LegalizeTypes.h revision 0d84c348ed83b6450c6d1a9dba3934eff5c5eaec 
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_Constant          (SDNode *N, SDOperand &Lo, SDOperand &Hi);
271  void ExpandIntRes_CTLZ              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
272  void ExpandIntRes_CTPOP             (SDNode *N, SDOperand &Lo, SDOperand &Hi);
273  void ExpandIntRes_CTTZ              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
274  void ExpandIntRes_LOAD          (LoadSDNode *N, SDOperand &Lo, SDOperand &Hi);
275  void ExpandIntRes_SIGN_EXTEND       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
276  void ExpandIntRes_SIGN_EXTEND_INREG (SDNode *N, SDOperand &Lo, SDOperand &Hi);
277  void ExpandIntRes_TRUNCATE          (SDNode *N, SDOperand &Lo, SDOperand &Hi);
278  void ExpandIntRes_ZERO_EXTEND       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
279  void ExpandIntRes_FP_TO_SINT        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
280  void ExpandIntRes_FP_TO_UINT        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
281
282  void ExpandIntRes_Logical           (SDNode *N, SDOperand &Lo, SDOperand &Hi);
283  void ExpandIntRes_BSWAP             (SDNode *N, SDOperand &Lo, SDOperand &Hi);
284  void ExpandIntRes_ADDSUB            (SDNode *N, SDOperand &Lo, SDOperand &Hi);
285  void ExpandIntRes_ADDSUBC           (SDNode *N, SDOperand &Lo, SDOperand &Hi);
286  void ExpandIntRes_ADDSUBE           (SDNode *N, SDOperand &Lo, SDOperand &Hi);
287  void ExpandIntRes_MUL               (SDNode *N, SDOperand &Lo, SDOperand &Hi);
288  void ExpandIntRes_SDIV              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
289  void ExpandIntRes_SREM              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
290  void ExpandIntRes_UDIV              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
291  void ExpandIntRes_UREM              (SDNode *N, SDOperand &Lo, SDOperand &Hi);
292  void ExpandIntRes_Shift             (SDNode *N, SDOperand &Lo, SDOperand &Hi);
293
294  void ExpandShiftByConstant(SDNode *N, unsigned Amt,
295                             SDOperand &Lo, SDOperand &Hi);
296  bool ExpandShiftWithKnownAmountBit(SDNode *N, SDOperand &Lo, SDOperand &Hi);
297
298  // Integer Operand Expansion.
299  bool ExpandIntegerOperand(SDNode *N, unsigned OperandNo);
300  SDOperand ExpandIntOp_BIT_CONVERT(SDNode *N);
301  SDOperand ExpandIntOp_BR_CC(SDNode *N);
302  SDOperand ExpandIntOp_BUILD_VECTOR(SDNode *N);
303  SDOperand ExpandIntOp_EXTRACT_ELEMENT(SDNode *N);
304  SDOperand ExpandIntOp_SETCC(SDNode *N);
305  SDOperand ExpandIntOp_SINT_TO_FP(SDOperand Source, MVT DestTy);
306  SDOperand ExpandIntOp_STORE(StoreSDNode *N, unsigned OpNo);
307  SDOperand ExpandIntOp_TRUNCATE(SDNode *N);
308  SDOperand ExpandIntOp_UINT_TO_FP(SDOperand Source, MVT DestTy);
309
310  void ExpandSetCCOperands(SDOperand &NewLHS, SDOperand &NewRHS,
311                           ISD::CondCode &CCCode);
312
313  //===--------------------------------------------------------------------===//
314  // Float to Integer Conversion Support: LegalizeFloatTypes.cpp
315  //===--------------------------------------------------------------------===//
316
317  SDOperand GetSoftenedFloat(SDOperand Op) {
318    SDOperand &SoftenedOp = SoftenedFloats[Op];
319    RemapNode(SoftenedOp);
320    assert(SoftenedOp.Val && "Operand wasn't converted to integer?");
321    return SoftenedOp;
322  }
323  void SetSoftenedFloat(SDOperand Op, SDOperand Result);
324
325  // Result Float to Integer Conversion.
