Fix terrible interaction with code flushing.

src/heap/mark-compact.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 880 matching lines @@
     SharedFunctionInfo* shared = candidate->shared();
 
     Code* code = shared->code();
     MarkBit code_mark = Marking::MarkBitFrom(code);
     if (Marking::IsWhite(code_mark)) {
       if (FLAG_trace_code_flushing && shared->is_compiled()) {
         PrintF("[code-flushing clears: ");
         shared->ShortPrint();
         PrintF(" - age: %d]\n", code->GetAge());
       }
+      // Always flush the optimized code map if requested by flag.
+      if (FLAG_cache_optimized_code && FLAG_flush_optimized_code_cache &&
+          !shared->optimized_code_map()->IsSmi()) {
+        shared->ClearOptimizedCodeMap();
+      }
       shared->set_code(lazy_compile);
       candidate->set_code(lazy_compile);
     } else {
       DCHECK(Marking::IsBlack(code_mark));
       candidate->set_code(code);
     }
 
     // We are in the middle of a GC cycle so the write barrier in the code
     // setter did not record the slot update and we have to do that manually.
     Address slot = candidate->address() + JSFunction::kCodeEntryOffset;
@@ skipping 23 matching lines @@
     ClearNextCandidate(candidate);
 
     Code* code = candidate->code();
     MarkBit code_mark = Marking::MarkBitFrom(code);
     if (Marking::IsWhite(code_mark)) {
       if (FLAG_trace_code_flushing && candidate->is_compiled()) {
         PrintF("[code-flushing clears: ");
         candidate->ShortPrint();
         PrintF(" - age: %d]\n", code->GetAge());
       }
+      // Always flush the optimized code map if requested by flag.
+      if (FLAG_cache_optimized_code && FLAG_flush_optimized_code_cache &&
+          !candidate->optimized_code_map()->IsSmi()) {
+        candidate->ClearOptimizedCodeMap();
+      }
       candidate->set_code(lazy_compile);
     }
 
     Object** code_slot =
         HeapObject::RawField(candidate, SharedFunctionInfo::kCodeOffset);
     isolate_->heap()->mark_compact_collector()->RecordSlot(code_slot, code_slot,
                                                            *code_slot);
 
     candidate = next_candidate;
   }
@@ skipping 3782 matching lines @@
   SlotsBuffer* buffer = *buffer_address;
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 }  // namespace internal
 }  // namespace v8