#include <vector>
namespace llvm {
+ class BitVector;
class CalleeSavedInfo;
class MachineFunction;
class RegScavenger;
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