326  void SoftenFloatResult(SDNode *N, unsigned OpNo);
327  SDOperand SoftenFloatRes_BIT_CONVERT(SDNode *N);
328  SDOperand SoftenFloatRes_BUILD_PAIR(SDNode *N);
329  SDOperand SoftenFloatRes_ConstantFP(ConstantFPSDNode *N);
330  SDOperand SoftenFloatRes_FADD(SDNode *N);
331  SDOperand SoftenFloatRes_FCOPYSIGN(SDNode *N);
332  SDOperand SoftenFloatRes_FMUL(SDNode *N);
333  SDOperand SoftenFloatRes_FSUB(SDNode *N);
334  SDOperand SoftenFloatRes_LOAD(SDNode *N);
335  SDOperand SoftenFloatRes_XINT_TO_FP(SDNode *N);
336
337  // Operand Float to Integer Conversion.
338  bool SoftenFloatOperand(SDNode *N, unsigned OpNo);
339  SDOperand SoftenFloatOp_BIT_CONVERT(SDNode *N);
340
341  //===--------------------------------------------------------------------===//
342  // Float Expansion Support: LegalizeFloatTypes.cpp
343  //===--------------------------------------------------------------------===//
344
345  void GetExpandedFloat(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
346  void SetExpandedFloat(SDOperand Op, SDOperand Lo, SDOperand Hi);
347
348  // Float Result Expansion.
349  void ExpandFloatResult(SDNode *N, unsigned ResNo);
350  void ExpandFloatRes_LOAD(SDNode *N, SDOperand &Lo, SDOperand &Hi);
351
352  // Float Operand Expansion.
353  bool ExpandFloatOperand(SDNode *N, unsigned OperandNo);
354  SDOperand ExpandFloatOp_STORE(SDNode *N, unsigned OpNo);
355
356  //===--------------------------------------------------------------------===//
357  // Scalarization Support: LegalizeVectorTypes.cpp
358  //===--------------------------------------------------------------------===//
359
360  SDOperand GetScalarizedVector(SDOperand Op) {
361    SDOperand &ScalarizedOp = ScalarizedVectors[Op];
362    RemapNode(ScalarizedOp);
363    assert(ScalarizedOp.Val && "Operand wasn't scalarized?");
364    return ScalarizedOp;
365  }
366  void SetScalarizedVector(SDOperand Op, SDOperand Result);
367
368  // Vector Result Scalarization: <1 x ty> -> ty.
369  void ScalarizeResult(SDNode *N, unsigned OpNo);
370  SDOperand ScalarizeVecRes_BinOp(SDNode *N);
371  SDOperand ScalarizeVecRes_UnaryOp(SDNode *N);
372
373  SDOperand ScalarizeVecRes_BIT_CONVERT(SDNode *N);
374  SDOperand ScalarizeVecRes_FPOWI(SDNode *N);
375  SDOperand ScalarizeVecRes_INSERT_VECTOR_ELT(SDNode *N);
376  SDOperand ScalarizeVecRes_LOAD(LoadSDNode *N);
377  SDOperand ScalarizeVecRes_SELECT(SDNode *N);
378  SDOperand ScalarizeVecRes_UNDEF(SDNode *N);
379  SDOperand ScalarizeVecRes_VECTOR_SHUFFLE(SDNode *N);
380
381  // Vector Operand Scalarization: <1 x ty> -> ty.
382  bool ScalarizeOperand(SDNode *N, unsigned OpNo);
383  SDOperand ScalarizeVecOp_BIT_CONVERT(SDNode *N);
384  SDOperand ScalarizeVecOp_EXTRACT_VECTOR_ELT(SDNode *N);
385  SDOperand ScalarizeVecOp_STORE(StoreSDNode *N, unsigned OpNo);
386
387  //===--------------------------------------------------------------------===//
388  // Vector Splitting Support: LegalizeVectorTypes.cpp
389  //===--------------------------------------------------------------------===//
390
391  void GetSplitVector(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
392  void SetSplitVector(SDOperand Op, SDOperand Lo, SDOperand Hi);
393
394  // Vector Result Splitting: <128 x ty> -> 2 x <64 x ty>.
