[turbofan] Address the useless overflow bit materialization.

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 422 matching lines @@
       break;
     case IrOpcode::kCheckBounds:
       state = LowerCheckBounds(node, frame_state, *effect, *control);
       break;
     case IrOpcode::kCheckTaggedPointer:
       state = LowerCheckTaggedPointer(node, frame_state, *effect, *control);
       break;
     case IrOpcode::kCheckTaggedSigned:
       state = LowerCheckTaggedSigned(node, frame_state, *effect, *control);
       break;
+    case IrOpcode::kCheckedInt32Add:
+      state = LowerCheckedInt32Add(node, frame_state, *effect, *control);
+      break;
+    case IrOpcode::kCheckedInt32Sub:
+      state = LowerCheckedInt32Sub(node, frame_state, *effect, *control);
+      break;
     case IrOpcode::kCheckedUint32ToInt32:
       state = LowerCheckedUint32ToInt32(node, frame_state, *effect, *control);
       break;
     case IrOpcode::kCheckedFloat64ToInt32:
       state = LowerCheckedFloat64ToInt32(node, frame_state, *effect, *control);
       break;
     case IrOpcode::kCheckedTaggedToInt32:
       state = LowerCheckedTaggedToInt32(node, frame_state, *effect, *control);
       break;
     case IrOpcode::kCheckedTaggedToFloat64:
@@ skipping 16 matching lines @@
       break;
     case IrOpcode::kObjectIsString:
       state = LowerObjectIsString(node, *effect, *control);
       break;
     case IrOpcode::kObjectIsUndetectable:
       state = LowerObjectIsUndetectable(node, *effect, *control);
       break;
     case IrOpcode::kStringFromCharCode:
       state = LowerStringFromCharCode(node, *effect, *control);
       break;
-    case IrOpcode::kCheckIf:
-      state = LowerCheckIf(node, frame_state, *effect, *control);
-      break;
     case IrOpcode::kCheckFloat64Hole:
       state = LowerCheckFloat64Hole(node, frame_state, *effect, *control);
       break;
     case IrOpcode::kCheckTaggedHole:
       state = LowerCheckTaggedHole(node, frame_state, *effect, *control);
       break;
     case IrOpcode::kPlainPrimitiveToNumber:
       state = LowerPlainPrimitiveToNumber(node, *effect, *control);
       break;
     case IrOpcode::kPlainPrimitiveToWord32:
@@ skipping 55 matching lines @@
 
   // We need to create a box for negative 0.
   if_smi = graph()->NewNode(common()->Merge(2), if_notzero, if_notnegative);
   if_box = graph()->NewNode(common()->Merge(2), if_box, if_negative);
 
   // On 64-bit machines we can just wrap the 32-bit integer in a smi, for 32-bit
   // machines we need to deal with potential overflow and fallback to boxing.
   if (machine()->Is64()) {
     vsmi = ChangeInt32ToSmi(value32);
   } else {
-    Node* smi_tag =
-        graph()->NewNode(machine()->Int32AddWithOverflow(), value32, value32);
+    Node* smi_tag = graph()->NewNode(machine()->Int32AddWithOverflow(), value32,
+                                     value32, if_smi);
 
-    Node* check_ovf = graph()->NewNode(common()->Projection(1), smi_tag);
+    Node* check_ovf =
+        graph()->NewNode(common()->Projection(1), smi_tag, if_smi);
     Node* branch_ovf = graph()->NewNode(common()->Branch(BranchHint::kFalse),
                                         check_ovf, if_smi);
 
     Node* if_ovf = graph()->NewNode(common()->IfTrue(), branch_ovf);
     if_box = graph()->NewNode(common()->Merge(2), if_ovf, if_box);
 
     if_smi = graph()->NewNode(common()->IfFalse(), branch_ovf);
-    vsmi = graph()->NewNode(common()->Projection(0), smi_tag);
+    vsmi = graph()->NewNode(common()->Projection(0), smi_tag, if_smi);
   }
 
   // Allocate the box for the {value}.
   ValueEffectControl box = AllocateHeapNumberWithValue(value, effect, if_box);
 
   control = graph()->NewNode(common()->Merge(2), if_smi, box.control);
   value = graph()->NewNode(common()->Phi(MachineRepresentation::kTagged, 2),
                            vsmi, box.value, control);
   effect =
       graph()->NewNode(common()->EffectPhi(2), effect, box.effect, control);
@@ skipping 31 matching lines @@
 
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerChangeInt32ToTagged(Node* node, Node* effect,
                                                   Node* control) {
   Node* value = node->InputAt(0);
 
   if (machine()->Is64()) {
     return ValueEffectControl(ChangeInt32ToSmi(value), effect, control);
   }
 
-  Node* add = graph()->NewNode(machine()->Int32AddWithOverflow(), value, value);
+  Node* add = graph()->NewNode(machine()->Int32AddWithOverflow(), value, value,
+                               control);
 
-  Node* ovf = graph()->NewNode(common()->Projection(1), add);
+  Node* ovf = graph()->NewNode(common()->Projection(1), add, control);
   Node* branch =
       graph()->NewNode(common()->Branch(BranchHint::kFalse), ovf, control);
 
   Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
   ValueEffectControl alloc =
       AllocateHeapNumberWithValue(ChangeInt32ToFloat64(value), effect, if_true);
 
   Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
-  Node* vfalse = graph()->NewNode(common()->Projection(0), add);
+  Node* vfalse = graph()->NewNode(common()->Projection(0), add, if_false);
 
   Node* merge = graph()->NewNode(common()->Merge(2), alloc.control, if_false);
   Node* phi = graph()->NewNode(common()->Phi(MachineRepresentation::kTagged, 2),
                                alloc.value, vfalse, merge);
   Node* ephi =
       graph()->NewNode(common()->EffectPhi(2), alloc.effect, effect, merge);
 
   return ValueEffectControl(phi, ephi, merge);
 }
 
@@ skipping 186 matching lines @@
   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::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);
@@ skipping 517 matching lines @@
 
   control = graph()->NewNode(common()->Merge(2), if_true0, if_false0);
   effect = graph()->NewNode(common()->EffectPhi(2), etrue0, efalse0, control);
   value = graph()->NewNode(common()->Phi(MachineRepresentation::kTagged, 2),
                            vtrue0, vfalse0, control);
 
   return ValueEffectControl(value, effect, control);
 }
 
 EffectControlLinearizer::ValueEffectControl
-EffectControlLinearizer::LowerCheckIf(Node* node, Node* frame_state,
-                                      Node* effect, Node* control) {
-  NodeProperties::ReplaceEffectInput(node, effect);
-  NodeProperties::ReplaceControlInput(node, control);
-  DCHECK_NOT_NULL(frame_state);
-  node->InsertInput(graph()->zone(), 1, frame_state);
-  NodeProperties::ChangeOp(node, common()->DeoptimizeIf());
-  return ValueEffectControl(node, node, node);
-}
-
-EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckFloat64Hole(Node* node, Node* frame_state,
                                                Node* effect, Node* control) {
   // If we reach this point w/o eliminating the {node} that's marked
   // 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));
@@ skipping 229 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