LLVM  3.7.0
InlineAsm.h
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1 //===-- llvm/InlineAsm.h - Class to represent inline asm strings-*- C++ -*-===//
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 class represents the inline asm strings, which are Value*'s that are
11 // used as the callee operand of call instructions. InlineAsm's are uniqued
12 // like constants, and created via InlineAsm::get(...).
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_IR_INLINEASM_H
17 #define LLVM_IR_INLINEASM_H
18 
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/IR/Value.h"
21 #include <vector>
22 
23 namespace llvm {
24 
25 class PointerType;
26 class FunctionType;
27 class Module;
28 
29 struct InlineAsmKeyType;
30 template <class ConstantClass> class ConstantUniqueMap;
31 
32 class InlineAsm : public Value {
33 public:
34  enum AsmDialect {
37  };
38 
39 private:
40  friend struct InlineAsmKeyType;
42 
43  InlineAsm(const InlineAsm &) = delete;
44  void operator=(const InlineAsm&) = delete;
45 
46  std::string AsmString, Constraints;
47  bool HasSideEffects;
48  bool IsAlignStack;
49  AsmDialect Dialect;
50 
51  InlineAsm(PointerType *Ty, const std::string &AsmString,
52  const std::string &Constraints, bool hasSideEffects,
53  bool isAlignStack, AsmDialect asmDialect);
54  ~InlineAsm() override;
55 
56  /// When the ConstantUniqueMap merges two types and makes two InlineAsms
57  /// identical, it destroys one of them with this method.
58  void destroyConstant();
59 public:
60 
61  /// InlineAsm::get - Return the specified uniqued inline asm string.
62  ///
63  static InlineAsm *get(FunctionType *Ty, StringRef AsmString,
64  StringRef Constraints, bool hasSideEffects,
65  bool isAlignStack = false,
66  AsmDialect asmDialect = AD_ATT);
67 
68  bool hasSideEffects() const { return HasSideEffects; }
69  bool isAlignStack() const { return IsAlignStack; }
70  AsmDialect getDialect() const { return Dialect; }
71 
72  /// getType - InlineAsm's are always pointers.
73  ///
74  PointerType *getType() const {
75  return reinterpret_cast<PointerType*>(Value::getType());
76  }
77 
78  /// getFunctionType - InlineAsm's are always pointers to functions.
79  ///
81 
82  const std::string &getAsmString() const { return AsmString; }
83  const std::string &getConstraintString() const { return Constraints; }
84 
85  /// Verify - This static method can be used by the parser to check to see if
86  /// the specified constraint string is legal for the type. This returns true
87  /// if legal, false if not.
88  ///
89  static bool Verify(FunctionType *Ty, StringRef Constraints);
90 
91  // Constraint String Parsing
93  isInput, // 'x'
94  isOutput, // '=x'
95  isClobber // '~x'
96  };
97 
98  typedef std::vector<std::string> ConstraintCodeVector;
99 
101  /// MatchingInput - If this is not -1, this is an output constraint where an
102  /// input constraint is required to match it (e.g. "0"). The value is the
103  /// constraint number that matches this one (for example, if this is
104  /// constraint #0 and constraint #4 has the value "0", this will be 4).
105  signed char MatchingInput;
106  /// Code - The constraint code, either the register name (in braces) or the
107  /// constraint letter/number.
109  /// Default constructor.
111  };
112 
113  typedef std::vector<SubConstraintInfo> SubConstraintInfoVector;
115  typedef std::vector<ConstraintInfo> ConstraintInfoVector;
116 
117  struct ConstraintInfo {
118  /// Type - The basic type of the constraint: input/output/clobber
119  ///
121 
122  /// isEarlyClobber - "&": output operand writes result before inputs are all
123  /// read. This is only ever set for an output operand.
125 
126  /// MatchingInput - If this is not -1, this is an output constraint where an
127  /// input constraint is required to match it (e.g. "0"). The value is the
128  /// constraint number that matches this one (for example, if this is
129  /// constraint #0 and constraint #4 has the value "0", this will be 4).
130  signed char MatchingInput;
131 
132  /// hasMatchingInput - Return true if this is an output constraint that has
133  /// a matching input constraint.
134  bool hasMatchingInput() const { return MatchingInput != -1; }
135 
136  /// isCommutative - This is set to true for a constraint that is commutative
137  /// with the next operand.
139 
140  /// isIndirect - True if this operand is an indirect operand. This means
141  /// that the address of the source or destination is present in the call
142  /// instruction, instead of it being returned or passed in explicitly. This
143  /// is represented with a '*' in the asm string.
145 
146  /// Code - The constraint code, either the register name (in braces) or the
147  /// constraint letter/number.
