LegalizeTypes.h revision 4fc4fd657d4266059dac3849133a3a351b03d99d 
1//===-- LegalizeTypes.h - Definition of the DAG Type Legalizer class ------===//
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 defines the DAGTypeLegalizer class.  This is a private interface
11// shared between the code that implements the SelectionDAG::LegalizeTypes
12// method.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef SELECTIONDAG_LEGALIZETYPES_H
17#define SELECTIONDAG_LEGALIZETYPES_H
18
19#define DEBUG_TYPE "legalize-types"
20#include "llvm/CodeGen/SelectionDAG.h"
21#include "llvm/Target/TargetLowering.h"
22#include "llvm/ADT/DenseMap.h"
23#include "llvm/Support/Compiler.h"
24#include "llvm/Support/Debug.h"
25
26namespace llvm {
27
28//===----------------------------------------------------------------------===//
29/// DAGTypeLegalizer - This takes an arbitrary SelectionDAG as input and
30/// hacks on it until the target machine can handle it.  This involves
31/// eliminating value sizes the machine cannot handle (promoting small sizes to
32/// large sizes or splitting up large values into small values) as well as
33/// eliminating operations the machine cannot handle.
34///
35/// This code also does a small amount of optimization and recognition of idioms
36/// as part of its processing.  For example, if a target does not support a
37/// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
38/// will attempt merge setcc and brc instructions into brcc's.
39///
40class VISIBILITY_HIDDEN DAGTypeLegalizer {
41  TargetLowering &TLI;
42  SelectionDAG &DAG;
43public:
44  // NodeIDFlags - This pass uses the NodeID on the SDNodes to hold information
45  // about the state of the node.  The enum has all the values.
46  enum NodeIDFlags {
47    /// ReadyToProcess - All operands have been processed, so this node is ready
48    /// to be handled.
49    ReadyToProcess = 0,
50
51    /// NewNode - This is a new node that was created in the process of
52    /// legalizing some other node.
53    NewNode = -1,
54
55    /// Processed - This is a node that has already been processed.
56    Processed = -2
57
58    // 1+ - This is a node which has this many unlegalized operands.
59  };
60private:
61  enum LegalizeAction {
62    Legal,          // The target natively supports this type.
63    PromoteInteger, // Replace this integer type with a larger one.
64    ExpandInteger,  // Split this integer type into two of half the size.
65    SoftenFloat,    // Convert this float type to a same size integer type.
66    ExpandFloat,    // Split this float type into two of half the size.
67    Scalarize,      // Replace this one-element vector type with its element type.
68    Split           // This vector type should be split into smaller vectors.
69  };
70
71  /// ValueTypeActions - This is a bitvector that contains two bits for each
72  /// simple value type, where the two bits correspond to the LegalizeAction
73  /// enum from TargetLowering.  This can be queried with "getTypeAction(VT)".
74  TargetLowering::ValueTypeActionImpl ValueTypeActions;
75
76  /// getTypeAction - Return how we should legalize values of this type, either
77  /// it is already legal, or we need to promote it to a larger integer type, or
78  /// we need to expand it into multiple registers of a smaller integer type, or
79  /// we need to scalarize a one-element vector type into the element type, or
80  /// we need to split a vector type into smaller vector types.
81  LegalizeAction getTypeAction(MVT VT) const {
82    switch (ValueTypeActions.getTypeAction(VT)) {
83    default:
84      assert(false && "Unknown legalize action!");
85    case TargetLowering::Legal:
86      return Legal;
87    case TargetLowering::Promote:
88      return PromoteInteger;
89    case TargetLowering::Expand:
90      // Expand can mean
91      // 1) split scalar in half, 2) convert a float to an integer,
92      // 3) scalarize a single-element vector, 4) split a vector in two.
