Make x87 stack tracking more robust and avoid spilling

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 34 matching lines @@
 class LGapNode;
 class SafepointGenerator;
 
 class LCodeGen V8_FINAL BASE_EMBEDDED {
  public:
   LCodeGen(LChunk* chunk, MacroAssembler* assembler, CompilationInfo* info)
       : zone_(info->zone()),
         chunk_(static_cast<LPlatformChunk*>(chunk)),
         masm_(assembler),
         info_(info),
-        current_block_(-1),
+        current_block_(NULL),
         current_instruction_(-1),
         instructions_(chunk->instructions()),
         deoptimizations_(4, info->zone()),
         jump_table_(4, info->zone()),
         deoptimization_literals_(8, info->zone()),
         inlined_function_count_(0),
         scope_(info->scope()),
         status_(UNUSED),
         translations_(info->zone()),
         deferred_(8, info->zone()),
@@ skipping 47 matching lines @@
   Immediate ToImmediate(LOperand* op, const Representation& r) const {
     return Immediate(ToRepresentation(LConstantOperand::cast(op), r));
   }
   double ToDouble(LConstantOperand* op) const;
 
   // Support for non-sse2 (x87) floating point stack handling.
   // These functions maintain the mapping of physical stack registers to our
   // virtual registers between instructions.
   enum X87OperandType { kX87DoubleOperand, kX87FloatOperand, kX87IntOperand };
 
+  void X87Mov(X87Register reg, X87Register src);
   void X87Mov(X87Register reg, Operand src,
       X87OperandType operand = kX87DoubleOperand);
   void X87Mov(Operand src, X87Register reg,
       X87OperandType operand = kX87DoubleOperand);
 
   void X87PrepareBinaryOp(
       X87Register left, X87Register right, X87Register result);
 
   void X87LoadForUsage(X87Register reg);
   void X87PrepareToWrite(X87Register reg) { x87_stack_.PrepareToWrite(reg); }
@@ skipping 274 matching lines @@
   // Emits code for pushing either a tagged constant, a (non-double)
   // register, or a stack slot operand.
   void EmitPushTaggedOperand(LOperand* operand);
 
   void X87Fld(Operand src, X87OperandType opts);
 
   void EmitFlushX87ForDeopt();
   void FlushX87StackIfNecessary(LInstruction* instr) {
     x87_stack_.FlushIfNecessary(instr, this);
   }
+  void RestoreX87StackIfNecessary(LInstruction* instr) {
+    x87_stack_.RestoreIfNecessary(instr, this);
+  }
+  void PreRecordX87StackUsage();
+
   friend class LGapResolver;
 
 #ifdef _MSC_VER
   // On windows, you may not access the stack more than one page below
   // the most recently mapped page. To make the allocated area randomly
   // accessible, we write an arbitrary value to each page in range
   // esp + offset - page_size .. esp in turn.
   void MakeSureStackPagesMapped(int offset);
 #endif
 
   Zone* zone_;
   LPlatformChunk* const chunk_;
   MacroAssembler* const masm_;
   CompilationInfo* const info_;
 
-  int current_block_;
+  HBasicBlock* current_block_;
   int current_instruction_;
   const ZoneList<LInstruction*>* instructions_;
   ZoneList<LEnvironment*> deoptimizations_;
   ZoneList<Deoptimizer::JumpTableEntry> jump_table_;
   ZoneList<Handle<Object> > deoptimization_literals_;
   int inlined_function_count_;
   Scope* const scope_;
   Status status_;
   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(const X87Stack& other)
-        : stack_depth_(0), masm_(other.masm_) {
-      stack_depth_ = other.stack_depth_;
-      for (int i = 0; i < stack_depth_; i++) {
-        stack_[i] = other.stack_[i];
+    explicit X87Stack(MacroAssembler* masm) : stack_depth_(0), masm_(masm) {
+      for (int i = 0; i < X87Register::kNumAllocatableRegisters; i++) {
+        first_defined_[i] = NULL;
       }
     }
-    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 Fxch(X87Register reg, X87Register src);
     void Free(X87Register reg);
     void PrepareToWrite(X87Register reg);
     void CommitWrite(X87Register reg);
     void FlushIfNecessary(LInstruction* instr, LCodeGen* cgen);
+    void RestoreIfNecessary(LInstruction* instr, LCodeGen* cgen);
+    int PhysicalPos(X87Register reg);
     int depth() const { return stack_depth_; }
     void pop() { stack_depth_--; }
+
     void push(X87Register reg) {
       ASSERT(stack_depth_ < X87Register::kNumAllocatableRegisters);
       stack_[stack_depth_] = reg;
       stack_depth_++;
     }
 
+    void leaving(HBasicBlock* block, HBasicBlock* next);
+    void record_usage(X87Register reg, HBasicBlock* block);
+    void record_definition(X87Register reg, HBasicBlock* block);
+
     MacroAssembler* masm() const { return masm_; }
 
    private:
     int ArrayIndex(X87Register reg);
     int st2idx(int pos);
     X87Register stack_[X87Register::kNumAllocatableRegisters];
+    HBasicBlock* first_defined_[X87Register::kNumAllocatableRegisters];
+    HBasicBlock* dominated_[X87Register::kNumAllocatableRegisters];
     int stack_depth_;
     MacroAssembler* const 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.
@@ skipping 56 matching lines @@
   LCodeGen* codegen_;
   Label entry_;
   Label exit_;
   Label* external_exit_;
   int instruction_index_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_LITHIUM_CODEGEN_IA32_H_