| //===-- llvm/CodeGen/ExpandISelPseudos.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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Expand Pseudo-instructions produced by ISel. These are usually 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/Support/Debug.h" |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "expand-isel-pseudos" |
| |
| namespace { |
| class ExpandISelPseudos : public MachineFunctionPass { |
| public: |
| static char ID; // Pass identification, replacement for typeid |
| ExpandISelPseudos() : MachineFunctionPass(ID) {} |
| |
| private: |
| bool runOnMachineFunction(MachineFunction &MF) override; |
| |
| void getAnalysisUsage(AnalysisUsage &AU) const override { |
| MachineFunctionPass::getAnalysisUsage(AU); |
| } |
| }; |
| } // end anonymous namespace |
| |
| char ExpandISelPseudos::ID = 0; |
| char &llvm::ExpandISelPseudosID = ExpandISelPseudos::ID; |
| INITIALIZE_PASS(ExpandISelPseudos, DEBUG_TYPE, |
| "Expand ISel Pseudo-instructions", false, false) |
| |
| bool ExpandISelPseudos::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(); |
| } |
| } |
| } |
| } |
| |
| return Changed; |
| } |