Fix missing x87 tracking for deferred code

src/ia32/lithium-codegen-ia32.h

 // 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 430 matching lines @@
   TranslationBuffer translations_;
   ZoneList<LDeferredCode*> deferred_;
   bool dynamic_frame_alignment_;
   bool support_aligned_spilled_doubles_;
   int osr_pc_offset_;
   int last_lazy_deopt_pc_;
   bool frame_is_built_;
 
   class X87Stack {
    public:
-    explicit X87Stack(MacroAssembler* masm) : stack_depth_(0), masm_(masm) { }
+    explicit X87Stack(MacroAssembler* masm)
+        : stack_depth_(0), copy_(false), masm_(masm) { }
     explicit X87Stack(const X87Stack& other)
-        : stack_depth_(0), masm_(other.masm_) {
-      stack_depth_ = other.stack_depth_;
+        : stack_depth_(other.stack_depth_), copy_(true), masm_(masm()) {
       for (int i = 0; i < stack_depth_; i++) {
         stack_[i] = other.stack_[i];
       }
     }
     bool operator==(const X87Stack& other) const {
       if (stack_depth_ != other.stack_depth_) return false;
       for (int i = 0; i < stack_depth_; i++) {
         if (!stack_[i].is(other.stack_[i])) return false;
       }
       return true;
     }
     bool Contains(X87Register reg);
     void Fxch(X87Register reg, int other_slot = 0);
     void Free(X87Register reg);
     void PrepareToWrite(X87Register reg);
     void CommitWrite(X87Register reg);

[Michael Starzinger, 2013/08/29 08:55:56]

I think both, "PrepareToWrite" and "CommitWrite" should also check the
mutability predicate explicitly.

[oliv, 2013/08/29 09:23:25]

Done.

     void FlushIfNecessary(LInstruction* instr, LCodeGen* cgen);
     int depth() const { return stack_depth_; }
-    void pop() { stack_depth_--; }
+    void pop() {
+      ASSERT(!copy_);
+      stack_depth_--;
+    }
     void push(X87Register reg) {
+      ASSERT(!copy_);
       ASSERT(stack_depth_ < X87Register::kNumAllocatableRegisters);
       stack_[stack_depth_] = reg;
       stack_depth_++;
     }
 
     MacroAssembler* masm() const { return masm_; }
 
    private:
     int ArrayIndex(X87Register reg);
     int st2idx(int pos);
+
     X87Register stack_[X87Register::kNumAllocatableRegisters];
     int stack_depth_;
-    MacroAssembler* const masm_;
+    bool copy_;

[Michael Starzinger, 2013/08/29 08:55:56]

Let's call this "is_mutable_" instead and reverse the semantics. I think that's
easier to understand. WDYT?

[oliv, 2013/08/29 09:23:25]

Done.

+    MacroAssembler* masm_;
   };
   X87Stack x87_stack_;
 
   // Builder that keeps track of safepoints in the code. The table
   // itself is emitted at the end of the generated code.
   SafepointTableBuilder safepoints_;
 
   // Compiler from a set of parallel moves to a sequential list of moves.
   LGapResolver resolver_;
 
@@ skipping 23 matching lines @@
 
   friend class LDeferredCode;
   friend class LEnvironment;
   friend class SafepointGenerator;
   DISALLOW_COPY_AND_ASSIGN(LCodeGen);
 };
 
 
 class LDeferredCode : public ZoneObject {
  public:
-  explicit LDeferredCode(LCodeGen* codegen)
+  explicit LDeferredCode(LCodeGen* codegen, const LCodeGen::X87Stack& x87_stack)
       : codegen_(codegen),
         external_exit_(NULL),
-        instruction_index_(codegen->current_instruction_) {
+        instruction_index_(codegen->current_instruction_),
+        x87_stack_(x87_stack) {
     codegen->AddDeferredCode(this);
   }
 
   virtual ~LDeferredCode() {}
   virtual void Generate() = 0;
   virtual LInstruction* instr() = 0;
 
   void SetExit(Label* exit) { external_exit_ = exit; }
   Label* entry() { return &entry_; }
   Label* exit() { return external_exit_ != NULL ? external_exit_ : &exit_; }
   int instruction_index() const { return instruction_index_; }
+  const LCodeGen::X87Stack& x87_stack() const { return x87_stack_; }
 
  protected:
   LCodeGen* codegen() const { return codegen_; }
   MacroAssembler* masm() const { return codegen_->masm(); }
 
  private:
   LCodeGen* codegen_;
   Label entry_;
   Label exit_;
   Label* external_exit_;
   int instruction_index_;
+  LCodeGen::X87Stack x87_stack_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_LITHIUM_CODEGEN_IA32_H_