[turbofan] Introduce representation-change.cc, move stuff there, minus dead code.

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 276 matching lines @@
            base::bits::IsPowerOfTwo32(output & kRepMask));
     GetInfo(node)->set_output_type(output);
   }
 
   bool BothInputsAre(Node* node, Type* type) {
     DCHECK_EQ(2, node->InputCount());
     return NodeProperties::GetType(node->InputAt(0))->Is(type) &&
            NodeProperties::GetType(node->InputAt(1))->Is(type);
   }
 
-  void ProcessTruncateWord32Input(Node* node, int index) {
-    Node* input = node->InputAt(index);
-    if (phase_ == PROPAGATE) {
-      // In the propagate phase, propagate the usage information backward.
-      Enqueue(input, UseInfo::TruncatingWord32());
-    } else {
-      // In the change phase, insert a change before the use if necessary.
-      MachineTypeUnion output = GetInfo(input)->output_type();
-      if ((output & (kRepBit | kRepWord8 | kRepWord16 | kRepWord32)) == 0) {
-        // Output representation doesn't match usage.
-        TRACE("  truncate-to-int32: #%d:%s(@%d #%d:%s) ", node->id(),
-              node->op()->mnemonic(), index, input->id(),
-              input->op()->mnemonic());
-        TRACE(" from ");
-        PrintInfo(output);
-        TRACE("\n");
-        Node* n = changer_->GetTruncatedWord32For(input, output);
-        node->ReplaceInput(index, n);
-      }
-    }
-  }
-
   void EnqueueInputUse(Node* node, int index, UseInfo use) {
     Enqueue(node->InputAt(index), use);
   }
 
   void ConvertInput(Node* node, int index, UseInfo use) {
     Node* input = node->InputAt(index);
     // In the change phase, insert a change before the use if necessary.
     if (use.preferred() == kMachNone)
       return;  // No input requirement on the use.
     MachineTypeUnion output = GetInfo(input)->output_type();
@@ skipping 1290 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