Reference RegionPass to stop it being eliminated.

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

diff --git a/include/llvm/CodeGen/FastISel.h b/include/llvm/CodeGen/FastISel.h
index c5c457db0c182793ddfffab5cef4f54d81e9959a..d7506bedfb4adada3f116e5eb43a51514d33404c 100644 (file)
--- a/include/llvm/CodeGen/FastISel.h
+++ b/include/llvm/CodeGen/FastISel.h
@@ -19,6 +19,7 @@
 #include "llvm/ADT/SmallSet.h"
 #endif
 #include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
 
 namespace llvm {
 
@@ -38,13 +39,13 @@ 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
 /// lowering, but runs quickly.
 class FastISel {
 protected:
-  MachineBasicBlock *MBB;
   DenseMap<const Value *, unsigned> LocalValueMap;
   FunctionLoweringInfo &FuncInfo;
   MachineRegisterInfo &MRI;
@@ -56,23 +57,21 @@ protected:
   const TargetInstrInfo &TII;
   const TargetLowering &TLI;
   const TargetRegisterInfo &TRI;
-  bool IsBottomUp;
+  MachineInstr *LastLocalValue;
 
 public:
+  /// getLastLocalValue - Return the position of the last instruction
+  /// emitted for materializing constants for use in the current block.
+  MachineInstr *getLastLocalValue() { return LastLocalValue; }
+
+  /// setLastLocalValue - Update the position of the last instruction
+  /// emitted for materializing constants for use in the current block.
+  void setLastLocalValue(MachineInstr *I) { LastLocalValue = I; }
+
   /// startNewBlock - Set the current block to which generated machine
   /// instructions will be appended, and clear the local CSE map.
   ///
-  void startNewBlock(MachineBasicBlock *mbb) {
-    setCurrentBlock(mbb);
-    LocalValueMap.clear();
-  }
-
-  /// setCurrentBlock - Set the current block to which generated machine
-  /// instructions will be appended.
-  ///
-  void setCurrentBlock(MachineBasicBlock *mbb) {
-    MBB = mbb;
-  }
+  void startNewBlock();
 
   /// getCurDebugLoc() - Return current debug location information.
   DebugLoc getCurDebugLoc() const { return DL; }
@@ -104,6 +103,31 @@ public:
   /// index value.
   std::pair<unsigned, bool> getRegForGEPIndex(const Value *V);
 
+  /// 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.
+  SavePoint enterLocalValueArea();
+
+  /// leaveLocalValueArea - Reset InsertPt to the given old insert position.
+  void leaveLocalValueArea(SavePoint Old);
+
   virtual ~FastISel();
 
 protected:
@@ -293,8 +317,6 @@ protected:
   }
 
 private:
-  bool SelectLoad(const User *I);
-
   bool SelectBinaryOp(const User *I, unsigned ISDOpcode);
 
   bool SelectFNeg(const User *I);