[turbofan] Eliminate a few redundant bounds checks.

src/compiler/simplified-lowering.cc

 // Copyright 2014 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/simplified-lowering.h"
 
 #include <limits>
 
 #include "src/address-map.h"
 #include "src/base/bits.h"
@@ skipping 1252 matching lines @@
           // No input representation requirement; adapt during lowering.
           ProcessInput(node, 0, UseInfo::AnyTruncatingToBool());
           SetOutput(node, MachineRepresentation::kWord32);
         }
         return;
       }
       case IrOpcode::kNumberEqual:
       case IrOpcode::kNumberLessThan:
       case IrOpcode::kNumberLessThanOrEqual: {
         // Number comparisons reduce to integer comparisons for integer inputs.
-        if (TypeOf(node->InputAt(0))->Is(Type::Signed32()) &&
-            TypeOf(node->InputAt(1))->Is(Type::Signed32())) {
+        if (TypeOf(node->InputAt(0))->Is(Type::Unsigned32()) &&
+            TypeOf(node->InputAt(1))->Is(Type::Unsigned32())) {
+          // => unsigned Int32Cmp
+          VisitUint32Cmp(node);
+          if (lower()) NodeProperties::ChangeOp(node, Uint32Op(node));
+        } else if (TypeOf(node->InputAt(0))->Is(Type::Signed32()) &&
+                   TypeOf(node->InputAt(1))->Is(Type::Signed32())) {
           // => signed Int32Cmp
           VisitInt32Cmp(node);
           if (lower()) NodeProperties::ChangeOp(node, Int32Op(node));
-        } else if (TypeOf(node->InputAt(0))->Is(Type::Unsigned32()) &&
-                   TypeOf(node->InputAt(1))->Is(Type::Unsigned32())) {
-          // => unsigned Int32Cmp
-          VisitUint32Cmp(node);
-          if (lower()) NodeProperties::ChangeOp(node, Uint32Op(node));
         } else {
           // => Float64Cmp
           VisitFloat64Cmp(node);
           if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
         }
         return;
       }
 
       case IrOpcode::kSpeculativeNumberAdd:
       case IrOpcode::kSpeculativeNumberSubtract:
         return VisitSpeculativeAdditiveOp(node, truncation, lowering);
 
       case IrOpcode::kSpeculativeNumberLessThan:
       case IrOpcode::kSpeculativeNumberLessThanOrEqual:
       case IrOpcode::kSpeculativeNumberEqual: {
         // Number comparisons reduce to integer comparisons for integer inputs.
-        if (TypeOf(node->InputAt(0))->Is(Type::Signed32()) &&
-            TypeOf(node->InputAt(1))->Is(Type::Signed32())) {
+        if (TypeOf(node->InputAt(0))->Is(Type::Unsigned32()) &&
+            TypeOf(node->InputAt(1))->Is(Type::Unsigned32())) {
+          // => unsigned Int32Cmp
+          VisitUint32Cmp(node);
+          if (lower()) ChangeToPureOp(node, Uint32Op(node));
+          return;
+        } else if (TypeOf(node->InputAt(0))->Is(Type::Signed32()) &&
+                   TypeOf(node->InputAt(1))->Is(Type::Signed32())) {
           // => signed Int32Cmp
           VisitInt32Cmp(node);
           if (lower()) ChangeToPureOp(node, Int32Op(node));
           return;
-        } else if (TypeOf(node->InputAt(0))->Is(Type::Unsigned32()) &&
-                   TypeOf(node->InputAt(1))->Is(Type::Unsigned32())) {
-          // => unsigned Int32Cmp
-          VisitUint32Cmp(node);
-          if (lower()) ChangeToPureOp(node, Uint32Op(node));
-          return;
         }
         // Try to use type feedback.
         CompareOperationHints::Hint hint = CompareOperationHintOf(node->op());
 
         if (hint == CompareOperationHints::kSignedSmall) {
           VisitBinop(node, UseInfo::CheckedSigned32AsWord32(),
                      MachineRepresentation::kBit);
           if (lower()) ChangeToPureOp(node, Int32Op(node));
           return;
         }
@@ skipping 1942 matching lines @@
         isolate(), graph()->zone(), callable.descriptor(), 0, flags,
         Operator::kNoProperties);
     to_number_operator_.set(common()->Call(desc));
   }
   return to_number_operator_.get();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8