1 //===-- PPCInstPrinter.cpp - Convert PPC MCInst to assembly syntax --------===//
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 class prints an PPC MCInst to a .s file.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "PPCInstPrinter.h"
15 #include "MCTargetDesc/PPCMCTargetDesc.h"
16 #include "MCTargetDesc/PPCPredicates.h"
17 #include "llvm/MC/MCExpr.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCInstrInfo.h"
20 #include "llvm/MC/MCSymbol.h"
21 #include "llvm/Support/CommandLine.h"
22 #include "llvm/Support/raw_ostream.h"
23 #include "llvm/Target/TargetOpcodes.h"
24 using namespace llvm;
25 
26 #define DEBUG_TYPE "asm-printer"
27 
28 // FIXME: Once the integrated assembler supports full register names, tie this
29 // to the verbose-asm setting.
30 static cl::opt<bool>
31 FullRegNames("ppc-asm-full-reg-names", cl::Hidden, cl::init(false),
32              cl::desc("Use full register names when printing assembly"));
33 
34 #include "PPCGenAsmWriter.inc"
35 
printRegName(raw_ostream & OS,unsigned RegNo) const36 void PPCInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
37   const char *RegName = getRegisterName(RegNo);
38   if (RegName[0] == 'q' /* QPX */) {
39     // The system toolchain on the BG/Q does not understand QPX register names
40     // in .cfi_* directives, so print the name of the floating-point
41     // subregister instead.
42     std::string RN(RegName);
43 
44     RN[0] = 'f';
45     OS << RN;
46 
47     return;
48   }
49 
50   OS << RegName;
51 }
52 
printInst(const MCInst * MI,raw_ostream & O,StringRef Annot,const MCSubtargetInfo & STI)53 void PPCInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
54                                StringRef Annot, const MCSubtargetInfo &STI) {
55   // Check for slwi/srwi mnemonics.
56   if (MI->getOpcode() == PPC::RLWINM) {
57     unsigned char SH = MI->getOperand(2).getImm();
58     unsigned char MB = MI->getOperand(3).getImm();
59     unsigned char ME = MI->getOperand(4).getImm();
60     bool useSubstituteMnemonic = false;
61     if (SH <= 31 && MB == 0 && ME == (31-SH)) {
62       O << "\tslwi "; useSubstituteMnemonic = true;
63     }
64     if (SH <= 31 && MB == (32-SH) && ME == 31) {
65       O << "\tsrwi "; useSubstituteMnemonic = true;
66       SH = 32-SH;
67     }
68     if (useSubstituteMnemonic) {
69       printOperand(MI, 0, O);
70       O << ", ";
71       printOperand(MI, 1, O);
72       O << ", " << (unsigned int)SH;
73 
74       printAnnotation(O, Annot);
75       return;
76     }
77   }
78 
79   if ((MI->getOpcode() == PPC::OR || MI->getOpcode() == PPC::OR8) &&
80       MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
81     O << "\tmr ";
82     printOperand(MI, 0, O);
83     O << ", ";
84     printOperand(MI, 1, O);
85     printAnnotation(O, Annot);
86     return;
87   }
88 
89   if (MI->getOpcode() == PPC::RLDICR) {
90     unsigned char SH = MI->getOperand(2).getImm();
91     unsigned char ME = MI->getOperand(3).getImm();
92     // rldicr RA, RS, SH, 63-SH == sldi RA, RS, SH
93     if (63-SH == ME) {
94       O << "\tsldi ";
95       printOperand(MI, 0, O);
96       O << ", ";
97       printOperand(MI, 1, O);
98       O << ", " << (unsigned int)SH;
99       printAnnotation(O, Annot);
100       return;
101     }
102   }
103 
104   // For fast-isel, a COPY_TO_REGCLASS may survive this long.  This is
105   // used when converting a 32-bit float to a 64-bit float as part of
106   // conversion to an integer (see PPCFastISel.cpp:SelectFPToI()),
107   // as otherwise we have problems with incorrect register classes
108   // in machine instruction verification.  For now, just avoid trying
109   // to print it as such an instruction has no effect (a 32-bit float
110   // in a register is already in 64-bit form, just with lower
111   // precision).  FIXME: Is there a better solution?
