CodeGenInstruction.cpp revision af3eb7c7583555ea5fd08e99f28b0042811e4dc2 
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 Name = CStr.substr(0, pos);
25
26  // TIED_TO: $src1 = $dst
27  std::string::size_type wpos = Name.find_first_of(" \t");
28  if (wpos == std::string::npos)
29    throw "Illegal format for tied-to constraint: '" + CStr + "'";
30  std::string DestOpName = Name.substr(0, wpos);
31  std::pair<unsigned,unsigned> DestOp = I->ParseOperandName(DestOpName, false);
32
33  Name = CStr.substr(pos+1);
34  wpos = Name.find_first_not_of(" \t");
35  if (wpos == std::string::npos)
36    throw "Illegal format for tied-to constraint: '" + CStr + "'";
37
38  std::pair<unsigned,unsigned> SrcOp =
39  I->ParseOperandName(Name.substr(wpos), false);
40  if (SrcOp > DestOp)
41    throw "Illegal tied-to operand constraint '" + CStr + "'";
42
43
44  unsigned FlatOpNo = I->getFlattenedOperandNumber(SrcOp);
45  // Build the string for the operand.
46  std::string OpConstraint =
47  "((" + utostr(FlatOpNo) + " << 16) | (1 << TOI::TIED_TO))";
48
49
50  if (!I->OperandList[DestOp.first].Constraints[DestOp.second].empty())
51    throw "Operand '" + DestOpName + "' cannot have multiple constraints!";
52  I->OperandList[DestOp.first].Constraints[DestOp.second] = OpConstraint;
53}
54
55static void ParseConstraints(const std::string &CStr, CodeGenInstruction *I) {
56  // Make sure the constraints list for each operand is large enough to hold
57  // constraint info, even if none is present.
58  for (unsigned i = 0, e = I->OperandList.size(); i != e; ++i)
59    I->OperandList[i].Constraints.resize(I->OperandList[i].MINumOperands);
60
61  if (CStr.empty()) return;
62
63  const std::string delims(",");
64  std::string::size_type bidx, eidx;
65
66  bidx = CStr.find_first_not_of(delims);
67  while (bidx != std::string::npos) {
68    eidx = CStr.find_first_of(delims, bidx);
69    if (eidx == std::string::npos)
70      eidx = CStr.length();
71
72    ParseConstraint(CStr.substr(bidx, eidx), I);
73    bidx = CStr.find_first_not_of(delims, eidx);
74  }
75}
76
77CodeGenInstruction::CodeGenInstruction(Record *R, const std::string &AsmStr)
78  : TheDef(R), AsmString(AsmStr) {
79  Namespace = R->getValueAsString("Namespace");
80
81  isReturn     = R->getValueAsBit("isReturn");
82  isBranch     = R->getValueAsBit("isBranch");
83  isIndirectBranch = R->getValueAsBit("isIndirectBranch");
84  isBarrier    = R->getValueAsBit("isBarrier");
85  isCall       = R->getValueAsBit("isCall");
86  isSimpleLoad = R->getValueAsBit("isSimpleLoad");
87  mayStore     = R->getValueAsBit("mayStore");
88  isImplicitDef= R->getValueAsBit("isImplicitDef");
89  bool isTwoAddress = R->getValueAsBit("isTwoAddress");
90  isPredicable = R->getValueAsBit("isPredicable");
91  isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");
92  isCommutable = R->getValueAsBit("isCommutable");
93  isTerminator = R->getValueAsBit("isTerminator");
94  isReMaterializable = R->getValueAsBit("isReMaterializable");
95  hasDelaySlot = R->getValueAsBit("hasDelaySlot");
96  usesCustomDAGSchedInserter = R->getValueAsBit("usesCustomDAGSchedInserter");
97  hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
98  isNotDuplicable = R->getValueAsBit("isNotDuplicable");
99  mayHaveSideEffects = R->getValueAsBit("mayHaveSideEffects");
100  neverHasSideEffects = R->getValueAsBit("neverHasSideEffects");
101  hasOptionalDef = false;
102  hasVariableNumberOfOperands = false;
103
104  if (mayHaveSideEffects && neverHasSideEffects)
105    throw R->getName() +
106      ": cannot have both 'mayHaveSideEffects' and 'neverHasSideEffects' set!";
107
108  DagInit *DI;
109  try {
110    DI = R->getValueAsDag("OutOperandList");
111  } catch (...) {
112    // Error getting operand list, just ignore it (sparcv9).
113    AsmString.clear();
114    OperandList.clear();
115    return;
116  }
117  NumDefs = DI->getNumArgs();
118
119  DagInit *IDI;
120  try {
121    IDI = R->getValueAsDag("InOperandList");
122  } catch (...) {
123    // Error getting operand list, just ignore it (sparcv9).
124    AsmString.clear();
125    OperandList.clear();
126    return;
127  }
128  DI = (DagInit*)(new BinOpInit(BinOpInit::CONCAT, DI, IDI))->Fold();
129
130  unsigned MIOperandNo = 0;
131  std::set<std::string> OperandNames;
132  for (unsigned i = 0, e = DI->getNumArgs(); i != e; ++i) {
133    DefInit *Arg = dynamic_cast<DefInit*>(DI->getArg(i));
134    if (!Arg)
135      throw "Illegal operand for the '" + R->getName() + "' instruction!";
136
137    Record *Rec = Arg->getDef();
138    std::string PrintMethod = "printOperand";
139    unsigned NumOps = 1;
140    DagInit *MIOpInfo = 0;
141    if (Rec->isSubClassOf("Operand")) {
142      PrintMethod = Rec->getValueAsString("PrintMethod");
143      MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
144
145      // Verify that MIOpInfo has an 'ops' root value.
