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Diffstat (limited to 'contrib/llvm/lib/Target/ARM/Thumb1FrameLowering.h')
-rw-r--r-- | contrib/llvm/lib/Target/ARM/Thumb1FrameLowering.h | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/ARM/Thumb1FrameLowering.h b/contrib/llvm/lib/Target/ARM/Thumb1FrameLowering.h new file mode 100644 index 0000000..812f983 --- /dev/null +++ b/contrib/llvm/lib/Target/ARM/Thumb1FrameLowering.h @@ -0,0 +1,88 @@ +//===-- Thumb1FrameLowering.h - Thumb1-specific frame info stuff --*- C++ -*-=// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_LIB_TARGET_ARM_THUMB1FRAMELOWERING_H +#define LLVM_LIB_TARGET_ARM_THUMB1FRAMELOWERING_H + +#include "ARMFrameLowering.h" +#include "Thumb1InstrInfo.h" +#include "ThumbRegisterInfo.h" +#include "llvm/Target/TargetFrameLowering.h" + +namespace llvm { + +class Thumb1FrameLowering : public ARMFrameLowering { +public: + explicit Thumb1FrameLowering(const ARMSubtarget &sti); + + /// emitProlog/emitEpilog - These methods insert prolog and epilog code into + /// the function. + void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override; + void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override; + + bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MI, + const std::vector<CalleeSavedInfo> &CSI, + const TargetRegisterInfo *TRI) const override; + bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MI, + const std::vector<CalleeSavedInfo> &CSI, + const TargetRegisterInfo *TRI) const override; + + bool hasReservedCallFrame(const MachineFunction &MF) const override; + + void + eliminateCallFramePseudoInstr(MachineFunction &MF, + MachineBasicBlock &MBB, + MachineBasicBlock::iterator MI) const override; + + /// Check whether or not the given \p MBB can be used as a epilogue + /// for the target. + /// The epilogue will be inserted before the first terminator of that block. + /// This method is used by the shrink-wrapping pass to decide if + /// \p MBB will be correctly handled by the target. + bool canUseAsEpilogue(const MachineBasicBlock &MBB) const override; + +private: + /// Check if the frame lowering of \p MF needs a special fixup + /// code sequence for the epilogue. + /// Unlike T2 and ARM mode, the T1 pop instruction cannot restore + /// to LR, and we can't pop the value directly to the PC when + /// we need to update the SP after popping the value. So instead + /// we have to emit: + /// POP {r3} + /// ADD sp, #offset + /// BX r3 + /// If this would clobber a return value, then generate this sequence instead: + /// MOV ip, r3 + /// POP {r3} + /// ADD sp, #offset + /// MOV lr, r3 + /// MOV r3, ip + /// BX lr + bool needPopSpecialFixUp(const MachineFunction &MF) const; + + /// Emit the special fixup code sequence for the epilogue. + /// \see needPopSpecialFixUp for more details. + /// \p DoIt, tells this method whether or not to actually insert + /// the code sequence in \p MBB. I.e., when \p DoIt is false, + /// \p MBB is left untouched. + /// \returns For \p DoIt == true: True when the emission succeeded + /// false otherwise. For \p DoIt == false: True when the emission + /// would have been possible, false otherwise. + bool emitPopSpecialFixUp(MachineBasicBlock &MBB, bool DoIt) const; +}; + +} // End llvm namespace + +#endif |