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 20 using namespace llvm; 21 22 #define DEBUG_TYPE "si-fix-vgpr-copies" 23 24 namespace { 25 26 class SIFixVGPRCopies : public MachineFunctionPass { 27 public: 28 static char ID; 29 30 public: 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 42 INITIALIZE_PASS(SIFixVGPRCopies, DEBUG_TYPE, "SI Fix VGPR copies", false, false) 43 44 char SIFixVGPRCopies::ID = 0; 45 46 char &llvm::SIFixVGPRCopiesID = SIFixVGPRCopies::ID; 47 48 bool 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