summaryrefslogtreecommitdiff
path: root/lib/Target/PIC16/PIC16InstrInfo.cpp
blob: e3581ce441fc3a8126f214ccb8966dc124465160 (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
//===- PIC16InstrInfo.cpp - PIC16 Instruction Information -----------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source 
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the PIC16 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//

#include "PIC16.h"
#include "PIC16InstrInfo.h"
#include "llvm/Function.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "PIC16GenInstrInfo.inc"

using namespace llvm;

// FIXME: Add the subtarget support on this constructor.
PIC16InstrInfo::PIC16InstrInfo(PIC16TargetMachine &tm)
  : TargetInstrInfoImpl(PIC16Insts, array_lengthof(PIC16Insts)),
    TM(tm), RI(*this) {}

static bool isZeroImm(const MachineOperand &op) {
  return op.isImmediate() && op.getImm() == 0;
}


/// isLoadFromStackSlot - If the specified machine instruction is a direct
/// load from a stack slot, return the virtual or physical register number of
/// the destination along with the FrameIndex of the loaded stack slot.  If
/// not, return 0.  This predicate must return 0 if the instruction has
/// any side effects other than loading from the stack slot.
unsigned PIC16InstrInfo::
isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const 
{
  if (MI->getOpcode() == PIC16::MOVF) {
    if ((MI->getOperand(2).isFrameIndex()) && // is a stack slot
        (MI->getOperand(1).isImmediate()) &&  // the imm is zero
        (isZeroImm(MI->getOperand(1)))) {
      FrameIndex = MI->getOperand(2).getIndex();
      return MI->getOperand(0).getReg();
    }
  }

  return 0;
}

/// isStoreToStackSlot - If the specified machine instruction is a direct
/// store to a stack slot, return the virtual or physical register number of
/// the source reg along with the FrameIndex of the loaded stack slot.  If
/// not, return 0.  This predicate must return 0 if the instruction has
/// any side effects other than storing to the stack slot.
unsigned PIC16InstrInfo::
isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const 
{
  if (MI->getOpcode() == PIC16::MOVWF) {
    if ((MI->getOperand(0).isFrameIndex()) && // is a stack slot
        (MI->getOperand(1).isImmediate()) &&  // the imm is zero
        (isZeroImm(MI->getOperand(1)))) {
      FrameIndex = MI->getOperand(0).getIndex();
      return MI->getOperand(2).getReg();
    }
  }
  return 0;
}

void PIC16InstrInfo::
storeRegToStackSlot(MachineBasicBlock &MBB,
                    MachineBasicBlock::iterator I,
                    unsigned SrcReg, bool isKill, int FI,
                    const TargetRegisterClass *RC) const {
  const Function *Func = MBB.getParent()->getFunction();
  const std::string FuncName = Func->getName();

  char *tmpName = new char [strlen(FuncName.c_str()) +  6];
  sprintf(tmpName, "%s_tmp_%d",FuncName.c_str(),FI);

  if (RC == PIC16::CPURegsRegisterClass) {
    //src is always WREG. 
    BuildMI(MBB, I, this->get(PIC16::MOVWF))
        .addReg(SrcReg,false,false,true,true)
        .addExternalSymbol(tmpName)   // the current printer expects 3 operands,
        .addExternalSymbol(tmpName);  // all we need is actually one, 
                                      // so we repeat.
  }
  else
    assert(0 && "Can't store this register to stack slot");
}

void PIC16InstrInfo::
loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                     unsigned DestReg, int FI,
                     const TargetRegisterClass *RC) const 
{
  const Function *Func = MBB.getParent()->getFunction();
  const std::string FuncName = Func->getName();

  char *tmpName = new char [strlen(FuncName.c_str()) +  6];
  sprintf(tmpName, "%s_tmp_%d",FuncName.c_str(),FI);

  if (RC == PIC16::CPURegsRegisterClass)
    BuildMI(MBB, I, this->get(PIC16::MOVF), DestReg)
      .addExternalSymbol(tmpName)   // the current printer expects 3 operands,
      .addExternalSymbol(tmpName);  // all we need is actually one,so we repeat.
  else
    assert(0 && "Can't load this register from stack slot");
}

/// InsertBranch - Insert a branch into the end of the specified
/// MachineBasicBlock.  This operands to this method are the same as those
/// returned by AnalyzeBranch.  This is invoked in cases where AnalyzeBranch
/// returns success and when an unconditional branch (TBB is non-null, FBB is
/// null, Cond is empty) needs to be inserted. It returns the number of
/// instructions inserted.
unsigned PIC16InstrInfo::
InsertBranch(MachineBasicBlock &MBB, 
             MachineBasicBlock *TBB, MachineBasicBlock *FBB,
             const SmallVectorImpl<MachineOperand> &Cond) const
{
  // Shouldn't be a fall through.
  assert(TBB && "InsertBranch must not be told to insert a fallthrough");

  if (FBB == 0) { // One way branch.
    if (Cond.empty()) {
      // Unconditional branch?
      BuildMI(&MBB, get(PIC16::GOTO)).addMBB(TBB);
    } 
    return 1;
  }

  // FIXME: If the there are some conditions specified then conditional branch 
  // should be generated.
  // For the time being no instruction is being generated therefore 
  // returning NULL.
  return 0;
}