93      if (!VT.isVector()) {
94        if (VT.isInteger())
95          return ExpandInteger;
96        else if (VT.getSizeInBits() ==
97                 TLI.getTypeToTransformTo(VT).getSizeInBits())
98          return SoftenFloat;
99        else
100          return ExpandFloat;
101      } else if (VT.getVectorNumElements() == 1) {
102        return Scalarize;
103      } else {
104        return Split;
105      }
106    }
107  }
108
109  /// isTypeLegal - Return true if this type is legal on this target.
110  bool isTypeLegal(MVT VT) const {
111    return ValueTypeActions.getTypeAction(VT) == TargetLowering::Legal;
112  }
113
114  /// PromotedIntegers - For integer nodes that are below legal width, this map
115  /// indicates what promoted value to use.
116  DenseMap<SDOperand, SDOperand> PromotedIntegers;
117
118  /// ExpandedIntegers - For integer nodes that need to be expanded this map
119  /// indicates which operands are the expanded version of the input.
120  DenseMap<SDOperand, std::pair<SDOperand, SDOperand> > ExpandedIntegers;
121
122  /// SoftenedFloats - For floating point nodes converted to integers of
123  /// the same size, this map indicates the converted value to use.
124  DenseMap<SDOperand, SDOperand> SoftenedFloats;
125
126  /// ExpandedFloats - For float nodes that need to be expanded this map
127  /// indicates which operands are the expanded version of the input.
128  DenseMap<SDOperand, std::pair<SDOperand, SDOperand> > ExpandedFloats;
129
130  /// ScalarizedVectors - For nodes that are <1 x ty>, this map indicates the
131  /// scalar value of type 'ty' to use.
132  DenseMap<SDOperand, SDOperand> ScalarizedVectors;
133
134  /// SplitVectors - For nodes that need to be split this map indicates
135  /// which operands are the expanded version of the input.
136  DenseMap<SDOperand, std::pair<SDOperand, SDOperand> > SplitVectors;
137
138  /// ReplacedNodes - For nodes that have been replaced with another,
139  /// indicates the replacement node to use.
140  DenseMap<SDOperand, SDOperand> ReplacedNodes;
141
142  /// Worklist - This defines a worklist of nodes to process.  In order to be
143  /// pushed onto this worklist, all operands of a node must have already been
144  /// processed.
145  SmallVector<SDNode*, 128> Worklist;
146
147public:
148  explicit DAGTypeLegalizer(SelectionDAG &dag)
149    : TLI(dag.getTargetLoweringInfo()), DAG(dag),
150    ValueTypeActions(TLI.getValueTypeActions()) {
151    assert(MVT::LAST_VALUETYPE <= 32 &&
152           "Too many value types for ValueTypeActions to hold!");
153  }
154
155  void run();
156
157  /// ReanalyzeNode - Recompute the NodeID and correct processed operands
158  /// for the specified node, adding it to the worklist if ready.
159  void ReanalyzeNode(SDNode *N) {
160    N->setNodeId(NewNode);
161    AnalyzeNewNode(N);
162  }
163
164  void NoteReplacement(SDOperand From, SDOperand To) {
165    ExpungeNode(From);
166    ExpungeNode(To);
167    ReplacedNodes[From] = To;
168  }
169
170private:
171  void AnalyzeNewNode(SDNode *&N);
172
173  void ReplaceValueWith(SDOperand From, SDOperand To);
174  void ReplaceNodeWith(SDNode *From, SDNode *To);
175
176  void RemapNode(SDOperand &N);
177  void ExpungeNode(SDOperand N);
178
179  // Common routines.
