[turbofan] remove checks for virtual register overflow

src/compiler/register-allocator.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_REGISTER_ALLOCATOR_H_
 #define V8_REGISTER_ALLOCATOR_H_
 
 #include "src/compiler/instruction.h"
 #include "src/zone-containers.h"
 
@@ skipping 359 matching lines @@
 };
 
 
 class RegisterAllocator FINAL : public ZoneObject {
  public:
   explicit RegisterAllocator(const RegisterConfiguration* config,
                              Zone* local_zone, Frame* frame,
                              InstructionSequence* code,
                              const char* debug_name = nullptr);
 
-  bool AllocationOk() { return allocation_ok_; }
-
   const ZoneVector<LiveRange*>& live_ranges() const { return live_ranges_; }
   const ZoneVector<LiveRange*>& fixed_live_ranges() const {
     return fixed_live_ranges_;
   }
   const ZoneVector<LiveRange*>& fixed_double_live_ranges() const {
     return fixed_double_live_ranges_;
   }
   InstructionSequence* code() const { return code_; }
   // This zone is for datastructures only needed during register allocation.
   Zone* local_zone() const { return local_zone_; }
@@ skipping 22 matching lines @@
   // Phase 7: compute values for pointer maps.
   void PopulatePointerMaps();  // TODO(titzer): rename to PopulateReferenceMaps.
 
   // Phase 8: reconnect split ranges with moves.
   void ConnectRanges();
 
   // Phase 9: insert moves to connect ranges across basic blocks.
   void ResolveControlFlow();
 
  private:
-  int GetVirtualRegister() {
-    int vreg = code()->NextVirtualRegister();
-    if (vreg >= UnallocatedOperand::kMaxVirtualRegisters) {
-      allocation_ok_ = false;
-      // Maintain the invariant that we return something below the maximum.
-      return 0;
-    }
-    return vreg;
-  }
+  int GetVirtualRegister() { return code()->NextVirtualRegister(); }
 
   // Checks whether the value of a given virtual register is a reference.
   // TODO(titzer): rename this to IsReference.
   bool HasTaggedValue(int virtual_register) const;
 
   // Returns the register kind required by the given virtual register.
   RegisterKind RequiredRegisterKind(int virtual_register) const;
 
   // This zone is for InstructionOperands and moves that live beyond register
   // allocation.
@@ skipping 175 matching lines @@
   ZoneVector<LiveRange*> inactive_live_ranges_;
   ZoneVector<LiveRange*> reusable_slots_;
   ZoneVector<SpillRange*> spill_ranges_;
 
   RegisterKind mode_;
   int num_registers_;
 
   BitVector* assigned_registers_;
   BitVector* assigned_double_registers_;
 
-  // Indicates success or failure during register allocation.
-  bool allocation_ok_;
-
 #ifdef DEBUG
   LifetimePosition allocation_finger_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(RegisterAllocator);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGISTER_ALLOCATOR_H_