[turbofan] Pre-spill ranges that have a slot use.

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 2367 matching lines @@
     const LiveRange* range, int instruction_index) {
   LifetimePosition ret = LifetimePosition::Invalid();
 
   ret = LifetimePosition::GapFromInstructionIndex(instruction_index);
   if (range->Start() >= ret || ret >= range->End()) {
     return LifetimePosition::Invalid();
   }
   return ret;
 }
 
-
-void RegisterAllocator::SplitAndSpillRangesDefinedByMemoryOperand(
-    bool operands_only) {
+void RegisterAllocator::SplitAndSpillRangesDefinedByMemoryOperand() {
   size_t initial_range_count = data()->live_ranges().size();
   for (size_t i = 0; i < initial_range_count; ++i) {
     TopLevelLiveRange* range = data()->live_ranges()[i];
     if (!CanProcessRange(range)) continue;
-    if (!range->HasSpillOperand()) continue;
-
+    if (range->HasNoSpillType() ||
+        (range->HasSpillRange() && !range->has_slot_use())) {
+      continue;
+    }
     LifetimePosition start = range->Start();
     TRACE("Live range %d:%d is defined by a spill operand.\n",
           range->TopLevel()->vreg(), range->relative_id());
     LifetimePosition next_pos = start;
     if (next_pos.IsGapPosition()) {
       next_pos = next_pos.NextStart();
     }
     UsePosition* pos = range->NextUsePositionRegisterIsBeneficial(next_pos);
     // If the range already has a spill operand and it doesn't need a
     // register immediately, split it and spill the first part of the range.
@@ skipping 157 matching lines @@
   DCHECK(RegisterConfiguration::kMaxFPRegisters >=
          this->data()->config()->num_general_registers());
 }
 
 
 void LinearScanAllocator::AllocateRegisters() {
   DCHECK(unhandled_live_ranges().empty());
   DCHECK(active_live_ranges().empty());
   DCHECK(inactive_live_ranges().empty());
 
-  SplitAndSpillRangesDefinedByMemoryOperand(code()->VirtualRegisterCount() <=
-                                            num_allocatable_registers());
+  SplitAndSpillRangesDefinedByMemoryOperand();
 
   for (TopLevelLiveRange* range : data()->live_ranges()) {
     if (!CanProcessRange(range)) continue;
     for (LiveRange* to_add = range; to_add != nullptr;
          to_add = to_add->next()) {
       if (!to_add->spilled()) {
         AddToUnhandledUnsorted(to_add);
       }
     }
   }
@@ skipping 1035 matching lines @@
         }
       }
     }
   }
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8