112   if (MI->getOpcode() == TargetOpcode::COPY_TO_REGCLASS)
113     return;
114 
115   printInstruction(MI, O);
116   printAnnotation(O, Annot);
117 }
118 
119 
printPredicateOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)120 void PPCInstPrinter::printPredicateOperand(const MCInst *MI, unsigned OpNo,
121                                            raw_ostream &O,
122                                            const char *Modifier) {
123   unsigned Code = MI->getOperand(OpNo).getImm();
124 
125   if (StringRef(Modifier) == "cc") {
126     switch ((PPC::Predicate)Code) {
127     case PPC::PRED_LT_MINUS:
128     case PPC::PRED_LT_PLUS:
129     case PPC::PRED_LT:
130       O << "lt";
131       return;
132     case PPC::PRED_LE_MINUS:
133     case PPC::PRED_LE_PLUS:
134     case PPC::PRED_LE:
135       O << "le";
136       return;
137     case PPC::PRED_EQ_MINUS:
138     case PPC::PRED_EQ_PLUS:
139     case PPC::PRED_EQ:
140       O << "eq";
141       return;
142     case PPC::PRED_GE_MINUS:
143     case PPC::PRED_GE_PLUS:
144     case PPC::PRED_GE:
145       O << "ge";
146       return;
147     case PPC::PRED_GT_MINUS:
148     case PPC::PRED_GT_PLUS:
149     case PPC::PRED_GT:
150       O << "gt";
151       return;
152     case PPC::PRED_NE_MINUS:
153     case PPC::PRED_NE_PLUS:
154     case PPC::PRED_NE:
155       O << "ne";
156       return;
157     case PPC::PRED_UN_MINUS:
158     case PPC::PRED_UN_PLUS:
159     case PPC::PRED_UN:
160       O << "un";
161       return;
162     case PPC::PRED_NU_MINUS:
163     case PPC::PRED_NU_PLUS:
164     case PPC::PRED_NU:
165       O << "nu";
166       return;
167     case PPC::PRED_BIT_SET:
168     case PPC::PRED_BIT_UNSET:
169       llvm_unreachable("Invalid use of bit predicate code");
170     }
171     llvm_unreachable("Invalid predicate code");
172   }
173 
174   if (StringRef(Modifier) == "pm") {
175     switch ((PPC::Predicate)Code) {
176     case PPC::PRED_LT:
177     case PPC::PRED_LE:
178     case PPC::PRED_EQ:
179     case PPC::PRED_GE:
180     case PPC::PRED_GT:
181     case PPC::PRED_NE:
182     case PPC::PRED_UN:
183     case PPC::PRED_NU:
184       return;
185     case PPC::PRED_LT_MINUS:
186     case PPC::PRED_LE_MINUS:
187     case PPC::PRED_EQ_MINUS:
188     case PPC::PRED_GE_MINUS:
189     case PPC::PRED_GT_MINUS:
190     case PPC::PRED_NE_MINUS:
191     case PPC::PRED_UN_MINUS:
192     case PPC::PRED_NU_MINUS:
193       O << "-";
194       return;
195     case PPC::PRED_LT_PLUS:
196     case PPC::PRED_LE_PLUS:
197     case PPC::PRED_EQ_PLUS:
198     case PPC::PRED_GE_PLUS:
199     case PPC::PRED_GT_PLUS:
200     case PPC::PRED_NE_PLUS:
201     case PPC::PRED_UN_PLUS:
202     case PPC::PRED_NU_PLUS:
203       O << "+";
204       return;
205     case PPC::PRED_BIT_SET:
206     case PPC::PRED_BIT_UNSET:
207       llvm_unreachable("Invalid use of bit predicate code");
208     }
209     llvm_unreachable("Invalid predicate code");
210   }
211 
212   assert(StringRef(Modifier) == "reg" &&
213          "Need to specify 'cc', 'pm' or 'reg' as predicate op modifier!");
214   printOperand(MI, OpNo+1, O);
215 }
216 
printU1ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)217 void PPCInstPrinter::printU1ImmOperand(const MCInst *MI, unsigned OpNo,
218                                        raw_ostream &O) {
219   unsigned int Value = MI->getOperand(OpNo).getImm();
220   assert(Value <= 1 && "Invalid u1imm argument!");
221   O << (unsigned int)Value;
222 }
223 
