[turbofan] Live Range unit tests

src/compiler/register-allocator.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/base/adapters.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/register-allocator.h"
 #include "src/string-stream.h"
 
 namespace v8 {
@@ skipping 419 matching lines @@
   if (child->next() == nullptr) {
     TopLevel()->set_last_child(child);
   }
   return child;
 }
 
 
 void LiveRange::DetachAt(LifetimePosition position, LiveRange* result,
                          Zone* zone) {
   DCHECK(Start() < position);
+  DCHECK(End() > position);
   DCHECK(result->IsEmpty());
   // Find the last interval that ends before the position. If the
   // position is contained in one of the intervals in the chain, we
   // split that interval and use the first part.
   auto current = FirstSearchIntervalForPosition(position);
 
   // If the split position coincides with the beginning of a use interval
   // we need to split use positons in a special way.
   bool split_at_start = false;
 
@@ skipping 421 matching lines @@
 
   result->SetSplinteredFrom(this);
 }
 
 
 void TopLevelLiveRange::SetSplinteredFrom(TopLevelLiveRange* splinter_parent) {
   // The splinter parent is always the original "Top".
   DCHECK(splinter_parent->Start() < Start());
 
   splintered_from_ = splinter_parent;
-  if (!HasSpillOperand()) {
+  if (!HasSpillOperand() && splinter_parent->spill_range_ != nullptr) {
     SetSpillRange(splinter_parent->spill_range_);
   }
 }
 
 
 void TopLevelLiveRange::UpdateSpillRangePostMerge(TopLevelLiveRange* merged) {
   DCHECK(merged->TopLevel() == this);
 
   if (HasNoSpillType() && merged->HasSpillRange()) {
     set_spill_type(merged->spill_type());
@@ skipping 2421 matching lines @@
     auto eliminate = moves->PrepareInsertAfter(move);
     to_insert.push_back(move);
     if (eliminate != nullptr) to_eliminate.push_back(eliminate);
   }
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8