149 
150  /// isMultipleAlternative - '|': has multiple-alternative constraints.
152 
153  /// multipleAlternatives - If there are multiple alternative constraints,
154  /// this array will contain them. Otherwise it will be empty.
156 
157  /// The currently selected alternative constraint index.
159 
160  ///Default constructor.
161  ConstraintInfo();
162 
163  /// Parse - Analyze the specified string (e.g. "=*&{eax}") and fill in the
164  /// fields in this structure. If the constraint string is not understood,
165  /// return true, otherwise return false.
166  bool Parse(StringRef Str, ConstraintInfoVector &ConstraintsSoFar);
167 
168  /// selectAlternative - Point this constraint to the alternative constraint
169  /// indicated by the index.
170  void selectAlternative(unsigned index);
171  };
172 
173  /// ParseConstraints - Split up the constraint string into the specific
174  /// constraints and their prefixes. If this returns an empty vector, and if
175  /// the constraint string itself isn't empty, there was an error parsing.
176  static ConstraintInfoVector ParseConstraints(StringRef ConstraintString);
177 
178  /// ParseConstraints - Parse the constraints of this inlineasm object,
179  /// returning them the same way that ParseConstraints(str) does.
181  return ParseConstraints(Constraints);
182  }
183 
184  // Methods for support type inquiry through isa, cast, and dyn_cast:
185  static inline bool classof(const Value *V) {
186  return V->getValueID() == Value::InlineAsmVal;
187  }
188 
189 
190  // These are helper methods for dealing with flags in the INLINEASM SDNode
191  // in the backend.
192  //
193  // The encoding of the flag word is currently:
194  // Bits 2-0 - A Kind_* value indicating the kind of the operand.
195  // Bits 15-3 - The number of SDNode operands associated with this inline
196  // assembly operand.
197  // If bit 31 is set:
198  // Bit 30-16 - The operand number that this operand must match.
199  // When bits 2-0 are Kind_Mem, the Constraint_* value must be
200  // obtained from the flags for this operand number.
201  // Else if bits 2-0 are Kind_Mem:
202  // Bit 30-16 - A Constraint_* value indicating the original constraint
203  // code.
204  // Else:
205  // Bit 30-16 - The register class ID to use for the operand.
206 
207  enum : uint32_t {
208  // Fixed operands on an INLINEASM SDNode.
212  Op_ExtraInfo = 3, // HasSideEffects, IsAlignStack, AsmDialect.
214 
215  // Fixed operands on an INLINEASM MachineInstr.
217  MIOp_ExtraInfo = 1, // HasSideEffects, IsAlignStack, AsmDialect.
219 
220  // Interpretation of the MIOp_ExtraInfo bit field.
226 
227  // Inline asm operands map to multiple SDNode / MachineInstr operands.
228  // The first operand is an immediate describing the asm operand, the low
229  // bits is the kind:
230  Kind_RegUse = 1, // Input register, "r".
231  Kind_RegDef = 2, // Output register, "=r".
232  Kind_RegDefEarlyClobber = 3, // Early-clobber output register, "=&r".
233  Kind_Clobber = 4, // Clobbered register, "~r".
234  Kind_Imm = 5, // Immediate.
235  Kind_Mem = 6, // Memory operand, "m".
236 
237  // Memory constraint codes.
238  // These could be tablegenerated but there's little need to do that since
239  // there's plenty of space in the encoding to support the union of all
240  // constraint codes for all targets.
264 
265  Flag_MatchingOperand = 0x80000000
266  };
267 
268  static unsigned getFlagWord(unsigned Kind, unsigned NumOps) {
269  assert(((NumOps << 3) & ~0xffff) == 0 && "Too many inline asm operands!");
270  assert(Kind >= Kind_RegUse && Kind <= Kind_Mem && "Invalid Kind");
271  return Kind | (NumOps << 3);
272  }
273 
274  /// getFlagWordForMatchingOp - Augment an existing flag word returned by
275  /// getFlagWord with information indicating that this input operand is tied
276  /// to a previous output operand.
277  static unsigned getFlagWordForMatchingOp(unsigned InputFlag,
278  unsigned MatchedOperandNo) {
279  assert(MatchedOperandNo <= 0x7fff && "Too big matched operand");
280  assert((InputFlag & ~0xffff) == 0 && "High bits already contain data");
281  return InputFlag | Flag_MatchingOperand | (MatchedOperandNo << 16);
282  }
283 
284  /// getFlagWordForRegClass - Augment an existing flag word returned by
285  /// getFlagWord with the required register class for the following register
286  /// operands.
287  /// A tied use operand cannot have a register class, use the register class
288  /// from the def operand instead.
