1 //===- CodeGenInstruction.cpp - CodeGen Instruction Class Wrapper ---------===//
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 CodeGenInstruction class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenInstruction.h"
15 #include "CodeGenTarget.h"
16 #include "Record.h"
17 #include "llvm/ADT/StringExtras.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include <set>
20 using namespace llvm;
21 
22 static void ParseConstraint(const std::string &CStr, CodeGenInstruction *I) {
23   // EARLY_CLOBBER: @early $reg
24   std::string::size_type wpos = CStr.find_first_of(" \t");
25   std::string::size_type start = CStr.find_first_not_of(" \t");
26   std::string Tok = CStr.substr(start, wpos - start);
27   if (Tok == "@earlyclobber") {
28     std::string Name = CStr.substr(wpos+1);
29     wpos = Name.find_first_not_of(" \t");
30     if (wpos == std::string::npos)
31       throw "Illegal format for @earlyclobber constraint: '" + CStr + "'";
32     Name = Name.substr(wpos);
33     std::pair<unsigned,unsigned> Op =
34       I->ParseOperandName(Name, false);
35 
36     // Build the string for the operand
37     if (!I->OperandList[Op.first].Constraints[Op.second].isNone())
38       throw "Operand '" + Name + "' cannot have multiple constraints!";
39     I->OperandList[Op.first].Constraints[Op.second] =
40       CodeGenInstruction::ConstraintInfo::getEarlyClobber();
41     return;
42   }
43 
44   // Only other constraint is "TIED_TO" for now.
45   std::string::size_type pos = CStr.find_first_of('=');
46   assert(pos != std::string::npos && "Unrecognized constraint");
47   start = CStr.find_first_not_of(" \t");
48   std::string Name = CStr.substr(start, pos - start);
49 
50   // TIED_TO: $src1 = $dst
51   wpos = Name.find_first_of(" \t");
52   if (wpos == std::string::npos)
53     throw "Illegal format for tied-to constraint: '" + CStr + "'";
54   std::string DestOpName = Name.substr(0, wpos);
55   std::pair<unsigned,unsigned> DestOp = I->ParseOperandName(DestOpName, false);
56 
57   Name = CStr.substr(pos+1);
58   wpos = Name.find_first_not_of(" \t");
59   if (wpos == std::string::npos)
60     throw "Illegal format for tied-to constraint: '" + CStr + "'";
61 
62   std::pair<unsigned,unsigned> SrcOp =
63   I->ParseOperandName(Name.substr(wpos), false);
64   if (SrcOp > DestOp)
65     throw "Illegal tied-to operand constraint '" + CStr + "'";
66 
67 
68   unsigned FlatOpNo = I->getFlattenedOperandNumber(SrcOp);
69 
70   if (!I->OperandList[DestOp.first].Constraints[DestOp.second].isNone())
71     throw "Operand '" + DestOpName + "' cannot have multiple constraints!";
72   I->OperandList[DestOp.first].Constraints[DestOp.second] =
73     CodeGenInstruction::ConstraintInfo::getTied(FlatOpNo);
74 }
75 
76 static void ParseConstraints(const std::string &CStr, CodeGenInstruction *I) {
77   // Make sure the constraints list for each operand is large enough to hold
78   // constraint info, even if none is present.
79   for (unsigned i = 0, e = I->OperandList.size(); i != e; ++i)
80     I->OperandList[i].Constraints.resize(I->OperandList[i].MINumOperands);
81 
82   if (CStr.empty()) return;
83 
84   const std::string delims(",");
85   std::string::size_type bidx, eidx;
86 
87   bidx = CStr.find_first_not_of(delims);
88   while (bidx != std::string::npos) {
89     eidx = CStr.find_first_of(delims, bidx);
90     if (eidx == std::string::npos)
91       eidx = CStr.length();
92 
93     ParseConstraint(CStr.substr(bidx, eidx - bidx), I);
94     bidx = CStr.find_first_not_of(delims, eidx);
95   }
96 }
97 
98 CodeGenInstruction::CodeGenInstruction(Record *R, const std::string &AsmStr)
99   : TheDef(R), AsmString(AsmStr) {
100   Namespace = R->getValueAsString("Namespace");
101 
102   isReturn     = R->getValueAsBit("isReturn");
103   isBranch     = R->getValueAsBit("isBranch");
104   isIndirectBranch = R->getValueAsBit("isIndirectBranch");
105   isCompare    = R->getValueAsBit("isCompare");
106   isBarrier    = R->getValueAsBit("isBarrier");
107   isCall       = R->getValueAsBit("isCall");
108   canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
109   mayLoad      = R->getValueAsBit("mayLoad");
110   mayStore     = R->getValueAsBit("mayStore");
