1 //===-- PPCMCCodeEmitter.cpp - Convert PPC code to machine code -----------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the PPCMCCodeEmitter class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #define DEBUG_TYPE "mccodeemitter"
15 #include "MCTargetDesc/PPCBaseInfo.h"
16 #include "MCTargetDesc/PPCFixupKinds.h"
17 #include "llvm/MC/MCCodeEmitter.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/ADT/Statistic.h"
20 #include "llvm/Support/raw_ostream.h"
21 #include "llvm/Support/ErrorHandling.h"
22 using namespace llvm;
23
24 STATISTIC(MCNumEmitted, "Number of MC instructions emitted");
25
26 namespace {
27 class PPCMCCodeEmitter : public MCCodeEmitter {
28 PPCMCCodeEmitter(const PPCMCCodeEmitter &); // DO NOT IMPLEMENT
29 void operator=(const PPCMCCodeEmitter &); // DO NOT IMPLEMENT
30
31 public:
PPCMCCodeEmitter(const MCInstrInfo & mcii,const MCSubtargetInfo & sti,MCContext & ctx)32 PPCMCCodeEmitter(const MCInstrInfo &mcii, const MCSubtargetInfo &sti,
33 MCContext &ctx) {
34 }
35
~PPCMCCodeEmitter()36 ~PPCMCCodeEmitter() {}
37
38 unsigned getDirectBrEncoding(const MCInst &MI, unsigned OpNo,
39 SmallVectorImpl<MCFixup> &Fixups) const;
40 unsigned getCondBrEncoding(const MCInst &MI, unsigned OpNo,
41 SmallVectorImpl<MCFixup> &Fixups) const;
42 unsigned getHA16Encoding(const MCInst &MI, unsigned OpNo,
43 SmallVectorImpl<MCFixup> &Fixups) const;
44 unsigned getLO16Encoding(const MCInst &MI, unsigned OpNo,
45 SmallVectorImpl<MCFixup> &Fixups) const;
46 unsigned getMemRIEncoding(const MCInst &MI, unsigned OpNo,
47 SmallVectorImpl<MCFixup> &Fixups) const;
48 unsigned getMemRIXEncoding(const MCInst &MI, unsigned OpNo,
49 SmallVectorImpl<MCFixup> &Fixups) const;
50 unsigned get_crbitm_encoding(const MCInst &MI, unsigned OpNo,
51 SmallVectorImpl<MCFixup> &Fixups) const;
52
53 /// getMachineOpValue - Return binary encoding of operand. If the machine
54 /// operand requires relocation, record the relocation and return zero.
55 unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
56 SmallVectorImpl<MCFixup> &Fixups) const;
57
58 // getBinaryCodeForInstr - TableGen'erated function for getting the
59 // binary encoding for an instruction.
60 uint64_t getBinaryCodeForInstr(const MCInst &MI,
61 SmallVectorImpl<MCFixup> &Fixups) const;
EncodeInstruction(const MCInst & MI,raw_ostream & OS,SmallVectorImpl<MCFixup> & Fixups) const62 void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
63 SmallVectorImpl<MCFixup> &Fixups) const {
64 unsigned Bits = getBinaryCodeForInstr(MI, Fixups);
65
66 // Output the constant in big endian byte order.
67 for (unsigned i = 0; i != 4; ++i) {
68 OS << (char)(Bits >> 24);
69 Bits <<= 8;
70 }
71
72 ++MCNumEmitted; // Keep track of the # of mi's emitted.
73 }
74
75 };
76
77 } // end anonymous namespace
78
createPPCMCCodeEmitter(const MCInstrInfo & MCII,const MCRegisterInfo & MRI,const MCSubtargetInfo & STI,MCContext & Ctx)79 MCCodeEmitter *llvm::createPPCMCCodeEmitter(const MCInstrInfo &MCII,
80 const MCRegisterInfo &MRI,
81 const MCSubtargetInfo &STI,
82 MCContext &Ctx) {
83 return new PPCMCCodeEmitter(MCII, STI, Ctx);
84 }
85
86 unsigned PPCMCCodeEmitter::
getDirectBrEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups) const87 getDirectBrEncoding(const MCInst &MI, unsigned OpNo,
88 SmallVectorImpl<MCFixup> &Fixups) const {
89 const MCOperand &MO = MI.getOperand(OpNo);
90 if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups);
91
92 // Add a fixup for the branch target.
