1//===-- SIFixVGPRCopies.cpp - Fix VGPR Copies after regalloc --------------===//
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/// \file
10/// Add implicit use of exec to vector register copies.
11///
12//===----------------------------------------------------------------------===//
13
14#include "AMDGPU.h"
15#include "AMDGPUSubtarget.h"
16#include "SIInstrInfo.h"
17#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
18#include "llvm/CodeGen/MachineFunctionPass.h"
19
20using namespace llvm;
21
22#define DEBUG_TYPE "si-fix-vgpr-copies"
23
24namespace {
25
26class SIFixVGPRCopies : public MachineFunctionPass {
27public:
28  static char ID;
29
30public:
31  SIFixVGPRCopies() : MachineFunctionPass(ID) {
32    initializeSIFixVGPRCopiesPass(*PassRegistry::getPassRegistry());
33  }
34
35  bool runOnMachineFunction(MachineFunction &MF) override;
36
37  StringRef getPassName() const override { return "SI Fix VGPR copies"; }
38};
39
40} // End anonymous namespace.
41
42INITIALIZE_PASS(SIFixVGPRCopies, DEBUG_TYPE, "SI Fix VGPR copies", false, false)
43
44char SIFixVGPRCopies::ID = 0;
45
46char &llvm::SIFixVGPRCopiesID = SIFixVGPRCopies::ID;
47
48bool SIFixVGPRCopies::runOnMachineFunction(MachineFunction &MF) {
49  const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
50  const SIRegisterInfo *TRI = ST.getRegisterInfo();
51  const SIInstrInfo *TII = ST.getInstrInfo();
52  bool Changed = false;
53
54  for (MachineBasicBlock &MBB : MF) {
55    for (MachineInstr &MI : MBB) {
56      switch (MI.getOpcode()) {
57      case AMDGPU::COPY:
58        if (TII->isVGPRCopy(MI) && !MI.readsRegister(AMDGPU::EXEC, TRI)) {
59          MI.addOperand(MF,
60                        MachineOperand::CreateReg(AMDGPU::EXEC, false, true));
61          LLVM_DEBUG(dbgs() << "Add exec use to " << MI);
62          Changed = true;
63        }
64        break;
65      default:
66        break;
67      }
68    }
69  }
70
71  return Changed;
72}
73