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 "GCNSubtarget.h"
16#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
17#include "llvm/CodeGen/MachineFunctionPass.h"
18
19using namespace llvm;
20
21#define DEBUG_TYPE "si-fix-vgpr-copies"
22
23namespace {
24
25class SIFixVGPRCopies : public MachineFunctionPass {
26public:
27 static char ID;
28
29public:
30 SIFixVGPRCopies() : MachineFunctionPass(ID) {
31 initializeSIFixVGPRCopiesPass(*PassRegistry::getPassRegistry());
32 }
33
34 void getAnalysisUsage(AnalysisUsage &AU) const override {
35 AU.setPreservesAll();
36 MachineFunctionPass::getAnalysisUsage(AU);
37 }
38
39 bool runOnMachineFunction(MachineFunction &MF) override;
40
41 StringRef getPassName() const override { return "SI Fix VGPR copies"; }
42};
43
44} // End anonymous namespace.
45
46INITIALIZE_PASS(SIFixVGPRCopies, DEBUG_TYPE, "SI Fix VGPR copies", false, false)
47
48char SIFixVGPRCopies::ID = 0;
49
50char &llvm::SIFixVGPRCopiesID = SIFixVGPRCopies::ID;
51
52bool SIFixVGPRCopies::runOnMachineFunction(MachineFunction &MF) {
53 const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
54 const SIRegisterInfo *TRI = ST.getRegisterInfo();
55 const SIInstrInfo *TII = ST.getInstrInfo();
56 bool Changed = false;
57
58 for (MachineBasicBlock &MBB : MF) {
59 for (MachineInstr &MI : MBB) {
60 switch (MI.getOpcode()) {
61 case AMDGPU::COPY:
62 if (TII->isVGPRCopy(MI) && !MI.readsRegister(Reg: AMDGPU::EXEC, TRI)) {
63 MI.addOperand(MF,
64 Op: MachineOperand::CreateReg(Reg: AMDGPU::EXEC, isDef: false, isImp: true));
65 LLVM_DEBUG(dbgs() << "Add exec use to " << MI);
66 Changed = true;
67 }
68 break;
69 default:
70 break;
71 }
72 }
73 }
74
75 return Changed;
76}
77