printU2ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)224 void PPCInstPrinter::printU2ImmOperand(const MCInst *MI, unsigned OpNo,
225                                        raw_ostream &O) {
226   unsigned int Value = MI->getOperand(OpNo).getImm();
227   assert(Value <= 3 && "Invalid u2imm argument!");
228   O << (unsigned int)Value;
229 }
230 
printU3ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)231 void PPCInstPrinter::printU3ImmOperand(const MCInst *MI, unsigned OpNo,
232                                        raw_ostream &O) {
233   unsigned int Value = MI->getOperand(OpNo).getImm();
234   assert(Value <= 8 && "Invalid u3imm argument!");
235   O << (unsigned int)Value;
236 }
237 
printU4ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)238 void PPCInstPrinter::printU4ImmOperand(const MCInst *MI, unsigned OpNo,
239                                        raw_ostream &O) {
240   unsigned int Value = MI->getOperand(OpNo).getImm();
241   assert(Value <= 15 && "Invalid u4imm argument!");
242   O << (unsigned int)Value;
243 }
244 
printS5ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)245 void PPCInstPrinter::printS5ImmOperand(const MCInst *MI, unsigned OpNo,
246                                        raw_ostream &O) {
247   int Value = MI->getOperand(OpNo).getImm();
248   Value = SignExtend32<5>(Value);
249   O << (int)Value;
250 }
251 
printU5ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)252 void PPCInstPrinter::printU5ImmOperand(const MCInst *MI, unsigned OpNo,
253                                        raw_ostream &O) {
254   unsigned int Value = MI->getOperand(OpNo).getImm();
255   assert(Value <= 31 && "Invalid u5imm argument!");
256   O << (unsigned int)Value;
257 }
258 
printU6ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)259 void PPCInstPrinter::printU6ImmOperand(const MCInst *MI, unsigned OpNo,
260                                        raw_ostream &O) {
261   unsigned int Value = MI->getOperand(OpNo).getImm();
262   assert(Value <= 63 && "Invalid u6imm argument!");
263   O << (unsigned int)Value;
264 }
265 
printU12ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)266 void PPCInstPrinter::printU12ImmOperand(const MCInst *MI, unsigned OpNo,
267                                         raw_ostream &O) {
268   unsigned short Value = MI->getOperand(OpNo).getImm();
269   assert(Value <= 4095 && "Invalid u12imm argument!");
270   O << (unsigned short)Value;
271 }
272 
printS16ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)273 void PPCInstPrinter::printS16ImmOperand(const MCInst *MI, unsigned OpNo,
274                                         raw_ostream &O) {
275   if (MI->getOperand(OpNo).isImm())
276     O << (short)MI->getOperand(OpNo).getImm();
277   else
278     printOperand(MI, OpNo, O);
279 }
280 
printU16ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)281 void PPCInstPrinter::printU16ImmOperand(const MCInst *MI, unsigned OpNo,
282                                         raw_ostream &O) {
283   if (MI->getOperand(OpNo).isImm())
284     O << (unsigned short)MI->getOperand(OpNo).getImm();
285   else
286     printOperand(MI, OpNo, O);
287 }
288 
printBranchOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)289 void PPCInstPrinter::printBranchOperand(const MCInst *MI, unsigned OpNo,
290                                         raw_ostream &O) {
291   if (!MI->getOperand(OpNo).isImm())
292     return printOperand(MI, OpNo, O);
293 
294   // Branches can take an immediate operand.  This is used by the branch
295   // selection pass to print .+8, an eight byte displacement from the PC.
