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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/Support/CommandLine.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include "llvm/Target/TargetOpcodes.h"
23 using namespace llvm;
24 
25 #define DEBUG_TYPE "asm-printer"
26 
27 // FIXME: Once the integrated assembler supports full register names, tie this
28 // to the verbose-asm setting.
29 static cl::opt<bool>
30 FullRegNames("ppc-asm-full-reg-names", cl::Hidden, cl::init(false),
31              cl::desc("Use full register names when printing assembly"));
32 
33 #include "PPCGenAsmWriter.inc"
34 
printRegName(raw_ostream & OS,unsigned RegNo) const35 void PPCInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
36   OS << getRegisterName(RegNo);
37 }
38 
printInst(const MCInst * MI,raw_ostream & O,StringRef Annot)39 void PPCInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
40                                StringRef Annot) {
41   // Check for slwi/srwi mnemonics.
42   if (MI->getOpcode() == PPC::RLWINM) {
43     unsigned char SH = MI->getOperand(2).getImm();
44     unsigned char MB = MI->getOperand(3).getImm();
45     unsigned char ME = MI->getOperand(4).getImm();
46     bool useSubstituteMnemonic = false;
47     if (SH <= 31 && MB == 0 && ME == (31-SH)) {
48       O << "\tslwi "; useSubstituteMnemonic = true;
49     }
50     if (SH <= 31 && MB == (32-SH) && ME == 31) {
51       O << "\tsrwi "; useSubstituteMnemonic = true;
52       SH = 32-SH;
53     }
54     if (useSubstituteMnemonic) {
55       printOperand(MI, 0, O);
56       O << ", ";
57       printOperand(MI, 1, O);
58       O << ", " << (unsigned int)SH;
59 
60       printAnnotation(O, Annot);
61       return;
62     }
63   }
64 
65   if ((MI->getOpcode() == PPC::OR || MI->getOpcode() == PPC::OR8) &&
66       MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
67     O << "\tmr ";
68     printOperand(MI, 0, O);
69     O << ", ";
70     printOperand(MI, 1, O);
71     printAnnotation(O, Annot);
72     return;
73   }
74 
75   if (MI->getOpcode() == PPC::RLDICR) {
76     unsigned char SH = MI->getOperand(2).getImm();
77     unsigned char ME = MI->getOperand(3).getImm();
78     // rldicr RA, RS, SH, 63-SH == sldi RA, RS, SH
79     if (63-SH == ME) {
80       O << "\tsldi ";
81       printOperand(MI, 0, O);
82       O << ", ";
83       printOperand(MI, 1, O);
84       O << ", " << (unsigned int)SH;
85       printAnnotation(O, Annot);
86       return;
87     }
88   }
89 
90   // For fast-isel, a COPY_TO_REGCLASS may survive this long.  This is
91   // used when converting a 32-bit float to a 64-bit float as part of
92   // conversion to an integer (see PPCFastISel.cpp:SelectFPToI()),
93   // as otherwise we have problems with incorrect register classes
94   // in machine instruction verification.  For now, just avoid trying
95   // to print it as such an instruction has no effect (a 32-bit float
96   // in a register is already in 64-bit form, just with lower
97   // precision).  FIXME: Is there a better solution?
98   if (MI->getOpcode() == TargetOpcode::COPY_TO_REGCLASS)
99     return;
100 
101   printInstruction(MI, O);
102   printAnnotation(O, Annot);
103 }
104 
105 
printPredicateOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)106 void PPCInstPrinter::printPredicateOperand(const MCInst *MI, unsigned OpNo,
107                                            raw_ostream &O,
108                                            const char *Modifier) {
109   unsigned Code = MI->getOperand(OpNo).getImm();
110 
111   if (StringRef(Modifier) == "cc") {
112     switch ((PPC::Predicate)Code) {
113     case PPC::PRED_LT_MINUS:
114     case PPC::PRED_LT_PLUS:
115     case PPC::PRED_LT:
116       O << "lt";
117       return;
118     case PPC::PRED_LE_MINUS:
119     case PPC::PRED_LE_PLUS:
120     case PPC::PRED_LE:
121       O << "le";
122       return;
123     case PPC::PRED_EQ_MINUS:
124     case PPC::PRED_EQ_PLUS:
125     case PPC::PRED_EQ:
126       O << "eq";
127       return;
128     case PPC::PRED_GE_MINUS:
129     case PPC::PRED_GE_PLUS:
130     case PPC::PRED_GE:
131       O << "ge";
132       return;
133     case PPC::PRED_GT_MINUS:
134     case PPC::PRED_GT_PLUS:
135     case PPC::PRED_GT:
136       O << "gt";
137       return;
138     case PPC::PRED_NE_MINUS:
139     case PPC::PRED_NE_PLUS:
