
       jsgraph()->Int32Constant(HeapNumber::kSize), effect, control);
   effect = graph()->NewNode(simplified()->StoreField(AccessBuilder::ForMap()),
@@ skipping 188 matching lines @@
         isolate(), graph()->zone(), callable.descriptor(), 0, flags,
         Operator::kNoThrow);
     to_number_operator_.set(common()->Call(desc));
   }
   return to_number_operator_.get();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8