111   isPredicable = R->getValueAsBit("isPredicable");
112   isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");
113   isCommutable = R->getValueAsBit("isCommutable");
114   isTerminator = R->getValueAsBit("isTerminator");
115   isReMaterializable = R->getValueAsBit("isReMaterializable");
116   hasDelaySlot = R->getValueAsBit("hasDelaySlot");
117   usesCustomInserter = R->getValueAsBit("usesCustomInserter");
118   hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
119   isNotDuplicable = R->getValueAsBit("isNotDuplicable");
120   hasSideEffects = R->getValueAsBit("hasSideEffects");
121   neverHasSideEffects = R->getValueAsBit("neverHasSideEffects");
122   isAsCheapAsAMove = R->getValueAsBit("isAsCheapAsAMove");
123   hasExtraSrcRegAllocReq = R->getValueAsBit("hasExtraSrcRegAllocReq");
124   hasExtraDefRegAllocReq = R->getValueAsBit("hasExtraDefRegAllocReq");
125   hasOptionalDef = false;
126   isVariadic = false;
127   ImplicitDefs = R->getValueAsListOfDefs("Defs");
128   ImplicitUses = R->getValueAsListOfDefs("Uses");
129 
130   if (neverHasSideEffects + hasSideEffects > 1)
131     throw R->getName() + ": multiple conflicting side-effect flags set!";
132 
133   DagInit *OutDI = R->getValueAsDag("OutOperandList");
134 
135   if (DefInit *Init = dynamic_cast<DefInit*>(OutDI->getOperator())) {
136     if (Init->getDef()->getName() != "outs")
137       throw R->getName() + ": invalid def name for output list: use 'outs'";
138   } else
139     throw R->getName() + ": invalid output list: use 'outs'";
140 
141   NumDefs = OutDI->getNumArgs();
142 
143   DagInit *InDI = R->getValueAsDag("InOperandList");
144   if (DefInit *Init = dynamic_cast<DefInit*>(InDI->getOperator())) {
145     if (Init->getDef()->getName() != "ins")
146       throw R->getName() + ": invalid def name for input list: use 'ins'";
147   } else
148     throw R->getName() + ": invalid input list: use 'ins'";
149 
150   unsigned MIOperandNo = 0;
151   std::set<std::string> OperandNames;
152   for (unsigned i = 0, e = InDI->getNumArgs()+OutDI->getNumArgs(); i != e; ++i){
153     Init *ArgInit;
154     std::string ArgName;
155     if (i < NumDefs) {
156       ArgInit = OutDI->getArg(i);
157       ArgName = OutDI->getArgName(i);
158     } else {
159       ArgInit = InDI->getArg(i-NumDefs);
160       ArgName = InDI->getArgName(i-NumDefs);
161     }
162 
163     DefInit *Arg = dynamic_cast<DefInit*>(ArgInit);
164     if (!Arg)
165       throw "Illegal operand for the '" + R->getName() + "' instruction!";
166 
167     Record *Rec = Arg->getDef();
168     std::string PrintMethod = "printOperand";
169     std::string EncoderMethod;
170     unsigned NumOps = 1;
171     DagInit *MIOpInfo = 0;
172     if (Rec->isSubClassOf("Operand")) {
173       PrintMethod = Rec->getValueAsString("PrintMethod");
174       // If there is an explicit encoder method, use it.
175       if (Rec->getValue("EncoderMethod"))
176         EncoderMethod = Rec->getValueAsString("EncoderMethod");
177       MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
178 
179       // Verify that MIOpInfo has an 'ops' root value.
180       if (!dynamic_cast<DefInit*>(MIOpInfo->getOperator()) ||
181           dynamic_cast<DefInit*>(MIOpInfo->getOperator())
182                ->getDef()->getName() != "ops")
183         throw "Bad value for MIOperandInfo in operand '" + Rec->getName() +
184               "'\n";
185 
186       // If we have MIOpInfo, then we have #operands equal to number of entries
187       // in MIOperandInfo.
188       if (unsigned NumArgs = MIOpInfo->getNumArgs())
189         NumOps = NumArgs;
190 
191       if (Rec->isSubClassOf("PredicateOperand"))
192         isPredicable = true;
193       else if (Rec->isSubClassOf("OptionalDefOperand"))
194         hasOptionalDef = true;
195     } else if (Rec->getName() == "variable_ops") {
196       isVariadic = true;
197       continue;
198     } else if (!Rec->isSubClassOf("RegisterClass") &&
199                Rec->getName() != "ptr_rc" && Rec->getName() != "unknown")
200       throw "Unknown operand class '" + Rec->getName() +
201             "' in '" + R->getName() + "' instruction!";
202 
203     // Check that the operand has a name and that it's unique.