140     case PPC::PRED_NE:
141       O << "ne";
142       return;
143     case PPC::PRED_UN_MINUS:
144     case PPC::PRED_UN_PLUS:
145     case PPC::PRED_UN:
146       O << "un";
147       return;
148     case PPC::PRED_NU_MINUS:
149     case PPC::PRED_NU_PLUS:
150     case PPC::PRED_NU:
151       O << "nu";
152       return;
153     case PPC::PRED_BIT_SET:
154     case PPC::PRED_BIT_UNSET:
155       llvm_unreachable("Invalid use of bit predicate code");
156     }
157     llvm_unreachable("Invalid predicate code");
158   }
159 
160   if (StringRef(Modifier) == "pm") {
161     switch ((PPC::Predicate)Code) {
162     case PPC::PRED_LT:
163     case PPC::PRED_LE:
164     case PPC::PRED_EQ:
165     case PPC::PRED_GE:
166     case PPC::PRED_GT:
167     case PPC::PRED_NE:
168     case PPC::PRED_UN:
169     case PPC::PRED_NU:
170       return;
171     case PPC::PRED_LT_MINUS:
172     case PPC::PRED_LE_MINUS:
173     case PPC::PRED_EQ_MINUS:
174     case PPC::PRED_GE_MINUS:
175     case PPC::PRED_GT_MINUS:
176     case PPC::PRED_NE_MINUS:
177     case PPC::PRED_UN_MINUS:
178     case PPC::PRED_NU_MINUS:
179       O << "-";
180       return;
181     case PPC::PRED_LT_PLUS:
182     case PPC::PRED_LE_PLUS:
183     case PPC::PRED_EQ_PLUS:
184     case PPC::PRED_GE_PLUS:
185     case PPC::PRED_GT_PLUS:
186     case PPC::PRED_NE_PLUS:
187     case PPC::PRED_UN_PLUS:
188     case PPC::PRED_NU_PLUS:
189       O << "+";
190       return;
191     case PPC::PRED_BIT_SET:
192     case PPC::PRED_BIT_UNSET:
193       llvm_unreachable("Invalid use of bit predicate code");
194     }
195     llvm_unreachable("Invalid predicate code");
196   }
197 
198   assert(StringRef(Modifier) == "reg" &&
199          "Need to specify 'cc', 'pm' or 'reg' as predicate op modifier!");
200   printOperand(MI, OpNo+1, O);
201 }
202 
printU2ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)203 void PPCInstPrinter::printU2ImmOperand(const MCInst *MI, unsigned OpNo,
204                                        raw_ostream &O) {
205   unsigned int Value = MI->getOperand(OpNo).getImm();
206   assert(Value <= 3 && "Invalid u2imm argument!");
207   O << (unsigned int)Value;
208 }
209 
printS5ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)210 void PPCInstPrinter::printS5ImmOperand(const MCInst *MI, unsigned OpNo,
211                                        raw_ostream &O) {
212   int Value = MI->getOperand(OpNo).getImm();
213   Value = SignExtend32<5>(Value);
214   O << (int)Value;
215 }
216 
printU5ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)217 void PPCInstPrinter::printU5ImmOperand(const MCInst *MI, unsigned OpNo,
218                                        raw_ostream &O) {
219   unsigned int Value = MI->getOperand(OpNo).getImm();
220   assert(Value <= 31 && "Invalid u5imm argument!");
221   O << (unsigned int)Value;
222 }
223 
printU6ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)224 void PPCInstPrinter::printU6ImmOperand(const MCInst *MI, unsigned OpNo,
225                                        raw_ostream &O) {
226   unsigned int Value = MI->getOperand(OpNo).getImm();
227   assert(Value <= 63 && "Invalid u6imm argument!");
228   O << (unsigned int)Value;
229 }
230 
printS16ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)231 void PPCInstPrinter::printS16ImmOperand(const MCInst *MI, unsigned OpNo,
232                                         raw_ostream &O) {
233   if (MI->getOperand(OpNo).isImm())
234     O << (short)MI->getOperand(OpNo).getImm();
235   else
236     printOperand(MI, OpNo, O);
237 }
238 
printU16ImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)239 void PPCInstPrinter::printU16ImmOperand(const MCInst *MI, unsigned OpNo,
240                                         raw_ostream &O) {
241   if (MI->getOperand(OpNo).isImm())
242     O << (unsigned short)MI->getOperand(OpNo).getImm();
243   else
244     printOperand(MI, OpNo, O);
245 }
246 
printBranchOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)247 void PPCInstPrinter::printBranchOperand(const MCInst *MI, unsigned OpNo,
248                                         raw_ostream &O) {
249   if (!MI->getOperand(OpNo).isImm())
250     return printOperand(MI, OpNo, O);
251 
252   // Branches can take an immediate operand.  This is used by the branch
253   // selection pass to print .+8, an eight byte displacement from the PC.
