llvm-project/llvm/lib/Target/NVPTX/NVPTXFrameLowering.cpp
Shivam Gupta e2632fbcdd [NVPTX] Use MBB.begin() instead MBB.front() in NVPTXFrameLowering::emitPrologue
The second argument of `NVPTXFrameLowering::emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB)` is the first MBB of the MF. In that function, it assumes the first MBB always contains instructions, so it gets the first instruction by MachineInstr *MI = &MBB.front();. However, with the reproducer/test case attached, all instructions in the first MBB is cleared in a previous pass for stack coloring. As a consequence, MBB.front() triggers the assertion that the first node is actually a sentinel node. Hence we are using MachineBasicBlock::iterator to iterate over MBB.

Fix #52623.

Differential Revision: https://reviews.llvm.org/D132663
2022-09-14 08:30:55 +05:30

96 lines
3.6 KiB
C++

//=======- NVPTXFrameLowering.cpp - NVPTX Frame Information ---*- C++ -*-=====//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the NVPTX implementation of TargetFrameLowering class.
//
//===----------------------------------------------------------------------===//
#include "NVPTXFrameLowering.h"
#include "NVPTX.h"
#include "NVPTXRegisterInfo.h"
#include "NVPTXSubtarget.h"
#include "NVPTXTargetMachine.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/MC/MachineLocation.h"
using namespace llvm;
NVPTXFrameLowering::NVPTXFrameLowering()
: TargetFrameLowering(TargetFrameLowering::StackGrowsUp, Align(8), 0) {}
bool NVPTXFrameLowering::hasFP(const MachineFunction &MF) const { return true; }
void NVPTXFrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
if (MF.getFrameInfo().hasStackObjects()) {
assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineRegisterInfo &MR = MF.getRegInfo();
const NVPTXRegisterInfo *NRI =
MF.getSubtarget<NVPTXSubtarget>().getRegisterInfo();
// This instruction really occurs before first instruction
// in the BB, so giving it no debug location.
DebugLoc dl = DebugLoc();
// Emits
// mov %SPL, %depot;
// cvta.local %SP, %SPL;
// for local address accesses in MF.
bool Is64Bit =
static_cast<const NVPTXTargetMachine &>(MF.getTarget()).is64Bit();
unsigned CvtaLocalOpcode =
(Is64Bit ? NVPTX::cvta_local_yes_64 : NVPTX::cvta_local_yes);
unsigned MovDepotOpcode =
(Is64Bit ? NVPTX::MOV_DEPOT_ADDR_64 : NVPTX::MOV_DEPOT_ADDR);
if (!MR.use_empty(NRI->getFrameRegister(MF))) {
// If %SP is not used, do not bother emitting "cvta.local %SP, %SPL".
MBBI = BuildMI(MBB, MBBI, dl,
MF.getSubtarget().getInstrInfo()->get(CvtaLocalOpcode),
NRI->getFrameRegister(MF))
.addReg(NRI->getFrameLocalRegister(MF));
}
BuildMI(MBB, MBBI, dl,
MF.getSubtarget().getInstrInfo()->get(MovDepotOpcode),
NRI->getFrameLocalRegister(MF))
.addImm(MF.getFunctionNumber());
}
}
StackOffset
NVPTXFrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,
Register &FrameReg) const {
const MachineFrameInfo &MFI = MF.getFrameInfo();
FrameReg = NVPTX::VRDepot;
return StackOffset::getFixed(MFI.getObjectOffset(FI) -
getOffsetOfLocalArea());
}
void NVPTXFrameLowering::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {}
// This function eliminates ADJCALLSTACKDOWN,
// ADJCALLSTACKUP pseudo instructions
MachineBasicBlock::iterator NVPTXFrameLowering::eliminateCallFramePseudoInstr(
MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
// Simply discard ADJCALLSTACKDOWN,
// ADJCALLSTACKUP instructions.
return MBB.erase(I);
}
TargetFrameLowering::DwarfFrameBase
NVPTXFrameLowering::getDwarfFrameBase(const MachineFunction &MF) const {
return {DwarfFrameBase::CFA, {0}};
}