Use instruction itinerary to determine what instructions are 'cheap'.

[oota-llvm.git] / include / llvm / CodeGen / FastISel.h

diff --git a/include/llvm/CodeGen/FastISel.h b/include/llvm/CodeGen/FastISel.h
index 7f3a7c77693149f3b78b80c0bdb0dd977a2a22f2..d7506bedfb4adada3f116e5eb43a51514d33404c 100644 (file)
--- a/include/llvm/CodeGen/FastISel.h
+++ b/include/llvm/CodeGen/FastISel.h
@@ -39,6 +39,7 @@ class TargetLowering;
 class TargetMachine;
 class TargetRegisterClass;
 class TargetRegisterInfo;
+class LoadInst;
 
 /// FastISel - This is a fast-path instruction selection class that
 /// generates poor code and doesn't support illegal types or non-trivial
@@ -102,16 +103,30 @@ public:
   /// index value.
   std::pair<unsigned, bool> getRegForGEPIndex(const Value *V);
 
-  /// recomputeInsertPt - Reset InsertPt to prepare for insterting instructions
+  /// TryToFoldLoad - The specified machine instr operand is a vreg, and that
+  /// vreg is being provided by the specified load instruction.  If possible,
+  /// try to fold the load as an operand to the instruction, returning true if
+  /// possible.
+  virtual bool TryToFoldLoad(MachineInstr * /*MI*/, unsigned /*OpNo*/,
+                             const LoadInst * /*LI*/) {
+    return false;
+  }
+  
+  /// recomputeInsertPt - Reset InsertPt to prepare for inserting instructions
   /// into the current block.
   void recomputeInsertPt();
 
+  struct SavePoint {
+    MachineBasicBlock::iterator InsertPt;
+    DebugLoc DL;
+  };
+
   /// enterLocalValueArea - Prepare InsertPt to begin inserting instructions
   /// into the local value area and return the old insert position.
-  MachineBasicBlock::iterator enterLocalValueArea();
+  SavePoint enterLocalValueArea();
 
-  /// leaveLocalValueArea - Reset InsertPt to the given old insert position
-  void leaveLocalValueArea(MachineBasicBlock::iterator OldInsertPt);
+  /// leaveLocalValueArea - Reset InsertPt to the given old insert position.
+  void leaveLocalValueArea(SavePoint Old);
 
   virtual ~FastISel();
 
@@ -302,8 +317,6 @@ protected:
   }
 
 private:
-  bool SelectLoad(const User *I);
-
   bool SelectBinaryOp(const User *I, unsigned ISDOpcode);
 
   bool SelectFNeg(const User *I);