93 Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
94 (MCFixupKind)PPC::fixup_ppc_br24));
95 return 0;
96 }
97
getCondBrEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups) const98 unsigned PPCMCCodeEmitter::getCondBrEncoding(const MCInst &MI, unsigned OpNo,
99 SmallVectorImpl<MCFixup> &Fixups) const {
100 const MCOperand &MO = MI.getOperand(OpNo);
101 if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups);
102
103 // Add a fixup for the branch target.
104 Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
105 (MCFixupKind)PPC::fixup_ppc_brcond14));
106 return 0;
107 }
108
getHA16Encoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups) const109 unsigned PPCMCCodeEmitter::getHA16Encoding(const MCInst &MI, unsigned OpNo,
110 SmallVectorImpl<MCFixup> &Fixups) const {
111 const MCOperand &MO = MI.getOperand(OpNo);
112 if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups);
113
114 // Add a fixup for the branch target.
115 Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
116 (MCFixupKind)PPC::fixup_ppc_ha16));
117 return 0;
118 }
119
getLO16Encoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups) const120 unsigned PPCMCCodeEmitter::getLO16Encoding(const MCInst &MI, unsigned OpNo,
121 SmallVectorImpl<MCFixup> &Fixups) const {
122 const MCOperand &MO = MI.getOperand(OpNo);
123 if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups);
124
125 // Add a fixup for the branch target.
126 Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
127 (MCFixupKind)PPC::fixup_ppc_lo16));
128 return 0;
129 }
130
getMemRIEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups) const131 unsigned PPCMCCodeEmitter::getMemRIEncoding(const MCInst &MI, unsigned OpNo,
132 SmallVectorImpl<MCFixup> &Fixups) const {
133 // Encode (imm, reg) as a memri, which has the low 16-bits as the
134 // displacement and the next 5 bits as the register #.
135 assert(MI.getOperand(OpNo+1).isReg());
136 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups) << 16;
137
138 const MCOperand &MO = MI.getOperand(OpNo);
139 if (MO.isImm())
140 return (getMachineOpValue(MI, MO, Fixups) & 0xFFFF) | RegBits;
141
142 // Add a fixup for the displacement field.
143 Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
144 (MCFixupKind)PPC::fixup_ppc_lo16));
145 return RegBits;
146 }
147
148
getMemRIXEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups) const149 unsigned PPCMCCodeEmitter::getMemRIXEncoding(const MCInst &MI, unsigned OpNo,
150 SmallVectorImpl<MCFixup> &Fixups) const {
151 // Encode (imm, reg) as a memrix, which has the low 14-bits as the
152 // displacement and the next 5 bits as the register #.
153 assert(MI.getOperand(OpNo+1).isReg());
154 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups) << 14;
155
156 const MCOperand &MO = MI.getOperand(OpNo);
157 if (MO.isImm())
158 return (getMachineOpValue(MI, MO, Fixups) & 0x3FFF) | RegBits;
159
160 // Add a fixup for the branch target.
161 Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
162 (MCFixupKind)PPC::fixup_ppc_lo14));
163 return RegBits;
164 }
165
166
167 unsigned PPCMCCodeEmitter::
get_crbitm_encoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups) const168 get_crbitm_encoding(const MCInst &MI, unsigned OpNo,
169 SmallVectorImpl<MCFixup> &Fixups) const {
170 const MCOperand &MO = MI.getOperand(OpNo);
171 assert((MI.getOpcode() == PPC::MTCRF || MI.getOpcode() == PPC::MFOCRF) &&
172 (MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7));
173 return 0x80 >> getPPCRegisterNumbering(MO.getReg());
174 }
175
176
177 unsigned PPCMCCodeEmitter::
getMachineOpValue(const MCInst & MI,const MCOperand & MO,SmallVectorImpl<MCFixup> & Fixups) const178 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
179 SmallVectorImpl<MCFixup> &Fixups) const {
180 if (MO.isReg()) {
181 // MTCRF/MFOCRF should go through get_crbitm_encoding for the CR operand.
182 // The GPR operand should come through here though.
183 assert((MI.getOpcode() != PPC::MTCRF && MI.getOpcode() != PPC::MFOCRF) ||
184 MO.getReg() < PPC::CR0 || MO.getReg() > PPC::CR7);
185 return getPPCRegisterNumbering(MO.getReg());
186 }
187
188 assert(MO.isImm() &&
189 "Relocation required in an instruction that we cannot encode!");
190 return MO.getImm();
191 }
192
193
194 #include "PPCGenMCCodeEmitter.inc"
195