146      if (!dynamic_cast<DefInit*>(MIOpInfo->getOperator()) ||
147          dynamic_cast<DefInit*>(MIOpInfo->getOperator())
148               ->getDef()->getName() != "ops")
149        throw "Bad value for MIOperandInfo in operand '" + Rec->getName() +
150              "'\n";
151
152      // If we have MIOpInfo, then we have #operands equal to number of entries
153      // in MIOperandInfo.
154      if (unsigned NumArgs = MIOpInfo->getNumArgs())
155        NumOps = NumArgs;
156
157      if (Rec->isSubClassOf("PredicateOperand"))
158        isPredicable = true;
159      else if (Rec->isSubClassOf("OptionalDefOperand"))
160        hasOptionalDef = true;
161    } else if (Rec->getName() == "variable_ops") {
162      hasVariableNumberOfOperands = true;
163      continue;
164    } else if (!Rec->isSubClassOf("RegisterClass") &&
165               Rec->getName() != "ptr_rc")
166      throw "Unknown operand class '" + Rec->getName() +
167            "' in instruction '" + R->getName() + "' instruction!";
168
169    // Check that the operand has a name and that it's unique.
170    if (DI->getArgName(i).empty())
171      throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
172        " has no name!";
173    if (!OperandNames.insert(DI->getArgName(i)).second)
174      throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
175        " has the same name as a previous operand!";
176
177    OperandList.push_back(OperandInfo(Rec, DI->getArgName(i), PrintMethod,
178                                      MIOperandNo, NumOps, MIOpInfo));
179    MIOperandNo += NumOps;
180  }
181
182  // Parse Constraints.
183  ParseConstraints(R->getValueAsString("Constraints"), this);
184
185  // For backward compatibility: isTwoAddress means operand 1 is tied to
186  // operand 0.
187  if (isTwoAddress) {
188    if (!OperandList[1].Constraints[0].empty())
189      throw R->getName() + ": cannot use isTwoAddress property: instruction "
190            "already has constraint set!";
191    OperandList[1].Constraints[0] = "((0 << 16) | (1 << TOI::TIED_TO))";
192  }
193
194  // Any operands with unset constraints get 0 as their constraint.
195  for (unsigned op = 0, e = OperandList.size(); op != e; ++op)
196    for (unsigned j = 0, e = OperandList[op].MINumOperands; j != e; ++j)
197      if (OperandList[op].Constraints[j].empty())
198        OperandList[op].Constraints[j] = "0";
199
200  // Parse the DisableEncoding field.
201  std::string DisableEncoding = R->getValueAsString("DisableEncoding");
202  while (1) {
203    std::string OpName = getToken(DisableEncoding, " ,\t");
204    if (OpName.empty()) break;
205
206    // Figure out which operand this is.
207    std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
208
209    // Mark the operand as not-to-be encoded.
210    if (Op.second >= OperandList[Op.first].DoNotEncode.size())
211      OperandList[Op.first].DoNotEncode.resize(Op.second+1);
212    OperandList[Op.first].DoNotEncode[Op.second] = true;
213  }
214}
215
216/// getOperandNamed - Return the index of the operand with the specified
217/// non-empty name.  If the instruction does not have an operand with the
218/// specified name, throw an exception.
219///
220unsigned CodeGenInstruction::getOperandNamed(const std::string &Name) const {
221  assert(!Name.empty() && "Cannot search for operand with no name!");
222  for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
223    if (OperandList[i].Name == Name) return i;
224  throw "Instruction '" + TheDef->getName() +
225        "' does not have an operand named '$" + Name + "'!";
226}
227
228std::pair<unsigned,unsigned>
229CodeGenInstruction::ParseOperandName(const std::string &Op,
230                                     bool AllowWholeOp) {
231  if (Op.empty() || Op[0] != '$')
232    throw TheDef->getName() + ": Illegal operand name: '" + Op + "'";
233
234  std::string OpName = Op.substr(1);
235  std::string SubOpName;
236
237  // Check to see if this is $foo.bar.
238  std::string::size_type DotIdx = OpName.find_first_of(".");
239  if (DotIdx != std::string::npos) {
240    SubOpName = OpName.substr(DotIdx+1);
241    if (SubOpName.empty())
242      throw TheDef->getName() + ": illegal empty suboperand name in '" +Op +"'";
243    OpName = OpName.substr(0, DotIdx);
244  }
245
246  unsigned OpIdx = getOperandNamed(OpName);
247
248  if (SubOpName.empty()) {  // If no suboperand name was specified:
249    // If one was needed, throw.
250    if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
251        SubOpName.empty())
252      throw TheDef->getName() + ": Illegal to refer to"
253            " whole operand part of complex operand '" + Op + "'";
254
255    // Otherwise, return the operand.
256    return std::make_pair(OpIdx, 0U);
257  }
258
259  // Find the suboperand number involved.
260  DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
261  if (MIOpInfo == 0)
262    throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
263
264  // Find the operand with the right name.
265  for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
266    if (MIOpInfo->getArgName(i) == SubOpName)
267      return std::make_pair(OpIdx, i);
268
269  // Otherwise, didn't find it!
270  throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
271}
272