Fix pc to code cache so it can cope with a pointer to the start of the code

object.  Rename it to be the inner pointer to code cache.
Review URL: http://codereview.chromium.org/7969013

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9336 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/frames-inl.h

@@ -106,7 +106,7 @@ inline StackHandler* StackFrame::top_handler() const {
 
 
 inline Code* StackFrame::GetContainingCode(Isolate* isolate, Address pc) {
-  return isolate->pc_to_code_cache()->GetCacheEntry(pc)->code;
+  return isolate->inner_pointer_to_code_cache()->GetCacheEntry(pc)->code;
 }
 
 

src/frames.cc

@@ -366,16 +366,17 @@ void SafeStackTraceFrameIterator::Advance() {
 
 
 Code* StackFrame::GetSafepointData(Isolate* isolate,
-                                   Address pc,
+                                   Address inner_pointer,
                                    SafepointEntry* safepoint_entry,
                                    unsigned* stack_slots) {
-  PcToCodeCache::PcToCodeCacheEntry* entry =
-      isolate->pc_to_code_cache()->GetCacheEntry(pc);
+  InnerPointerToCodeCache::InnerPointerToCodeCacheEntry* entry =
+      isolate->inner_pointer_to_code_cache()->GetCacheEntry(inner_pointer);
   if (!entry->safepoint_entry.is_valid()) {
-    entry->safepoint_entry = entry->code->GetSafepointEntry(pc);
+    entry->safepoint_entry = entry->code->GetSafepointEntry(inner_pointer);
     ASSERT(entry->safepoint_entry.is_valid());
   } else {
-    ASSERT(entry->safepoint_entry.Equals(entry->code->GetSafepointEntry(pc)));
+    ASSERT(entry->safepoint_entry.Equals(
+        entry->code->GetSafepointEntry(inner_pointer)));
   }
 
   // Fill in the results and return the code.
@@ -819,7 +820,8 @@ DeoptimizationInputData* OptimizedFrame::GetDeoptimizationData(
   // back to a slow search in this case to find the original optimized
   // code object.
   if (!code->contains(pc())) {
-    code = isolate()->pc_to_code_cache()->GcSafeFindCodeForPc(pc());
+    code = isolate()->inner_pointer_to_code_cache()->
+        GcSafeFindCodeForInnerPointer(pc());
   }
   ASSERT(code != NULL);
   ASSERT(code->kind() == Code::OPTIMIZED_FUNCTION);
@@ -1155,9 +1157,10 @@ JavaScriptFrame* StackFrameLocator::FindJavaScriptFrame(int n) {
 // -------------------------------------------------------------------------
 
 
-Code* PcToCodeCache::GcSafeCastToCode(HeapObject* object, Address pc) {
+Code* InnerPointerToCodeCache::GcSafeCastToCode(HeapObject* object,
+                                                Address inner_pointer) {
   Code* code = reinterpret_cast<Code*>(object);
-  ASSERT(code != NULL && code->contains(pc));
+  ASSERT(code != NULL && code->contains(inner_pointer));
   return code;
 }
 
@@ -1170,17 +1173,20 @@ static int GcSafeSizeOfCodeSpaceObject(HeapObject* object) {
 }
 
 
-Code* PcToCodeCache::GcSafeFindCodeForPc(Address pc) {
+Code* InnerPointerToCodeCache::GcSafeFindCodeForInnerPointer(
+    Address inner_pointer) {
   Heap* heap = isolate_->heap();
-  // Check if the pc points into a large object chunk.
-  LargePage* large_page = heap->lo_space()->FindPageContainingPc(pc);
-  if (large_page != NULL) return GcSafeCastToCode(large_page->GetObject(), pc);
+  // Check if the inner pointer points into a large object chunk.
+  LargePage* large_page = heap->lo_space()->FindPageContainingPc(inner_pointer);
+  if (large_page != NULL) {
+    return GcSafeCastToCode(large_page->GetObject(), inner_pointer);
+  }
 
   // Iterate through the page until we reach the end or find an object starting
-  // after the pc.
-  Page* page = Page::FromAddress(pc);
+  // after the inner pointer.
+  Page* page = Page::FromAddress(inner_pointer);
 
-  Address addr = page->skip_list()->StartFor(pc);
+  Address addr = page->skip_list()->StartFor(inner_pointer);
 