180  SDOperand CreateStackStoreLoad(SDOperand Op, MVT DestVT);
181  SDOperand MakeLibCall(RTLIB::Libcall LC, MVT RetVT,
182                        const SDOperand *Ops, unsigned NumOps, bool isSigned);
183
184  SDOperand BitConvertToInteger(SDOperand Op);
185  SDOperand JoinIntegers(SDOperand Lo, SDOperand Hi);
186  void SplitInteger(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
187  void SplitInteger(SDOperand Op, MVT LoVT, MVT HiVT,
188                    SDOperand &Lo, SDOperand &Hi);
189
190  SDOperand GetVectorElementPointer(SDOperand VecPtr, MVT EltVT,
191                                    SDOperand Index);
192
193  //===--------------------------------------------------------------------===//
194  // Integer Promotion Support: LegalizeIntegerTypes.cpp
195  //===--------------------------------------------------------------------===//
196
197  SDOperand GetPromotedInteger(SDOperand Op) {
198    SDOperand &PromotedOp = PromotedIntegers[Op];
199    RemapNode(PromotedOp);
200    assert(PromotedOp.Val && "Operand wasn't promoted?");
201    return PromotedOp;
202  }
203  void SetPromotedInteger(SDOperand Op, SDOperand Result);
204
205  /// ZExtPromotedInteger - Get a promoted operand and zero extend it to the
206  /// final size.
207  SDOperand ZExtPromotedInteger(SDOperand Op) {
208    MVT OldVT = Op.getValueType();
209    Op = GetPromotedInteger(Op);
210    return DAG.getZeroExtendInReg(Op, OldVT);
211  }
212
213  // Integer Result Promotion.
214  void PromoteIntegerResult(SDNode *N, unsigned ResNo);
215  SDOperand PromoteIntRes_BIT_CONVERT(SDNode *N);
216  SDOperand PromoteIntRes_BUILD_PAIR(SDNode *N);
217  SDOperand PromoteIntRes_Constant(SDNode *N);
218  SDOperand PromoteIntRes_CTLZ(SDNode *N);
219  SDOperand PromoteIntRes_CTPOP(SDNode *N);
220  SDOperand PromoteIntRes_CTTZ(SDNode *N);
221  SDOperand PromoteIntRes_EXTRACT_VECTOR_ELT(SDNode *N);
222  SDOperand PromoteIntRes_FP_ROUND(SDNode *N);
223  SDOperand PromoteIntRes_FP_TO_XINT(SDNode *N);
224  SDOperand PromoteIntRes_INT_EXTEND(SDNode *N);
225  SDOperand PromoteIntRes_LOAD(LoadSDNode *N);
226  SDOperand PromoteIntRes_SDIV(SDNode *N);
227  SDOperand PromoteIntRes_SELECT   (SDNode *N);
228  SDOperand PromoteIntRes_SELECT_CC(SDNode *N);
229  SDOperand PromoteIntRes_SETCC(SDNode *N);
230  SDOperand PromoteIntRes_SHL(SDNode *N);
231  SDOperand PromoteIntRes_SimpleIntBinOp(SDNode *N);
232  SDOperand PromoteIntRes_SRA(SDNode *N);
233  SDOperand PromoteIntRes_SRL(SDNode *N);
234  SDOperand PromoteIntRes_TRUNCATE(SDNode *N);
235  SDOperand PromoteIntRes_UDIV(SDNode *N);
236  SDOperand PromoteIntRes_UNDEF(SDNode *N);
237
238  // Integer Operand Promotion.
