llvm-6502/lib/Target/Hexagon/HexagonFrameLowering.h
Matthias Braun a36268215f PrologEpilogInserter: Rewrite API to determine callee save regsiters.
This changes TargetFrameLowering::processFunctionBeforeCalleeSavedScan():

- Rename the function to determineCalleeSaves()
- Pass a bitset of callee saved registers by reference, thus avoiding
  the function-global PhysRegUsed bitset in MachineRegisterInfo.
- Without PhysRegUsed the implementation is fine tuned to not save
  physcial registers which are only read but never modified.

Related to rdar://21539507

Differential Revision: http://reviews.llvm.org/D10909

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242165 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 17:17:13 +00:00

105 lines
4.0 KiB
C++

//=- HexagonFrameLowering.h - Define frame lowering for Hexagon --*- 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_HEXAGON_HEXAGONFRAMELOWERING_H
#define LLVM_LIB_TARGET_HEXAGON_HEXAGONFRAMELOWERING_H
#include "Hexagon.h"
#include "llvm/Target/TargetFrameLowering.h"
namespace llvm {
class HexagonInstrInfo;
class HexagonRegisterInfo;
class HexagonFrameLowering : public TargetFrameLowering {
public:
explicit HexagonFrameLowering()
: TargetFrameLowering(StackGrowsDown, 8, 0, 1, true) {}
// All of the prolog/epilog functionality, including saving and restoring
// callee-saved registers is handled in emitPrologue. This is to have the
// logic for shrink-wrapping in one place.
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 {
return true;
}
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI, const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override {
return true;
}
void eliminateCallFramePseudoInstr(MachineFunction &MF,
MachineBasicBlock &MBB, MachineBasicBlock::iterator I) const override;
void processFunctionBeforeFrameFinalized(MachineFunction &MF,
RegScavenger *RS = nullptr) const override;
void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
RegScavenger *RS) const override;
bool targetHandlesStackFrameRounding() const override {
return true;
}
int getFrameIndexOffset(const MachineFunction &MF, int FI) const override;
bool hasFP(const MachineFunction &MF) const override;
const SpillSlot *getCalleeSavedSpillSlots(unsigned &NumEntries)
const override {
static const SpillSlot Offsets[] = {
{ Hexagon::R17, -4 }, { Hexagon::R16, -8 }, { Hexagon::D8, -8 },
{ Hexagon::R19, -12 }, { Hexagon::R18, -16 }, { Hexagon::D9, -16 },
{ Hexagon::R21, -20 }, { Hexagon::R20, -24 }, { Hexagon::D10, -24 },
{ Hexagon::R23, -28 }, { Hexagon::R22, -32 }, { Hexagon::D11, -32 },
{ Hexagon::R25, -36 }, { Hexagon::R24, -40 }, { Hexagon::D12, -40 },
{ Hexagon::R27, -44 }, { Hexagon::R26, -48 }, { Hexagon::D13, -48 }
};
NumEntries = array_lengthof(Offsets);
return Offsets;
}
bool assignCalleeSavedSpillSlots(MachineFunction &MF,
const TargetRegisterInfo *TRI, std::vector<CalleeSavedInfo> &CSI)
const override;
bool needsAligna(const MachineFunction &MF) const;
MachineInstr *getAlignaInstr(MachineFunction &MF) const;
private:
typedef std::vector<CalleeSavedInfo> CSIVect;
void expandAlloca(MachineInstr *AI, const HexagonInstrInfo &TII,
unsigned SP, unsigned CF) const;
void insertPrologueInBlock(MachineBasicBlock &MBB) const;
void insertEpilogueInBlock(MachineBasicBlock &MBB) const;
bool insertCSRSpillsInBlock(MachineBasicBlock &MBB, const CSIVect &CSI,
const HexagonRegisterInfo &HRI) const;
bool insertCSRRestoresInBlock(MachineBasicBlock &MBB, const CSIVect &CSI,
const HexagonRegisterInfo &HRI) const;
void adjustForCalleeSavedRegsSpillCall(MachineFunction &MF) const;
bool replacePredRegPseudoSpillCode(MachineFunction &MF) const;
bool replaceVecPredRegPseudoSpillCode(MachineFunction &MF) const;
void findShrunkPrologEpilog(MachineFunction &MF, MachineBasicBlock *&PrologB,
MachineBasicBlock *&EpilogB) const;
bool shouldInlineCSR(llvm::MachineFunction&, const CSIVect&) const;
bool useSpillFunction(MachineFunction &MF, const CSIVect &CSI) const;
bool useRestoreFunction(MachineFunction &MF, const CSIVect &CSI) const;
};
} // End llvm namespace
#endif