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 "Record.h"
16 #include "llvm/ADT/StringExtras.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include <set>
19 using namespace llvm;
20 
21 static void ParseConstraint(const std::string &CStr, CodeGenInstruction *I) {
22   // EARLY_CLOBBER: @early $reg
23   std::string::size_type wpos = CStr.find_first_of(" \t");
24   std::string::size_type start = CStr.find_first_not_of(" \t");
25   std::string Tok = CStr.substr(start, wpos - start);
26   if (Tok == "@earlyclobber") {
27     std::string Name = CStr.substr(wpos+1);
28     wpos = Name.find_first_not_of(" \t");
29     if (wpos == std::string::npos)
30       throw "Illegal format for @earlyclobber constraint: '" + CStr + "'";
31     Name = Name.substr(wpos);
32     std::pair<unsigned,unsigned> Op =
33       I->ParseOperandName(Name, false);
34 
35     // Build the string for the operand
36     if (!I->OperandList[Op.first].Constraints[Op.second].isNone())
37       throw "Operand '" + Name + "' cannot have multiple constraints!";
38     I->OperandList[Op.first].Constraints[Op.second] =
39       CodeGenInstruction::ConstraintInfo::getEarlyClobber();
40     return;
41   }
42 
43   // Only other constraint is "TIED_TO" for now.
44   std::string::size_type pos = CStr.find_first_of('=');
45   assert(pos != std::string::npos && "Unrecognized constraint");
46   start = CStr.find_first_not_of(" \t");
47   std::string Name = CStr.substr(start, pos - start);
48 
49   // TIED_TO: $src1 = $dst
50   wpos = Name.find_first_of(" \t");
51   if (wpos == std::string::npos)
52     throw "Illegal format for tied-to constraint: '" + CStr + "'";
53   std::string DestOpName = Name.substr(0, wpos);
54   std::pair<unsigned,unsigned> DestOp = I->ParseOperandName(DestOpName, false);
55 
56   Name = CStr.substr(pos+1);
57   wpos = Name.find_first_not_of(" \t");
58   if (wpos == std::string::npos)
59     throw "Illegal format for tied-to constraint: '" + CStr + "'";
60 
61   std::pair<unsigned,unsigned> SrcOp =
62   I->ParseOperandName(Name.substr(wpos), false);
63   if (SrcOp > DestOp)
64     throw "Illegal tied-to operand constraint '" + CStr + "'";
65 
66 
67   unsigned FlatOpNo = I->getFlattenedOperandNumber(SrcOp);
68 
69   if (!I->OperandList[DestOp.first].Constraints[DestOp.second].isNone())
70     throw "Operand '" + DestOpName + "' cannot have multiple constraints!";
71   I->OperandList[DestOp.first].Constraints[DestOp.second] =
72     CodeGenInstruction::ConstraintInfo::getTied(FlatOpNo);
73 }
74 
75 static void ParseConstraints(const std::string &CStr, CodeGenInstruction *I) {
76   // Make sure the constraints list for each operand is large enough to hold
77   // constraint info, even if none is present.
