LegalizeTypes.h revision 7d0d8460646d1a06ff561775d40123a4cf65bf4d 
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    Promote,    // This type should be executed in a larger type.
64    Expand,     // This type should be split into two types of half the size.
65    FloatToInt, // Convert a floating point type to an integer of the same size.
66    Scalarize,  // Replace this one-element vector type with its element type.
67    Split       // This vector type should be split into smaller vectors.
68  };
69
70  /// ValueTypeActions - This is a bitvector that contains two bits for each
71  /// simple value type, where the two bits correspond to the LegalizeAction
72  /// enum from TargetLowering.  This can be queried with "getTypeAction(VT)".
73  TargetLowering::ValueTypeActionImpl ValueTypeActions;
74
75  /// getTypeAction - Return how we should legalize values of this type, either
76  /// it is already legal, or we need to promote it to a larger integer type, or
77  /// we need to expand it into multiple registers of a smaller integer type, or
78  /// we need to scalarize a one-element vector type into the element type, or
79  /// we need to split a vector type into smaller vector types.
80  LegalizeAction getTypeAction(MVT VT) const {
81    switch (ValueTypeActions.getTypeAction(VT)) {
82    default:
83      assert(false && "Unknown legalize action!");
84    case TargetLowering::Legal:
85      return Legal;
86    case TargetLowering::Promote:
87      return Promote;
88    case TargetLowering::Expand:
89      // Expand can mean
90      // 1) split scalar in half, 2) convert a float to an integer,
91      // 3) scalarize a single-element vector, 4) split a vector in two.
92      if (!VT.isVector()) {
93        if (VT.getSizeInBits() == TLI.getTypeToTransformTo(VT).getSizeInBits())
94          return FloatToInt;
95        else
96          return Expand;
97      } else if (VT.getVectorNumElements() == 1) {
98        return Scalarize;
99      } else {
100        return Split;
101      }
102    }
103  }
104
105  /// isTypeLegal - Return true if this type is legal on this target.
106  bool isTypeLegal(MVT VT) const {
107    return ValueTypeActions.getTypeAction(VT) == TargetLowering::Legal;
108  }
109
110  /// PromotedNodes - For nodes that are below legal width, this map indicates
111  /// what promoted value to use.
112  DenseMap<SDOperand, SDOperand> PromotedNodes;
113
114  /// ExpandedNodes - For nodes that need to be expanded this map indicates
115  /// which operands are the expanded version of the input.
116  DenseMap<SDOperand, std::pair<SDOperand, SDOperand> > ExpandedNodes;
117
118  /// FloatToIntedNodes - For floating point nodes converted to integers of
119  /// the same size, this map indicates the converted value to use.
120  DenseMap<SDOperand, SDOperand> FloatToIntedNodes;
121
122  /// ScalarizedNodes - For nodes that are <1 x ty>, this map indicates the
123  /// scalar value of type 'ty' to use.
124  DenseMap<SDOperand, SDOperand> ScalarizedNodes;
125
126  /// SplitNodes - For nodes that need to be split this map indicates
127  /// which operands are the expanded version of the input.
128  DenseMap<SDOperand, std::pair<SDOperand, SDOperand> > SplitNodes;
129
130  /// ReplacedNodes - For nodes that have been replaced with another,
131  /// indicates the replacement node to use.
132  DenseMap<SDOperand, SDOperand> ReplacedNodes;
133
134  /// Worklist - This defines a worklist of nodes to process.  In order to be
135  /// pushed onto this worklist, all operands of a node must have already been
136  /// processed.
137  SmallVector<SDNode*, 128> Worklist;
138
139public:
140  explicit DAGTypeLegalizer(SelectionDAG &dag)
141    : TLI(dag.getTargetLoweringInfo()), DAG(dag),
142    ValueTypeActions(TLI.getValueTypeActions()) {
143    assert(MVT::LAST_VALUETYPE <= 32 &&
144           "Too many value types for ValueTypeActions to hold!");
145  }
146
147  void run();
148
149  /// ReanalyzeNode - Recompute the NodeID and correct processed operands
150  /// for the specified node, adding it to the worklist if ready.
151  void ReanalyzeNode(SDNode *N) {
152    N->setNodeId(NewNode);
153    AnalyzeNewNode(N);
154  }
155
156  void NoteReplacement(SDOperand From, SDOperand To) {
157    ExpungeNode(From);
158    ExpungeNode(To);
159    ReplacedNodes[From] = To;
160  }
161
162private:
163  void AnalyzeNewNode(SDNode *&N);
164
165  void ReplaceValueWith(SDOperand From, SDOperand To);
166  void ReplaceNodeWith(SDNode *From, SDNode *To);
167
168  void RemapNode(SDOperand &N);
169  void ExpungeNode(SDOperand N);
170
171  // Common routines.
