Add dynamic stack frame alignment to optimized functions with untagged doubles on the stack.

src/heap.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
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 //
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@@ skipping 2224 matching lines @@
   }
   set_the_hole_value(obj);
 
   { MaybeObject* maybe_obj = CreateOddball("arguments_marker",
                                            Smi::FromInt(-4),
                                            Oddball::kArgumentMarker);
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   set_arguments_marker(obj);
 
+  { MaybeObject* maybe_obj = CreateOddball("frame_alignment_marker",
+                                           Smi::FromInt(-5),

[Kevin Millikin (Chromium), 2011/09/23 09:38:49]

I guess it's useful to give the hidden oddballs distinct toNumber values, but
then you should either reorder their allocation so the numbers are consecutive
or renumber them.

[William Hesse, 2011/09/23 12:50:11]

Done.

+                                           Oddball::kFrameAlignmentMarker);
+    if (!maybe_obj->ToObject(&obj)) return false;
+  }
+  set_frame_alignment_marker(obj);
+
   { MaybeObject* maybe_obj = CreateOddball("no_interceptor_result_sentinel",
                                            Smi::FromInt(-2),
                                            Oddball::kOther);
     if (!maybe_obj->ToObject(&obj)) return false;
   }
   set_no_interceptor_result_sentinel(obj);
 
   { MaybeObject* maybe_obj = CreateOddball("termination_exception",
                                            Smi::FromInt(-3),
                                            Oddball::kOther);
@@ skipping 4092 matching lines @@
   }
   isolate_->heap()->store_buffer()->Filter(MemoryChunk::ABOUT_TO_BE_FREED);
   for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) {
     next = chunk->next_chunk();
     isolate_->memory_allocator()->Free(chunk);
   }
   chunks_queued_for_free_ = NULL;
 }
 
 } }  // namespace v8::internal