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 #include "MCTargetDesc/PPCMCTargetDesc.h"
15 #include "MCTargetDesc/PPCFixupKinds.h"
16 #include "llvm/ADT/Statistic.h"
17 #include "llvm/MC/MCAsmInfo.h"
18 #include "llvm/MC/MCCodeEmitter.h"
19 #include "llvm/MC/MCContext.h"
20 #include "llvm/MC/MCExpr.h"
21 #include "llvm/MC/MCInst.h"
22 #include "llvm/MC/MCInstrInfo.h"
23 #include "llvm/MC/MCRegisterInfo.h"
24 #include "llvm/MC/MCSubtargetInfo.h"
25 #include "llvm/Support/EndianStream.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include "llvm/Support/raw_ostream.h"
28 #include "llvm/Target/TargetOpcodes.h"
29 using namespace llvm;
30
31 #define DEBUG_TYPE "mccodeemitter"
32
33 STATISTIC(MCNumEmitted, "Number of MC instructions emitted");
34
35 namespace {
36 class PPCMCCodeEmitter : public MCCodeEmitter {
37 PPCMCCodeEmitter(const PPCMCCodeEmitter &) = delete;
38 void operator=(const PPCMCCodeEmitter &) = delete;
39
40 const MCInstrInfo &MCII;
41 const MCContext &CTX;
42 bool IsLittleEndian;
43
44 public:
PPCMCCodeEmitter(const MCInstrInfo & mcii,MCContext & ctx)45 PPCMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx)
46 : MCII(mcii), CTX(ctx),
47 IsLittleEndian(ctx.getAsmInfo()->isLittleEndian()) {}
48
~PPCMCCodeEmitter()49 ~PPCMCCodeEmitter() override {}
50
51 unsigned getDirectBrEncoding(const MCInst &MI, unsigned OpNo,
52 SmallVectorImpl<MCFixup> &Fixups,
53 const MCSubtargetInfo &STI) const;
54 unsigned getCondBrEncoding(const MCInst &MI, unsigned OpNo,
55 SmallVectorImpl<MCFixup> &Fixups,
56 const MCSubtargetInfo &STI) const;
57 unsigned getAbsDirectBrEncoding(const MCInst &MI, unsigned OpNo,
58 SmallVectorImpl<MCFixup> &Fixups,
59 const MCSubtargetInfo &STI) const;
60 unsigned getAbsCondBrEncoding(const MCInst &MI, unsigned OpNo,
61 SmallVectorImpl<MCFixup> &Fixups,
62 const MCSubtargetInfo &STI) const;
63 unsigned getImm16Encoding(const MCInst &MI, unsigned OpNo,
64 SmallVectorImpl<MCFixup> &Fixups,
65 const MCSubtargetInfo &STI) const;
66 unsigned getMemRIEncoding(const MCInst &MI, unsigned OpNo,
67 SmallVectorImpl<MCFixup> &Fixups,
68 const MCSubtargetInfo &STI) const;
69 unsigned getMemRIXEncoding(const MCInst &MI, unsigned OpNo,
70 SmallVectorImpl<MCFixup> &Fixups,
71 const MCSubtargetInfo &STI) const;
72 unsigned getSPE8DisEncoding(const MCInst &MI, unsigned OpNo,
73 SmallVectorImpl<MCFixup> &Fixups,
74 const MCSubtargetInfo &STI) const;
75 unsigned getSPE4DisEncoding(const MCInst &MI, unsigned OpNo,
76 SmallVectorImpl<MCFixup> &Fixups,
77 const MCSubtargetInfo &STI) const;
78 unsigned getSPE2DisEncoding(const MCInst &MI, unsigned OpNo,
79 SmallVectorImpl<MCFixup> &Fixups,
80 const MCSubtargetInfo &STI) const;
81 unsigned getTLSRegEncoding(const MCInst &MI, unsigned OpNo,
82 SmallVectorImpl<MCFixup> &Fixups,
83 const MCSubtargetInfo &STI) const;
84 unsigned getTLSCallEncoding(const MCInst &MI, unsigned OpNo,
85 SmallVectorImpl<MCFixup> &Fixups,
86 const MCSubtargetInfo &STI) const;
87 unsigned get_crbitm_encoding(const MCInst &MI, unsigned OpNo,
88 SmallVectorImpl<MCFixup> &Fixups,
89 const MCSubtargetInfo &STI) const;
90
91 /// getMachineOpValue - Return binary encoding of operand. If the machine
92 /// operand requires relocation, record the relocation and return zero.
93 unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
94 SmallVectorImpl<MCFixup> &Fixups,
95 const MCSubtargetInfo &STI) const;
96
97 // getBinaryCodeForInstr - TableGen'erated function for getting the
98 // binary encoding for an instruction.
99 uint64_t getBinaryCodeForInstr(const MCInst &MI,
100 SmallVectorImpl<MCFixup> &Fixups,
101 const MCSubtargetInfo &STI) const;
encodeInstruction(const MCInst & MI,raw_ostream & OS,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const102 void encodeInstruction(const MCInst &MI, raw_ostream &OS,
103 SmallVectorImpl<MCFixup> &Fixups,
104 const MCSubtargetInfo &STI) const override {
105 // For fast-isel, a float COPY_TO_REGCLASS can survive this long.
106 // It's just a nop to keep the register classes happy, so don't
107 // generate anything.
108 unsigned Opcode = MI.getOpcode();
109 const MCInstrDesc &Desc = MCII.get(Opcode);
110 if (Opcode == TargetOpcode::COPY_TO_REGCLASS)
111 return;
112
113 uint64_t Bits = getBinaryCodeForInstr(MI, Fixups, STI);
114
115 // Output the constant in big/little endian byte order.
116 unsigned Size = Desc.getSize();
117 switch (Size) {
118 case 4:
119 if (IsLittleEndian) {
120 support::endian::Writer<support::little>(OS).write<uint32_t>(Bits);
121 } else {
122 support::endian::Writer<support::big>(OS).write<uint32_t>(Bits);
123 }
124 break;
125 case 8:
126 // If we emit a pair of instructions, the first one is
127 // always in the top 32 bits, even on little-endian.
128 if (IsLittleEndian) {
129 uint64_t Swapped = (Bits << 32) | (Bits >> 32);
130 support::endian::Writer<support::little>(OS).write<uint64_t>(Swapped);
131 } else {
132 support::endian::Writer<support::big>(OS).write<uint64_t>(Bits);
133 }
134 break;
135 default:
136 llvm_unreachable ("Invalid instruction size");
137 }
138
139 ++MCNumEmitted; // Keep track of the # of mi's emitted.
140 }
141
142 };
143
144 } // end anonymous namespace
145
createPPCMCCodeEmitter(const MCInstrInfo & MCII,const MCRegisterInfo & MRI,MCContext & Ctx)146 MCCodeEmitter *llvm::createPPCMCCodeEmitter(const MCInstrInfo &MCII,
147 const MCRegisterInfo &MRI,
148 MCContext &Ctx) {
149 return new PPCMCCodeEmitter(MCII, Ctx);
150 }
151
152 unsigned PPCMCCodeEmitter::
getDirectBrEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const153 getDirectBrEncoding(const MCInst &MI, unsigned OpNo,
154 SmallVectorImpl<MCFixup> &Fixups,
155 const MCSubtargetInfo &STI) const {
156 const MCOperand &MO = MI.getOperand(OpNo);
157 if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups, STI);
158
159 // Add a fixup for the branch target.
160 Fixups.push_back(MCFixup::create(0, MO.getExpr(),
161 (MCFixupKind)PPC::fixup_ppc_br24));
162 return 0;
163 }
164
getCondBrEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const165 unsigned PPCMCCodeEmitter::getCondBrEncoding(const MCInst &MI, unsigned OpNo,
166 SmallVectorImpl<MCFixup> &Fixups,
167 const MCSubtargetInfo &STI) const {
168 const MCOperand &MO = MI.getOperand(OpNo);
169 if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups, STI);
170
171 // Add a fixup for the branch target.
172 Fixups.push_back(MCFixup::create(0, MO.getExpr(),
173 (MCFixupKind)PPC::fixup_ppc_brcond14));
174 return 0;
175 }
176
177 unsigned PPCMCCodeEmitter::
getAbsDirectBrEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const178 getAbsDirectBrEncoding(const MCInst &MI, unsigned OpNo,
179 SmallVectorImpl<MCFixup> &Fixups,
180 const MCSubtargetInfo &STI) const {
181 const MCOperand &MO = MI.getOperand(OpNo);
182 if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups, STI);
183
184 // Add a fixup for the branch target.
185 Fixups.push_back(MCFixup::create(0, MO.getExpr(),
186 (MCFixupKind)PPC::fixup_ppc_br24abs));
187 return 0;
188 }
189
190 unsigned PPCMCCodeEmitter::
getAbsCondBrEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const191 getAbsCondBrEncoding(const MCInst &MI, unsigned OpNo,
192 SmallVectorImpl<MCFixup> &Fixups,
193 const MCSubtargetInfo &STI) const {
194 const MCOperand &MO = MI.getOperand(OpNo);
195 if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups, STI);
196
197 // Add a fixup for the branch target.
198 Fixups.push_back(MCFixup::create(0, MO.getExpr(),
199 (MCFixupKind)PPC::fixup_ppc_brcond14abs));
200 return 0;
201 }
202
getImm16Encoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const203 unsigned PPCMCCodeEmitter::getImm16Encoding(const MCInst &MI, unsigned OpNo,
204 SmallVectorImpl<MCFixup> &Fixups,
205 const MCSubtargetInfo &STI) const {
206 const MCOperand &MO = MI.getOperand(OpNo);
207 if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups, STI);
208
209 // Add a fixup for the immediate field.
210 Fixups.push_back(MCFixup::create(IsLittleEndian? 0 : 2, MO.getExpr(),
211 (MCFixupKind)PPC::fixup_ppc_half16));
212 return 0;
213 }
214
getMemRIEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const215 unsigned PPCMCCodeEmitter::getMemRIEncoding(const MCInst &MI, unsigned OpNo,
216 SmallVectorImpl<MCFixup> &Fixups,
217 const MCSubtargetInfo &STI) const {
218 // Encode (imm, reg) as a memri, which has the low 16-bits as the
219 // displacement and the next 5 bits as the register #.
220 assert(MI.getOperand(OpNo+1).isReg());
221 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI) << 16;
222
223 const MCOperand &MO = MI.getOperand(OpNo);
224 if (MO.isImm())
225 return (getMachineOpValue(MI, MO, Fixups, STI) & 0xFFFF) | RegBits;
226
227 // Add a fixup for the displacement field.
228 Fixups.push_back(MCFixup::create(IsLittleEndian? 0 : 2, MO.getExpr(),
229 (MCFixupKind)PPC::fixup_ppc_half16));
230 return RegBits;
231 }
232
233
getMemRIXEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const234 unsigned PPCMCCodeEmitter::getMemRIXEncoding(const MCInst &MI, unsigned OpNo,
235 SmallVectorImpl<MCFixup> &Fixups,
236 const MCSubtargetInfo &STI) const {
237 // Encode (imm, reg) as a memrix, which has the low 14-bits as the
238 // displacement and the next 5 bits as the register #.
239 assert(MI.getOperand(OpNo+1).isReg());
240 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI) << 14;
241
242 const MCOperand &MO = MI.getOperand(OpNo);
243 if (MO.isImm())
244 return ((getMachineOpValue(MI, MO, Fixups, STI) >> 2) & 0x3FFF) | RegBits;
245
246 // Add a fixup for the displacement field.
247 Fixups.push_back(MCFixup::create(IsLittleEndian? 0 : 2, MO.getExpr(),
248 (MCFixupKind)PPC::fixup_ppc_half16ds));
249 return RegBits;
250 }
251
252
getSPE8DisEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const253 unsigned PPCMCCodeEmitter::getSPE8DisEncoding(const MCInst &MI, unsigned OpNo,
254 SmallVectorImpl<MCFixup> &Fixups,
255 const MCSubtargetInfo &STI)
256 const {
257 // Encode (imm, reg) as a spe8dis, which has the low 5-bits of (imm / 8)
258 // as the displacement and the next 5 bits as the register #.
259 assert(MI.getOperand(OpNo+1).isReg());
260 uint32_t RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI) << 5;
261
262 const MCOperand &MO = MI.getOperand(OpNo);
263 assert(MO.isImm());
264 uint32_t Imm = getMachineOpValue(MI, MO, Fixups, STI) >> 3;
265 return reverseBits(Imm | RegBits) >> 22;
266 }
267
268
getSPE4DisEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const269 unsigned PPCMCCodeEmitter::getSPE4DisEncoding(const MCInst &MI, unsigned OpNo,
270 SmallVectorImpl<MCFixup> &Fixups,
271 const MCSubtargetInfo &STI)
272 const {
273 // Encode (imm, reg) as a spe4dis, which has the low 5-bits of (imm / 4)
274 // as the displacement and the next 5 bits as the register #.
275 assert(MI.getOperand(OpNo+1).isReg());
276 uint32_t RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI) << 5;
277
278 const MCOperand &MO = MI.getOperand(OpNo);
279 assert(MO.isImm());
280 uint32_t Imm = getMachineOpValue(MI, MO, Fixups, STI) >> 2;
281 return reverseBits(Imm | RegBits) >> 22;
282 }
283
284
getSPE2DisEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const285 unsigned PPCMCCodeEmitter::getSPE2DisEncoding(const MCInst &MI, unsigned OpNo,
286 SmallVectorImpl<MCFixup> &Fixups,
287 const MCSubtargetInfo &STI)
288 const {
289 // Encode (imm, reg) as a spe2dis, which has the low 5-bits of (imm / 2)
290 // as the displacement and the next 5 bits as the register #.
291 assert(MI.getOperand(OpNo+1).isReg());
292 uint32_t RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI) << 5;
293
294 const MCOperand &MO = MI.getOperand(OpNo);
295 assert(MO.isImm());
296 uint32_t Imm = getMachineOpValue(MI, MO, Fixups, STI) >> 1;
297 return reverseBits(Imm | RegBits) >> 22;
298 }
299
300
getTLSRegEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const301 unsigned PPCMCCodeEmitter::getTLSRegEncoding(const MCInst &MI, unsigned OpNo,
302 SmallVectorImpl<MCFixup> &Fixups,
303 const MCSubtargetInfo &STI) const {
304 const MCOperand &MO = MI.getOperand(OpNo);
305 if (MO.isReg()) return getMachineOpValue(MI, MO, Fixups, STI);
306
307 // Add a fixup for the TLS register, which simply provides a relocation
308 // hint to the linker that this statement is part of a relocation sequence.
309 // Return the thread-pointer register's encoding.
310 Fixups.push_back(MCFixup::create(0, MO.getExpr(),
311 (MCFixupKind)PPC::fixup_ppc_nofixup));
312 const Triple &TT = STI.getTargetTriple();
313 bool isPPC64 = TT.getArch() == Triple::ppc64 || TT.getArch() == Triple::ppc64le;
314 return CTX.getRegisterInfo()->getEncodingValue(isPPC64 ? PPC::X13 : PPC::R2);
315 }
316
getTLSCallEncoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const317 unsigned PPCMCCodeEmitter::getTLSCallEncoding(const MCInst &MI, unsigned OpNo,
318 SmallVectorImpl<MCFixup> &Fixups,
319 const MCSubtargetInfo &STI) const {
320 // For special TLS calls, we need two fixups; one for the branch target
321 // (__tls_get_addr), which we create via getDirectBrEncoding as usual,
322 // and one for the TLSGD or TLSLD symbol, which is emitted here.
323 const MCOperand &MO = MI.getOperand(OpNo+1);
324 Fixups.push_back(MCFixup::create(0, MO.getExpr(),
325 (MCFixupKind)PPC::fixup_ppc_nofixup));
326 return getDirectBrEncoding(MI, OpNo, Fixups, STI);
327 }
328
329 unsigned PPCMCCodeEmitter::
get_crbitm_encoding(const MCInst & MI,unsigned OpNo,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const330 get_crbitm_encoding(const MCInst &MI, unsigned OpNo,
331 SmallVectorImpl<MCFixup> &Fixups,
332 const MCSubtargetInfo &STI) const {
333 const MCOperand &MO = MI.getOperand(OpNo);
334 assert((MI.getOpcode() == PPC::MTOCRF || MI.getOpcode() == PPC::MTOCRF8 ||
335 MI.getOpcode() == PPC::MFOCRF || MI.getOpcode() == PPC::MFOCRF8) &&
336 (MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7));
337 return 0x80 >> CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
338 }
339
340
341 unsigned PPCMCCodeEmitter::
getMachineOpValue(const MCInst & MI,const MCOperand & MO,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const342 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
343 SmallVectorImpl<MCFixup> &Fixups,
344 const MCSubtargetInfo &STI) const {
345 if (MO.isReg()) {
346 // MTOCRF/MFOCRF should go through get_crbitm_encoding for the CR operand.
347 // The GPR operand should come through here though.
348 assert((MI.getOpcode() != PPC::MTOCRF && MI.getOpcode() != PPC::MTOCRF8 &&
349 MI.getOpcode() != PPC::MFOCRF && MI.getOpcode() != PPC::MFOCRF8) ||
350 MO.getReg() < PPC::CR0 || MO.getReg() > PPC::CR7);
351 return CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
352 }
353
354 assert(MO.isImm() &&
355 "Relocation required in an instruction that we cannot encode!");
356 return MO.getImm();
357 }
358
359
360 #include "PPCGenMCCodeEmitter.inc"
361