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 MachineBasicBlock::iterator MBBI = MBB.begin();
37 MachineRegisterInfo &MR = MF.getRegInfo();
38
39 const NVPTXRegisterInfo *NRI =
40 MF.getSubtarget<NVPTXSubtarget>().getRegisterInfo();
41
42 // This instruction really occurs before first instruction
43 // in the BB, so giving it no debug location.
44 DebugLoc dl = DebugLoc();
45
46 // Emits
47 // mov %SPL, %depot;
48 // cvta.local %SP, %SPL;
49 // for local address accesses in MF.
50 bool Is64Bit =
51 static_cast<const NVPTXTargetMachine &>(MF.getTarget()).is64Bit();
52 unsigned CvtaLocalOpcode =
53 (Is64Bit ? NVPTX::cvta_local_64 : NVPTX::cvta_local);
54 unsigned MovDepotOpcode =
55 (Is64Bit ? NVPTX::MOV_DEPOT_ADDR_64 : NVPTX::MOV_DEPOT_ADDR);
56 if (!MR.use_empty(NRI->getFrameRegister(MF))) {
57 // If %SP is not used, do not bother emitting "cvta.local %SP, %SPL".
58 MBBI = BuildMI(MBB, MBBI, dl,
59 MF.getSubtarget().getInstrInfo()->get(CvtaLocalOpcode),
60 NRI->getFrameRegister(MF))
61 .addReg(NRI->getFrameLocalRegister(MF));
62 }
63 if (!MR.use_empty(NRI->getFrameLocalRegister(MF))) {
64 BuildMI(MBB, MBBI, dl,
65 MF.getSubtarget().getInstrInfo()->get(MovDepotOpcode),
66 NRI->getFrameLocalRegister(MF))
67 .addImm(MF.getFunctionNumber());
68 }
69 }
70 }
71
72 StackOffset
getFrameIndexReference(const MachineFunction & MF,int FI,Register & FrameReg) const73 NVPTXFrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,
74 Register &FrameReg) const {
75 const MachineFrameInfo &MFI = MF.getFrameInfo();
76 FrameReg = NVPTX::VRDepot;
77 return StackOffset::getFixed(MFI.getObjectOffset(FI) -
78 getOffsetOfLocalArea());
79 }
80
emitEpilogue(MachineFunction & MF,MachineBasicBlock & MBB) const81 void NVPTXFrameLowering::emitEpilogue(MachineFunction &MF,
82 MachineBasicBlock &MBB) const {}
83
84 // This function eliminates ADJCALLSTACKDOWN,
85 // ADJCALLSTACKUP pseudo instructions
eliminateCallFramePseudoInstr(MachineFunction & MF,MachineBasicBlock & MBB,MachineBasicBlock::iterator I) const86 MachineBasicBlock::iterator NVPTXFrameLowering::eliminateCallFramePseudoInstr(
87 MachineFunction &MF, MachineBasicBlock &MBB,
88 MachineBasicBlock::iterator I) const {
89 // Simply discard ADJCALLSTACKDOWN,
90 // ADJCALLSTACKUP instructions.
91 return MBB.erase(I);
92 }
93
94 TargetFrameLowering::DwarfFrameBase
getDwarfFrameBase(const MachineFunction & MF) const95 NVPTXFrameLowering::getDwarfFrameBase(const MachineFunction &MF) const {
96 DwarfFrameBase FrameBase;
97 FrameBase.Kind = DwarfFrameBase::CFA;
98 FrameBase.Location.Offset = 0;
99 return FrameBase;
100 }
101