//===-- llvm/CodeGen/FinalizeISel.cpp ---------------------------*- C++ -*-===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // /// This pass expands Pseudo-instructions produced by ISel, fixes register /// reservations and may do machine frame information adjustments. /// The pseudo instructions are used to allow the expansion to contain control /// flow, such as a conditional move implemented with a conditional branch and a /// phi, or an atomic operation implemented with a loop. // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineFunctionPass.h" #include "llvm/CodeGen/Passes.h" #include "llvm/CodeGen/TargetLowering.h" #include "llvm/CodeGen/TargetSubtargetInfo.h" #include "llvm/InitializePasses.h" #include "llvm/Support/Debug.h" using namespace llvm; #define DEBUG_TYPE "finalize-isel" namespace { class FinalizeISel : public MachineFunctionPass { public: static char ID; // Pass identification, replacement for typeid FinalizeISel() : MachineFunctionPass(ID) {} private: bool runOnMachineFunction(MachineFunction &MF) override; void getAnalysisUsage(AnalysisUsage &AU) const override { MachineFunctionPass::getAnalysisUsage(AU); } }; } // end anonymous namespace char FinalizeISel::ID = 0; char &llvm::FinalizeISelID = FinalizeISel::ID; INITIALIZE_PASS(FinalizeISel, DEBUG_TYPE, "Finalize ISel and expand pseudo-instructions", false, false) bool FinalizeISel::runOnMachineFunction(MachineFunction &MF) { bool Changed = false; const TargetLowering *TLI = MF.getSubtarget().getTargetLowering(); // Iterate through each instruction in the function, looking for pseudos. for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) { MachineBasicBlock *MBB = &*I; for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end(); MBBI != MBBE; ) { MachineInstr &MI = *MBBI++; // If MI is a pseudo, expand it. if (MI.usesCustomInsertionHook()) { Changed = true; MachineBasicBlock *NewMBB = TLI->EmitInstrWithCustomInserter(MI, MBB); // The expansion may involve new basic blocks. if (NewMBB != MBB) { MBB = NewMBB; I = NewMBB->getIterator(); MBBI = NewMBB->begin(); MBBE = NewMBB->end(); } } } } TLI->finalizeLowering(MF); return Changed; } |