CodeGenInstruction.cpp revision 799d697bf8d45ec404d0d105fc788ea5cf81c841 
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 <set>
18using namespace llvm;
19
20static void ParseConstraint(const std::string &CStr, CodeGenInstruction *I) {
21  // FIXME: Only supports TIED_TO for now.
22  std::string::size_type pos = CStr.find_first_of('=');
23  assert(pos != std::string::npos && "Unrecognized constraint");
24  std::string::size_type start = CStr.find_first_not_of(" \t");
25  std::string Name = CStr.substr(start, pos - start);
26
27  // TIED_TO: $src1 = $dst
28  std::string::size_type wpos = Name.find_first_of(" \t");
29  if (wpos == std::string::npos)
30    throw "Illegal format for tied-to constraint: '" + CStr + "'";
31  std::string DestOpName = Name.substr(0, wpos);
32  std::pair<unsigned,unsigned> DestOp = I->ParseOperandName(DestOpName, false);
33
34  Name = CStr.substr(pos+1);
35  wpos = Name.find_first_not_of(" \t");
36  if (wpos == std::string::npos)
37    throw "Illegal format for tied-to constraint: '" + CStr + "'";
38
39  std::pair<unsigned,unsigned> SrcOp =
40  I->ParseOperandName(Name.substr(wpos), false);
41  if (SrcOp > DestOp)
42    throw "Illegal tied-to operand constraint '" + CStr + "'";
43
44
45  unsigned FlatOpNo = I->getFlattenedOperandNumber(SrcOp);
46  // Build the string for the operand.
47  std::string OpConstraint =
48  "((" + utostr(FlatOpNo) + " << 16) | (1 << TOI::TIED_TO))";
49
50
51  if (!I->OperandList[DestOp.first].Constraints[DestOp.second].empty())
52    throw "Operand '" + DestOpName + "' cannot have multiple constraints!";
53  I->OperandList[DestOp.first].Constraints[DestOp.second] = OpConstraint;
54}
55
56static void ParseConstraints(const std::string &CStr, CodeGenInstruction *I) {
57  // Make sure the constraints list for each operand is large enough to hold
58  // constraint info, even if none is present.
59  for (unsigned i = 0, e = I->OperandList.size(); i != e; ++i)
60    I->OperandList[i].Constraints.resize(I->OperandList[i].MINumOperands);
61
62  if (CStr.empty()) return;
63
64  const std::string delims(",");
65  std::string::size_type bidx, eidx;
66
67  bidx = CStr.find_first_not_of(delims);
68  while (bidx != std::string::npos) {
69    eidx = CStr.find_first_of(delims, bidx);
70    if (eidx == std::string::npos)
71      eidx = CStr.length();
72
73    ParseConstraint(CStr.substr(bidx, eidx - bidx), I);
74    bidx = CStr.find_first_not_of(delims, eidx);
75  }
76}
77
78CodeGenInstruction::CodeGenInstruction(Record *R, const std::string &AsmStr)
79  : TheDef(R), AsmString(AsmStr) {
80  Namespace = R->getValueAsString("Namespace");
81
82  isReturn     = R->getValueAsBit("isReturn");
83  isBranch     = R->getValueAsBit("isBranch");
84  isIndirectBranch = R->getValueAsBit("isIndirectBranch");
85  isBarrier    = R->getValueAsBit("isBarrier");
86  isCall       = R->getValueAsBit("isCall");
87  canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
88  mayLoad      = R->getValueAsBit("mayLoad");
89  mayStore     = R->getValueAsBit("mayStore");
90  bool isTwoAddress = R->getValueAsBit("isTwoAddress");
91  isPredicable = R->getValueAsBit("isPredicable");
92  isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");
93  isCommutable = R->getValueAsBit("isCommutable");
94  isTerminator = R->getValueAsBit("isTerminator");
