Reference RegionPass to stop it being eliminated.

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

diff --git a/include/llvm/CodeGen/MachineRegisterInfo.h b/include/llvm/CodeGen/MachineRegisterInfo.h
index fa14fdc3f19f7973741ce34fc5b0a145626f73ae..ddba61bf189ab733cd24a696e9bc48cc633d0b62 100644 (file)
--- a/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -35,7 +35,7 @@ class MachineRegisterInfo {
   /// RegClassVRegMap - This vector acts as a map from TargetRegisterClass to
   /// virtual registers. For each target register class, it keeps a list of
   /// virtual registers belonging to the class.
-  std::vector<std::vector<unsigned> > RegClass2VRegMap;
+  std::vector<unsigned> *RegClass2VRegMap;
 
   /// RegAllocHints - This vector records register allocation hints for virtual
   /// registers. For each virtual register, it keeps a register and hint type
@@ -203,6 +203,14 @@ public:
   ///
   void setRegClass(unsigned Reg, const TargetRegisterClass *RC);
 
+  /// constrainRegClass - Constrain the register class of the specified virtual
+  /// register to be a common subclass of RC and the current register class.
+  /// Return the new register class, or NULL if no such class exists.
+  /// This should only be used when the constraint is known to be trivial, like
+  /// GR32 -> GR32_NOSP. Beware of increasing register pressure.
+  const TargetRegisterClass *constrainRegClass(unsigned Reg,
+                                               const TargetRegisterClass *RC);
+
   /// createVirtualRegister - Create and return a new virtual register in the
   /// function with the specified register class.
   ///
@@ -363,7 +371,18 @@ public:
     defusechain_iterator operator++(int) {        // Postincrement
       defusechain_iterator tmp = *this; ++*this; return tmp;
     }
-    
+
+    /// skipInstruction - move forward until reaching a different instruction.
+    /// Return the skipped instruction that is no longer pointed to, or NULL if
+    /// already pointing to end().
+    MachineInstr *skipInstruction() {
+      if (!Op) return 0;
+      MachineInstr *MI = Op->getParent();
+      do ++*this;
+      while (Op && Op->getParent() == MI);
+      return MI;
+    }
+
     MachineOperand &getOperand() const {
       assert(Op && "Cannot dereference end iterator!");
       return *Op;