[Turbofan] Make fixed live ranges all double when aliasing is simple.

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 1342 matching lines @@
       code_(code),
       debug_name_(debug_name),
       config_(config),
       phi_map_(allocation_zone()),
       live_in_sets_(code->InstructionBlockCount(), nullptr, allocation_zone()),
       live_out_sets_(code->InstructionBlockCount(), nullptr, allocation_zone()),
       live_ranges_(code->VirtualRegisterCount() * 2, nullptr,
                    allocation_zone()),
       fixed_live_ranges_(this->config()->num_general_registers(), nullptr,
                          allocation_zone()),
-      fixed_float_live_ranges_(this->config()->num_float_registers(), nullptr,
-                               allocation_zone()),
+      fixed_float_live_ranges_(allocation_zone()),
       fixed_double_live_ranges_(this->config()->num_double_registers(), nullptr,
                                 allocation_zone()),
-      fixed_simd128_live_ranges_(this->config()->num_simd128_registers(),
-                                 nullptr, allocation_zone()),
+      fixed_simd128_live_ranges_(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()),
       preassigned_slot_ranges_(zone) {
+  if (!kSimpleFPAliasing) {
+    fixed_float_live_ranges_.resize(this->config()->num_float_registers(),
+                                    nullptr);
+    fixed_simd128_live_ranges_.resize(this->config()->num_simd128_registers(),
+                                      nullptr);
+  }
+
   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_);
 }
 
 
 MoveOperands* RegisterAllocationData::AddGapMove(
@@ skipping 523 matching lines @@
     DCHECK(result->IsFixed());
     result->set_assigned_register(index);
     data()->MarkAllocated(rep, index);
     data()->fixed_live_ranges()[index] = result;
   }
   return result;
 }
 
 TopLevelLiveRange* LiveRangeBuilder::FixedFPLiveRangeFor(
     int index, MachineRepresentation rep) {
-  int num_regs = -1;
-  ZoneVector<TopLevelLiveRange*>* live_ranges = nullptr;
-  switch (rep) {
-    case MachineRepresentation::kFloat32:
-      num_regs = config()->num_float_registers();
-      live_ranges = &data()->fixed_float_live_ranges();
-      break;
-    case MachineRepresentation::kFloat64:
-      num_regs = config()->num_double_registers();
-      live_ranges = &data()->fixed_double_live_ranges();
-      break;
-    case MachineRepresentation::kSimd128:
-      num_regs = config()->num_simd128_registers();
-      live_ranges = &data()->fixed_simd128_live_ranges();
-      break;
-    default:
-      UNREACHABLE();
-      break;
+  int num_regs = config()->num_double_registers();
+  ZoneVector<TopLevelLiveRange*>* live_ranges =
+      &data()->fixed_double_live_ranges();
+  if (!kSimpleFPAliasing) {
+    switch (rep) {
+      case MachineRepresentation::kFloat32:
+        num_regs = config()->num_float_registers();
+        live_ranges = &data()->fixed_float_live_ranges();
+        break;
+      case MachineRepresentation::kSimd128:
+        num_regs = config()->num_simd128_registers();
+        live_ranges = &data()->fixed_simd128_live_ranges();
+        break;
+      default:
+        break;
+    }
   }
 
   DCHECK(index < num_regs);
   TopLevelLiveRange* result = (*live_ranges)[index];
   if (result == nullptr) {
     result = data()->NewLiveRange(FixedFPLiveRangeID(index, rep), rep);
     DCHECK(result->IsFixed());
     result->set_assigned_register(index);
     data()->MarkAllocated(rep, index);
     (*live_ranges)[index] = result;
@@ skipping 787 matching lines @@
     }
   }
   SortUnhandled();
   DCHECK(UnhandledIsSorted());
 
   if (mode() == GENERAL_REGISTERS) {
     for (TopLevelLiveRange* current : data()->fixed_live_ranges()) {
       if (current != nullptr) AddToInactive(current);
     }
   } else {
-    for (TopLevelLiveRange* current : data()->fixed_float_live_ranges()) {
-      if (current != nullptr) AddToInactive(current);
-    }
     for (TopLevelLiveRange* current : data()->fixed_double_live_ranges()) {
       if (current != nullptr) AddToInactive(current);
     }
-    for (TopLevelLiveRange* current : data()->fixed_simd128_live_ranges()) {
-      if (current != nullptr) AddToInactive(current);
+    if (!kSimpleFPAliasing) {
+      for (TopLevelLiveRange* current : data()->fixed_float_live_ranges()) {
+        if (current != nullptr) AddToInactive(current);
+      }
+      for (TopLevelLiveRange* current : data()->fixed_simd128_live_ranges()) {
+        if (current != nullptr) AddToInactive(current);
+      }
     }
   }
 
   while (!unhandled_live_ranges().empty()) {
     DCHECK(UnhandledIsSorted());
     LiveRange* current = unhandled_live_ranges().back();
     unhandled_live_ranges().pop_back();
     DCHECK(UnhandledIsSorted());
     LifetimePosition position = current->Start();
 #ifdef DEBUG
@@ skipping 1189 matching lines @@
         }
       }
     }
   }
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8