172  SDOperand CreateStackStoreLoad(SDOperand Op, MVT DestVT);
173  SDOperand MakeLibCall(RTLIB::Libcall LC, MVT RetVT,
174                        const SDOperand *Ops, unsigned NumOps, bool isSigned);
175
176  SDOperand BitConvertToInteger(SDOperand Op);
177  SDOperand JoinIntegers(SDOperand Lo, SDOperand Hi);
178  void SplitInteger(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
179  void SplitInteger(SDOperand Op, MVT LoVT, MVT HiVT,
180                    SDOperand &Lo, SDOperand &Hi);
181
182  SDOperand GetVectorElementPointer(SDOperand VecPtr, MVT EltVT,
183                                    SDOperand Index);
184
185  //===--------------------------------------------------------------------===//
186  // Promotion Support: LegalizeTypesPromote.cpp
187  //===--------------------------------------------------------------------===//
188
189  SDOperand GetPromotedOp(SDOperand Op) {
190    SDOperand &PromotedOp = PromotedNodes[Op];
191    RemapNode(PromotedOp);
192    assert(PromotedOp.Val && "Operand wasn't promoted?");
193    return PromotedOp;
194  }
195  void SetPromotedOp(SDOperand Op, SDOperand Result);
196
197  /// GetPromotedZExtOp - Get a promoted operand and zero extend it to the final
198  /// size.
199  SDOperand GetPromotedZExtOp(SDOperand Op) {
200    MVT OldVT = Op.getValueType();
201    Op = GetPromotedOp(Op);
202    return DAG.getZeroExtendInReg(Op, OldVT);
203  }
204
205  // Result Promotion.
206  void PromoteResult(SDNode *N, unsigned ResNo);
207  SDOperand PromoteResult_BIT_CONVERT(SDNode *N);
208  SDOperand PromoteResult_BUILD_PAIR(SDNode *N);
209  SDOperand PromoteResult_Constant(SDNode *N);
210  SDOperand PromoteResult_CTLZ(SDNode *N);
211  SDOperand PromoteResult_CTPOP(SDNode *N);
212  SDOperand PromoteResult_CTTZ(SDNode *N);
213  SDOperand PromoteResult_EXTRACT_VECTOR_ELT(SDNode *N);
214  SDOperand PromoteResult_FP_ROUND(SDNode *N);
215  SDOperand PromoteResult_FP_TO_XINT(SDNode *N);
216  SDOperand PromoteResult_INT_EXTEND(SDNode *N);
217  SDOperand PromoteResult_LOAD(LoadSDNode *N);
218  SDOperand PromoteResult_SDIV(SDNode *N);
219  SDOperand PromoteResult_SELECT   (SDNode *N);
220  SDOperand PromoteResult_SELECT_CC(SDNode *N);
221  SDOperand PromoteResult_SETCC(SDNode *N);
222  SDOperand PromoteResult_SHL(SDNode *N);
223  SDOperand PromoteResult_SimpleIntBinOp(SDNode *N);
224  SDOperand PromoteResult_SRA(SDNode *N);
225  SDOperand PromoteResult_SRL(SDNode *N);
226  SDOperand PromoteResult_TRUNCATE(SDNode *N);
227  SDOperand PromoteResult_UDIV(SDNode *N);
228  SDOperand PromoteResult_UNDEF(SDNode *N);
229
230  // Operand Promotion.