   Address top = heap->code_space()->top();
   Address limit = heap->code_space()->limit();
@@ -1194,30 +1200,31 @@ Code* PcToCodeCache::GcSafeFindCodeForPc(Address pc) {
     HeapObject* obj = HeapObject::FromAddress(addr);
     int obj_size = GcSafeSizeOfCodeSpaceObject(obj);
     Address next_addr = addr + obj_size;
-    if (next_addr >= pc) return GcSafeCastToCode(obj, pc);
+    if (next_addr > inner_pointer) return GcSafeCastToCode(obj, inner_pointer);
     addr = next_addr;
   }
 }
 
 
-PcToCodeCache::PcToCodeCacheEntry* PcToCodeCache::GetCacheEntry(Address pc) {
+InnerPointerToCodeCache::InnerPointerToCodeCacheEntry*
+    InnerPointerToCodeCache::GetCacheEntry(Address inner_pointer) {
   isolate_->counters()->pc_to_code()->Increment();
-  ASSERT(IsPowerOf2(kPcToCodeCacheSize));
+  ASSERT(IsPowerOf2(kInnerPointerToCodeCacheSize));
   uint32_t hash = ComputeIntegerHash(
-      static_cast<uint32_t>(reinterpret_cast<uintptr_t>(pc)));
-  uint32_t index = hash & (kPcToCodeCacheSize - 1);
-  PcToCodeCacheEntry* entry = cache(index);
-  if (entry->pc == pc) {
+      static_cast<uint32_t>(reinterpret_cast<uintptr_t>(inner_pointer)));
+  uint32_t index = hash & (kInnerPointerToCodeCacheSize - 1);
+  InnerPointerToCodeCacheEntry* entry = cache(index);
+  if (entry->inner_pointer == inner_pointer) {
     isolate_->counters()->pc_to_code_cached()->Increment();
-    ASSERT(entry->code == GcSafeFindCodeForPc(pc));
+    ASSERT(entry->code == GcSafeFindCodeForInnerPointer(inner_pointer));
   } else {
     // Because this code may be interrupted by a profiling signal that
-    // also queries the cache, we cannot update pc before the code has
-    // been set. Otherwise, we risk trying to use a cache entry before
+    // also queries the cache, we cannot update inner_pointer before the code
+    // has been set. Otherwise, we risk trying to use a cache entry before
     // the code has been computed.
-    entry->code = GcSafeFindCodeForPc(pc);
+    entry->code = GcSafeFindCodeForInnerPointer(inner_pointer);
     entry->safepoint_entry.Reset();
-    entry->pc = pc;
+    entry->inner_pointer = inner_pointer;
   }
   return entry;
 }

src/frames.h

@@ -49,36 +49,36 @@ class StackFrameIterator;
 class ThreadLocalTop;
 class Isolate;
 
-class PcToCodeCache {
+class InnerPointerToCodeCache {
  public:
-  struct PcToCodeCacheEntry {
-    Address pc;
+  struct InnerPointerToCodeCacheEntry {
+    Address inner_pointer;
     Code* code;
     SafepointEntry safepoint_entry;
   };
 
-  explicit PcToCodeCache(Isolate* isolate) : isolate_(isolate) {
+  explicit InnerPointerToCodeCache(Isolate* isolate) : isolate_(isolate) {
     Flush();
   }
 
-  Code* GcSafeFindCodeForPc(Address pc);
-  Code* GcSafeCastToCode(HeapObject* object, Address pc);
+  Code* GcSafeFindCodeForInnerPointer(Address inner_pointer);
+  Code* GcSafeCastToCode(HeapObject* object, Address inner_pointer);
 
   void Flush() {
     memset(&cache_[0], 0, sizeof(cache_));
   }
 
-  PcToCodeCacheEntry* GetCacheEntry(Address pc);
+  InnerPointerToCodeCacheEntry* GetCacheEntry(Address inner_pointer);
 
  private:
-  PcToCodeCacheEntry* cache(int index) { return &cache_[index]; }
+  InnerPointerToCodeCacheEntry* cache(int index) { return &cache_[index]; }
 
   Isolate* isolate_;
 
-  static const int kPcToCodeCacheSize = 1024;
-  PcToCodeCacheEntry cache_[kPcToCodeCacheSize];
+  static const int kInnerPointerToCodeCacheSize = 1024;
+  InnerPointerToCodeCacheEntry cache_[kInnerPointerToCodeCacheSize];
 
-  DISALLOW_COPY_AND_ASSIGN(PcToCodeCache);
+  DISALLOW_COPY_AND_ASSIGN(InnerPointerToCodeCache);
 };
 
