summaryrefslogtreecommitdiff
path: root/lib/Target/Hexagon/HexagonExpandPredSpillCode.cpp
blob: 3dafe80ffc48b52c29c1043a478510268b5cf5a1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
//===-- HexagonExpandPredSpillCode.cpp - Expand Predicate Spill Code ------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// The Hexagon processor has no instructions that load or store predicate
// registers directly.  So, when these registers must be spilled a general
// purpose register must be found and the value copied to/from it from/to
// the predicate register.  This code currently does not use the register
// scavenger mechanism available in the allocator.  There are two registers
// reserved to allow spilling/restoring predicate registers.  One is used to
// hold the predicate value.  The other is used when stack frame offsets are
// too large.
//
//===----------------------------------------------------------------------===//

#include "Hexagon.h"
#include "HexagonMachineFunctionInfo.h"
#include "HexagonSubtarget.h"
#include "HexagonTargetMachine.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/LatencyPriorityQueue.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/CodeGen/SchedulerRegistry.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"

using namespace llvm;


namespace llvm {
  void initializeHexagonExpandPredSpillCodePass(PassRegistry&);
}


namespace {

class HexagonExpandPredSpillCode : public MachineFunctionPass {
    const HexagonTargetMachine& QTM;
    const HexagonSubtarget &QST;

 public:
    static char ID;
    HexagonExpandPredSpillCode(const HexagonTargetMachine& TM) :
      MachineFunctionPass(ID), QTM(TM), QST(*TM.getSubtargetImpl()) {
      PassRegistry &Registry = *PassRegistry::getPassRegistry();
      initializeHexagonExpandPredSpillCodePass(Registry);
    }

    const char *getPassName() const override {
      return "Hexagon Expand Predicate Spill Code";
    }
    bool runOnMachineFunction(MachineFunction &Fn) override;
};


char HexagonExpandPredSpillCode::ID = 0;


bool HexagonExpandPredSpillCode::runOnMachineFunction(MachineFunction &Fn) {

  const HexagonInstrInfo *TII = QTM.getInstrInfo();

