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 19 using namespace llvm; 20 21 #define DEBUG_TYPE "si-fix-vgpr-copies" 22 23 namespace { 24 25 class SIFixVGPRCopies : public MachineFunctionPass { 26 public: 27 static char ID; 28 29 public: 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 46 INITIALIZE_PASS(SIFixVGPRCopies, DEBUG_TYPE, "SI Fix VGPR copies", false, false) 47 48 char SIFixVGPRCopies::ID = 0; 49 50 char &llvm::SIFixVGPRCopiesID = SIFixVGPRCopies::ID; 51 52 bool 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(AMDGPU::EXEC, TRI)) { 63 MI.addOperand(MF, 64 MachineOperand::CreateReg(AMDGPU::EXEC, false, 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