289  static unsigned getFlagWordForRegClass(unsigned InputFlag, unsigned RC) {
290  // Store RC + 1, reserve the value 0 to mean 'no register class'.
291  ++RC;
292  assert(RC <= 0x7fff && "Too large register class ID");
293  assert((InputFlag & ~0xffff) == 0 && "High bits already contain data");
294  return InputFlag | (RC << 16);
295  }
296 
297  /// Augment an existing flag word returned by getFlagWord with the constraint
298  /// code for a memory constraint.
299  static unsigned getFlagWordForMem(unsigned InputFlag, unsigned Constraint) {
300  assert(Constraint <= 0x7fff && "Too large a memory constraint ID");
301  assert(Constraint <= Constraints_Max && "Unknown constraint ID");
302  assert((InputFlag & ~0xffff) == 0 && "High bits already contain data");
303  return InputFlag | (Constraint << Constraints_ShiftAmount);
304  }
305 
306  static unsigned convertMemFlagWordToMatchingFlagWord(unsigned InputFlag) {
307  assert(isMemKind(InputFlag));
308  return InputFlag & ~(0x7fff << Constraints_ShiftAmount);
309  }
310 
311  static unsigned getKind(unsigned Flags) {
312  return Flags & 7;
313  }
314 
315  static bool isRegDefKind(unsigned Flag){ return getKind(Flag) == Kind_RegDef;}
316  static bool isImmKind(unsigned Flag) { return getKind(Flag) == Kind_Imm; }
317  static bool isMemKind(unsigned Flag) { return getKind(Flag) == Kind_Mem; }
318  static bool isRegDefEarlyClobberKind(unsigned Flag) {
319  return getKind(Flag) == Kind_RegDefEarlyClobber;
320  }
321  static bool isClobberKind(unsigned Flag) {
322  return getKind(Flag) == Kind_Clobber;
323  }
324 
325  static unsigned getMemoryConstraintID(unsigned Flag) {
326  assert(isMemKind(Flag));
327  return (Flag >> Constraints_ShiftAmount) & 0x7fff;
328  }
329 
330  /// getNumOperandRegisters - Extract the number of registers field from the
331  /// inline asm operand flag.
332  static unsigned getNumOperandRegisters(unsigned Flag) {
333  return (Flag & 0xffff) >> 3;
334  }
335 
336  /// isUseOperandTiedToDef - Return true if the flag of the inline asm
337  /// operand indicates it is an use operand that's matched to a def operand.
338  static bool isUseOperandTiedToDef(unsigned Flag, unsigned &Idx) {
339  if ((Flag & Flag_MatchingOperand) == 0)
340  return false;
341  Idx = (Flag & ~Flag_MatchingOperand) >> 16;
342  return true;
343  }
344 
345  /// hasRegClassConstraint - Returns true if the flag contains a register
346  /// class constraint. Sets RC to the register class ID.
347  static bool hasRegClassConstraint(unsigned Flag, unsigned &RC) {
348  if (Flag & Flag_MatchingOperand)
349  return false;
350  unsigned High = Flag >> 16;
351  // getFlagWordForRegClass() uses 0 to mean no register class, and otherwise
352  // stores RC + 1.
353  if (!High)
354  return false;
355  RC = High - 1;
356  return true;
357  }
358 
359 };
360 
361 } // End llvm namespace
362 
363 #endif
AsmDialect getDialect() const
Definition: InlineAsm.h:70
static unsigned getFlagWord(unsigned Kind, unsigned NumOps)
Definition: InlineAsm.h:268
const std::string & getAsmString() const
Definition: InlineAsm.h:82
static bool isClobberKind(unsigned Flag)
Definition: InlineAsm.h:321
const std::string & getConstraintString() const
Definition: InlineAsm.h:83
bool Parse(StringRef Str, ConstraintInfoVector &ConstraintsSoFar)
Parse - Analyze the specified string (e.g.
Definition: InlineAsm.cpp:70
static bool isImmKind(unsigned Flag)
Definition: InlineAsm.h:316
static bool isUseOperandTiedToDef(unsigned Flag, unsigned &Idx)
isUseOperandTiedToDef - Return true if the flag of the inline asm operand indicates it is an use oper...
Definition: InlineAsm.h:338
ConstraintCodeVector Codes
Code - The constraint code, either the register name (in braces) or the constraint letter/number...
Definition: InlineAsm.h:148
static unsigned getFlagWordForRegClass(unsigned InputFlag, unsigned RC)
getFlagWordForRegClass - Augment an existing flag word returned by getFlagWord with the required regi...
Definition: InlineAsm.h:289
bool isCommutative
isCommutative - This is set to true for a constraint that is commutative with the next operand...
