Refactor back edge table related code into a new class.

src/ia32/deoptimizer-ia32.cc

 // Copyright 2012 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 159 matching lines @@
 
   // Handle the junk part after the new relocation info. We will create
   // a non-live object in the extra space at the end of the former reloc info.
   Address junk_address = reloc_info->address() + reloc_info->Size();
   ASSERT(junk_address <= reloc_end_address);
   isolate->heap()->CreateFillerObjectAt(junk_address,
                                         reloc_end_address - junk_address);
 }
 
 
-static const byte kJnsInstruction = 0x79;
-static const byte kJnsOffset = 0x11;
-static const byte kCallInstruction = 0xe8;
-static const byte kNopByteOne = 0x66;
-static const byte kNopByteTwo = 0x90;
-
-// The back edge bookkeeping code matches the pattern:
-//
-//     sub <profiling_counter>, <delta>
-//     jns ok
-//     call <interrupt stub>
-//   ok:
-//
-// The patched back edge looks like this:
-//
-//     sub <profiling_counter>, <delta>  ;; Not changed
-//     nop
-//     nop
-//     call <on-stack replacment>
-//   ok:
-
-void Deoptimizer::PatchInterruptCodeAt(Code* unoptimized_code,
-                                       Address pc_after,
-                                       Code* replacement_code) {
-  // Turn the jump into nops.
-  Address call_target_address = pc_after - kIntSize;
-  *(call_target_address - 3) = kNopByteOne;
-  *(call_target_address - 2) = kNopByteTwo;
-  // Replace the call address.
-  Assembler::set_target_address_at(call_target_address,
-                                   replacement_code->entry());
-
-  unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
-      unoptimized_code, call_target_address, replacement_code);
-}
-
-
-void Deoptimizer::RevertInterruptCodeAt(Code* unoptimized_code,
-                                        Address pc_after,
-                                        Code* interrupt_code) {
-  // Restore the original jump.
-  Address call_target_address = pc_after - kIntSize;
-  *(call_target_address - 3) = kJnsInstruction;
-  *(call_target_address - 2) = kJnsOffset;
-  // Restore the original call address.
-  Assembler::set_target_address_at(call_target_address,
-                                   interrupt_code->entry());
-
-  interrupt_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
-      unoptimized_code, call_target_address, interrupt_code);
-}
-
-
-#ifdef DEBUG
-Deoptimizer::InterruptPatchState Deoptimizer::GetInterruptPatchState(
-    Isolate* isolate,
-    Code* unoptimized_code,
-    Address pc_after) {
-  Address call_target_address = pc_after - kIntSize;
-  ASSERT_EQ(kCallInstruction, *(call_target_address - 1));
-  if (*(call_target_address - 3) == kNopByteOne) {
-    ASSERT_EQ(kNopByteTwo,      *(call_target_address - 2));
-    Code* osr_builtin =
-        isolate->builtins()->builtin(Builtins::kOnStackReplacement);
-    ASSERT_EQ(osr_builtin->entry(),
-              Assembler::target_address_at(call_target_address));
-    return PATCHED_FOR_OSR;
-  } else {
-    // Get the interrupt stub code object to match against from cache.
-    Code* interrupt_builtin =
-        isolate->builtins()->builtin(Builtins::kInterruptCheck);
-    ASSERT_EQ(interrupt_builtin->entry(),
-              Assembler::target_address_at(call_target_address));
-    ASSERT_EQ(kJnsInstruction,  *(call_target_address - 3));
-    ASSERT_EQ(kJnsOffset,       *(call_target_address - 2));
-    return NOT_PATCHED;
-  }
-}
-#endif  // DEBUG
-
-
 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
   // Set the register values. The values are not important as there are no
   // callee saved registers in JavaScript frames, so all registers are
   // spilled. Registers ebp and esp are set to the correct values though.
 
   for (int i = 0; i < Register::kNumRegisters; i++) {
     input_->SetRegister(i, i * 4);
   }
   input_->SetRegister(esp.code(), reinterpret_cast<intptr_t>(frame->sp()));
   input_->SetRegister(ebp.code(), reinterpret_cast<intptr_t>(frame->fp()));
@@ skipping 244 matching lines @@
   SetFrameSlot(offset, value);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32