231  bool PromoteOperand(SDNode *N, unsigned OperandNo);
232  SDOperand PromoteOperand_ANY_EXTEND(SDNode *N);
233  SDOperand PromoteOperand_BUILD_PAIR(SDNode *N);
234  SDOperand PromoteOperand_BR_CC(SDNode *N, unsigned OpNo);
235  SDOperand PromoteOperand_BRCOND(SDNode *N, unsigned OpNo);
236  SDOperand PromoteOperand_BUILD_VECTOR(SDNode *N);
237  SDOperand PromoteOperand_FP_EXTEND(SDNode *N);
238  SDOperand PromoteOperand_FP_ROUND(SDNode *N);
239  SDOperand PromoteOperand_INT_TO_FP(SDNode *N);
240  SDOperand PromoteOperand_INSERT_VECTOR_ELT(SDNode *N, unsigned OpNo);
241  SDOperand PromoteOperand_MEMBARRIER(SDNode *N);
242  SDOperand PromoteOperand_RET(SDNode *N, unsigned OpNo);
243  SDOperand PromoteOperand_SELECT(SDNode *N, unsigned OpNo);
244  SDOperand PromoteOperand_SETCC(SDNode *N, unsigned OpNo);
245  SDOperand PromoteOperand_SIGN_EXTEND(SDNode *N);
246  SDOperand PromoteOperand_STORE(StoreSDNode *N, unsigned OpNo);
247  SDOperand PromoteOperand_TRUNCATE(SDNode *N);
248  SDOperand PromoteOperand_ZERO_EXTEND(SDNode *N);
249
250  void PromoteSetCCOperands(SDOperand &LHS,SDOperand &RHS, ISD::CondCode Code);
251
252  //===--------------------------------------------------------------------===//
253  // Expansion Support: LegalizeTypesExpand.cpp
254  //===--------------------------------------------------------------------===//
255
256  void GetExpandedOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
257  void SetExpandedOp(SDOperand Op, SDOperand Lo, SDOperand Hi);
258
259  // Result Expansion.
260  void ExpandResult(SDNode *N, unsigned ResNo);
261  void ExpandResult_ANY_EXTEND (SDNode *N, SDOperand &Lo, SDOperand &Hi);
262  void ExpandResult_AssertZext (SDNode *N, SDOperand &Lo, SDOperand &Hi);
263  void ExpandResult_BIT_CONVERT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
264  void ExpandResult_BUILD_PAIR (SDNode *N, SDOperand &Lo, SDOperand &Hi);
265  void ExpandResult_Constant   (SDNode *N, SDOperand &Lo, SDOperand &Hi);
266  void ExpandResult_CTLZ       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
267  void ExpandResult_CTPOP      (SDNode *N, SDOperand &Lo, SDOperand &Hi);
268  void ExpandResult_CTTZ       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
269  void ExpandResult_EXTRACT_VECTOR_ELT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
270  void ExpandResult_LOAD       (LoadSDNode *N, SDOperand &Lo, SDOperand &Hi);
271  void ExpandResult_MERGE_VALUES(SDNode *N, SDOperand &Lo, SDOperand &Hi);
272  void ExpandResult_SIGN_EXTEND(SDNode *N, SDOperand &Lo, SDOperand &Hi);
273  void ExpandResult_SIGN_EXTEND_INREG(SDNode *N, SDOperand &Lo, SDOperand &Hi);
274  void ExpandResult_TRUNCATE   (SDNode *N, SDOperand &Lo, SDOperand &Hi);
275  void ExpandResult_UNDEF      (SDNode *N, SDOperand &Lo, SDOperand &Hi);
276  void ExpandResult_ZERO_EXTEND(SDNode *N, SDOperand &Lo, SDOperand &Hi);
277  void ExpandResult_FP_TO_SINT (SDNode *N, SDOperand &Lo, SDOperand &Hi);
278  void ExpandResult_FP_TO_UINT (SDNode *N, SDOperand &Lo, SDOperand &Hi);
279
280  void ExpandResult_Logical    (SDNode *N, SDOperand &Lo, SDOperand &Hi);
281  void ExpandResult_BSWAP      (SDNode *N, SDOperand &Lo, SDOperand &Hi);
282  void ExpandResult_ADDSUB     (SDNode *N, SDOperand &Lo, SDOperand &Hi);
283  void ExpandResult_ADDSUBC    (SDNode *N, SDOperand &Lo, SDOperand &Hi);
284  void ExpandResult_ADDSUBE    (SDNode *N, SDOperand &Lo, SDOperand &Hi);
285  void ExpandResult_SELECT     (SDNode *N, SDOperand &Lo, SDOperand &Hi);
286  void ExpandResult_SELECT_CC  (SDNode *N, SDOperand &Lo, SDOperand &Hi);
287  void ExpandResult_MUL        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
288  void ExpandResult_SDIV       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
289  void ExpandResult_SREM       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
290  void ExpandResult_UDIV       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
291  void ExpandResult_UREM       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
292  void ExpandResult_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  // Operand Expansion.
