CodeGenInstruction.cpp revision f55eed299b84a9312c3c112d59ff4e6cb048b795 
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>
19using namespace llvm;
20
21static 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
75static 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
97CodeGenInstruction::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  neverHasSideEffects = R->getValueAsBit("neverHasSideEffects");
121  isAsCheapAsAMove = R->getValueAsBit("isAsCheapAsAMove");
122  hasExtraSrcRegAllocReq = R->getValueAsBit("hasExtraSrcRegAllocReq");
123  hasExtraDefRegAllocReq = R->getValueAsBit("hasExtraDefRegAllocReq");
124  hasOptionalDef = false;
125  isVariadic = false;
126
127  if (neverHasSideEffects + hasSideEffects > 1)
128    throw R->getName() + ": multiple conflicting side-effect flags set!";
129
130  DagInit *OutDI = R->getValueAsDag("OutOperandList");
131
132  if (DefInit *Init = dynamic_cast<DefInit*>(OutDI->getOperator())) {
133    if (Init->getDef()->getName() != "outs")
134      throw R->getName() + ": invalid def name for output list: use 'outs'";
135  } else
136    throw R->getName() + ": invalid output list: use 'outs'";
137
138  NumDefs = OutDI->getNumArgs();
139
140  DagInit *InDI = R->getValueAsDag("InOperandList");
141  if (DefInit *Init = dynamic_cast<DefInit*>(InDI->getOperator())) {
142    if (Init->getDef()->getName() != "ins")
143      throw R->getName() + ": invalid def name for input list: use 'ins'";
144  } else
145    throw R->getName() + ": invalid input list: use 'ins'";
146
147  unsigned MIOperandNo = 0;
148  std::set<std::string> OperandNames;
149  for (unsigned i = 0, e = InDI->getNumArgs()+OutDI->getNumArgs(); i != e; ++i){
150    Init *ArgInit;
151    std::string ArgName;
152    if (i < NumDefs) {
153      ArgInit = OutDI->getArg(i);
154      ArgName = OutDI->getArgName(i);
155    } else {
156      ArgInit = InDI->getArg(i-NumDefs);
157      ArgName = InDI->getArgName(i-NumDefs);
158    }
159
160    DefInit *Arg = dynamic_cast<DefInit*>(ArgInit);
161    if (!Arg)
162      throw "Illegal operand for the '" + R->getName() + "' instruction!";
163
164    Record *Rec = Arg->getDef();
165    std::string PrintMethod = "printOperand";
166    unsigned NumOps = 1;
167    DagInit *MIOpInfo = 0;
168    if (Rec->isSubClassOf("Operand")) {
169      PrintMethod = Rec->getValueAsString("PrintMethod");
170      MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
171
172      // Verify that MIOpInfo has an 'ops' root value.
173      if (!dynamic_cast<DefInit*>(MIOpInfo->getOperator()) ||
174          dynamic_cast<DefInit*>(MIOpInfo->getOperator())
175               ->getDef()->getName() != "ops")
176        throw "Bad value for MIOperandInfo in operand '" + Rec->getName() +
177              "'\n";
178
179      // If we have MIOpInfo, then we have #operands equal to number of entries
180      // in MIOperandInfo.
181      if (unsigned NumArgs = MIOpInfo->getNumArgs())
182        NumOps = NumArgs;
183
184      if (Rec->isSubClassOf("PredicateOperand"))
185        isPredicable = true;
186      else if (Rec->isSubClassOf("OptionalDefOperand"))
187        hasOptionalDef = true;
188    } else if (Rec->getName() == "variable_ops") {
189      isVariadic = true;
190      continue;
191    } else if (!Rec->isSubClassOf("RegisterClass") &&
192               Rec->getName() != "ptr_rc" && Rec->getName() != "unknown")
193      throw "Unknown operand class '" + Rec->getName() +
194            "' in '" + R->getName() + "' instruction!";
195
196    // Check that the operand has a name and that it's unique.
197    if (ArgName.empty())
198      throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
199        " has no name!";
200    if (!OperandNames.insert(ArgName).second)
201      throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
202        " has the same name as a previous operand!";
203
204    OperandList.push_back(OperandInfo(Rec, ArgName, PrintMethod,
205                                      MIOperandNo, NumOps, MIOpInfo));
206    MIOperandNo += NumOps;
207  }
208
209  // Parse Constraints.
210  ParseConstraints(R->getValueAsString("Constraints"), this);
211
212  // For backward compatibility: isTwoAddress means operand 1 is tied to
213  // operand 0.
214  if (isTwoAddress) {
215    if (!OperandList[1].Constraints[0].isNone())
216      throw R->getName() + ": cannot use isTwoAddress property: instruction "
217            "already has constraint set!";
218    OperandList[1].Constraints[0] =
219      CodeGenInstruction::ConstraintInfo::getTied(0);
220  }
221
222  // Parse the DisableEncoding field.
223  std::string DisableEncoding = R->getValueAsString("DisableEncoding");
224  while (1) {
225    std::string OpName;
226    tie(OpName, DisableEncoding) = getToken(DisableEncoding, " ,\t");
227    if (OpName.empty()) break;
228
229    // Figure out which operand this is.
230    std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
231
232    // Mark the operand as not-to-be encoded.
233    if (Op.second >= OperandList[Op.first].DoNotEncode.size())
234      OperandList[Op.first].DoNotEncode.resize(Op.second+1);
235    OperandList[Op.first].DoNotEncode[Op.second] = true;
236  }
237}
238
239/// getOperandNamed - Return the index of the operand with the specified
240/// non-empty name.  If the instruction does not have an operand with the
241/// specified name, throw an exception.
242///
243unsigned CodeGenInstruction::getOperandNamed(const std::string &Name) const {
244  assert(!Name.empty() && "Cannot search for operand with no name!");
245  for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
246    if (OperandList[i].Name == Name) return i;
247  throw "Instruction '" + TheDef->getName() +
248        "' does not have an operand named '$" + Name + "'!";
249}
250
251std::pair<unsigned,unsigned>
252CodeGenInstruction::ParseOperandName(const std::string &Op,
253                                     bool AllowWholeOp) {
254  if (Op.empty() || Op[0] != '$')
255    throw TheDef->getName() + ": Illegal operand name: '" + Op + "'";
256
257  std::string OpName = Op.substr(1);
258  std::string SubOpName;
259
260  // Check to see if this is $foo.bar.
261  std::string::size_type DotIdx = OpName.find_first_of(".");
262  if (DotIdx != std::string::npos) {
263    SubOpName = OpName.substr(DotIdx+1);
264    if (SubOpName.empty())
265      throw TheDef->getName() + ": illegal empty suboperand name in '" +Op +"'";
266    OpName = OpName.substr(0, DotIdx);
267  }
268
269  unsigned OpIdx = getOperandNamed(OpName);
270
271  if (SubOpName.empty()) {  // If no suboperand name was specified:
272    // If one was needed, throw.
273    if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
274        SubOpName.empty())
275      throw TheDef->getName() + ": Illegal to refer to"
276            " whole operand part of complex operand '" + Op + "'";
277
278    // Otherwise, return the operand.
279    return std::make_pair(OpIdx, 0U);
280  }
281
282  // Find the suboperand number involved.
283  DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
284  if (MIOpInfo == 0)
285    throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
286
287  // Find the operand with the right name.
288  for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
289    if (MIOpInfo->getArgName(i) == SubOpName)
290      return std::make_pair(OpIdx, i);
291
292  // Otherwise, didn't find it!
293  throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
294}
295