42 lines · cpp
1//===- ReduceVirtualRegisters.cpp - Specialized Delta Pass ----------------===//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-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements a function which calls the Generic Delta pass in order10// to simplify virtual registers in MIR.11//12//===----------------------------------------------------------------------===//13 14#include "ReduceVirtualRegisters.h"15#include "llvm/CodeGen/MachineModuleInfo.h"16#include "llvm/CodeGen/MachineRegisterInfo.h"17 18using namespace llvm;19 20static void dropRegisterHintsFromFunction(Oracle &O, MachineFunction &MF) {21 MachineRegisterInfo &MRI = MF.getRegInfo();22 for (unsigned I = 0, E = MRI.getNumVirtRegs(); I != E; ++I) {23 Register Reg = Register::index2VirtReg(I);24 25 const std::pair<unsigned, SmallVector<Register, 4>> *Hints =26 MRI.getRegAllocationHints(Reg);27 if (!Hints || Hints->second.empty())28 continue;29 30 if (!O.shouldKeep())31 MRI.clearSimpleHint(Reg);32 }33}34 35void llvm::reduceVirtualRegisterHintsDeltaPass(Oracle &O,36 ReducerWorkItem &WorkItem) {37 for (const Function &F : WorkItem.getModule()) {38 if (auto *MF = WorkItem.MMI->getMachineFunction(F))39 dropRegisterHintsFromFunction(O, *MF);40 }41}42