Deoptimization support for accessors.

src/ia32/deoptimizer-ia32.cc

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 // modification, are permitted provided that the following conditions are
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 //
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@@ skipping 676 matching lines @@
 
   ASSERT(0 == output_offset);
 
   uint32_t pc = reinterpret_cast<uint32_t>(
       construct_stub->instruction_start() +
       isolate_->heap()->construct_stub_deopt_pc_offset()->value());
   output_frame->SetPc(pc);
 }
 
 
+void Deoptimizer::DoComputeSetterStubFrame(TranslationIterator* iterator,
+                                           int frame_index) {
+  JSFunction* setter = JSFunction::cast(ComputeLiteral(iterator->Next()));
+  // The receiver and RHS are expected in registers by the IC, so they don't

[Michael Starzinger, 2012/08/16 17:20:04]

s/IC/StoreIC/

[Sven Panne, 2012/08/17 07:27:26]

Done here and on other platforms.

+  // belong to the output stack frame. This means that we have to use a height
+  // of 0 instead of 2.

[Michael Starzinger, 2012/08/16 17:20:04]

Drop the "instead of 2" part.

[Sven Panne, 2012/08/17 07:27:26]

... it's cleaner! ;-) Done here and on other platforms.

+  unsigned height = 0;
+  unsigned height_in_bytes = height * kPointerSize;
+  if (FLAG_trace_deopt) {
+    PrintF("  translating setter stub => height=%u\n", height_in_bytes);
+  }
+
+  // 1 stack entry for the return address + 4 stack entries from

[Michael Starzinger, 2012/08/16 17:20:04]

Can we start this sentence with a word, not a number, to make it a proper
sentence.

Also we should really think about moving these constants in frames-[arch].h at
some point, but that's for a followup CL.

[Sven Panne, 2012/08/17 07:27:26]

Done here and on other platforms.
Definitely, but we should then do this for all deoptimizer functions at once.

+  // StackFrame::INTERNAL (FP, context, frame type, code object, see
+  // MacroAssembler::EnterFrame) + 1 stack entry from setter stub (RHS, see
+  // StoreStubCompiler::CompileStoreViaSetter).
+  unsigned fixed_frame_size = (1 + 4 + 1) * kPointerSize;
+  unsigned output_frame_size = height_in_bytes + fixed_frame_size;
+
+  // Allocate and store the output frame description.
+  FrameDescription* output_frame =
+      new(output_frame_size) FrameDescription(output_frame_size, setter);
+  output_frame->SetFrameType(StackFrame::INTERNAL);
+
+  // A frame for a setter stub can not be the topmost or bottommost one.
+  ASSERT(frame_index > 0 && frame_index < output_count_ - 1);
+  ASSERT(output_[frame_index] == NULL);
+  output_[frame_index] = output_frame;
+
+  // The top address of the frame is computed from the previous frame's top and
+  // this frame's size.
+  intptr_t top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
+  output_frame->SetTop(top_address);
+
+  unsigned output_offset = output_frame_size;
+
+  // Read caller's PC from the previous frame.
+  output_offset -= kPointerSize;
+  intptr_t callers_pc = output_[frame_index - 1]->GetPc();
+  output_frame->SetFrameSlot(output_offset, callers_pc);
+  if (FLAG_trace_deopt) {
+    PrintF("    0x%08" V8PRIxPTR ": [top + %u] <- 0x%08" V8PRIxPTR
+           " ; caller's pc\n",
+           top_address + output_offset, output_offset, callers_pc);
+  }
+
+  // Read caller's FP from the previous frame, and set this frame's FP.
+  output_offset -= kPointerSize;
+  intptr_t value = output_[frame_index - 1]->GetFp();
+  output_frame->SetFrameSlot(output_offset, value);
+  intptr_t fp_value = top_address + output_offset;
+  output_frame->SetFp(fp_value);
+  if (FLAG_trace_deopt) {
+    PrintF("    0x%08" V8PRIxPTR ": [top + %u] <- 0x%08" V8PRIxPTR
+           " ; caller's fp\n",
+           fp_value, output_offset, value);
+  }
+
+  // The context can be gotten from the previous frame.
+  output_offset -= kPointerSize;
+  value = output_[frame_index - 1]->GetContext();
+  output_frame->SetFrameSlot(output_offset, value);
+  if (FLAG_trace_deopt) {
+    PrintF("    0x%08" V8PRIxPTR ": [top + %u] <- 0x%08" V8PRIxPTR
+           " ; context\n",
+           top_address + output_offset, output_offset, value);
+  }
+
+  // A marker value is used in place of the function.
+  output_offset -= kPointerSize;
+  value = reinterpret_cast<intptr_t>(Smi::FromInt(StackFrame::INTERNAL));
+  output_frame->SetFrameSlot(output_offset, value);
+  if (FLAG_trace_deopt) {
+    PrintF("    0x%08" V8PRIxPTR ": [top + %u] <- 0x%08" V8PRIxPTR
+           " ; function (setter sentinel)\n",
+           top_address + output_offset, output_offset, value);
+  }
+
+  // Get Code object from setter function.
+  output_offset -= kPointerSize;
+  value = reinterpret_cast<intptr_t>(setter->code());

[Michael Starzinger, 2012/08/16 17:20:04]

I don't think this is quite right. What you want here is the code object for the
setter stub, not for the JavaScript setter. So this should be "setter_stub"
instead.

[Sven Panne, 2012/08/17 07:27:26]

Good catch. Done here and on other platforms.

+  output_frame->SetFrameSlot(output_offset, value);
+  if (FLAG_trace_deopt) {
+    PrintF("    0x%08" V8PRIxPTR ": [top + %u] <- 0x%08" V8PRIxPTR
+           " ; code object\n",
+           top_address + output_offset, output_offset, value);
+  }
+
+  // Skip receiver.
+  Translation::Opcode opcode =
+      static_cast<Translation::Opcode>(iterator->Next());
+  iterator->Skip(Translation::NumberOfOperandsFor(opcode));
+
+  // The RHS was part of the artificial setter stub environment.

[Michael Starzinger, 2012/08/16 17:20:04]

I would use "implicit return value" or "passed value" here instead of RHS,
because RHS only applies to ordinary assignments, it has little meaning for
counting or compound assignments.

[Sven Panne, 2012/08/17 07:27:26]

Done here and on other platforms.

+  output_offset -= kPointerSize;
+  DoTranslateCommand(iterator, frame_index, output_offset);
+
+  ASSERT(0 == output_offset);
+
+  Code* setter_stub =

[Michael Starzinger, 2012/08/16 17:20:04]

Move this up, you already need if for the code object.

[Sven Panne, 2012/08/17 07:27:26]

Done here and on other platforms.

+      isolate_->builtins()->builtin(Builtins::kSetterStubForDeopt);
+  intptr_t pc = reinterpret_cast<intptr_t>(
+      setter_stub->instruction_start() +
+      isolate_->heap()->setter_stub_deopt_pc_offset()->value());
+  output_frame->SetPc(pc);
+}
+
+
 void Deoptimizer::DoComputeJSFrame(TranslationIterator* iterator,
                                    int frame_index) {
   BailoutId node_id = BailoutId(iterator->Next());
   JSFunction* function;
   if (frame_index != 0) {
     function = JSFunction::cast(ComputeLiteral(iterator->Next()));
   } else {
     int closure_id = iterator->Next();
     USE(closure_id);
     ASSERT_EQ(Translation::kSelfLiteralId, closure_id);
@@ skipping 387 matching lines @@
   }
   __ bind(&done);
 }
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32