summaryrefslogtreecommitdiff
path: root/lib/Target/SystemZ/MCTargetDesc/SystemZMCCodeEmitter.cpp
blob: 7721b1ffab046b09d65ed1377866d94a2da67477 (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
//===-- SystemZMCCodeEmitter.cpp - Convert SystemZ code to machine code ---===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SystemZMCCodeEmitter class.
//
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "mccodeemitter"
#include "MCTargetDesc/SystemZMCTargetDesc.h"
#include "MCTargetDesc/SystemZMCFixups.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInstrInfo.h"

using namespace llvm;

namespace {
class SystemZMCCodeEmitter : public MCCodeEmitter {
  const MCInstrInfo &MCII;
  MCContext &Ctx;

public:
  SystemZMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx)
    : MCII(mcii), Ctx(ctx) {
  }

  ~SystemZMCCodeEmitter() {}

  // OVerride MCCodeEmitter.
  virtual void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
                                 SmallVectorImpl<MCFixup> &Fixups) const
    LLVM_OVERRIDE;

private:
  // Automatically generated by TableGen.
  uint64_t getBinaryCodeForInstr(const MCInst &MI,
                                 SmallVectorImpl<MCFixup> &Fixups) const;

  // Called by the TableGen code to get the binary encoding of operand
  // MO in MI.  Fixups is the list of fixups against MI.
  uint64_t getMachineOpValue(const MCInst &MI, const MCOperand &MO,
                             SmallVectorImpl<MCFixup> &Fixups) const;

  // Called by the TableGen code to get the binary encoding of an address.
  // The index, if any, is encoded first, followed by the base,
  // followed by the displacement.  In a 20-bit displacement,
  // the low 12 bits are encoded before the high 8 bits.
  uint64_t getBDAddr12Encoding(const MCInst &MI, unsigned OpNum,
                               SmallVectorImpl<MCFixup> &Fixups) const;
  uint64_t getBDAddr20Encoding(const MCInst &MI, unsigned OpNum,
                               SmallVectorImpl<MCFixup> &Fixups) const;
  uint64_t getBDXAddr12Encoding(const MCInst &MI, unsigned OpNum,
                                SmallVectorImpl<MCFixup> &Fixups) const;
  uint64_t getBDXAddr20Encoding(const MCInst &MI, unsigned OpNum,
                                SmallVectorImpl<MCFixup> &Fixups) const;

  // Operand OpNum of MI needs a PC-relative fixup of kind Kind at
  // Offset bytes from the start of MI.  Add the fixup to Fixups
  // and return the in-place addend, which since we're a RELA target
  // is always 0.
  uint64_t getPCRelEncoding(const MCInst &MI, unsigned OpNum,
                            SmallVectorImpl<MCFixup> &Fixups,
                            unsigned Kind, int64_t Offset) const;

  uint64_t getPC16DBLEncoding(const MCInst &MI, unsigned OpNum,
                              SmallVectorImpl<MCFixup> &Fixups) const {
    return getPCRelEncoding(MI, OpNum, Fixups, SystemZ::FK_390_PC16DBL, 2);
  }
  uint64_t getPC32DBLEncoding(const MCInst &MI, unsigned OpNum,
                              SmallVectorImpl<MCFixup> &Fixups) const {
    return getPCRelEncoding(MI, OpNum, Fixups, SystemZ::FK_390_PC32DBL, 2);
  }
  uint64_t getPLT16DBLEncoding(const MCInst &MI, unsigned OpNum,
                               SmallVectorImpl<MCFixup> &Fixups) const {
    return getPCRelEncoding(MI, OpNum, Fixups, SystemZ::FK_390_PLT16DBL, 2);
  }
  uint64_t getPLT32DBLEncoding(const MCInst &MI, unsigned OpNum,
                               SmallVectorImpl<MCFixup> &Fixups) const {
    return getPCRelEncoding(MI, OpNum, Fixups, SystemZ::FK_390_PLT32DBL, 2);
  }
};
}