395  void SplitResult(SDNode *N, unsigned OpNo);
396
397  void SplitVecRes_UNDEF(SDNode *N, SDOperand &Lo, SDOperand &Hi);
398  void SplitVecRes_LOAD(LoadSDNode *N, SDOperand &Lo, SDOperand &Hi);
399  void SplitVecRes_BUILD_PAIR(SDNode *N, SDOperand &Lo, SDOperand &Hi);
400  void SplitVecRes_INSERT_VECTOR_ELT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
401  void SplitVecRes_VECTOR_SHUFFLE(SDNode *N, SDOperand &Lo, SDOperand &Hi);
402
403  void SplitVecRes_BUILD_VECTOR(SDNode *N, SDOperand &Lo, SDOperand &Hi);
404  void SplitVecRes_CONCAT_VECTORS(SDNode *N, SDOperand &Lo, SDOperand &Hi);
405  void SplitVecRes_BIT_CONVERT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
406  void SplitVecRes_UnOp(SDNode *N, SDOperand &Lo, SDOperand &Hi);
407  void SplitVecRes_BinOp(SDNode *N, SDOperand &Lo, SDOperand &Hi);
408  void SplitVecRes_FPOWI(SDNode *N, SDOperand &Lo, SDOperand &Hi);
409  void SplitVecRes_SELECT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
410
411  // Vector Operand Splitting: <128 x ty> -> 2 x <64 x ty>.
412  bool SplitOperand(SDNode *N, unsigned OpNo);
413
414  SDOperand SplitVecOp_BIT_CONVERT(SDNode *N);
415  SDOperand SplitVecOp_EXTRACT_SUBVECTOR(SDNode *N);
416  SDOperand SplitVecOp_EXTRACT_VECTOR_ELT(SDNode *N);
417  SDOperand SplitVecOp_RET(SDNode *N, unsigned OpNo);
418  SDOperand SplitVecOp_STORE(StoreSDNode *N, unsigned OpNo);
419  SDOperand SplitVecOp_VECTOR_SHUFFLE(SDNode *N, unsigned OpNo);
420
421  //===--------------------------------------------------------------------===//
422  // Generic Splitting: LegalizeTypesGeneric.cpp
423  //===--------------------------------------------------------------------===//
424
425  // Legalization methods which only use that the illegal type is split into two
426  // not necessarily identical types.  As such they can be used for splitting
427  // vectors and expanding integers and floats.
428
429  void GetSplitOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi) {
430    if (Op.getValueType().isVector())
431      GetSplitVector(Op, Lo, Hi);
432    else if (Op.getValueType().isInteger())
433      GetExpandedInteger(Op, Lo, Hi);
434    else
435      GetExpandedFloat(Op, Lo, Hi);
436  }
437
438  /// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type
439  /// which is split (or expanded) into two not necessarily identical pieces.
440  void GetSplitDestVTs(MVT InVT, MVT &LoVT, MVT &HiVT);
441
442  // Generic Result Splitting.
443  void SplitRes_MERGE_VALUES(SDNode *N, SDOperand &Lo, SDOperand &Hi);
444  void SplitRes_SELECT      (SDNode *N, SDOperand &Lo, SDOperand &Hi);
445  void SplitRes_SELECT_CC   (SDNode *N, SDOperand &Lo, SDOperand &Hi);
446  void SplitRes_UNDEF       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
447
448  //===--------------------------------------------------------------------===//
449  // Generic Expansion: LegalizeTypesGeneric.cpp
450  //===--------------------------------------------------------------------===//
451
452  // Legalization methods which only use that the illegal type is split into two
453  // identical types of half the size, and that the Lo/Hi part is stored first
454  // in memory on little/big-endian machines, followed by the Hi/Lo part.  As
455  // such they can be used for expanding integers and floats.
456
457  void GetExpandedOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi) {
458    if (Op.getValueType().isInteger())
459      GetExpandedInteger(Op, Lo, Hi);
460    else
461      GetExpandedFloat(Op, Lo, Hi);
462  }
463
464  // Generic Result Expansion.
465  void ExpandRes_BIT_CONVERT       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
466  void ExpandRes_BUILD_PAIR        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
467  void ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
468  void ExpandRes_NON_EXTLOAD       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
469
470  // Generic Operand Expansion.
471  SDOperand ExpandOp_BIT_CONVERT    (SDNode *N);
472  SDOperand ExpandOp_BUILD_VECTOR   (SDNode *N);
473  SDOperand ExpandOp_EXTRACT_ELEMENT(SDNode *N);
474  SDOperand ExpandOp_NON_TRUNCStore (SDNode *N, unsigned OpNo);
475
476};
477
478} // end namespace llvm.
479
480#endif
481