-/// usesTheStack - This function checks if any of the users of EFLAGS
-/// copies the EFLAGS. We know that the code that lowers COPY of EFLAGS has
-/// to use the stack, and if we don't adjust the stack we clobber the first
-/// frame index.
-/// See X86InstrInfo::copyPhysReg.
-static bool usesTheStack(const MachineFunction &MF) {
- const MachineRegisterInfo &MRI = MF.getRegInfo();
-
- return any_of(MRI.reg_instructions(X86::EFLAGS),
- [](const MachineInstr &RI) { return RI.isCopy(); });
-}
-
-static bool doesStackUseImplyFP(const MachineFunction &MF) {
- bool IsWin64Prologue = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
- return IsWin64Prologue && usesTheStack(MF);
-}
-