Definition: InlineAsm.h:138
std::vector< SubConstraintInfo > SubConstraintInfoVector
Definition: InlineAsm.h:113
ConstraintInfoVector ParseConstraints() const
ParseConstraints - Parse the constraints of this inlineasm object, returning them the same way that P...
Definition: InlineAsm.h:180
static bool isRegDefEarlyClobberKind(unsigned Flag)
Definition: InlineAsm.h:318
static unsigned convertMemFlagWordToMatchingFlagWord(unsigned InputFlag)
Definition: InlineAsm.h:306
FunctionType - Class to represent function types.
Definition: DerivedTypes.h:96
signed char MatchingInput
MatchingInput - If this is not -1, this is an output constraint where an input constraint is required...
Definition: InlineAsm.h:130
static bool Verify(FunctionType *Ty, StringRef Constraints)
Verify - This static method can be used by the parser to check to see if the specified constraint str...
Definition: InlineAsm.cpp:245
ConstraintPrefix Type
Type - The basic type of the constraint: input/output/clobber.
Definition: InlineAsm.h:120
static bool isRegDefKind(unsigned Flag)
Definition: InlineAsm.h:315
PointerType - Class to represent pointers.
Definition: DerivedTypes.h:449
Flag
These should be considered private to the implementation of the MCInstrDesc class.
Definition: MCInstrDesc.h:97
bool isEarlyClobber
isEarlyClobber - "&": output operand writes result before inputs are all read.
Definition: InlineAsm.h:124
static bool classof(const Value *V)
Definition: InlineAsm.h:185
bool hasSideEffects() const
Definition: InlineAsm.h:68
unsigned currentAlternativeIndex
The currently selected alternative constraint index.
Definition: InlineAsm.h:158
bool isIndirect
isIndirect - True if this operand is an indirect operand.
Definition: InlineAsm.h:144
ConstraintInfo()
Default constructor.
Definition: InlineAsm.cpp:60
SubConstraintInfoVector multipleAlternatives
multipleAlternatives - If there are multiple alternative constraints, this array will contain them...
Definition: InlineAsm.h:155
PointerType * getType() const
getType - InlineAsm's are always pointers.
Definition: InlineAsm.h:74
static unsigned getNumOperandRegisters(unsigned Flag)
getNumOperandRegisters - Extract the number of registers field from the inline asm operand flag...
Definition: InlineAsm.h:332
static unsigned getMemoryConstraintID(unsigned Flag)
Definition: InlineAsm.h:325
unsigned getValueID() const
Return an ID for the concrete type of this object.
Definition: Value.h:362
static unsigned getKind(unsigned Flags)
Definition: InlineAsm.h:311
static unsigned getFlagWordForMem(unsigned InputFlag, unsigned Constraint)
Augment an existing flag word returned by getFlagWord with the constraint code for a memory constrain...
Definition: InlineAsm.h:299
static bool isMemKind(unsigned Flag)
Definition: InlineAsm.h:317
SubConstraintInfo()
Default constructor.
Definition: InlineAsm.h:110
signed char MatchingInput
MatchingInput - If this is not -1, this is an output constraint where an input constraint is required...
Definition: InlineAsm.h:105
FunctionType * getFunctionType() const
getFunctionType - InlineAsm's are always pointers to functions.
Definition: InlineAsm.cpp:55
std::vector< std::string > ConstraintCodeVector
Definition: InlineAsm.h:98
ConstraintCodeVector Codes
Code - The constraint code, either the register name (in braces) or the constraint letter/number...
Definition: InlineAsm.h:108
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:222
bool hasMatchingInput() const
hasMatchingInput - Return true if this is an output constraint that has a matching input constraint...
Definition: InlineAsm.h:134
static bool hasRegClassConstraint(unsigned Flag, unsigned &RC)
hasRegClassConstraint - Returns true if the flag contains a register class constraint.
Definition: InlineAsm.h:347
const ARM::ArchExtKind Kind
LLVM Value Representation.
Definition: Value.h:69
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:40
bool isAlignStack() const
Definition: InlineAsm.h:69
std::vector< ConstraintInfo > ConstraintInfoVector
Definition: InlineAsm.h:114
bool isMultipleAlternative
isMultipleAlternative - '|': has multiple-alternative constraints.
Definition: InlineAsm.h:151
static unsigned getFlagWordForMatchingOp(unsigned InputFlag, unsigned MatchedOperandNo)
getFlagWordForMatchingOp - Augment an existing flag word returned by getFlagWord with information ind...
Definition: InlineAsm.h:277
void selectAlternative(unsigned index)
selectAlternative - Point this constraint to the alternative constraint indicated by the index...
Definition: InlineAsm.cpp:198