[codegen] Use kNoDeoptIndex consistently

This removes the redundant {Safepoint::kNoDeoptimizationIndex}
definition, and uses {SafepointEntry::kNoDeoptIndex} consistently.

R=jkummerow@chromium.org

Bug: v8:12401
Change-Id: I4e12862d96a2b97245f8dde62243013425e53ff1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3289159Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77979}

src/codegen/safepoint-table.cc

@@ -143,7 +143,7 @@ void SafepointTableBuilder::Emit(Assembler* assembler, int bits_per_entry) {
     if (info.register_indexes) {
       // We emit the register indexes in the same bits as the deopt_index.
       // Register indexes and deopt_index should not exist at the same time.
-      DCHECK_EQ(info.deopt_index, Safepoint::kNoDeoptimizationIndex);
+      DCHECK_EQ(info.deopt_index, SafepointEntry::kNoDeoptIndex);
       assembler->dd(info.register_indexes);
     } else {
       assembler->dd(info.deopt_index);

src/codegen/safepoint-table.h

@@ -22,6 +22,9 @@ class WasmCode;
 
 class SafepointEntry {
  public:
+  static constexpr int kNoDeoptIndex = -1;
+  static constexpr int kNoTrampolinePC = -1;
+
   SafepointEntry() = default;
 
   SafepointEntry(int deopt_index, uint8_t* bits, uint8_t* bits_end,
@@ -40,16 +43,13 @@ class SafepointEntry {
   }
 
   void Reset() {
-    deopt_index_ = 0;
+    deopt_index_ = kNoDeoptIndex;
     bits_ = nullptr;
     bits_end_ = nullptr;
   }
 
   int trampoline_pc() { return trampoline_pc_; }
 
-  static constexpr int kNoDeoptIndex = -1;
-  static constexpr int kNoTrampolinePC = -1;
-
   int deoptimization_index() const {
     DCHECK(is_valid() && has_deoptimization_index());
     return deopt_index_;
@@ -84,7 +84,7 @@ class SafepointEntry {
   size_t entry_size() const { return bits_end_ - bits_; }
 
  private:
-  int deopt_index_ = 0;
+  int deopt_index_ = kNoDeoptIndex;
   uint8_t* bits_ = nullptr;
   uint8_t* bits_end_ = nullptr;
   int trampoline_pc_ = kNoTrampolinePC;
@@ -191,13 +191,11 @@ class SafepointTable {
 
 class Safepoint {
  public:
-  static const int kNoDeoptimizationIndex = SafepointEntry::kNoDeoptIndex;
-
   void DefinePointerSlot(int index) { stack_indexes_->push_back(index); }
 
   void DefineRegister(int reg_code) {
     // Make sure the recorded index is always less than 31, so that we don't
-    // generate {kNoDeoptimizationIndex} by accident.
+    // generate {kNoDeoptIndex} by accident.
     DCHECK_LT(reg_code, 31);
     *register_indexes_ |= 1u << reg_code;
   }
@@ -247,8 +245,8 @@ class SafepointTableBuilder {
     uint32_t register_indexes;
     DeoptimizationInfo(Zone* zone, int pc)
         : pc(pc),
-          deopt_index(Safepoint::kNoDeoptimizationIndex),
-          trampoline(-1),
+          deopt_index(SafepointEntry::kNoDeoptIndex),
+          trampoline(SafepointEntry::kNoTrampolinePC),
           stack_indexes(zone->New<ZoneChunkList<int>>(
               zone, ZoneChunkList<int>::StartMode::kSmall)),
           register_indexes(0) {}

src/deoptimizer/translated-state.cc

@@ -1279,11 +1279,11 @@ Address TranslatedState::DecompressIfNeeded(intptr_t value) {
 
 TranslatedState::TranslatedState(const JavaScriptFrame* frame)
     : purpose_(kFrameInspection) {
-  int deopt_index = Safepoint::kNoDeoptimizationIndex;
+  int deopt_index = SafepointEntry::kNoDeoptIndex;
   DeoptimizationData data =
       static_cast<const OptimizedFrame*>(frame)->GetDeoptimizationData(
           &deopt_index);
-  DCHECK(!data.is_null() && deopt_index != Safepoint::kNoDeoptimizationIndex);
+  DCHECK(!data.is_null() && deopt_index != SafepointEntry::kNoDeoptIndex);
   TranslationArrayIterator it(data.TranslationByteArray(),
                               data.TranslationIndex(deopt_index).value());
   int actual_argc = frame->GetActualArgumentCount();

src/execution/frames.cc

@@ -1642,9 +1642,9 @@ void OptimizedFrame::Summarize(std::vector<FrameSummary>* frames) const {
     return JavaScriptFrame::Summarize(frames);
   }
 
-  int deopt_index = Safepoint::kNoDeoptimizationIndex;
+  int deopt_index = SafepointEntry::kNoDeoptIndex;
   DeoptimizationData const data = GetDeoptimizationData(&deopt_index);
-  if (deopt_index == Safepoint::kNoDeoptimizationIndex) {
+  if (deopt_index == SafepointEntry::kNoDeoptIndex) {
     CHECK(data.is_null());
     FATAL("Missing deoptimization information for OptimizedFrame::Summarize.");
   }
@@ -1754,7 +1754,7 @@ DeoptimizationData OptimizedFrame::GetDeoptimizationData(
     *deopt_index = safepoint_entry.deoptimization_index();
     return DeoptimizationData::cast(code.deoptimization_data());
   }
-  *deopt_index = Safepoint::kNoDeoptimizationIndex;
+  *deopt_index = SafepointEntry::kNoDeoptIndex;
   return DeoptimizationData();
 }
 
@@ -1771,10 +1771,10 @@ void OptimizedFrame::GetFunctions(
   }
 
   DisallowGarbageCollection no_gc;
-  int deopt_index = Safepoint::kNoDeoptimizationIndex;
+  int deopt_index = SafepointEntry::kNoDeoptIndex;
   DeoptimizationData const data = GetDeoptimizationData(&deopt_index);
   DCHECK(!data.is_null());
-  DCHECK_NE(Safepoint::kNoDeoptimizationIndex, deopt_index);
+  DCHECK_NE(SafepointEntry::kNoDeoptIndex, deopt_index);
   DeoptimizationLiteralArray const literal_array = data.LiteralArray();
 
   TranslationArrayIterator it(data.TranslationByteArray(),