239  bool PromoteIntegerOperand(SDNode *N, unsigned OperandNo);
240  SDOperand PromoteIntOp_ANY_EXTEND(SDNode *N);
241  SDOperand PromoteIntOp_BUILD_PAIR(SDNode *N);
242  SDOperand PromoteIntOp_BR_CC(SDNode *N, unsigned OpNo);
243  SDOperand PromoteIntOp_BRCOND(SDNode *N, unsigned OpNo);
244  SDOperand PromoteIntOp_BUILD_VECTOR(SDNode *N);
245  SDOperand PromoteIntOp_FP_EXTEND(SDNode *N);
246  SDOperand PromoteIntOp_FP_ROUND(SDNode *N);
247  SDOperand PromoteIntOp_INT_TO_FP(SDNode *N);
248  SDOperand PromoteIntOp_INSERT_VECTOR_ELT(SDNode *N, unsigned OpNo);
249  SDOperand PromoteIntOp_MEMBARRIER(SDNode *N);
250  SDOperand PromoteIntOp_SELECT(SDNode *N, unsigned OpNo);
251  SDOperand PromoteIntOp_SETCC(SDNode *N, unsigned OpNo);
252  SDOperand PromoteIntOp_SIGN_EXTEND(SDNode *N);
253  SDOperand PromoteIntOp_STORE(StoreSDNode *N, unsigned OpNo);
254  SDOperand PromoteIntOp_TRUNCATE(SDNode *N);
255  SDOperand PromoteIntOp_ZERO_EXTEND(SDNode *N);
256
257  void PromoteSetCCOperands(SDOperand &LHS,SDOperand &RHS, ISD::CondCode Code);
258
259  //===--------------------------------------------------------------------===//
260  // Integer Expansion Support: LegalizeIntegerTypes.cpp
261  //===--------------------------------------------------------------------===//
262
263  void GetExpandedInteger(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
264  void SetExpandedInteger(SDOperand Op, SDOperand Lo, SDOperand Hi);
265
266  // Integer Result Expansion.
267  void ExpandIntegerResult(SDNode *N, unsigned ResNo);
268  void ExpandIntRes_ANY_EXTEND        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
269  void ExpandIntRes_AssertZext        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
270  void ExpandIntRes_BIT_CONVERT       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
271  void ExpandIntRes_BUILD_PAIR        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
272  void ExpandIntRes_Constant          (SDNode *N, SDOperand &Lo, SDOperand &Hi);
273  void ExpandIntRes_CTLZ              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
274  void ExpandIntRes_CTPOP             (SDNode *N, SDOperand &Lo, SDOperand &Hi);
275  void ExpandIntRes_CTTZ              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
276  void ExpandIntRes_EXTRACT_VECTOR_ELT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
277  void ExpandIntRes_LOAD          (LoadSDNode *N, SDOperand &Lo, SDOperand &Hi);
278  void ExpandIntRes_MERGE_VALUES      (SDNode *N, SDOperand &Lo, SDOperand &Hi);
279  void ExpandIntRes_SIGN_EXTEND       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
280  void ExpandIntRes_SIGN_EXTEND_INREG (SDNode *N, SDOperand &Lo, SDOperand &Hi);
281  void ExpandIntRes_TRUNCATE          (SDNode *N, SDOperand &Lo, SDOperand &Hi);
282  void ExpandIntRes_UNDEF             (SDNode *N, SDOperand &Lo, SDOperand &Hi);
283  void ExpandIntRes_ZERO_EXTEND       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
284  void ExpandIntRes_FP_TO_SINT        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
285  void ExpandIntRes_FP_TO_UINT        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
286
287  void ExpandIntRes_Logical           (SDNode *N, SDOperand &Lo, SDOperand &Hi);
288  void ExpandIntRes_BSWAP             (SDNode *N, SDOperand &Lo, SDOperand &Hi);
289  void ExpandIntRes_ADDSUB            (SDNode *N, SDOperand &Lo, SDOperand &Hi);
290  void ExpandIntRes_ADDSUBC           (SDNode *N, SDOperand &Lo, SDOperand &Hi);
291  void ExpandIntRes_ADDSUBE           (SDNode *N, SDOperand &Lo, SDOperand &Hi);
292  void ExpandIntRes_SELECT            (SDNode *N, SDOperand &Lo, SDOperand &Hi);
293  void ExpandIntRes_SELECT_CC         (SDNode *N, SDOperand &Lo, SDOperand &Hi);
294  void ExpandIntRes_MUL               (SDNode *N, SDOperand &Lo, SDOperand &Hi);
295  void ExpandIntRes_SDIV              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
296  void ExpandIntRes_SREM              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
297  void ExpandIntRes_UDIV              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
298  void ExpandIntRes_UREM              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
299  void ExpandIntRes_Shift             (SDNode *N, SDOperand &Lo, SDOperand &Hi);
300
301  void ExpandShiftByConstant(SDNode *N, unsigned Amt,
302                             SDOperand &Lo, SDOperand &Hi);
303  bool ExpandShiftWithKnownAmountBit(SDNode *N, SDOperand &Lo, SDOperand &Hi);
304
305  // Integer Operand Expansion.