95  isReMaterializable = R->getValueAsBit("isReMaterializable");
96  hasDelaySlot = R->getValueAsBit("hasDelaySlot");
97  usesCustomDAGSchedInserter = R->getValueAsBit("usesCustomDAGSchedInserter");
98  hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
99  isNotDuplicable = R->getValueAsBit("isNotDuplicable");
100  hasSideEffects = R->getValueAsBit("hasSideEffects");
101  mayHaveSideEffects = R->getValueAsBit("mayHaveSideEffects");
102  neverHasSideEffects = R->getValueAsBit("neverHasSideEffects");
103  isAsCheapAsAMove = R->getValueAsBit("isAsCheapAsAMove");
104  hasExtraSrcRegAllocReq = R->getValueAsBit("hasExtraSrcRegAllocReq");
105  hasExtraDefRegAllocReq = R->getValueAsBit("hasExtraDefRegAllocReq");
106  hasOptionalDef = false;
107  isVariadic = false;
108
109  if (mayHaveSideEffects + neverHasSideEffects + hasSideEffects > 1)
110    throw R->getName() + ": multiple conflicting side-effect flags set!";
111
112  DagInit *DI;
113  try {
114    DI = R->getValueAsDag("OutOperandList");
115  } catch (...) {
116    // Error getting operand list, just ignore it (sparcv9).
117    AsmString.clear();
118    OperandList.clear();
119    return;
120  }
121  NumDefs = DI->getNumArgs();
122
123  DagInit *IDI;
124  try {
125    IDI = R->getValueAsDag("InOperandList");
126  } catch (...) {
127    // Error getting operand list, just ignore it (sparcv9).
128    AsmString.clear();
129    OperandList.clear();
130    return;
131  }
132  DI = (DagInit*)(new BinOpInit(BinOpInit::CONCAT, DI, IDI, new DagRecTy))->Fold(R, 0);
133
134  unsigned MIOperandNo = 0;
135  std::set<std::string> OperandNames;
136  for (unsigned i = 0, e = DI->getNumArgs(); i != e; ++i) {
137    DefInit *Arg = dynamic_cast<DefInit*>(DI->getArg(i));
138    if (!Arg)
139      throw "Illegal operand for the '" + R->getName() + "' instruction!";
140
141    Record *Rec = Arg->getDef();
142    std::string PrintMethod = "printOperand";
143    unsigned NumOps = 1;
144    DagInit *MIOpInfo = 0;
145    if (Rec->isSubClassOf("Operand")) {
146      PrintMethod = Rec->getValueAsString("PrintMethod");
147      MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
148
149      // Verify that MIOpInfo has an 'ops' root value.
150      if (!dynamic_cast<DefInit*>(MIOpInfo->getOperator()) ||
151          dynamic_cast<DefInit*>(MIOpInfo->getOperator())
152               ->getDef()->getName() != "ops")
153        throw "Bad value for MIOperandInfo in operand '" + Rec->getName() +
154              "'\n";
155
156      // If we have MIOpInfo, then we have #operands equal to number of entries
157      // in MIOperandInfo.
158      if (unsigned NumArgs = MIOpInfo->getNumArgs())
159        NumOps = NumArgs;
160
161      if (Rec->isSubClassOf("PredicateOperand"))
162        isPredicable = true;
163      else if (Rec->isSubClassOf("OptionalDefOperand"))
164        hasOptionalDef = true;
165    } else if (Rec->getName() == "variable_ops") {
166      isVariadic = true;
167      continue;
168    } else if (!Rec->isSubClassOf("RegisterClass") &&
169               Rec->getName() != "ptr_rc" && Rec->getName() != "unknown")
170      throw "Unknown operand class '" + Rec->getName() +
171            "' in '" + R->getName() + "' instruction!";
172
173    // Check that the operand has a name and that it's unique.
