Fix OSR for nested loops.

src/objects.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 9079 matching lines @@
   return statement_position;
 }
 
 
 SafepointEntry Code::GetSafepointEntry(Address pc) {
   SafepointTable table(this);
   return table.FindEntry(pc);
 }
 
 
-void Code::SetNoStackCheckTable() {
-  // Indicate the absence of a stack-check table by a table start after the
-  // end of the instructions.  Table start must be aligned, so round up.
-  set_stack_check_table_offset(RoundUp(instruction_size(), kIntSize));
-}
-
-
 Map* Code::FindFirstMap() {
   ASSERT(is_inline_cache_stub());
   AssertNoAllocation no_allocation;
   int mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
   for (RelocIterator it(this, mask); !it.done(); it.next()) {
     RelocInfo* info = it.rinfo();
     Object* object = info->target_object();
     if (object->IsMap()) return Map::cast(object);
   }
   return NULL;
@@ skipping 498 matching lines @@
       } else {
         PrintF(out, "  <none>");
       }
       if (entry.argument_count() > 0) {
         PrintF(out, " argc: %d", entry.argument_count());
       }
       PrintF(out, "\n");
     }
     PrintF(out, "\n");
   } else if (kind() == FUNCTION) {
-    unsigned offset = stack_check_table_offset();
-    // If there is no stack check table, the "table start" will at or after
+    unsigned offset = back_edge_table_offset();
+    // If there is no back table, the "table start" will at or after

[Jakob Kummerow, 2013/04/09 17:23:25]

nit: s/back/back edge/, s/will at/will be at/

[Yang, 2013/04/10 08:08:30]

Done.

     // (due to alignment) the end of the instruction stream.
     if (static_cast<int>(offset) < instruction_size()) {
-      unsigned* address =
-          reinterpret_cast<unsigned*>(instruction_start() + offset);
-      unsigned length = address[0];
-      PrintF(out, "Stack checks (size = %u)\n", length);
-      PrintF(out, "ast_id  pc_offset\n");
-      for (unsigned i = 0; i < length; ++i) {
-        unsigned index = (2 * i) + 1;
-        PrintF(out, "%6u  %9u\n", address[index], address[index + 1]);
+      Address back_edge_cursor = instruction_start() + offset;
+      uint32_t table_length = Memory::uint32_at(back_edge_cursor);
+      PrintF(out, "Back edges (size = %u)\n", table_length);
+      PrintF(out, "ast_id  pc_offset  loop_depth\n");
+      static const int kBackEdgeEntrySize = 2 * kIntSize + kOneByteSize;
+      for (uint32_t i = 0; i < table_length; ++i) {
+        uint32_t ast_id = Memory::uint32_at(back_edge_cursor + kIntSize);

[Jakob Kummerow, 2013/04/09 17:23:25]

typo: should be Memory::uint32_at(back_edge_cursor);

[Yang, 2013/04/10 08:08:30]

Done.

+        uint32_t pc_offset = Memory::uint32_at(back_edge_cursor + kIntSize);
+        uint8_t loop_depth = Memory::uint8_at(back_edge_cursor + 2 * kIntSize);
+        PrintF(out, "%6u  %9u  %10u\n", ast_id, pc_offset, loop_depth);
+        back_edge_cursor += kBackEdgeEntrySize;
       }
       PrintF(out, "\n");
     }
 #ifdef OBJECT_PRINT
     if (!type_feedback_info()->IsUndefined()) {
       TypeFeedbackInfo::cast(type_feedback_info())->TypeFeedbackInfoPrint(out);
       PrintF(out, "\n");
     }
 #endif
   }
@@ skipping 4818 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal