xref: /freebsd/contrib/llvm-project/llvm/lib/Target/PowerPC/MCTargetDesc/PPCInstPrinter.cpp (revision 79ac3c12a714bcd3f2354c52d948aed9575c46d6)
1 //===-- PPCInstPrinter.cpp - Convert PPC MCInst to assembly syntax --------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This class prints an PPC MCInst to a .s file.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "MCTargetDesc/PPCInstPrinter.h"
14 #include "MCTargetDesc/PPCMCTargetDesc.h"
15 #include "MCTargetDesc/PPCPredicates.h"
16 #include "PPCInstrInfo.h"
17 #include "llvm/CodeGen/TargetOpcodes.h"
18 #include "llvm/MC/MCExpr.h"
19 #include "llvm/MC/MCInst.h"
20 #include "llvm/MC/MCInstrInfo.h"
21 #include "llvm/MC/MCRegisterInfo.h"
22 #include "llvm/MC/MCSubtargetInfo.h"
23 #include "llvm/MC/MCSymbol.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/raw_ostream.h"
26 using namespace llvm;
27 
28 #define DEBUG_TYPE "asm-printer"
29 
30 // FIXME: Once the integrated assembler supports full register names, tie this
31 // to the verbose-asm setting.
32 static cl::opt<bool>
33 FullRegNames("ppc-asm-full-reg-names", cl::Hidden, cl::init(false),
34              cl::desc("Use full register names when printing assembly"));
35 
36 // Useful for testing purposes. Prints vs{31-63} as v{0-31} respectively.
37 static cl::opt<bool>
38 ShowVSRNumsAsVR("ppc-vsr-nums-as-vr", cl::Hidden, cl::init(false),
39              cl::desc("Prints full register names with vs{31-63} as v{0-31}"));
40 
41 // Prints full register names with percent symbol.
42 static cl::opt<bool>
43 FullRegNamesWithPercent("ppc-reg-with-percent-prefix", cl::Hidden,
44                         cl::init(false),
45                         cl::desc("Prints full register names with percent"));
46 
47 #define PRINT_ALIAS_INSTR
48 #include "PPCGenAsmWriter.inc"
49 
50 void PPCInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
51   const char *RegName = getRegisterName(RegNo);
52   OS << RegName;
53 }
54 
55 void PPCInstPrinter::printInst(const MCInst *MI, uint64_t Address,
56                                StringRef Annot, const MCSubtargetInfo &STI,
57                                raw_ostream &O) {
58   // Customize printing of the addis instruction on AIX. When an operand is a
59   // symbol reference, the instruction syntax is changed to look like a load
60   // operation, i.e:
61   //     Transform:  addis $rD, $rA, $src --> addis $rD, $src($rA).
62   if (TT.isOSAIX() &&
63       (MI->getOpcode() == PPC::ADDIS8 || MI->getOpcode() == PPC::ADDIS) &&
64       MI->getOperand(2).isExpr()) {
65     assert((MI->getOperand(0).isReg() && MI->getOperand(1).isReg()) &&
66            "The first and the second operand of an addis instruction"
67            " should be registers.");
68 
69     assert(isa<MCSymbolRefExpr>(MI->getOperand(2).getExpr()) &&
70            "The third operand of an addis instruction should be a symbol "
71            "reference expression if it is an expression at all.");
72 
73     O << "\taddis ";
74     printOperand(MI, 0, STI, O);
75     O << ", ";
76     printOperand(MI, 2, STI, O);
77     O << "(";
78     printOperand(MI, 1, STI, O);
79     O << ")";
80     return;
81   }
82 
83   // Check if the last operand is an expression with the variant kind
84   // VK_PPC_PCREL_OPT. If this is the case then this is a linker optimization
85   // relocation and the .reloc directive needs to be added.
86   unsigned LastOp = MI->getNumOperands() - 1;
87   if (MI->getNumOperands() > 1) {
88     const MCOperand &Operand = MI->getOperand(LastOp);
89     if (Operand.isExpr()) {
90       const MCExpr *Expr = Operand.getExpr();
91       const MCSymbolRefExpr *SymExpr =
92           static_cast<const MCSymbolRefExpr *>(Expr);
93 
94       if (SymExpr && SymExpr->getKind() == MCSymbolRefExpr::VK_PPC_PCREL_OPT) {
95         const MCSymbol &Symbol = SymExpr->getSymbol();
96         if (MI->getOpcode() == PPC::PLDpc) {
97           printInstruction(MI, Address, STI, O);
98           O << "\n";
99           Symbol.print(O, &MAI);
100           O << ":";
101           return;
102         } else {
103           O << "\t.reloc ";
104           Symbol.print(O, &MAI);
105           O << "-8,R_PPC64_PCREL_OPT,.-(";
106           Symbol.print(O, &MAI);
107           O << "-8)\n";
108         }
109       }
110     }
111   }
112 
113   // Check for slwi/srwi mnemonics.
114   if (MI->getOpcode() == PPC::RLWINM) {
115     unsigned char SH = MI->getOperand(2).getImm();
116     unsigned char MB = MI->getOperand(3).getImm();
117     unsigned char ME = MI->getOperand(4).getImm();
118     bool useSubstituteMnemonic = false;
119     if (SH <= 31 && MB == 0 && ME == (31-SH)) {
120       O << "\tslwi "; useSubstituteMnemonic = true;
121     }
122     if (SH <= 31 && MB == (32-SH) && ME == 31) {
123       O << "\tsrwi "; useSubstituteMnemonic = true;
124       SH = 32-SH;
125     }
126     if (useSubstituteMnemonic) {
127       printOperand(MI, 0, STI, O);
128       O << ", ";
129       printOperand(MI, 1, STI, O);
130       O << ", " << (unsigned int)SH;
131 
132       printAnnotation(O, Annot);
133       return;
134     }
135   }
136 
137   if (MI->getOpcode() == PPC::RLDICR ||
138       MI->getOpcode() == PPC::RLDICR_32) {
139     unsigned char SH = MI->getOperand(2).getImm();
140     unsigned char ME = MI->getOperand(3).getImm();
141     // rldicr RA, RS, SH, 63-SH == sldi RA, RS, SH
142     if (63-SH == ME) {
143       O << "\tsldi ";
144       printOperand(MI, 0, STI, O);
145       O << ", ";
146       printOperand(MI, 1, STI, O);
147       O << ", " << (unsigned int)SH;
148       printAnnotation(O, Annot);
149       return;
150     }
151   }
152 
153   // dcbt[st] is printed manually here because:
154   //  1. The assembly syntax is different between embedded and server targets
155   //  2. We must print the short mnemonics for TH == 0 because the
156   //     embedded/server syntax default will not be stable across assemblers
157   //  The syntax for dcbt is:
158   //    dcbt ra, rb, th [server]
159   //    dcbt th, ra, rb [embedded]
160   //  where th can be omitted when it is 0. dcbtst is the same.
161   if (MI->getOpcode() == PPC::DCBT || MI->getOpcode() == PPC::DCBTST) {
162     unsigned char TH = MI->getOperand(0).getImm();
163     O << "\tdcbt";
164     if (MI->getOpcode() == PPC::DCBTST)
165       O << "st";
166     if (TH == 16)
167       O << "t";
168     O << " ";
169 
170     bool IsBookE = STI.getFeatureBits()[PPC::FeatureBookE];
171     if (IsBookE && TH != 0 && TH != 16)
172       O << (unsigned int) TH << ", ";
173 
174     printOperand(MI, 1, STI, O);
175     O << ", ";
176     printOperand(MI, 2, STI, O);
177 
178     if (!IsBookE && TH != 0 && TH != 16)
179       O << ", " << (unsigned int) TH;
180 
181     printAnnotation(O, Annot);
182     return;
183   }
184 
185   if (MI->getOpcode() == PPC::DCBF) {
186     unsigned char L = MI->getOperand(0).getImm();
187     if (!L || L == 1 || L == 3 || L == 4 || L == 6) {
188       O << "\tdcb";
189       if (L != 6)
190         O << "f";
191       if (L == 1)
192         O << "l";
193       if (L == 3)
194         O << "lp";
195       if (L == 4)
196         O << "ps";
197       if (L == 6)
198         O << "stps";
199       O << " ";
200 
201       printOperand(MI, 1, STI, O);
202       O << ", ";
203       printOperand(MI, 2, STI, O);
204 
205       printAnnotation(O, Annot);
206       return;
207     }
208   }
209 
210   if (!printAliasInstr(MI, Address, STI, O))
211     printInstruction(MI, Address, STI, O);
212   printAnnotation(O, Annot);
213 }
214 
215 void PPCInstPrinter::printPredicateOperand(const MCInst *MI, unsigned OpNo,
216                                            const MCSubtargetInfo &STI,
217                                            raw_ostream &O,
218                                            const char *Modifier) {
219   unsigned Code = MI->getOperand(OpNo).getImm();
220 
221   if (StringRef(Modifier) == "cc") {
222     switch ((PPC::Predicate)Code) {
223     case PPC::PRED_LT_MINUS:
224     case PPC::PRED_LT_PLUS:
225     case PPC::PRED_LT:
226       O << "lt";
227       return;
228     case PPC::PRED_LE_MINUS:
229     case PPC::PRED_LE_PLUS:
230     case PPC::PRED_LE:
231       O << "le";
232       return;
233     case PPC::PRED_EQ_MINUS:
234     case PPC::PRED_EQ_PLUS:
235     case PPC::PRED_EQ:
236       O << "eq";
237       return;
238     case PPC::PRED_GE_MINUS:
239     case PPC::PRED_GE_PLUS:
240     case PPC::PRED_GE:
241       O << "ge";
242       return;
243     case PPC::PRED_GT_MINUS:
244     case PPC::PRED_GT_PLUS:
245     case PPC::PRED_GT:
246       O << "gt";
247       return;
248     case PPC::PRED_NE_MINUS:
249     case PPC::PRED_NE_PLUS:
250     case PPC::PRED_NE:
251       O << "ne";
252       return;
253     case PPC::PRED_UN_MINUS:
254     case PPC::PRED_UN_PLUS:
255     case PPC::PRED_UN:
256       O << "un";
257       return;
258     case PPC::PRED_NU_MINUS:
259     case PPC::PRED_NU_PLUS:
260     case PPC::PRED_NU:
261       O << "nu";
262       return;
263     case PPC::PRED_BIT_SET:
264     case PPC::PRED_BIT_UNSET:
265       llvm_unreachable("Invalid use of bit predicate code");
266     }
267     llvm_unreachable("Invalid predicate code");
268   }
269 
270   if (StringRef(Modifier) == "pm") {
271     switch ((PPC::Predicate)Code) {
272     case PPC::PRED_LT:
273     case PPC::PRED_LE:
274     case PPC::PRED_EQ:
275     case PPC::PRED_GE:
276     case PPC::PRED_GT:
277     case PPC::PRED_NE:
278     case PPC::PRED_UN:
279     case PPC::PRED_NU:
280       return;
281     case PPC::PRED_LT_MINUS:
282     case PPC::PRED_LE_MINUS:
283     case PPC::PRED_EQ_MINUS:
284     case PPC::PRED_GE_MINUS:
285     case PPC::PRED_GT_MINUS:
286     case PPC::PRED_NE_MINUS:
287     case PPC::PRED_UN_MINUS:
288     case PPC::PRED_NU_MINUS:
289       O << "-";
290       return;
291     case PPC::PRED_LT_PLUS:
292     case PPC::PRED_LE_PLUS:
293     case PPC::PRED_EQ_PLUS:
294     case PPC::PRED_GE_PLUS:
295     case PPC::PRED_GT_PLUS:
296     case PPC::PRED_NE_PLUS:
297     case PPC::PRED_UN_PLUS:
298     case PPC::PRED_NU_PLUS:
299       O << "+";
300       return;
301     case PPC::PRED_BIT_SET:
302     case PPC::PRED_BIT_UNSET:
303       llvm_unreachable("Invalid use of bit predicate code");
304     }
305     llvm_unreachable("Invalid predicate code");
306   }
307 
308   assert(StringRef(Modifier) == "reg" &&
309          "Need to specify 'cc', 'pm' or 'reg' as predicate op modifier!");
310   printOperand(MI, OpNo + 1, STI, O);
311 }
312 
313 void PPCInstPrinter::printATBitsAsHint(const MCInst *MI, unsigned OpNo,
314                                        const MCSubtargetInfo &STI,
315                                        raw_ostream &O) {
316   unsigned Code = MI->getOperand(OpNo).getImm();
317   if (Code == 2)
318     O << "-";
319   else if (Code == 3)
320     O << "+";
321 }
322 
323 void PPCInstPrinter::printU1ImmOperand(const MCInst *MI, unsigned OpNo,
324                                        const MCSubtargetInfo &STI,
325                                        raw_ostream &O) {
326   unsigned int Value = MI->getOperand(OpNo).getImm();
327   assert(Value <= 1 && "Invalid u1imm argument!");
328   O << (unsigned int)Value;
329 }
330 
331 void PPCInstPrinter::printU2ImmOperand(const MCInst *MI, unsigned OpNo,
332                                        const MCSubtargetInfo &STI,
333                                        raw_ostream &O) {
334   unsigned int Value = MI->getOperand(OpNo).getImm();
335   assert(Value <= 3 && "Invalid u2imm argument!");
336   O << (unsigned int)Value;
337 }
338 
339 void PPCInstPrinter::printU3ImmOperand(const MCInst *MI, unsigned OpNo,
340                                        const MCSubtargetInfo &STI,
341                                        raw_ostream &O) {
342   unsigned int Value = MI->getOperand(OpNo).getImm();
343   assert(Value <= 8 && "Invalid u3imm argument!");
344   O << (unsigned int)Value;
345 }
346 
347 void PPCInstPrinter::printU4ImmOperand(const MCInst *MI, unsigned OpNo,
348                                        const MCSubtargetInfo &STI,
349                                        raw_ostream &O) {
350   unsigned int Value = MI->getOperand(OpNo).getImm();
351   assert(Value <= 15 && "Invalid u4imm argument!");
352   O << (unsigned int)Value;
353 }
354 
355 void PPCInstPrinter::printS5ImmOperand(const MCInst *MI, unsigned OpNo,
356                                        const MCSubtargetInfo &STI,
357                                        raw_ostream &O) {
358   int Value = MI->getOperand(OpNo).getImm();
359   Value = SignExtend32<5>(Value);
360   O << (int)Value;
361 }
362 
363 void PPCInstPrinter::printImmZeroOperand(const MCInst *MI, unsigned OpNo,
364                                          const MCSubtargetInfo &STI,
365                                          raw_ostream &O) {
366   unsigned int Value = MI->getOperand(OpNo).getImm();
367   assert(Value == 0 && "Operand must be zero");
368   O << (unsigned int)Value;
369 }
370 
371 void PPCInstPrinter::printU5ImmOperand(const MCInst *MI, unsigned OpNo,
372                                        const MCSubtargetInfo &STI,
373                                        raw_ostream &O) {
374   unsigned int Value = MI->getOperand(OpNo).getImm();
375   assert(Value <= 31 && "Invalid u5imm argument!");
376   O << (unsigned int)Value;
377 }
378 
379 void PPCInstPrinter::printU6ImmOperand(const MCInst *MI, unsigned OpNo,
380                                        const MCSubtargetInfo &STI,
381                                        raw_ostream &O) {
382   unsigned int Value = MI->getOperand(OpNo).getImm();
383   assert(Value <= 63 && "Invalid u6imm argument!");
384   O << (unsigned int)Value;
385 }
386 
387 void PPCInstPrinter::printU7ImmOperand(const MCInst *MI, unsigned OpNo,
388                                        const MCSubtargetInfo &STI,
389                                        raw_ostream &O) {
390   unsigned int Value = MI->getOperand(OpNo).getImm();
391   assert(Value <= 127 && "Invalid u7imm argument!");
392   O << (unsigned int)Value;
393 }
394 
395 // Operands of BUILD_VECTOR are signed and we use this to print operands
396 // of XXSPLTIB which are unsigned. So we simply truncate to 8 bits and
397 // print as unsigned.
398 void PPCInstPrinter::printU8ImmOperand(const MCInst *MI, unsigned OpNo,
399                                        const MCSubtargetInfo &STI,
400                                        raw_ostream &O) {
401   unsigned char Value = MI->getOperand(OpNo).getImm();
402   O << (unsigned int)Value;
403 }
404 
405 void PPCInstPrinter::printU10ImmOperand(const MCInst *MI, unsigned OpNo,
406                                         const MCSubtargetInfo &STI,
407                                         raw_ostream &O) {
408   unsigned short Value = MI->getOperand(OpNo).getImm();
409   assert(Value <= 1023 && "Invalid u10imm argument!");
410   O << (unsigned short)Value;
411 }
412 
413 void PPCInstPrinter::printU12ImmOperand(const MCInst *MI, unsigned OpNo,
414                                         const MCSubtargetInfo &STI,
415                                         raw_ostream &O) {
416   unsigned short Value = MI->getOperand(OpNo).getImm();
417   assert(Value <= 4095 && "Invalid u12imm argument!");
418   O << (unsigned short)Value;
419 }
420 
421 void PPCInstPrinter::printS16ImmOperand(const MCInst *MI, unsigned OpNo,
422                                         const MCSubtargetInfo &STI,
423                                         raw_ostream &O) {
424   if (MI->getOperand(OpNo).isImm())
425     O << (short)MI->getOperand(OpNo).getImm();
426   else
427     printOperand(MI, OpNo, STI, O);
428 }
429 
430 void PPCInstPrinter::printS34ImmOperand(const MCInst *MI, unsigned OpNo,
431                                         const MCSubtargetInfo &STI,
432                                         raw_ostream &O) {
433   if (MI->getOperand(OpNo).isImm()) {
434     long long Value = MI->getOperand(OpNo).getImm();
435     assert(isInt<34>(Value) && "Invalid s34imm argument!");
436     O << (long long)Value;
437   }
438   else
439     printOperand(MI, OpNo, STI, O);
440 }
441 
442 void PPCInstPrinter::printU16ImmOperand(const MCInst *MI, unsigned OpNo,
443                                         const MCSubtargetInfo &STI,
444                                         raw_ostream &O) {
445   if (MI->getOperand(OpNo).isImm())
446     O << (unsigned short)MI->getOperand(OpNo).getImm();
447   else
448     printOperand(MI, OpNo, STI, O);
449 }
450 
451 void PPCInstPrinter::printBranchOperand(const MCInst *MI, uint64_t Address,
452                                         unsigned OpNo,
453                                         const MCSubtargetInfo &STI,
454                                         raw_ostream &O) {
455   if (!MI->getOperand(OpNo).isImm())
456     return printOperand(MI, OpNo, STI, O);
457   int32_t Imm = SignExtend32<32>((unsigned)MI->getOperand(OpNo).getImm() << 2);
458   if (PrintBranchImmAsAddress) {
459     uint64_t Target = Address + Imm;
460     if (!TT.isPPC64())
461       Target &= 0xffffffff;
462     O << formatHex(Target);
463   } else {
464     // Branches can take an immediate operand. This is used by the branch
465     // selection pass to print, for example `.+8` (for ELF) or `$+8` (for AIX)
466     // to express an eight byte displacement from the program counter.
467     if (!TT.isOSAIX())
468       O << ".";
469     else
470       O << "$";
471 
472     if (Imm >= 0)
473       O << "+";
474     O << Imm;
475   }
476 }
477 
478 void PPCInstPrinter::printAbsBranchOperand(const MCInst *MI, unsigned OpNo,
479                                            const MCSubtargetInfo &STI,
480                                            raw_ostream &O) {
481   if (!MI->getOperand(OpNo).isImm())
482     return printOperand(MI, OpNo, STI, O);
483 
484   O << SignExtend32<32>((unsigned)MI->getOperand(OpNo).getImm() << 2);
485 }
486 
487 void PPCInstPrinter::printcrbitm(const MCInst *MI, unsigned OpNo,
488                                  const MCSubtargetInfo &STI, raw_ostream &O) {
489   unsigned CCReg = MI->getOperand(OpNo).getReg();
490   unsigned RegNo;
491   switch (CCReg) {
492   default: llvm_unreachable("Unknown CR register");
493   case PPC::CR0: RegNo = 0; break;
494   case PPC::CR1: RegNo = 1; break;
495   case PPC::CR2: RegNo = 2; break;
496   case PPC::CR3: RegNo = 3; break;
497   case PPC::CR4: RegNo = 4; break;
498   case PPC::CR5: RegNo = 5; break;
499   case PPC::CR6: RegNo = 6; break;
500   case PPC::CR7: RegNo = 7; break;
501   }
502   O << (0x80 >> RegNo);
503 }
504 
505 void PPCInstPrinter::printMemRegImm(const MCInst *MI, unsigned OpNo,
506                                     const MCSubtargetInfo &STI,
507                                     raw_ostream &O) {
508   printS16ImmOperand(MI, OpNo, STI, O);
509   O << '(';
510   if (MI->getOperand(OpNo+1).getReg() == PPC::R0)
511     O << "0";
512   else
513     printOperand(MI, OpNo + 1, STI, O);
514   O << ')';
515 }
516 
517 void PPCInstPrinter::printMemRegImm34PCRel(const MCInst *MI, unsigned OpNo,
518                                            const MCSubtargetInfo &STI,
519                                            raw_ostream &O) {
520   printS34ImmOperand(MI, OpNo, STI, O);
521   O << '(';
522   printImmZeroOperand(MI, OpNo + 1, STI, O);
523   O << ')';
524 }
525 
526 void PPCInstPrinter::printMemRegImm34(const MCInst *MI, unsigned OpNo,
527                                       const MCSubtargetInfo &STI,
528                                       raw_ostream &O) {
529   printS34ImmOperand(MI, OpNo, STI, O);
530   O << '(';
531   printOperand(MI, OpNo + 1, STI, O);
532   O << ')';
533 }
534 
535 void PPCInstPrinter::printMemRegReg(const MCInst *MI, unsigned OpNo,
536                                     const MCSubtargetInfo &STI,
537                                     raw_ostream &O) {
538   // When used as the base register, r0 reads constant zero rather than
539   // the value contained in the register.  For this reason, the darwin
540   // assembler requires that we print r0 as 0 (no r) when used as the base.
541   if (MI->getOperand(OpNo).getReg() == PPC::R0)
542     O << "0";
543   else
544     printOperand(MI, OpNo, STI, O);
545   O << ", ";
546   printOperand(MI, OpNo + 1, STI, O);
547 }
548 
549 void PPCInstPrinter::printTLSCall(const MCInst *MI, unsigned OpNo,
550                                   const MCSubtargetInfo &STI, raw_ostream &O) {
551   // On PPC64, VariantKind is VK_None, but on PPC32, it's VK_PLT, and it must
552   // come at the _end_ of the expression.
553   const MCOperand &Op = MI->getOperand(OpNo);
554   const MCSymbolRefExpr *RefExp = nullptr;
555   const MCConstantExpr *ConstExp = nullptr;
556   if (const MCBinaryExpr *BinExpr = dyn_cast<MCBinaryExpr>(Op.getExpr())) {
557     RefExp = cast<MCSymbolRefExpr>(BinExpr->getLHS());
558     ConstExp = cast<MCConstantExpr>(BinExpr->getRHS());
559   } else
560     RefExp = cast<MCSymbolRefExpr>(Op.getExpr());
561 
562   O << RefExp->getSymbol().getName();
563   // The variant kind VK_PPC_NOTOC needs to be handled as a special case
564   // because we do not want the assembly to print out the @notoc at the
565   // end like __tls_get_addr(x@tlsgd)@notoc. Instead we want it to look
566   // like __tls_get_addr@notoc(x@tlsgd).
567   if (RefExp->getKind() == MCSymbolRefExpr::VK_PPC_NOTOC)
568     O << '@' << MCSymbolRefExpr::getVariantKindName(RefExp->getKind());
569   O << '(';
570   printOperand(MI, OpNo + 1, STI, O);
571   O << ')';
572   if (RefExp->getKind() != MCSymbolRefExpr::VK_None &&
573       RefExp->getKind() != MCSymbolRefExpr::VK_PPC_NOTOC)
574     O << '@' << MCSymbolRefExpr::getVariantKindName(RefExp->getKind());
575   if (ConstExp != nullptr)
576     O << '+' << ConstExp->getValue();
577 }
578 
579 /// showRegistersWithPercentPrefix - Check if this register name should be
580 /// printed with a percentage symbol as prefix.
581 bool PPCInstPrinter::showRegistersWithPercentPrefix(const char *RegName) const {
582   if (!FullRegNamesWithPercent || TT.getOS() == Triple::AIX)
583     return false;
584 
585   switch (RegName[0]) {
586   default:
587     return false;
588   case 'r':
589   case 'f':
590   case 'q':
591   case 'v':
592   case 'c':
593     return true;
594   }
595 }
596 
597 /// getVerboseConditionalRegName - This method expands the condition register
598 /// when requested explicitly or targetting Darwin.
599 const char *PPCInstPrinter::getVerboseConditionRegName(unsigned RegNum,
600                                                        unsigned RegEncoding)
601                                                        const {
602   if (!FullRegNames)
603     return nullptr;
604   if (RegNum < PPC::CR0EQ || RegNum > PPC::CR7UN)
605     return nullptr;
606   const char *CRBits[] = {
607     "lt", "gt", "eq", "un",
608     "4*cr1+lt", "4*cr1+gt", "4*cr1+eq", "4*cr1+un",
609     "4*cr2+lt", "4*cr2+gt", "4*cr2+eq", "4*cr2+un",
610     "4*cr3+lt", "4*cr3+gt", "4*cr3+eq", "4*cr3+un",
611     "4*cr4+lt", "4*cr4+gt", "4*cr4+eq", "4*cr4+un",
612     "4*cr5+lt", "4*cr5+gt", "4*cr5+eq", "4*cr5+un",
613     "4*cr6+lt", "4*cr6+gt", "4*cr6+eq", "4*cr6+un",
614     "4*cr7+lt", "4*cr7+gt", "4*cr7+eq", "4*cr7+un"
615   };
616   return CRBits[RegEncoding];
617 }
618 
619 // showRegistersWithPrefix - This method determines whether registers
620 // should be number-only or include the prefix.
621 bool PPCInstPrinter::showRegistersWithPrefix() const {
622   if (TT.getOS() == Triple::AIX)
623     return false;
624   return FullRegNamesWithPercent || FullRegNames;
625 }
626 
627 void PPCInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
628                                   const MCSubtargetInfo &STI, raw_ostream &O) {
629   const MCOperand &Op = MI->getOperand(OpNo);
630   if (Op.isReg()) {
631     unsigned Reg = Op.getReg();
632     if (!ShowVSRNumsAsVR)
633       Reg = PPCInstrInfo::getRegNumForOperand(MII.get(MI->getOpcode()),
634                                               Reg, OpNo);
635 
636     const char *RegName;
637     RegName = getVerboseConditionRegName(Reg, MRI.getEncodingValue(Reg));
638     if (RegName == nullptr)
639      RegName = getRegisterName(Reg);
640     if (showRegistersWithPercentPrefix(RegName))
641       O << "%";
642     if (!showRegistersWithPrefix())
643       RegName = PPCRegisterInfo::stripRegisterPrefix(RegName);
644 
645     O << RegName;
646     return;
647   }
648 
649   if (Op.isImm()) {
650     O << Op.getImm();
651     return;
652   }
653 
654   assert(Op.isExpr() && "unknown operand kind in printOperand");
655   Op.getExpr()->print(O, &MAI);
656 }
657