78   for (unsigned i = 0, e = I->OperandList.size(); i != e; ++i)
79     I->OperandList[i].Constraints.resize(I->OperandList[i].MINumOperands);
80 
81   if (CStr.empty()) return;
82 
83   const std::string delims(",");
84   std::string::size_type bidx, eidx;
85 
86   bidx = CStr.find_first_not_of(delims);
87   while (bidx != std::string::npos) {
88     eidx = CStr.find_first_of(delims, bidx);
89     if (eidx == std::string::npos)
90       eidx = CStr.length();
91 
92     ParseConstraint(CStr.substr(bidx, eidx - bidx), I);
93     bidx = CStr.find_first_not_of(delims, eidx);
94   }
95 }
96 
97 CodeGenInstruction::CodeGenInstruction(Record *R, const std::string &AsmStr)
98   : TheDef(R), AsmString(AsmStr) {
99   Namespace = R->getValueAsString("Namespace");
100 
101   isReturn     = R->getValueAsBit("isReturn");
102   isBranch     = R->getValueAsBit("isBranch");
103   isIndirectBranch = R->getValueAsBit("isIndirectBranch");
104   isBarrier    = R->getValueAsBit("isBarrier");
105   isCall       = R->getValueAsBit("isCall");
106   canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
107   mayLoad      = R->getValueAsBit("mayLoad");
108   mayStore     = R->getValueAsBit("mayStore");
109   bool isTwoAddress = R->getValueAsBit("isTwoAddress");
110   isPredicable = R->getValueAsBit("isPredicable");
111   isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");
112   isCommutable = R->getValueAsBit("isCommutable");
113   isTerminator = R->getValueAsBit("isTerminator");
114   isReMaterializable = R->getValueAsBit("isReMaterializable");
115   hasDelaySlot = R->getValueAsBit("hasDelaySlot");
116   usesCustomInserter = R->getValueAsBit("usesCustomInserter");
117   hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
118   isNotDuplicable = R->getValueAsBit("isNotDuplicable");
119   hasSideEffects = R->getValueAsBit("hasSideEffects");
120   mayHaveSideEffects = R->getValueAsBit("mayHaveSideEffects");
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 
128   if (mayHaveSideEffects + neverHasSideEffects + hasSideEffects > 1)
129     throw R->getName() + ": multiple conflicting side-effect flags set!";
130 
131   DagInit *DI;
132   try {
133     DI = R->getValueAsDag("OutOperandList");
134   } catch (...) {
135     // Error getting operand list, just ignore it (sparcv9).
136     AsmString.clear();
137     OperandList.clear();
138     return;
139   }
140   NumDefs = DI->getNumArgs();
141 
142   DagInit *IDI;
143   try {
144     IDI = R->getValueAsDag("InOperandList");
145   } catch (...) {
146     // Error getting operand list, just ignore it (sparcv9).
147     AsmString.clear();
148     OperandList.clear();
149     return;
150   }
151   DI = (DagInit*)(new BinOpInit(BinOpInit::CONCAT, DI, IDI, new DagRecTy))->Fold(R, 0);
152 
153   unsigned MIOperandNo = 0;
154   std::set<std::string> OperandNames;
155   for (unsigned i = 0, e = DI->getNumArgs(); i != e; ++i) {
156     DefInit *Arg = dynamic_cast<DefInit*>(DI->getArg(i));
157     if (!Arg)
158       throw "Illegal operand for the '" + R->getName() + "' instruction!";
159 
160     Record *Rec = Arg->getDef();
161     std::string PrintMethod = "printOperand";
162     unsigned NumOps = 1;
163     DagInit *MIOpInfo = 0;
164     if (Rec->isSubClassOf("Operand")) {
165       PrintMethod = Rec->getValueAsString("PrintMethod");
166       MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
167 
168       // Verify that MIOpInfo has an 'ops' root value.
169       if (!dynamic_cast<DefInit*>(MIOpInfo->getOperator()) ||
170           dynamic_cast<DefInit*>(MIOpInfo->getOperator())
171                ->getDef()->getName() != "ops")
172         throw "Bad value for MIOperandInfo in operand '" + Rec->getName() +
173               "'\n";
174 
175       // If we have MIOpInfo, then we have #operands equal to number of entries
176       // in MIOperandInfo.
177       if (unsigned NumArgs = MIOpInfo->getNumArgs())
178         NumOps = NumArgs;
179 
180       if (Rec->isSubClassOf("PredicateOperand"))
181         isPredicable = true;
182       else if (Rec->isSubClassOf("OptionalDefOperand"))
183         hasOptionalDef = true;
184     } else if (Rec->getName() == "variable_ops") {
185       isVariadic = true;
186       continue;
187     } else if (!Rec->isSubClassOf("RegisterClass") &&
188                Rec->getName() != "ptr_rc" && Rec->getName() != "unknown")
189       throw "Unknown operand class '" + Rec->getName() +
190             "' in '" + R->getName() + "' instruction!";
191 
192     // Check that the operand has a name and that it's unique.
