1 | //===-- llvm/CodeGen/FinalizeISel.cpp ---------------------------*- C++ -*-===// |
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 | /// This pass expands Pseudo-instructions produced by ISel, fixes register |
10 | /// reservations and may do machine frame information adjustments. |
11 | /// The pseudo instructions are used to allow the expansion to contain control |
12 | /// flow, such as a conditional move implemented with a conditional branch and a |
13 | /// phi, or an atomic operation implemented with a loop. |
14 | // |
15 | //===----------------------------------------------------------------------===// |
16 | |
17 | #include "llvm/CodeGen/MachineFunction.h" |
18 | #include "llvm/CodeGen/MachineFunctionPass.h" |
19 | #include "llvm/CodeGen/TargetLowering.h" |
20 | #include "llvm/CodeGen/TargetSubtargetInfo.h" |
21 | #include "llvm/InitializePasses.h" |
22 | using namespace llvm; |
23 | |
24 | #define DEBUG_TYPE "finalize-isel" |
25 | |
26 | namespace { |
27 | class FinalizeISel : public MachineFunctionPass { |
28 | public: |
29 | static char ID; // Pass identification, replacement for typeid |
30 | FinalizeISel() : MachineFunctionPass(ID) {} |
31 | |
32 | private: |
33 | bool runOnMachineFunction(MachineFunction &MF) override; |
34 | |
35 | void getAnalysisUsage(AnalysisUsage &AU) const override { |
36 | MachineFunctionPass::getAnalysisUsage(AU); |
37 | } |
38 | }; |
39 | } // end anonymous namespace |
40 | |
41 | char FinalizeISel::ID = 0; |
42 | char &llvm::FinalizeISelID = FinalizeISel::ID; |
43 | INITIALIZE_PASS(FinalizeISel, DEBUG_TYPE, |
44 | "Finalize ISel and expand pseudo-instructions" , false, false) |
45 | |
46 | bool FinalizeISel::runOnMachineFunction(MachineFunction &MF) { |
47 | bool Changed = false; |
48 | const TargetLowering *TLI = MF.getSubtarget().getTargetLowering(); |
49 | |
50 | // Iterate through each instruction in the function, looking for pseudos. |
51 | for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) { |
52 | MachineBasicBlock *MBB = &*I; |
53 | for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end(); |
54 | MBBI != MBBE; ) { |
55 | MachineInstr &MI = *MBBI++; |
56 | |
57 | // If MI is a pseudo, expand it. |
58 | if (MI.usesCustomInsertionHook()) { |
59 | Changed = true; |
60 | MachineBasicBlock *NewMBB = TLI->EmitInstrWithCustomInserter(MI, MBB); |
61 | // The expansion may involve new basic blocks. |
62 | if (NewMBB != MBB) { |
63 | MBB = NewMBB; |
64 | I = NewMBB->getIterator(); |
65 | MBBI = NewMBB->begin(); |
66 | MBBE = NewMBB->end(); |
67 | } |
68 | } |
69 | } |
70 | } |
71 | |
72 | TLI->finalizeLowering(MF); |
73 | |
74 | return Changed; |
75 | } |
76 | |