  // Loop over all of the basic blocks.
  for (MachineFunction::iterator MBBb = Fn.begin(), MBBe = Fn.end();
       MBBb != MBBe; ++MBBb) {
    MachineBasicBlock* MBB = MBBb;
    // Traverse the basic block.
    for (MachineBasicBlock::iterator MII = MBB->begin(); MII != MBB->end();
         ++MII) {
      MachineInstr *MI = MII;
      int Opc = MI->getOpcode();
      if (Opc == Hexagon::STriw_pred) {
        // STriw_pred [R30], ofst, SrcReg;
        unsigned FP = MI->getOperand(0).getReg();
        assert(FP == QTM.getRegisterInfo()->getFrameRegister() &&
               "Not a Frame Pointer, Nor a Spill Slot");
        assert(MI->getOperand(1).isImm() && "Not an offset");
        int Offset = MI->getOperand(1).getImm();
        int SrcReg = MI->getOperand(2).getReg();
        assert(Hexagon::PredRegsRegClass.contains(SrcReg) &&
               "Not a predicate register");
        if (!TII->isValidOffset(Hexagon::STriw_indexed, Offset)) {
          if (!TII->isValidOffset(Hexagon::ADD_ri, Offset)) {
            BuildMI(*MBB, MII, MI->getDebugLoc(),
                    TII->get(Hexagon::CONST32_Int_Real),
                      HEXAGON_RESERVED_REG_1).addImm(Offset);
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::ADD_rr),
                    HEXAGON_RESERVED_REG_1)
              .addReg(FP).addReg(HEXAGON_RESERVED_REG_1);
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_RsPd),
                      HEXAGON_RESERVED_REG_2).addReg(SrcReg);
            BuildMI(*MBB, MII, MI->getDebugLoc(),
                    TII->get(Hexagon::STriw_indexed))
              .addReg(HEXAGON_RESERVED_REG_1)
              .addImm(0).addReg(HEXAGON_RESERVED_REG_2);
          } else {
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::ADD_ri),
                      HEXAGON_RESERVED_REG_1).addReg(FP).addImm(Offset);
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_RsPd),
                      HEXAGON_RESERVED_REG_2).addReg(SrcReg);
            BuildMI(*MBB, MII, MI->getDebugLoc(),
                          TII->get(Hexagon::STriw_indexed))
              .addReg(HEXAGON_RESERVED_REG_1)
              .addImm(0)
              .addReg(HEXAGON_RESERVED_REG_2);
          }
        } else {
          BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_RsPd),
                    HEXAGON_RESERVED_REG_2).addReg(SrcReg);
          BuildMI(*MBB, MII, MI->getDebugLoc(),
                        TII->get(Hexagon::STriw_indexed)).
                    addReg(FP).addImm(Offset).addReg(HEXAGON_RESERVED_REG_2);
        }
        MII = MBB->erase(MI);
        --MII;
      } else if (Opc == Hexagon::LDriw_pred) {
        // DstReg = LDriw_pred [R30], ofst.
        int DstReg = MI->getOperand(0).getReg();
        assert(Hexagon::PredRegsRegClass.contains(DstReg) &&
               "Not a predicate register");
        unsigned FP = MI->getOperand(1).getReg();
        assert(FP == QTM.getRegisterInfo()->getFrameRegister() &&
               "Not a Frame Pointer, Nor a Spill Slot");
        assert(MI->getOperand(2).isImm() && "Not an offset");
        int Offset = MI->getOperand(2).getImm();
        if (!TII->isValidOffset(Hexagon::LDriw, Offset)) {
          if (!TII->isValidOffset(Hexagon::ADD_ri, Offset)) {
            BuildMI(*MBB, MII, MI->getDebugLoc(),
                    TII->get(Hexagon::CONST32_Int_Real),
                      HEXAGON_RESERVED_REG_1).addImm(Offset);
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::ADD_rr),
                    HEXAGON_RESERVED_REG_1)
              .addReg(FP)
              .addReg(HEXAGON_RESERVED_REG_1);
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::LDriw),
                      HEXAGON_RESERVED_REG_2)
              .addReg(HEXAGON_RESERVED_REG_1)
              .addImm(0);
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_PdRs),
                      DstReg).addReg(HEXAGON_RESERVED_REG_2);
          } else {
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::ADD_ri),
                      HEXAGON_RESERVED_REG_1).addReg(FP).addImm(Offset);
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::LDriw),
                      HEXAGON_RESERVED_REG_2)
              .addReg(HEXAGON_RESERVED_REG_1)
              .addImm(0);
            BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_PdRs),
                      DstReg).addReg(HEXAGON_RESERVED_REG_2);
          }
        } else {
          BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::LDriw),
                    HEXAGON_RESERVED_REG_2).addReg(FP).addImm(Offset);
          BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_PdRs),
                    DstReg).addReg(HEXAGON_RESERVED_REG_2);
        }
        MII = MBB->erase(MI);
        --MII;
      }
    }
  }

  return true;
}

}

//===----------------------------------------------------------------------===//
//                         Public Constructor Functions
//===----------------------------------------------------------------------===//

static void initializePassOnce(PassRegistry &Registry) {
  const char *Name = "Hexagon Expand Predicate Spill Code";
  PassInfo *PI = new PassInfo(Name, "hexagon-spill-pred",
                              &HexagonExpandPredSpillCode::ID,
                              nullptr, false, false);
  Registry.registerPass(*PI, true);
}

void llvm::initializeHexagonExpandPredSpillCodePass(PassRegistry &Registry) {
  CALL_ONCE_INITIALIZATION(initializePassOnce)
}

FunctionPass*
llvm::createHexagonExpandPredSpillCode(const HexagonTargetMachine &TM) {
  return new HexagonExpandPredSpillCode(TM);
}