LLVM  10.0.0svn
NVPTXFrameLowering.cpp
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1 //=======- NVPTXFrameLowering.cpp - NVPTX Frame Information ---*- C++ -*-=====//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains the NVPTX implementation of TargetFrameLowering class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "NVPTXFrameLowering.h"
14 #include "NVPTX.h"
15 #include "NVPTXRegisterInfo.h"
16 #include "NVPTXSubtarget.h"
17 #include "NVPTXTargetMachine.h"
24 
25 using namespace llvm;
26 
28  : TargetFrameLowering(TargetFrameLowering::StackGrowsUp, 8, 0) {}
29 
30 bool NVPTXFrameLowering::hasFP(const MachineFunction &MF) const { return true; }
31 
33  MachineBasicBlock &MBB) const {
34  if (MF.getFrameInfo().hasStackObjects()) {
35  assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
36  MachineInstr *MI = &MBB.front();
38 
39  // This instruction really occurs before first instruction
40  // in the BB, so giving it no debug location.
41  DebugLoc dl = DebugLoc();
42 
43  // Emits
44  // mov %SPL, %depot;
45  // cvta.local %SP, %SPL;
46  // for local address accesses in MF.
47  bool Is64Bit =
48  static_cast<const NVPTXTargetMachine &>(MF.getTarget()).is64Bit();
49  unsigned CvtaLocalOpcode =
50  (Is64Bit ? NVPTX::cvta_local_yes_64 : NVPTX::cvta_local_yes);
51  unsigned MovDepotOpcode =
52  (Is64Bit ? NVPTX::MOV_DEPOT_ADDR_64 : NVPTX::MOV_DEPOT_ADDR);
53  if (!MR.use_empty(NVPTX::VRFrame)) {
54  // If %SP is not used, do not bother emitting "cvta.local %SP, %SPL".
55  MI = BuildMI(MBB, MI, dl,
56  MF.getSubtarget().getInstrInfo()->get(CvtaLocalOpcode),
57  NVPTX::VRFrame)
58  .addReg(NVPTX::VRFrameLocal);
59  }
60  BuildMI(MBB, MI, dl, MF.getSubtarget().getInstrInfo()->get(MovDepotOpcode),
61  NVPTX::VRFrameLocal)
62  .addImm(MF.getFunctionNumber());
63  }
64 }
65 
67  int FI,
68  unsigned &FrameReg) const {
69  const MachineFrameInfo &MFI = MF.getFrameInfo();
70  FrameReg = NVPTX::VRDepot;
71  return MFI.getObjectOffset(FI) - getOffsetOfLocalArea();
72 }
73 
75  MachineBasicBlock &MBB) const {}
76 
77 // This function eliminates ADJCALLSTACKDOWN,
78 // ADJCALLSTACKUP pseudo instructions
82  // Simply discard ADJCALLSTACKDOWN,
83  // ADJCALLSTACKUP instructions.
84  return MBB.erase(I);
85 }
void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override
unsigned getFunctionNumber() const
getFunctionNumber - Return a unique ID for the current function.
This class represents lattice values for constants.
Definition: AllocatorList.h:23
bool hasStackObjects() const
Return true if there are any stack objects in this function.
A debug info location.
Definition: DebugLoc.h:33
int getOffsetOfLocalArea() const
getOffsetOfLocalArea - This method returns the offset of the local area from the stack pointer on ent...
void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override
emitProlog/emitEpilog - These methods insert prolog and epilog code into the function.
instr_iterator erase(instr_iterator I)
Remove an instruction from the instruction list and delete it.
int64_t getObjectOffset(int ObjectIdx) const
Return the assigned stack offset of the specified object from the incoming stack pointer.
The MachineFrameInfo class represents an abstract stack frame until prolog/epilog code is inserted...
virtual const TargetInstrInfo * getInstrInfo() const
MachineInstrBuilder BuildMI(MachineFunction &MF, const DebugLoc &DL, const MCInstrDesc &MCID)
Builder interface. Specify how to create the initial instruction itself.
const TargetSubtargetInfo & getSubtarget() const
getSubtarget - Return the subtarget for which this machine code is being compiled.
MachineFrameInfo & getFrameInfo()
getFrameInfo - Return the frame info object for the current function.
static bool is64Bit(const char *name)
const MachineBasicBlock & front() const
Information about stack frame layout on the target.
MachineBasicBlock::iterator eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, MachineBasicBlock::iterator I) const override
This method is called during prolog/epilog code insertion to eliminate call frame setup and destroy p...
int getFrameIndexReference(const MachineFunction &MF, int FI, unsigned &FrameReg) const override
getFrameIndexReference - This method should return the base register and offset used to reference a f...
bool use_empty(unsigned RegNo) const
use_empty - Return true if there are no instructions using the specified register.
MachineRegisterInfo - Keep track of information for virtual and physical registers, including vreg register classes, use/def chains for registers, etc.
Representation of each machine instruction.
Definition: MachineInstr.h:64
NVPTXTargetMachine.
MachineRegisterInfo & getRegInfo()
getRegInfo - Return information about the registers currently in use.
bool hasFP(const MachineFunction &MF) const override
hasFP - Return true if the specified function should have a dedicated frame pointer register...
const MCInstrDesc & get(unsigned Opcode) const
Return the machine instruction descriptor that corresponds to the specified instruction opcode...
Definition: MCInstrInfo.h:44
#define I(x, y, z)
Definition: MD5.cpp:58
const LLVMTargetMachine & getTarget() const
getTarget - Return the target machine this machine code is compiled with
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
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