306  bool ExpandIntegerOperand(SDNode *N, unsigned OperandNo);
307  SDOperand ExpandIntOp_BIT_CONVERT(SDNode *N);
308  SDOperand ExpandIntOp_BR_CC(SDNode *N);
309  SDOperand ExpandIntOp_BUILD_VECTOR(SDNode *N);
310  SDOperand ExpandIntOp_EXTRACT_ELEMENT(SDNode *N);
311  SDOperand ExpandIntOp_SETCC(SDNode *N);
312  SDOperand ExpandIntOp_SINT_TO_FP(SDOperand Source, MVT DestTy);
313  SDOperand ExpandIntOp_STORE(StoreSDNode *N, unsigned OpNo);
314  SDOperand ExpandIntOp_TRUNCATE(SDNode *N);
315  SDOperand ExpandIntOp_UINT_TO_FP(SDOperand Source, MVT DestTy);
316
317  void ExpandSetCCOperands(SDOperand &NewLHS, SDOperand &NewRHS,
318                           ISD::CondCode &CCCode);
319
320  //===--------------------------------------------------------------------===//
321  // Float to Integer Conversion Support: LegalizeFloatTypes.cpp
322  //===--------------------------------------------------------------------===//
323
324  SDOperand GetSoftenedFloat(SDOperand Op) {
325    SDOperand &SoftenedOp = SoftenedFloats[Op];
326    RemapNode(SoftenedOp);
327    assert(SoftenedOp.Val && "Operand wasn't converted to integer?");
328    return SoftenedOp;
329  }
330  void SetSoftenedFloat(SDOperand Op, SDOperand Result);
331
332  // Result Float to Integer Conversion.
333  void SoftenFloatResult(SDNode *N, unsigned OpNo);
334  SDOperand SoftenFloatRes_BIT_CONVERT(SDNode *N);
335  SDOperand SoftenFloatRes_BUILD_PAIR(SDNode *N);
336  SDOperand SoftenFloatRes_ConstantFP(ConstantFPSDNode *N);
337  SDOperand SoftenFloatRes_FADD(SDNode *N);
338  SDOperand SoftenFloatRes_FCOPYSIGN(SDNode *N);
339  SDOperand SoftenFloatRes_FMUL(SDNode *N);
340  SDOperand SoftenFloatRes_FSUB(SDNode *N);
341  SDOperand SoftenFloatRes_LOAD(SDNode *N);
342  SDOperand SoftenFloatRes_XINT_TO_FP(SDNode *N);
343
344  // Operand Float to Integer Conversion.
345  bool SoftenFloatOperand(SDNode *N, unsigned OpNo);
346  SDOperand SoftenFloatOp_BIT_CONVERT(SDNode *N);
347
348  //===--------------------------------------------------------------------===//
349  // Float Expansion Support: LegalizeFloatTypes.cpp
350  //===--------------------------------------------------------------------===//
351
352  void GetExpandedFloat(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
353  void SetExpandedFloat(SDOperand Op, SDOperand Lo, SDOperand Hi);
354
355  // Float Result Expansion.
356  void ExpandFloatResult(SDNode *N, unsigned ResNo);
357
358  // Float Operand Expansion.
359  bool ExpandFloatOperand(SDNode *N, unsigned OperandNo);
360
361  //===--------------------------------------------------------------------===//
362  // Scalarization Support: LegalizeVectorTypes.cpp
363  //===--------------------------------------------------------------------===//
364
365  SDOperand GetScalarizedVector(SDOperand Op) {
366    SDOperand &ScalarizedOp = ScalarizedVectors[Op];
367    RemapNode(ScalarizedOp);
368    assert(ScalarizedOp.Val && "Operand wasn't scalarized?");
369    return ScalarizedOp;
370  }
371  void SetScalarizedVector(SDOperand Op, SDOperand Result);
372
373  // Vector Result Scalarization: <1 x ty> -> ty.
