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"
18 #include "llvm/CodeGen/MachineFrameInfo.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 #include "llvm/CodeGen/MachineInstrBuilder.h"
21 #include "llvm/CodeGen/MachineRegisterInfo.h"
22 #include "llvm/CodeGen/TargetInstrInfo.h"
23 #include "llvm/MC/MachineLocation.h"
24
25 using namespace llvm;
26
NVPTXFrameLowering()27 NVPTXFrameLowering::NVPTXFrameLowering()
28 : TargetFrameLowering(TargetFrameLowering::StackGrowsUp, Align(8), 0) {}
29
hasFP(const MachineFunction & MF) const30 bool NVPTXFrameLowering::hasFP(const MachineFunction &MF) const { return true; }
31
emitPrologue(MachineFunction & MF,MachineBasicBlock & MBB) const32 void NVPTXFrameLowering::emitPrologue(MachineFunction &MF,
33 MachineBasicBlock &MBB) const {
34 if (MF.getFrameInfo().hasStackObjects()) {
35 assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
36 MachineInstr *MI = &MBB.front();
37 MachineRegisterInfo &MR = MF.getRegInfo();
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
getFrameIndexReference(const MachineFunction & MF,int FI,unsigned & FrameReg) const66 int NVPTXFrameLowering::getFrameIndexReference(const MachineFunction &MF,
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
emitEpilogue(MachineFunction & MF,MachineBasicBlock & MBB) const74 void NVPTXFrameLowering::emitEpilogue(MachineFunction &MF,
75 MachineBasicBlock &MBB) const {}
76
77 // This function eliminates ADJCALLSTACKDOWN,
78 // ADJCALLSTACKUP pseudo instructions
eliminateCallFramePseudoInstr(MachineFunction & MF,MachineBasicBlock & MBB,MachineBasicBlock::iterator I) const79 MachineBasicBlock::iterator NVPTXFrameLowering::eliminateCallFramePseudoInstr(
80 MachineFunction &MF, MachineBasicBlock &MBB,
81 MachineBasicBlock::iterator I) const {
82 // Simply discard ADJCALLSTACKDOWN,
83 // ADJCALLSTACKUP instructions.
84 return MBB.erase(I);
85 }
86