254   O << ".+";
255   printAbsBranchOperand(MI, OpNo, O);
256 }
257 
printAbsBranchOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)258 void PPCInstPrinter::printAbsBranchOperand(const MCInst *MI, unsigned OpNo,
259                                            raw_ostream &O) {
260   if (!MI->getOperand(OpNo).isImm())
261     return printOperand(MI, OpNo, O);
262 
263   O << (int)MI->getOperand(OpNo).getImm()*4;
264 }
265 
266 
printcrbitm(const MCInst * MI,unsigned OpNo,raw_ostream & O)267 void PPCInstPrinter::printcrbitm(const MCInst *MI, unsigned OpNo,
268                                  raw_ostream &O) {
269   unsigned CCReg = MI->getOperand(OpNo).getReg();
270   unsigned RegNo;
271   switch (CCReg) {
272   default: llvm_unreachable("Unknown CR register");
273   case PPC::CR0: RegNo = 0; break;
274   case PPC::CR1: RegNo = 1; break;
275   case PPC::CR2: RegNo = 2; break;
276   case PPC::CR3: RegNo = 3; break;
277   case PPC::CR4: RegNo = 4; break;
278   case PPC::CR5: RegNo = 5; break;
279   case PPC::CR6: RegNo = 6; break;
280   case PPC::CR7: RegNo = 7; break;
281   }
282   O << (0x80 >> RegNo);
283 }
284 
printMemRegImm(const MCInst * MI,unsigned OpNo,raw_ostream & O)285 void PPCInstPrinter::printMemRegImm(const MCInst *MI, unsigned OpNo,
286                                     raw_ostream &O) {
287   printS16ImmOperand(MI, OpNo, O);
288   O << '(';
289   if (MI->getOperand(OpNo+1).getReg() == PPC::R0)
290     O << "0";
291   else
292     printOperand(MI, OpNo+1, O);
293   O << ')';
294 }
295 
printMemRegReg(const MCInst * MI,unsigned OpNo,raw_ostream & O)296 void PPCInstPrinter::printMemRegReg(const MCInst *MI, unsigned OpNo,
297                                     raw_ostream &O) {
298   // When used as the base register, r0 reads constant zero rather than
299   // the value contained in the register.  For this reason, the darwin
300   // assembler requires that we print r0 as 0 (no r) when used as the base.
301   if (MI->getOperand(OpNo).getReg() == PPC::R0)
302     O << "0";
303   else
304     printOperand(MI, OpNo, O);
305   O << ", ";
306   printOperand(MI, OpNo+1, O);
307 }
308 
printTLSCall(const MCInst * MI,unsigned OpNo,raw_ostream & O)309 void PPCInstPrinter::printTLSCall(const MCInst *MI, unsigned OpNo,
310                                   raw_ostream &O) {
311   printBranchOperand(MI, OpNo, O);
312   O << '(';
313   printOperand(MI, OpNo+1, O);
314   O << ')';
315 }
316 
317 
318 /// stripRegisterPrefix - This method strips the character prefix from a
319 /// register name so that only the number is left.  Used by for linux asm.
stripRegisterPrefix(const char * RegName)320 static const char *stripRegisterPrefix(const char *RegName) {
321   if (FullRegNames)
322     return RegName;
323 
324   switch (RegName[0]) {
325   case 'r':
326   case 'f':
327   case 'v':
328     if (RegName[1] == 's')
329       return RegName + 2;
330     return RegName + 1;
331   case 'c': if (RegName[1] == 'r') return RegName + 2;
332   }
333 
334   return RegName;
335 }
336 
printOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)337 void PPCInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
338                                   raw_ostream &O) {
339   const MCOperand &Op = MI->getOperand(OpNo);
340   if (Op.isReg()) {
341     const char *RegName = getRegisterName(Op.getReg());
342     // The linux and AIX assembler does not take register prefixes.
343     if (!isDarwinSyntax())
344       RegName = stripRegisterPrefix(RegName);
345 
346     O << RegName;
347     return;
348   }
349 
350   if (Op.isImm()) {
351     O << Op.getImm();
352     return;
353   }
354 
355   assert(Op.isExpr() && "unknown operand kind in printOperand");
356   O << *Op.getExpr();
357 }
358 
359