193     if (DI->getArgName(i).empty())
194       throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
195         " has no name!";
196     if (!OperandNames.insert(DI->getArgName(i)).second)
197       throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
198         " has the same name as a previous operand!";
199 
200     OperandList.push_back(OperandInfo(Rec, DI->getArgName(i), PrintMethod,
201                                       MIOperandNo, NumOps, MIOpInfo));
202     MIOperandNo += NumOps;
203   }
204 
205   // Parse Constraints.
206   ParseConstraints(R->getValueAsString("Constraints"), this);
207 
208   // For backward compatibility: isTwoAddress means operand 1 is tied to
209   // operand 0.
210   if (isTwoAddress) {
211     if (!OperandList[1].Constraints[0].isNone())
212       throw R->getName() + ": cannot use isTwoAddress property: instruction "
213             "already has constraint set!";
214     OperandList[1].Constraints[0] =
215       CodeGenInstruction::ConstraintInfo::getTied(0);
216   }
217 
218   // Parse the DisableEncoding field.
219   std::string DisableEncoding = R->getValueAsString("DisableEncoding");
220   while (1) {
221     std::string OpName;
222     tie(OpName, DisableEncoding) = getToken(DisableEncoding, " ,\t");
223     if (OpName.empty()) break;
224 
225     // Figure out which operand this is.
226     std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
227 
228     // Mark the operand as not-to-be encoded.
229     if (Op.second >= OperandList[Op.first].DoNotEncode.size())
230       OperandList[Op.first].DoNotEncode.resize(Op.second+1);
231     OperandList[Op.first].DoNotEncode[Op.second] = true;
232   }
233 }
234 
235 /// getOperandNamed - Return the index of the operand with the specified
236 /// non-empty name.  If the instruction does not have an operand with the
237 /// specified name, throw an exception.
238 ///
239 unsigned CodeGenInstruction::getOperandNamed(const std::string &Name) const {
240   assert(!Name.empty() && "Cannot search for operand with no name!");
241   for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
242     if (OperandList[i].Name == Name) return i;
243   throw "Instruction '" + TheDef->getName() +
244         "' does not have an operand named '$" + Name + "'!";
245 }
246 
247 std::pair<unsigned,unsigned>
248 CodeGenInstruction::ParseOperandName(const std::string &Op,
249                                      bool AllowWholeOp) {
250   if (Op.empty() || Op[0] != '$')
251     throw TheDef->getName() + ": Illegal operand name: '" + Op + "'";
252 
253   std::string OpName = Op.substr(1);
254   std::string SubOpName;
255 
256   // Check to see if this is $foo.bar.
257   std::string::size_type DotIdx = OpName.find_first_of(".");
258   if (DotIdx != std::string::npos) {
259     SubOpName = OpName.substr(DotIdx+1);
260     if (SubOpName.empty())
261       throw TheDef->getName() + ": illegal empty suboperand name in '" +Op +"'";
262     OpName = OpName.substr(0, DotIdx);
263   }
264 
265   unsigned OpIdx = getOperandNamed(OpName);
266 
267   if (SubOpName.empty()) {  // If no suboperand name was specified:
268     // If one was needed, throw.
269     if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
270         SubOpName.empty())
271       throw TheDef->getName() + ": Illegal to refer to"
272             " whole operand part of complex operand '" + Op + "'";
273 
274     // Otherwise, return the operand.
275     return std::make_pair(OpIdx, 0U);
276   }
277 
278   // Find the suboperand number involved.
279   DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
280   if (MIOpInfo == 0)
281     throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
282 
283   // Find the operand with the right name.
284   for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
285     if (MIOpInfo->getArgName(i) == SubOpName)
286       return std::make_pair(OpIdx, i);
287 
288   // Otherwise, didn't find it!
289   throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
290 }
291