1 files changed, 10 insertions, 7 deletions
diff --git a/include/llvm/Target/TargetFrameLowering.h b/include/llvm/Target/TargetFrameLowering.h
index 0e317247a59f..3af2227410f7 100644
--- a/include/llvm/Target/TargetFrameLowering.h
+++ b/include/llvm/Target/TargetFrameLowering.h
@@ -19,6 +19,7 @@
 #include <vector>
 
 namespace llvm {
+  class BitVector;
   class CalleeSavedInfo;
   class MachineFunction;
   class RegScavenger;
@@ -226,13 +227,15 @@ public:
     return 0;
   }
 
-  /// processFunctionBeforeCalleeSavedScan - This method is called immediately
-  /// before PrologEpilogInserter scans the physical registers used to determine
-  /// what callee saved registers should be spilled. This method is optional.
-  virtual void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
-                                             RegScavenger *RS = nullptr) const {
-
-  }
+  /// This method determines which of the registers reported by
+  /// TargetRegisterInfo::getCalleeSavedRegs() should actually get saved.
+  /// The default implementation checks populates the \p SavedRegs bitset with
+  /// all registers which are modified in the function, targets may override
+  /// this function to save additional registers.
+  /// This method also sets up the register scavenger ensuring there is a free
+  /// register or a frameindex available.
+  virtual void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
+                                    RegScavenger *RS = nullptr) const;
 
   /// processFunctionBeforeFrameFinalized - This method is called immediately
   /// before the specified function's frame layout (MF.getFrameInfo()) is