llvm-6502/lib/Target/BPF/BPFFrameLowering.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

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1.4 KiB
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//===-- BPFFrameLowering.h - Define frame lowering for BPF -----*- C++ -*--===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class implements BPF-specific bits of TargetFrameLowering class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_BPF_BPFFRAMELOWERING_H
#define LLVM_LIB_TARGET_BPF_BPFFRAMELOWERING_H
#include "llvm/Target/TargetFrameLowering.h"
namespace llvm {
class BPFSubtarget;
class BPFFrameLowering : public TargetFrameLowering {
public:
explicit BPFFrameLowering(const BPFSubtarget &sti)
: TargetFrameLowering(TargetFrameLowering::StackGrowsDown, 8, 0) {}
void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
bool hasFP(const MachineFunction &MF) const override;
void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
RegScavenger *RS) const override;
void
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const override {
MBB.erase(MI);
}
};
}
#endif