[turbofan] Simplify representation inference for add/subtract.

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/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 456 matching lines @@
   const Operator* Uint32Op(Node* node) {
     return changer_->Uint32OperatorFor(node->opcode());
   }
 
   const Operator* Float64Op(Node* node) {
     return changer_->Float64OperatorFor(node->opcode());
   }
 
   bool CanLowerToInt32Binop(Node* node, MachineTypeUnion use) {
     return BothInputsAre(node, Type::Signed32()) &&
-           (!CanObserveNonInt32(use) ||
+           (!CanObserveNonWord32(use) ||
             NodeProperties::GetType(node)->Is(Type::Signed32()));
   }
 
-  bool CanLowerToInt32AdditiveBinop(Node* node, MachineTypeUnion use) {
+  bool CanLowerToWord32AdditiveBinop(Node* node, MachineTypeUnion use) {
     return BothInputsAre(node, safe_int_additive_range_) &&
-           !CanObserveNonInt32(use);
+           !CanObserveNonWord32(use);
   }
 
   bool CanLowerToUint32Binop(Node* node, MachineTypeUnion use) {
     return BothInputsAre(node, Type::Unsigned32()) &&
-           (!CanObserveNonUint32(use) ||
+           (!CanObserveNonWord32(use) ||
             NodeProperties::GetType(node)->Is(Type::Unsigned32()));
   }
 
-  bool CanLowerToUint32AdditiveBinop(Node* node, MachineTypeUnion use) {
-    return BothInputsAre(node, safe_int_additive_range_) &&
-           !CanObserveNonUint32(use);
-  }
-
   bool CanObserveNonWord32(MachineTypeUnion use) {
-    return (use & ~(kTypeUint32 | kTypeInt32)) != 0;
-  }
-
-  bool CanObserveNonInt32(MachineTypeUnion use) {
-    return (use & (kTypeUint32 | kTypeNumber | kTypeAny)) != 0;
+    return (use & kTypeMask & ~(kTypeInt32 | kTypeUint32)) != 0;
   }
 
   bool CanObserveMinusZero(MachineTypeUnion use) {
     // TODO(turbofan): technically Uint32 cannot observe minus zero either.
     return (use & (kTypeUint32 | kTypeNumber | kTypeAny)) != 0;
   }
 
   bool CanObserveNaN(MachineTypeUnion use) {
     return (use & (kTypeNumber | kTypeAny)) != 0;
   }
 
-  bool CanObserveNonUint32(MachineTypeUnion use) {
-    return (use & (kTypeInt32 | kTypeNumber | kTypeAny)) != 0;
-  }
-
   // Dispatching routine for visiting the node {node} with the usage {use}.
   // Depending on the operator, propagate new usage info to the inputs.
   void VisitNode(Node* node, MachineTypeUnion use,
                  SimplifiedLowering* lowering) {
     switch (node->opcode()) {
       //------------------------------------------------------------------
       // Common operators.
       //------------------------------------------------------------------
       case IrOpcode::kStart:
       case IrOpcode::kDead:
@@ skipping 109 matching lines @@
         break;
       }
       case IrOpcode::kNumberAdd:
       case IrOpcode::kNumberSubtract: {
         // Add and subtract reduce to Int32Add/Sub if the inputs
         // are already integers and all uses are truncating.
         if (CanLowerToInt32Binop(node, use)) {
           // => signed Int32Add/Sub
           VisitInt32Binop(node);
           if (lower()) NodeProperties::ChangeOp(node, Int32Op(node));
-        } else if (CanLowerToInt32AdditiveBinop(node, use)) {
+        } else if (CanLowerToUint32Binop(node, use)) {
+          // => unsigned Int32Add/Sub
+          VisitUint32Binop(node);
+          if (lower()) NodeProperties::ChangeOp(node, Uint32Op(node));
+        } else if (CanLowerToWord32AdditiveBinop(node, use)) {
           // => signed Int32Add/Sub, truncating inputs
           ProcessTruncateWord32Input(node, 0, kTypeInt32);
           ProcessTruncateWord32Input(node, 1, kTypeInt32);
           SetOutput(node, kMachInt32);
           if (lower()) NodeProperties::ChangeOp(node, Int32Op(node));
-        } else if (CanLowerToUint32Binop(node, use)) {
-          // => unsigned Int32Add/Sub
-          VisitUint32Binop(node);
-          if (lower()) NodeProperties::ChangeOp(node, Uint32Op(node));
-        } else if (CanLowerToUint32AdditiveBinop(node, use)) {
-          // => signed Int32Add/Sub, truncating inputs
-          ProcessTruncateWord32Input(node, 0, kTypeUint32);
-          ProcessTruncateWord32Input(node, 1, kTypeUint32);
-          SetOutput(node, kMachUint32);
-          if (lower()) NodeProperties::ChangeOp(node, Uint32Op(node));
         } else {
           // => Float64Add/Sub
           VisitFloat64Binop(node);
           if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
         }
         break;
       }
       case IrOpcode::kNumberMultiply: {
         NumberMatcher right(node->InputAt(1));
         if (right.IsInRange(-1048576, 1048576)) {  // must fit double mantissa.
@@ skipping 1025 matching lines @@
   ReplaceEffectUses(node, comparison);
   node->ReplaceInput(0, comparison);
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
   node->TrimInputCount(2);
   NodeProperties::ChangeOp(node, machine()->IntLessThanOrEqual());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8