 

src/heap.cc

@@ -844,7 +844,8 @@ void Heap::MarkCompactPrologue() {
 
 
 Object* Heap::FindCodeObject(Address a) {
-  return isolate()->pc_to_code_cache()->GcSafeFindCodeForPc(a);
+  return isolate()->inner_pointer_to_code_cache()->
+      GcSafeFindCodeForInnerPointer(a);
 }
 
 

src/incremental-marking.cc

@@ -87,8 +87,8 @@ void IncrementalMarking::RecordWriteForEvacuationFromCode(HeapObject* obj,
 
 void IncrementalMarking::RecordCodeTargetPatch(Address pc, HeapObject* value) {
   if (IsMarking()) {
-    Code* host =
-        heap_->isolate()->pc_to_code_cache()->GcSafeFindCodeForPc(pc);
+    Code* host = heap_->isolate()->inner_pointer_to_code_cache()->
+        GcSafeFindCodeForInnerPointer(pc);
     RelocInfo rinfo(pc, RelocInfo::CODE_TARGET, 0, host);
     RecordWriteIntoCode(host, &rinfo, value);
   }

src/isolate.cc

@@ -1403,7 +1403,7 @@ Isolate::Isolate()
       in_use_list_(0),
       free_list_(0),
       preallocated_storage_preallocated_(false),
-      pc_to_code_cache_(NULL),
+      inner_pointer_to_code_cache_(NULL),
       write_input_buffer_(NULL),
       global_handles_(NULL),
       context_switcher_(NULL),
@@ -1576,8 +1576,8 @@ Isolate::~Isolate() {
   compilation_cache_ = NULL;
   delete bootstrapper_;
   bootstrapper_ = NULL;
-  delete pc_to_code_cache_;
-  pc_to_code_cache_ = NULL;
+  delete inner_pointer_to_code_cache_;
+  inner_pointer_to_code_cache_ = NULL;
   delete write_input_buffer_;
   write_input_buffer_ = NULL;
 
@@ -1701,7 +1701,7 @@ bool Isolate::Init(Deserializer* des) {
   context_slot_cache_ = new ContextSlotCache();
   descriptor_lookup_cache_ = new DescriptorLookupCache();
   unicode_cache_ = new UnicodeCache();
-  pc_to_code_cache_ = new PcToCodeCache(this);
+  inner_pointer_to_code_cache_ = new InnerPointerToCodeCache(this);
   write_input_buffer_ = new StringInputBuffer();
   global_handles_ = new GlobalHandles(this);
   bootstrapper_ = new Bootstrapper();

src/isolate.h

@@ -66,7 +66,7 @@ class HandleScopeImplementer;
 class HeapProfiler;
 class InlineRuntimeFunctionsTable;
 class NoAllocationStringAllocator;
-class PcToCodeCache;
+class InnerPointerToCodeCache;
 class PreallocatedMemoryThread;
 class RegExpStack;
 class SaveContext;
@@ -841,7 +841,9 @@ class Isolate {
     return unicode_cache_;
   }
 
-  PcToCodeCache* pc_to_code_cache() { return pc_to_code_cache_; }
+  InnerPointerToCodeCache* inner_pointer_to_code_cache() {
+    return inner_pointer_to_code_cache_;
+  }
 
   StringInputBuffer* write_input_buffer() { return write_input_buffer_; }
 
@@ -1136,7 +1138,7 @@ class Isolate {
   PreallocatedStorage in_use_list_;
   PreallocatedStorage free_list_;
   bool preallocated_storage_preallocated_;
-  PcToCodeCache* pc_to_code_cache_;
+  InnerPointerToCodeCache* inner_pointer_to_code_cache_;
   StringInputBuffer* write_input_buffer_;
   GlobalHandles* global_handles_;
   ContextSwitcher* context_switcher_;

src/mark-compact.cc

@@ -281,7 +281,7 @@ void MarkCompactCollector::CollectGarbage() {
 
   if (!collect_maps_) ReattachInitialMaps();
 
-  heap_->isolate()->pc_to_code_cache()->Flush();
+  heap_->isolate()->inner_pointer_to_code_cache()->Flush();
 
   Finish();
 

src/objects-inl.h

@@ -3864,9 +3864,8 @@ byte* Code::entry() {
 }
 
 
-bool Code::contains(byte* pc) {
-  return (instruction_start() <= pc) &&
-      (pc <= instruction_start() + instruction_size());
+bool Code::contains(byte* inner_pointer) {
+  return (address() <= inner_pointer) && (inner_pointer <= address() + Size());
 }