[turbofan] Simplify representations selection for phi.

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 429 matching lines @@
     VisitBinop(node, UseInfo::TruncatingWord64(), kMachBool);
   }
   void VisitUint64Cmp(Node* node) {
     VisitBinop(node, UseInfo::TruncatingWord64(), kMachBool);
   }
 
   // Infer representation for phi-like nodes.
   static MachineType GetRepresentationForPhi(Node* node, MachineTypeUnion use) {
     // Phis adapt to the output representation their uses demand.
     Type* upper = NodeProperties::GetType(node);
-    if ((use & kRepMask) == kRepFloat32) {
-      // only float32 uses.
-      return kRepFloat32;
-    } else if ((use & kRepMask) == kRepFloat64) {
-      // only float64 uses.
-      return kRepFloat64;
-    } else if ((use & kRepMask) == kRepTagged) {
-      // only tagged uses.
-      return kRepTagged;
-    } else if (upper->Is(Type::Integral32())) {
-      // Integer within [-2^31, 2^32[ range.
-      if (upper->Is(Type::Signed32()) || upper->Is(Type::Unsigned32())) {
-        // multiple uses, but we are within 32 bits range => pick kRepWord32.
-        return kRepWord32;
-      } else if (!CanObserveNonWord32(use)) {
-        // We only use 32 bits.
-        return kRepWord32;
-      } else {
-        return kRepFloat64;
-      }
+    if (upper->Is(Type::Signed32()) || upper->Is(Type::Unsigned32())) {
+      // We are within 32 bits range => pick kRepWord32.
+      return kRepWord32;
+    } else if (!CanObserveNonWord32(use)) {
+      // We only use 32 bits.
+      return kRepWord32;
     } else if (upper->Is(Type::Boolean())) {
       // multiple uses => pick kRepBit.
       return kRepBit;
     } else if (upper->Is(Type::Number())) {
       // multiple uses => pick kRepFloat64.
       return kRepFloat64;
     } else if (upper->Is(Type::Internal())) {
       return kMachPtr;
     }
     return kRepTagged;
@@ skipping 1179 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