174    if (DI->getArgName(i).empty())
175      throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
176        " has no name!";
177    if (!OperandNames.insert(DI->getArgName(i)).second)
178      throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
179        " has the same name as a previous operand!";
180
181    OperandList.push_back(OperandInfo(Rec, DI->getArgName(i), PrintMethod,
182                                      MIOperandNo, NumOps, MIOpInfo));
183    MIOperandNo += NumOps;
184  }
185
186  // Parse Constraints.
187  ParseConstraints(R->getValueAsString("Constraints"), this);
188
189  // For backward compatibility: isTwoAddress means operand 1 is tied to
190  // operand 0.
191  if (isTwoAddress) {
192    if (!OperandList[1].Constraints[0].empty())
193      throw R->getName() + ": cannot use isTwoAddress property: instruction "
194            "already has constraint set!";
195    OperandList[1].Constraints[0] = "((0 << 16) | (1 << TOI::TIED_TO))";
196  }
197
198  // Any operands with unset constraints get 0 as their constraint.
199  for (unsigned op = 0, e = OperandList.size(); op != e; ++op)
200    for (unsigned j = 0, e = OperandList[op].MINumOperands; j != e; ++j)
201      if (OperandList[op].Constraints[j].empty())
202        OperandList[op].Constraints[j] = "0";
203
204  // Parse the DisableEncoding field.
205  std::string DisableEncoding = R->getValueAsString("DisableEncoding");
206  while (1) {
207    std::string OpName = getToken(DisableEncoding, " ,\t");
208    if (OpName.empty()) break;
209
210    // Figure out which operand this is.
211    std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
212
213    // Mark the operand as not-to-be encoded.
214    if (Op.second >= OperandList[Op.first].DoNotEncode.size())
215      OperandList[Op.first].DoNotEncode.resize(Op.second+1);
216    OperandList[Op.first].DoNotEncode[Op.second] = true;
217  }
218}
219
220/// getOperandNamed - Return the index of the operand with the specified
221/// non-empty name.  If the instruction does not have an operand with the
222/// specified name, throw an exception.
223///
224unsigned CodeGenInstruction::getOperandNamed(const std::string &Name) const {
225  assert(!Name.empty() && "Cannot search for operand with no name!");
226  for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
227    if (OperandList[i].Name == Name) return i;
228  throw "Instruction '" + TheDef->getName() +
229        "' does not have an operand named '$" + Name + "'!";
230}
231
232std::pair<unsigned,unsigned>
233CodeGenInstruction::ParseOperandName(const std::string &Op,
234                                     bool AllowWholeOp) {
235  if (Op.empty() || Op[0] != '$')
236    throw TheDef->getName() + ": Illegal operand name: '" + Op + "'";
237
238  std::string OpName = Op.substr(1);
239  std::string SubOpName;
240
241  // Check to see if this is $foo.bar.
242  std::string::size_type DotIdx = OpName.find_first_of(".");
243  if (DotIdx != std::string::npos) {
244    SubOpName = OpName.substr(DotIdx+1);
245    if (SubOpName.empty())
246      throw TheDef->getName() + ": illegal empty suboperand name in '" +Op +"'";
247    OpName = OpName.substr(0, DotIdx);
248  }
249
250  unsigned OpIdx = getOperandNamed(OpName);
251
252  if (SubOpName.empty()) {  // If no suboperand name was specified:
253    // If one was needed, throw.
254    if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
255        SubOpName.empty())
256      throw TheDef->getName() + ": Illegal to refer to"
257            " whole operand part of complex operand '" + Op + "'";
258
259    // Otherwise, return the operand.
260    return std::make_pair(OpIdx, 0U);
261  }
262
263  // Find the suboperand number involved.
264  DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
265  if (MIOpInfo == 0)
266    throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
267
268  // Find the operand with the right name.
269  for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
270    if (MIOpInfo->getArgName(i) == SubOpName)
271      return std::make_pair(OpIdx, i);
272
273  // Otherwise, didn't find it!
274  throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
275}
276