[turbofan] regalloc: model context and function mark as reg-defined.

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 756 matching lines @@
         if (move_op->IsEliminated()) continue;
         if (move_op->source().Equals(*to_spill->operand) &&
             move_op->destination().Equals(op)) {
           found = true;
           if (has_preassigned_slot()) move_op->Eliminate();
           break;
         }
       }
       if (found) continue;
     }
-    move->AddMove(*to_spill->operand, op);
+    if (!has_preassigned_slot()) {
+      move->AddMove(*to_spill->operand, op);
+    }
   }
 }
 
 
 void TopLevelLiveRange::SetSpillOperand(InstructionOperand* operand) {
   DCHECK(HasNoSpillType());
   DCHECK(!operand->IsUnallocated() && !operand->IsImmediate());
   set_spill_type(SpillType::kSpillOperand);
   spill_operand_ = operand;
 }
@@ skipping 338 matching lines @@
   if (this->use_interval_ == nullptr || other->use_interval_ == nullptr ||
       this->End() <= other->use_interval_->start() ||
       other->End() <= this->use_interval_->start()) {
     return false;
   }
   return AreUseIntervalsIntersecting(use_interval_, other->use_interval_);
 }
 
 
 bool SpillRange::TryMerge(SpillRange* other) {
+  if (HasSlot() || other->HasSlot()) return false;
   // TODO(dcarney): byte widths should be compared here not kinds.
   if (live_ranges_[0]->kind() != other->live_ranges_[0]->kind() ||
       IsIntersectingWith(other)) {
     return false;
   }
 
   auto max = LifetimePosition::MaxPosition();
   if (End() < other->End() && other->End() != max) {
     end_position_ = other->End();
   }
@@ skipping 81 matching lines @@
       live_ranges_(code->VirtualRegisterCount() * 2, nullptr,
                    allocation_zone()),
       fixed_live_ranges_(this->config()->num_general_registers(), nullptr,
                          allocation_zone()),
       fixed_double_live_ranges_(this->config()->num_double_registers(), nullptr,
                                 allocation_zone()),
       spill_ranges_(code->VirtualRegisterCount(), nullptr, allocation_zone()),
       delayed_references_(allocation_zone()),
       assigned_registers_(nullptr),
       assigned_double_registers_(nullptr),
-      virtual_register_count_(code->VirtualRegisterCount()) {
+      virtual_register_count_(code->VirtualRegisterCount()),
+      preassigned_slot_ranges_(allocation_zone()) {
   DCHECK(this->config()->num_general_registers() <=
          RegisterConfiguration::kMaxGeneralRegisters);
   DCHECK(this->config()->num_double_registers() <=
          RegisterConfiguration::kMaxDoubleRegisters);
   assigned_registers_ = new (code_zone())
       BitVector(this->config()->num_general_registers(), code_zone());
   assigned_double_registers_ = new (code_zone())
       BitVector(this->config()->num_double_registers(), code_zone());
   this->frame()->SetAllocatedRegisters(assigned_registers_);
   this->frame()->SetAllocatedDoubleRegisters(assigned_double_registers_);
@@ skipping 371 matching lines @@
     auto first_output = UnallocatedOperand::cast(output);
     auto range =
         data()->GetOrCreateLiveRangeFor(first_output->virtual_register());
     bool assigned = false;
     if (first_output->HasFixedPolicy()) {
       int output_vreg = first_output->virtual_register();
       UnallocatedOperand output_copy(UnallocatedOperand::ANY, output_vreg);
       bool is_tagged = code()->IsReference(output_vreg);
       if (first_output->HasSecondaryStorage()) {
         range->MarkHasPreassignedSlot();
-        InstructionOperand* spill_op = AllocatedOperand::New(
-            data()->code_zone(), LocationOperand::LocationKind::STACK_SLOT,
-            range->machine_type(), first_output->GetSecondaryStorage());
-        range->RecordSpillLocation(allocation_zone(), instr_index + 1,
-                                   first_output);
-        range->SetSpillOperand(spill_op);
-        range->SetSpillStartIndex(instr_index + 1);
-        assigned = true;
+        data()->preassigned_slot_ranges()[range] =
+            first_output->GetSecondaryStorage();
       }
       AllocateFixed(first_output, instr_index, is_tagged);
 
       // This value is produced on the stack, we never need to spill it.
       if (first_output->IsStackSlot()) {
         DCHECK(LocationOperand::cast(first_output)->index() <
                data()->frame()->GetTotalFrameSlotCount());
         range->SetSpillOperand(LocationOperand::cast(first_output));
         range->SetSpillStartIndex(instr_index + 1);
         assigned = true;
@@ skipping 510 matching lines @@
         if (pos->type() == UsePositionType::kRequiresSlot) continue;
         UsePositionType new_type = UsePositionType::kAny;
         // Can't mark phis as needing a register.
         if (!pos->pos().IsGapPosition()) {
           new_type = UsePositionType::kRequiresRegister;
         }
         pos->set_type(new_type, true);
       }
     }
   }
+  for (auto preassigned : data()->preassigned_slot_ranges()) {
+    TopLevelLiveRange* range = preassigned.first;
+    int slot_id = preassigned.second;
+    SpillRange* spill = range->HasSpillRange()
+                            ? range->GetSpillRange()
+                            : data()->AssignSpillRangeToLiveRange(range);
+    spill->set_assigned_slot(slot_id);
+  }
 #ifdef DEBUG
   Verify();
 #endif
 }
 
 
 void LiveRangeBuilder::MapPhiHint(InstructionOperand* operand,
                                   UsePosition* use_pos) {
   DCHECK(!use_pos->IsResolved());
   auto res = phi_hints_.insert(std::make_pair(operand, use_pos));
@@ skipping 799 matching lines @@
       SpillRange* other = spill_ranges[j];
       if (other != nullptr && !other->IsEmpty()) {
         range->TryMerge(other);
       }
     }
   }
   // Allocate slots for the merged spill ranges.
   for (SpillRange* range : spill_ranges) {
     if (range == nullptr || range->IsEmpty()) continue;
     // Allocate a new operand referring to the spill slot.
-    int byte_width = range->ByteWidth();
-    int index = data()->frame()->AllocateSpillSlot(byte_width);
-    range->set_assigned_slot(index);
+    if (!range->HasSlot()) {
+      int byte_width = range->ByteWidth();
+      int index = data()->frame()->AllocateSpillSlot(byte_width);
+      range->set_assigned_slot(index);
+    }
   }
 }
 
 
 void OperandAssigner::CommitAssignment() {
   for (TopLevelLiveRange* top_range : data()->live_ranges()) {
     if (top_range == nullptr || top_range->IsEmpty()) continue;
     InstructionOperand spill_operand;
     if (top_range->HasSpillOperand()) {
       spill_operand = *top_range->TopLevel()->GetSpillOperand();
@@ skipping 446 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