204     if (ArgName.empty())
205       throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
206         " has no name!";
207     if (!OperandNames.insert(ArgName).second)
208       throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
209         " has the same name as a previous operand!";
210 
211     OperandList.push_back(OperandInfo(Rec, ArgName, PrintMethod, EncoderMethod,
212                                       MIOperandNo, NumOps, MIOpInfo));
213     MIOperandNo += NumOps;
214   }
215 
216   // Parse Constraints.
217   ParseConstraints(R->getValueAsString("Constraints"), this);
218 
219   // Parse the DisableEncoding field.
220   std::string DisableEncoding = R->getValueAsString("DisableEncoding");
221   while (1) {
222     std::string OpName;
223     tie(OpName, DisableEncoding) = getToken(DisableEncoding, " ,\t");
224     if (OpName.empty()) break;
225 
226     // Figure out which operand this is.
227     std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
228 
229     // Mark the operand as not-to-be encoded.
230     if (Op.second >= OperandList[Op.first].DoNotEncode.size())
231       OperandList[Op.first].DoNotEncode.resize(Op.second+1);
232     OperandList[Op.first].DoNotEncode[Op.second] = true;
233   }
234 }
235 
236 /// getOperandNamed - Return the index of the operand with the specified
237 /// non-empty name.  If the instruction does not have an operand with the
238 /// specified name, throw an exception.
239 ///
240 unsigned CodeGenInstruction::getOperandNamed(const std::string &Name) const {
241   unsigned OpIdx;
242   if (hasOperandNamed(Name, OpIdx)) return OpIdx;
243   throw "Instruction '" + TheDef->getName() +
244         "' does not have an operand named '$" + Name + "'!";
245 }
246 
247 /// hasOperandNamed - Query whether the instruction has an operand of the
248 /// given name. If so, return true and set OpIdx to the index of the
249 /// operand. Otherwise, return false.
250 bool CodeGenInstruction::hasOperandNamed(const std::string &Name,
251                                          unsigned &OpIdx) const {
252   assert(!Name.empty() && "Cannot search for operand with no name!");
253   for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
254     if (OperandList[i].Name == Name) {
255       OpIdx = i;
256       return true;
257     }
258   return false;
259 }
260 
261 std::pair<unsigned,unsigned>
262 CodeGenInstruction::ParseOperandName(const std::string &Op,
263                                      bool AllowWholeOp) {
264   if (Op.empty() || Op[0] != '$')
265     throw TheDef->getName() + ": Illegal operand name: '" + Op + "'";
266 
267   std::string OpName = Op.substr(1);
268   std::string SubOpName;
269 
270   // Check to see if this is $foo.bar.
271   std::string::size_type DotIdx = OpName.find_first_of(".");
272   if (DotIdx != std::string::npos) {
273     SubOpName = OpName.substr(DotIdx+1);
274     if (SubOpName.empty())
275       throw TheDef->getName() + ": illegal empty suboperand name in '" +Op +"'";
276     OpName = OpName.substr(0, DotIdx);
277   }
278 
279   unsigned OpIdx = getOperandNamed(OpName);
280 
281   if (SubOpName.empty()) {  // If no suboperand name was specified:
282     // If one was needed, throw.
283     if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
284         SubOpName.empty())
285       throw TheDef->getName() + ": Illegal to refer to"
286             " whole operand part of complex operand '" + Op + "'";
287 
288     // Otherwise, return the operand.
289     return std::make_pair(OpIdx, 0U);
290   }
291 
292   // Find the suboperand number involved.
293   DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
294   if (MIOpInfo == 0)
295     throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
296 
297   // Find the operand with the right name.
298   for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
299     if (MIOpInfo->getArgName(i) == SubOpName)
300       return std::make_pair(OpIdx, i);
301 
302   // Otherwise, didn't find it!
303   throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
304 }
305 
306 
307 /// HasOneImplicitDefWithKnownVT - If the instruction has at least one
308 /// implicit def and it has a known VT, return the VT, otherwise return
309 /// MVT::Other.
310 MVT::SimpleValueType CodeGenInstruction::
311 HasOneImplicitDefWithKnownVT(const CodeGenTarget &TargetInfo) const {
312   if (ImplicitDefs.empty()) return MVT::Other;
313 
314   // Check to see if the first implicit def has a resolvable type.
315   Record *FirstImplicitDef = ImplicitDefs[0];
316   assert(FirstImplicitDef->isSubClassOf("Register"));
317   const std::vector<MVT::SimpleValueType> &RegVTs =
318     TargetInfo.getRegisterVTs(FirstImplicitDef);
319   if (RegVTs.size() == 1)
320     return RegVTs[0];
321   return MVT::Other;
322 }
323 
324