[turbofan] Don't generate unnecessary minus zero checks.

src/compiler/representation-change.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/representation-change.h"
 
 #include <sstream>
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 421 matching lines @@
     return node;  // Sloppy comparison -> word32
   } else if (output_rep == MachineRepresentation::kFloat64) {
     if (output_type->Is(Type::Unsigned32())) {
       op = machine()->ChangeFloat64ToUint32();
     } else if (output_type->Is(Type::Signed32())) {
       op = machine()->ChangeFloat64ToInt32();
     } else if (use_info.truncation().IsUsedAsWord32()) {
       op = machine()->TruncateFloat64ToWord32();
     } else if (use_info.type_check() == TypeCheckKind::kSignedSmall ||
                use_info.type_check() == TypeCheckKind::kSigned32) {
-      op = simplified()->CheckedFloat64ToInt32();
+      op = simplified()->CheckedFloat64ToInt32(
+          output_type->Maybe(Type::MinusZero())
+              ? CheckForMinusZeroMode::kCheckForMinusZero
+              : CheckForMinusZeroMode::kDontCheckForMinusZero);
     }
   } else if (output_rep == MachineRepresentation::kFloat32) {
     node = InsertChangeFloat32ToFloat64(node);  // float32 -> float64 -> int32
     if (output_type->Is(Type::Unsigned32())) {
       op = machine()->ChangeFloat64ToUint32();
     } else if (output_type->Is(Type::Signed32())) {
       op = machine()->ChangeFloat64ToInt32();
     } else if (use_info.truncation().IsUsedAsWord32()) {
       op = machine()->TruncateFloat64ToWord32();
     } else if (use_info.type_check() == TypeCheckKind::kSignedSmall ||
                use_info.type_check() == TypeCheckKind::kSigned32) {
-      op = simplified()->CheckedFloat64ToInt32();
+      op = simplified()->CheckedFloat64ToInt32(
+          output_type->Maybe(Type::MinusZero())
+              ? CheckForMinusZeroMode::kCheckForMinusZero
+              : CheckForMinusZeroMode::kDontCheckForMinusZero);
     }
   } else if (output_rep == MachineRepresentation::kTagged) {
     if (output_type->Is(Type::TaggedSigned())) {
       op = simplified()->ChangeTaggedSignedToInt32();
     } else if (output_type->Is(Type::Unsigned32())) {
       op = simplified()->ChangeTaggedToUint32();
     } else if (output_type->Is(Type::Signed32())) {
       op = simplified()->ChangeTaggedToInt32();
     } else if (use_info.truncation().IsUsedAsWord32()) {
       if (use_info.type_check() != TypeCheckKind::kNone) {
         op = simplified()->CheckedTruncateTaggedToWord32();
       } else {
         op = simplified()->TruncateTaggedToWord32();
       }
     } else if (use_info.type_check() == TypeCheckKind::kSignedSmall) {
       op = simplified()->CheckedTaggedSignedToInt32();
     } else if (use_info.type_check() == TypeCheckKind::kSigned32) {
-      op = simplified()->CheckedTaggedToInt32();
+      op = simplified()->CheckedTaggedToInt32(
+          output_type->Maybe(Type::MinusZero())
+              ? CheckForMinusZeroMode::kCheckForMinusZero
+              : CheckForMinusZeroMode::kDontCheckForMinusZero);
     }
   } else if (output_rep == MachineRepresentation::kWord32) {
     // Only the checked case should get here, the non-checked case is
     // handled in GetRepresentationFor.
     if (use_info.type_check() == TypeCheckKind::kSignedSmall ||
         use_info.type_check() == TypeCheckKind::kSigned32) {
       if (output_type->Is(Type::Signed32())) {
         return node;
       } else if (output_type->Is(Type::Unsigned32())) {
         op = simplified()->CheckedUint32ToInt32();
@@ skipping 312 matching lines @@
 }
 
 Node* RepresentationChanger::InsertChangeTaggedToFloat64(Node* node) {
   return jsgraph()->graph()->NewNode(simplified()->ChangeTaggedToFloat64(),
                                      node);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8