[turbofan] Readjust has_slot_use after splintering

src/compiler/live-range-separator.cc

 // Copyright 2015 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/live-range-separator.h"
 #include "src/compiler/register-allocator.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ skipping 40 matching lines @@
       data->live_ranges()[splinter->vreg()] = splinter;
       range->SetSplinter(splinter);
     }
     Zone *zone = data->allocation_zone();
     TRACE("creating splinter for range %d between %d and %d\n", range->vreg(),
           start.ToInstructionIndex(), end.ToInstructionIndex());
     range->Splinter(start, end, zone);
   }
 }
 
+void SetSlotUse(TopLevelLiveRange *range) {
+  range->set_has_slot_use(false);
+  for (const UsePosition *pos = range->first_pos();
+       !range->has_slot_use() && pos != nullptr; pos = pos->next()) {
+    if (pos->type() == UsePositionType::kRequiresSlot) {
+      range->set_has_slot_use(true);
+    }
+  }
+}
 
 void SplinterLiveRange(TopLevelLiveRange *range, RegisterAllocationData *data) {
   const InstructionSequence *code = data->code();
   UseInterval *interval = range->first_interval();
 
   LifetimePosition first_cut = LifetimePosition::Invalid();
   LifetimePosition last_cut = LifetimePosition::Invalid();
 
   while (interval != nullptr) {
     UseInterval *next_interval = interval->next();
@@ skipping 21 matching lines @@
         }
       }
     }
     interval = next_interval;
   }
   // When the range ends in deferred blocks, first_cut will be valid here.
   // Splinter from there to the last instruction that was in a deferred block.
   if (first_cut.IsValid()) {
     CreateSplinter(range, data, first_cut, last_cut);
   }
+
+  // Redo has_slot_use
+  if (range->has_slot_use() && range->splinter() != nullptr) {
+    SetSlotUse(range);
+    SetSlotUse(range->splinter());
+  }
 }
+
 }  // namespace
 
 
 void LiveRangeSeparator::Splinter() {
   size_t virt_reg_count = data()->live_ranges().size();
   for (size_t vreg = 0; vreg < virt_reg_count; ++vreg) {
     TopLevelLiveRange *range = data()->live_ranges()[vreg];
     if (range == nullptr || range->IsEmpty() || range->IsSplinter()) {
       continue;
     }
@@ skipping 42 matching lines @@
     int to_remove = range->vreg();
     splinter_parent->Merge(range, data()->allocation_zone());
     data()->live_ranges()[to_remove] = nullptr;
   }
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8