374  void ScalarizeResult(SDNode *N, unsigned OpNo);
375  SDOperand ScalarizeRes_BinOp(SDNode *N);
376  SDOperand ScalarizeRes_UnaryOp(SDNode *N);
377
378  SDOperand ScalarizeRes_BIT_CONVERT(SDNode *N);
379  SDOperand ScalarizeRes_FPOWI(SDNode *N);
380  SDOperand ScalarizeRes_INSERT_VECTOR_ELT(SDNode *N);
381  SDOperand ScalarizeRes_LOAD(LoadSDNode *N);
382  SDOperand ScalarizeRes_SELECT(SDNode *N);
383  SDOperand ScalarizeRes_UNDEF(SDNode *N);
384  SDOperand ScalarizeRes_VECTOR_SHUFFLE(SDNode *N);
385
386  // Vector Operand Scalarization: <1 x ty> -> ty.
387  bool ScalarizeOperand(SDNode *N, unsigned OpNo);
388  SDOperand ScalarizeOp_BIT_CONVERT(SDNode *N);
389  SDOperand ScalarizeOp_EXTRACT_VECTOR_ELT(SDNode *N);
390  SDOperand ScalarizeOp_STORE(StoreSDNode *N, unsigned OpNo);
391
392  //===--------------------------------------------------------------------===//
393  // Vector Splitting Support: LegalizeVectorTypes.cpp
394  //===--------------------------------------------------------------------===//
395
396  void GetSplitVector(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
397  void SetSplitVector(SDOperand Op, SDOperand Lo, SDOperand Hi);
398
399  // Vector Result Splitting: <128 x ty> -> 2 x <64 x ty>.
400  void SplitResult(SDNode *N, unsigned OpNo);
401
402  void SplitRes_UNDEF(SDNode *N, SDOperand &Lo, SDOperand &Hi);
403  void SplitRes_LOAD(LoadSDNode *N, SDOperand &Lo, SDOperand &Hi);
404  void SplitRes_BUILD_PAIR(SDNode *N, SDOperand &Lo, SDOperand &Hi);
405  void SplitRes_INSERT_VECTOR_ELT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
406  void SplitRes_VECTOR_SHUFFLE(SDNode *N, SDOperand &Lo, SDOperand &Hi);
407
408  void SplitRes_BUILD_VECTOR(SDNode *N, SDOperand &Lo, SDOperand &Hi);
409  void SplitRes_CONCAT_VECTORS(SDNode *N, SDOperand &Lo, SDOperand &Hi);
410  void SplitRes_BIT_CONVERT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
411  void SplitRes_UnOp(SDNode *N, SDOperand &Lo, SDOperand &Hi);
412  void SplitRes_BinOp(SDNode *N, SDOperand &Lo, SDOperand &Hi);
413  void SplitRes_FPOWI(SDNode *N, SDOperand &Lo, SDOperand &Hi);
414  void SplitRes_SELECT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
415
416  // Vector Operand Splitting: <128 x ty> -> 2 x <64 x ty>.
417  bool SplitOperand(SDNode *N, unsigned OpNo);
418
419  SDOperand SplitOp_BIT_CONVERT(SDNode *N);
420  SDOperand SplitOp_EXTRACT_SUBVECTOR(SDNode *N);
421  SDOperand SplitOp_EXTRACT_VECTOR_ELT(SDNode *N);
422  SDOperand SplitOp_RET(SDNode *N, unsigned OpNo);
423  SDOperand SplitOp_STORE(StoreSDNode *N, unsigned OpNo);
424  SDOperand SplitOp_VECTOR_SHUFFLE(SDNode *N, unsigned OpNo);
425};
426
427} // end namespace llvm.
428
429#endif
430