xref: /freebsd/contrib/llvm-project/llvm/lib/Target/ARC/ARCExpandPseudos.cpp (revision 62cfcf62f627e5093fb37026a6d8c98e4d2ef04c)
1 //===- ARCExpandPseudosPass - ARC expand pseudo loads -----------*- 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 stores with large offsets into an appropriate sequence.
10 //===----------------------------------------------------------------------===//
11 
12 #include "ARC.h"
13 #include "ARCInstrInfo.h"
14 #include "ARCRegisterInfo.h"
15 #include "ARCSubtarget.h"
16 #include "llvm/ADT/Statistic.h"
17 #include "llvm/CodeGen/MachineFunctionPass.h"
18 #include "llvm/CodeGen/MachineInstrBuilder.h"
19 #include "llvm/CodeGen/MachineRegisterInfo.h"
20 
21 using namespace llvm;
22 
23 #define DEBUG_TYPE "arc-expand-pseudos"
24 
25 namespace {
26 
27 class ARCExpandPseudos : public MachineFunctionPass {
28 public:
29   static char ID;
30   ARCExpandPseudos() : MachineFunctionPass(ID) {}
31 
32   bool runOnMachineFunction(MachineFunction &Fn) override;
33 
34   StringRef getPassName() const override { return "ARC Expand Pseudos"; }
35 
36 private:
37   void ExpandStore(MachineFunction &, MachineBasicBlock::iterator);
38 
39   const ARCInstrInfo *TII;
40 };
41 
42 char ARCExpandPseudos::ID = 0;
43 
44 } // end anonymous namespace
45 
46 static unsigned getMappedOp(unsigned PseudoOp) {
47   switch (PseudoOp) {
48   case ARC::ST_FAR:
49     return ARC::ST_rs9;
50   case ARC::STH_FAR:
51     return ARC::STH_rs9;
52   case ARC::STB_FAR:
53     return ARC::STB_rs9;
54   default:
55     llvm_unreachable("Unhandled pseudo op.");
56   }
57 }
58 
59 void ARCExpandPseudos::ExpandStore(MachineFunction &MF,
60                                    MachineBasicBlock::iterator SII) {
61   MachineInstr &SI = *SII;
62   unsigned AddrReg = MF.getRegInfo().createVirtualRegister(&ARC::GPR32RegClass);
63   unsigned AddOpc =
64       isUInt<6>(SI.getOperand(2).getImm()) ? ARC::ADD_rru6 : ARC::ADD_rrlimm;
65   BuildMI(*SI.getParent(), SI, SI.getDebugLoc(), TII->get(AddOpc), AddrReg)
66       .addReg(SI.getOperand(1).getReg())
67       .addImm(SI.getOperand(2).getImm());
68   BuildMI(*SI.getParent(), SI, SI.getDebugLoc(),
69           TII->get(getMappedOp(SI.getOpcode())))
70       .addReg(SI.getOperand(0).getReg())
71       .addReg(AddrReg)
72       .addImm(0);
73   SI.eraseFromParent();
74 }
75 
76 bool ARCExpandPseudos::runOnMachineFunction(MachineFunction &MF) {
77   const ARCSubtarget *STI = &MF.getSubtarget<ARCSubtarget>();
78   TII = STI->getInstrInfo();
79   bool ExpandedStore = false;
80   for (auto &MBB : MF) {
81     MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
82     while (MBBI != E) {
83       MachineBasicBlock::iterator NMBBI = std::next(MBBI);
84       switch (MBBI->getOpcode()) {
85       case ARC::ST_FAR:
86       case ARC::STH_FAR:
87       case ARC::STB_FAR:
88         ExpandStore(MF, MBBI);
89         ExpandedStore = true;
90         break;
91       default:
92         break;
93       }
94       MBBI = NMBBI;
95     }
96   }
97   return ExpandedStore;
98 }
99 
100 FunctionPass *llvm::createARCExpandPseudosPass() {
101   return new ARCExpandPseudos();
102 }
103