[turbofan]: Add better encapsulation to LinkageLocation

src/compiler/instruction-selector-impl.h

 // 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.
 
 #ifndef V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_
 #define V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_
 
 #include "src/compiler/instruction.h"
 #include "src/compiler/instruction-selector.h"
 #include "src/compiler/linkage.h"
@@ skipping 190 matching lines @@
   UnallocatedOperand Use(Node* node, UnallocatedOperand operand) {
     DCHECK_NOT_NULL(node);
     DCHECK_EQ(operand.virtual_register(), GetVReg(node));
     selector()->MarkAsUsed(node);
     return operand;
   }
 
   UnallocatedOperand ToUnallocatedOperand(LinkageLocation location,
                                           MachineType type,
                                           int virtual_register) {
-    if (location.location_ == LinkageLocation::ANY_REGISTER) {
+    if (location.IsAnyRegister()) {
       // any machine register.
       return UnallocatedOperand(UnallocatedOperand::MUST_HAVE_REGISTER,
                                 virtual_register);
     }
-    if (location.location_ < 0) {
+    if (location.IsCallerFrameSlot()) {
       // a location on the caller frame.
       return UnallocatedOperand(UnallocatedOperand::FIXED_SLOT,
-                                location.location_, virtual_register);
+                                location.AsCallerFrameSlot(), virtual_register);
     }
-    if (location.location_ > LinkageLocation::ANY_REGISTER) {
+    if (location.IsCalleeFrameSlot()) {
       // a spill location on this (callee) frame.
-      return UnallocatedOperand(
-          UnallocatedOperand::FIXED_SLOT,
-          location.location_ - LinkageLocation::ANY_REGISTER - 1,
-          virtual_register);
+      return UnallocatedOperand(UnallocatedOperand::FIXED_SLOT,
+                                location.AsCalleeFrameSlot(), virtual_register);
     }
     // a fixed register.
     if (RepresentationOf(type) == kRepFloat64) {
       return UnallocatedOperand(UnallocatedOperand::FIXED_DOUBLE_REGISTER,
-                                location.location_, virtual_register);
+                                location.AsRegister(), virtual_register);
     }
     return UnallocatedOperand(UnallocatedOperand::FIXED_REGISTER,
-                              location.location_, virtual_register);
+                              location.AsRegister(), virtual_register);
   }
 
   InstructionSelector* selector_;
 };
 
 
 // The flags continuation is a way to combine a branch or a materialization
 // of a boolean value with an instruction that sets the flags register.
 // The whole instruction is treated as a unit by the register allocator, and
 // thus no spills or moves can be introduced between the flags-setting
@@ skipping 132 matching lines @@
                : (frame_state_descriptor->GetTotalSize() +
                   1);  // Include deopt id.
   }
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_