MCCodeEmitter *llvm::createSystemZMCCodeEmitter(const MCInstrInfo &MCII,
                                                const MCRegisterInfo &MRI,
                                                const MCSubtargetInfo &MCSTI,
                                                MCContext &Ctx) {
  return new SystemZMCCodeEmitter(MCII, Ctx);
}

void SystemZMCCodeEmitter::
EncodeInstruction(const MCInst &MI, raw_ostream &OS,
                  SmallVectorImpl<MCFixup> &Fixups) const {
  uint64_t Bits = getBinaryCodeForInstr(MI, Fixups);
  unsigned Size = MCII.get(MI.getOpcode()).getSize();
  // Big-endian insertion of Size bytes.
  unsigned ShiftValue = (Size * 8) - 8;
  for (unsigned I = 0; I != Size; ++I) {
    OS << uint8_t(Bits >> ShiftValue);
    ShiftValue -= 8;
  }
}

uint64_t SystemZMCCodeEmitter::
getMachineOpValue(const MCInst &MI, const MCOperand &MO,
                  SmallVectorImpl<MCFixup> &Fixups) const {
  if (MO.isReg())
    return Ctx.getRegisterInfo().getEncodingValue(MO.getReg());
  if (MO.isImm())
    return static_cast<uint64_t>(MO.getImm());
  llvm_unreachable("Unexpected operand type!");
}

uint64_t SystemZMCCodeEmitter::
getBDAddr12Encoding(const MCInst &MI, unsigned OpNum,
                    SmallVectorImpl<MCFixup> &Fixups) const {
  uint64_t Base = getMachineOpValue(MI, MI.getOperand(OpNum), Fixups);
  uint64_t Disp = getMachineOpValue(MI, MI.getOperand(OpNum + 1), Fixups);
  assert(isUInt<4>(Base) && isUInt<12>(Disp));
  return (Base << 12) | Disp;
}

uint64_t SystemZMCCodeEmitter::
getBDAddr20Encoding(const MCInst &MI, unsigned OpNum,
                    SmallVectorImpl<MCFixup> &Fixups) const {
  uint64_t Base = getMachineOpValue(MI, MI.getOperand(OpNum), Fixups);
  uint64_t Disp = getMachineOpValue(MI, MI.getOperand(OpNum + 1), Fixups);
  assert(isUInt<4>(Base) && isInt<20>(Disp));
  return (Base << 20) | ((Disp & 0xfff) << 8) | ((Disp & 0xff000) >> 12);
}

uint64_t SystemZMCCodeEmitter::
getBDXAddr12Encoding(const MCInst &MI, unsigned OpNum,
                     SmallVectorImpl<MCFixup> &Fixups) const {
  uint64_t Base = getMachineOpValue(MI, MI.getOperand(OpNum), Fixups);
  uint64_t Disp = getMachineOpValue(MI, MI.getOperand(OpNum + 1), Fixups);
  uint64_t Index = getMachineOpValue(MI, MI.getOperand(OpNum + 2), Fixups);
  assert(isUInt<4>(Base) && isUInt<12>(Disp) && isUInt<4>(Index));
  return (Index << 16) | (Base << 12) | Disp;
}

uint64_t SystemZMCCodeEmitter::
getBDXAddr20Encoding(const MCInst &MI, unsigned OpNum,
                     SmallVectorImpl<MCFixup> &Fixups) const {
  uint64_t Base = getMachineOpValue(MI, MI.getOperand(OpNum), Fixups);
  uint64_t Disp = getMachineOpValue(MI, MI.getOperand(OpNum + 1), Fixups);
  uint64_t Index = getMachineOpValue(MI, MI.getOperand(OpNum + 2), Fixups);
  assert(isUInt<4>(Base) && isInt<20>(Disp) && isUInt<4>(Index));
  return (Index << 24) | (Base << 20) | ((Disp & 0xfff) << 8)
    | ((Disp & 0xff000) >> 12);
}

uint64_t
SystemZMCCodeEmitter::getPCRelEncoding(const MCInst &MI, unsigned OpNum,
                                       SmallVectorImpl<MCFixup> &Fixups,
                                       unsigned Kind, int64_t Offset) const {
  const MCOperand &MO = MI.getOperand(OpNum);
  const MCExpr *Expr;
  if (MO.isImm())
    Expr = MCConstantExpr::Create(MO.getImm() + Offset, Ctx);
  else {
    Expr = MO.getExpr();
    if (Offset) {
      // The operand value is relative to the start of MI, but the fixup
      // is relative to the operand field itself, which is Offset bytes
      // into MI.  Add Offset to the relocation value to cancel out
      // this difference.
      const MCExpr *OffsetExpr = MCConstantExpr::Create(Offset, Ctx);
      Expr = MCBinaryExpr::CreateAdd(Expr, OffsetExpr, Ctx);
    }
  }
  Fixups.push_back(MCFixup::Create(Offset, Expr, (MCFixupKind)Kind));
  return 0;
}

#include "SystemZGenMCCodeEmitter.inc"