296   O << ".+";
297   printAbsBranchOperand(MI, OpNo, O);
298 }
299 
printAbsBranchOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)300 void PPCInstPrinter::printAbsBranchOperand(const MCInst *MI, unsigned OpNo,
301                                            raw_ostream &O) {
302   if (!MI->getOperand(OpNo).isImm())
303     return printOperand(MI, OpNo, O);
304 
305   O << SignExtend32<32>((unsigned)MI->getOperand(OpNo).getImm() << 2);
306 }
307 
308 
printcrbitm(const MCInst * MI,unsigned OpNo,raw_ostream & O)309 void PPCInstPrinter::printcrbitm(const MCInst *MI, unsigned OpNo,
310                                  raw_ostream &O) {
311   unsigned CCReg = MI->getOperand(OpNo).getReg();
312   unsigned RegNo;
313   switch (CCReg) {
314   default: llvm_unreachable("Unknown CR register");
315   case PPC::CR0: RegNo = 0; break;
316   case PPC::CR1: RegNo = 1; break;
317   case PPC::CR2: RegNo = 2; break;
318   case PPC::CR3: RegNo = 3; break;
319   case PPC::CR4: RegNo = 4; break;
320   case PPC::CR5: RegNo = 5; break;
321   case PPC::CR6: RegNo = 6; break;
322   case PPC::CR7: RegNo = 7; break;
323   }
324   O << (0x80 >> RegNo);
325 }
326 
printMemRegImm(const MCInst * MI,unsigned OpNo,raw_ostream & O)327 void PPCInstPrinter::printMemRegImm(const MCInst *MI, unsigned OpNo,
328                                     raw_ostream &O) {
329   printS16ImmOperand(MI, OpNo, O);
330   O << '(';
331   if (MI->getOperand(OpNo+1).getReg() == PPC::R0)
332     O << "0";
333   else
334     printOperand(MI, OpNo+1, O);
335   O << ')';
336 }
337 
printMemRegReg(const MCInst * MI,unsigned OpNo,raw_ostream & O)338 void PPCInstPrinter::printMemRegReg(const MCInst *MI, unsigned OpNo,
339                                     raw_ostream &O) {
340   // When used as the base register, r0 reads constant zero rather than
341   // the value contained in the register.  For this reason, the darwin
342   // assembler requires that we print r0 as 0 (no r) when used as the base.
343   if (MI->getOperand(OpNo).getReg() == PPC::R0)
344     O << "0";
345   else
346     printOperand(MI, OpNo, O);
347   O << ", ";
348   printOperand(MI, OpNo+1, O);
349 }
350 
printTLSCall(const MCInst * MI,unsigned OpNo,raw_ostream & O)351 void PPCInstPrinter::printTLSCall(const MCInst *MI, unsigned OpNo,
352                                   raw_ostream &O) {
353   // On PPC64, VariantKind is VK_None, but on PPC32, it's VK_PLT, and it must
354   // come at the _end_ of the expression.
355   const MCOperand &Op = MI->getOperand(OpNo);
356   const MCSymbolRefExpr &refExp = cast<MCSymbolRefExpr>(*Op.getExpr());
357   O << refExp.getSymbol().getName();
358   O << '(';
359   printOperand(MI, OpNo+1, O);
360   O << ')';
361   if (refExp.getKind() != MCSymbolRefExpr::VK_None)
362     O << '@' << MCSymbolRefExpr::getVariantKindName(refExp.getKind());
363 }
364 
365 
366 /// stripRegisterPrefix - This method strips the character prefix from a
367 /// register name so that only the number is left.  Used by for linux asm.
stripRegisterPrefix(const char * RegName)368 static const char *stripRegisterPrefix(const char *RegName) {
369   if (FullRegNames)
370     return RegName;
371 
372   switch (RegName[0]) {
373   case 'r':
374   case 'f':
375   case 'q': // for QPX
376   case 'v':
377     if (RegName[1] == 's')
378       return RegName + 2;
379     return RegName + 1;
380   case 'c': if (RegName[1] == 'r') return RegName + 2;
381   }
382 
383   return RegName;
384 }
385 
printOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)386 void PPCInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
387                                   raw_ostream &O) {
388   const MCOperand &Op = MI->getOperand(OpNo);
389   if (Op.isReg()) {
390     const char *RegName = getRegisterName(Op.getReg());
391     // The linux and AIX assembler does not take register prefixes.
392     if (!isDarwinSyntax())
393       RegName = stripRegisterPrefix(RegName);
394 
395     O << RegName;
396     return;
397   }
398 
399   if (Op.isImm()) {
400     O << Op.getImm();
401     return;
402   }
403 
404   assert(Op.isExpr() && "unknown operand kind in printOperand");
405   O << *Op.getExpr();
406 }
407 
408