Implement X87 stack tracking and x87 multiplication

src/ia32/lithium-codegen-ia32.h

Index: src/ia32/lithium-codegen-ia32.h
diff --git a/src/ia32/lithium-codegen-ia32.h b/src/ia32/lithium-codegen-ia32.h
index d05da8a0841bb8f9328997ef4444282aa2a069f8..0e8be82efacbfd6ee19e16dff6f0ed18a6798ee4 100644
--- a/src/ia32/lithium-codegen-ia32.h
+++ b/src/ia32/lithium-codegen-ia32.h
@@ -105,7 +105,7 @@ class LCodeGen BASE_EMBEDDED {
   Operand ToOperand(LOperand* op) const;
   Register ToRegister(LOperand* op) const;
   XMMRegister ToDoubleRegister(LOperand* op) const;
-  bool IsX87TopOfStack(LOperand* op) const;
+  X87Register ToX87Register(LOperand* op) const;
 
   bool IsInteger32(LConstantOperand* op) const;
   bool IsSmi(LConstantOperand* op) const;
@@ -118,13 +118,18 @@ class LCodeGen BASE_EMBEDDED {
 
   // Support for non-sse2 (x87) floating point stack handling.
   // These functions maintain the depth of the stack (either 0 or 1)
-  void PushX87DoubleOperand(Operand src);
-  void PushX87FloatOperand(Operand src);
-  void ReadX87Operand(Operand dst);
-  bool X87StackNonEmpty() const { return x87_stack_depth_ > 0; }
-  void PopX87();
-  void CurrentInstructionReturnsX87Result();
-  void FlushX87StackIfNecessary(LInstruction* instr);
+  enum X87OperandType { kX87DoubleOperand, kX87FloatOperand, kX87IntOperand };

[mvstanton, 2013/07/04 12:30:55]

Maybe update the comment above, it's out of date now, talking about "either 0 or
1..."

+
+  void X87Mov(X87Register reg, Operand src,
+      X87OperandType operand = kX87DoubleOperand);
+  void X87Mov(Operand src, X87Register reg);
+
+  void X87PrepareBinaryOp(
+      X87Register left, X87Register right, X87Register result);
+
+  void X87LoadForUsage(X87Register reg);
+  void X87PrepareToWrite(X87Register reg);
+  void X87CommitWrite(X87Register reg);
 
   Handle<Object> ToHandle(LConstantOperand* op) const;
 
@@ -291,6 +296,7 @@ class LCodeGen BASE_EMBEDDED {
 
   Register ToRegister(int index) const;
   XMMRegister ToDoubleRegister(int index) const;
+  X87Register ToX87Register(int index) const;
   int ToInteger32(LConstantOperand* op) const;
 
   double ToDouble(LConstantOperand* op) const;
@@ -331,6 +337,7 @@ class LCodeGen BASE_EMBEDDED {
   void EmitNumberUntagDNoSSE2(
       Register input,
       Register temp,
+      X87Register res_reg,
       bool allow_undefined_as_nan,
       bool deoptimize_on_minus_zero,
       LEnvironment* env,
@@ -392,6 +399,15 @@ class LCodeGen BASE_EMBEDDED {
   // register, or a stack slot operand.
   void EmitPushTaggedOperand(LOperand* operand);
 
+  void X87Fxch(X87Register reg, int other_slot = 0);
+  void X87Fld(Operand src, X87OperandType opts);
+  void X87Free(X87Register reg);
+
+  void FlushX87StackIfNecessary(LInstruction* instr);
+  bool X87StackContains(X87Register reg);
+  int X87ArrayIndex(X87Register reg);
+  int x87_st2idx(int pos);
+
   Zone* zone_;
   LPlatformChunk* const chunk_;
   MacroAssembler* const masm_;
@@ -413,6 +429,7 @@ class LCodeGen BASE_EMBEDDED {
   int osr_pc_offset_;
   int last_lazy_deopt_pc_;
   bool frame_is_built_;
+  X87Register x87_stack_[8];

[mvstanton, 2013/07/04 12:30:55]

Can you replace the constant with something more official, like from
assembler-ia32.h?

   int x87_stack_depth_;
 
   // Builder that keeps track of safepoints in the code. The table