xref: /freebsd/contrib/llvm-project/llvm/lib/CodeGen/MIRNamerPass.cpp (revision 81ad626541db97eb356e2c1d4a20eb2a26a766ab)
1 //===----------------------- MIRNamer.cpp - MIR Namer ---------------------===//
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 // The purpose of this pass is to rename virtual register operands with the goal
10 // of making it easier to author easier to read tests for MIR. This pass reuses
11 // the vreg renamer used by MIRCanonicalizerPass.
12 //
13 // Basic Usage:
14 //
15 // llc -o - -run-pass mir-namer example.mir
16 //
17 //===----------------------------------------------------------------------===//
18 
19 #include "MIRVRegNamerUtils.h"
20 #include "llvm/ADT/PostOrderIterator.h"
21 #include "llvm/CodeGen/MachineFunctionPass.h"
22 #include "llvm/InitializePasses.h"
23 
24 using namespace llvm;
25 
26 namespace llvm {
27 extern char &MIRNamerID;
28 } // namespace llvm
29 
30 #define DEBUG_TYPE "mir-namer"
31 
32 namespace {
33 
34 class MIRNamer : public MachineFunctionPass {
35 public:
36   static char ID;
MIRNamer()37   MIRNamer() : MachineFunctionPass(ID) {}
38 
getPassName() const39   StringRef getPassName() const override {
40     return "Rename virtual register operands";
41   }
42 
getAnalysisUsage(AnalysisUsage & AU) const43   void getAnalysisUsage(AnalysisUsage &AU) const override {
44     AU.setPreservesCFG();
45     MachineFunctionPass::getAnalysisUsage(AU);
46   }
47 
runOnMachineFunction(MachineFunction & MF)48   bool runOnMachineFunction(MachineFunction &MF) override {
49     bool Changed = false;
50 
51     if (MF.empty())
52       return Changed;
53 
54     VRegRenamer Renamer(MF.getRegInfo());
55 
56     unsigned BBIndex = 0;
57     ReversePostOrderTraversal<MachineBasicBlock *> RPOT(&*MF.begin());
58     for (auto &MBB : RPOT)
59       Changed |= Renamer.renameVRegs(MBB, BBIndex++);
60 
61     return Changed;
62   }
63 };
64 
65 } // end anonymous namespace
66 
67 char MIRNamer::ID;
68 
69 char &llvm::MIRNamerID = MIRNamer::ID;
70 
71 INITIALIZE_PASS_BEGIN(MIRNamer, "mir-namer", "Rename Register Operands", false,
72                       false)
73 
74 INITIALIZE_PASS_END(MIRNamer, "mir-namer", "Rename Register Operands", false,
75                     false)
76