299  bool ExpandOperand(SDNode *N, unsigned OperandNo);
300  SDOperand ExpandOperand_BIT_CONVERT(SDNode *N);
301  SDOperand ExpandOperand_BR_CC(SDNode *N);
302  SDOperand ExpandOperand_BUILD_VECTOR(SDNode *N);
303  SDOperand ExpandOperand_EXTRACT_ELEMENT(SDNode *N);
304  SDOperand ExpandOperand_SETCC(SDNode *N);
305  SDOperand ExpandOperand_SINT_TO_FP(SDOperand Source, MVT DestTy);
306  SDOperand ExpandOperand_STORE(StoreSDNode *N, unsigned OpNo);
307  SDOperand ExpandOperand_TRUNCATE(SDNode *N);
308  SDOperand ExpandOperand_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: LegalizeTypesFloatToInt.cpp
315  //===--------------------------------------------------------------------===//
316
317  SDOperand GetIntegerOp(SDOperand Op) {
318    SDOperand &IntegerOp = FloatToIntedNodes[Op];
319    RemapNode(IntegerOp);
320    assert(IntegerOp.Val && "Operand wasn't converted to integer?");
321    return IntegerOp;
322  }
323  void SetIntegerOp(SDOperand Op, SDOperand Result);
324
325  // Result Float to Integer Conversion.
326  void FloatToIntResult(SDNode *N, unsigned OpNo);
327  SDOperand FloatToIntRes_BIT_CONVERT(SDNode *N);
328  SDOperand FloatToIntRes_BUILD_PAIR(SDNode *N);
329  SDOperand FloatToIntRes_ConstantFP(ConstantFPSDNode *N);
330  SDOperand FloatToIntRes_FADD(SDNode *N);
331  SDOperand FloatToIntRes_FCOPYSIGN(SDNode *N);
332  SDOperand FloatToIntRes_FMUL(SDNode *N);
333  SDOperand FloatToIntRes_FSUB(SDNode *N);
334  SDOperand FloatToIntRes_LOAD(SDNode *N);
335  SDOperand FloatToIntRes_XINT_TO_FP(SDNode *N);
336
337  // Operand Float to Integer Conversion.
338  bool FloatToIntOperand(SDNode *N, unsigned OpNo);
339  SDOperand FloatToIntOp_BIT_CONVERT(SDNode *N);
340
341  //===--------------------------------------------------------------------===//
342  // Scalarization Support: LegalizeTypesScalarize.cpp
343  //===--------------------------------------------------------------------===//
344
345  SDOperand GetScalarizedOp(SDOperand Op) {
346    SDOperand &ScalarOp = ScalarizedNodes[Op];
347    RemapNode(ScalarOp);
348    assert(ScalarOp.Val && "Operand wasn't scalarized?");
349    return ScalarOp;
350  }
351  void SetScalarizedOp(SDOperand Op, SDOperand Result);
352
353  // Result Vector Scalarization: <1 x ty> -> ty.
354  void ScalarizeResult(SDNode *N, unsigned OpNo);
355  SDOperand ScalarizeRes_BinOp(SDNode *N);
356  SDOperand ScalarizeRes_UnaryOp(SDNode *N);
357
358  SDOperand ScalarizeRes_BIT_CONVERT(SDNode *N);
359  SDOperand ScalarizeRes_FPOWI(SDNode *N);
360  SDOperand ScalarizeRes_INSERT_VECTOR_ELT(SDNode *N);
361  SDOperand ScalarizeRes_LOAD(LoadSDNode *N);
362  SDOperand ScalarizeRes_SELECT(SDNode *N);
363  SDOperand ScalarizeRes_UNDEF(SDNode *N);
364  SDOperand ScalarizeRes_VECTOR_SHUFFLE(SDNode *N);
365
366  // Operand Vector Scalarization: <1 x ty> -> ty.
367  bool ScalarizeOperand(SDNode *N, unsigned OpNo);
368  SDOperand ScalarizeOp_BIT_CONVERT(SDNode *N);
369  SDOperand ScalarizeOp_EXTRACT_VECTOR_ELT(SDNode *N);
370  SDOperand ScalarizeOp_STORE(StoreSDNode *N, unsigned OpNo);
371
372  //===--------------------------------------------------------------------===//
373  // Vector Splitting Support: LegalizeTypesSplit.cpp
374  //===--------------------------------------------------------------------===//
375
376  void GetSplitOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
377  void SetSplitOp(SDOperand Op, SDOperand Lo, SDOperand Hi);
378
379  // Result Vector Splitting: <128 x ty> -> 2 x <64 x ty>.
380  void SplitResult(SDNode *N, unsigned OpNo);
381
382  void SplitRes_UNDEF(SDNode *N, SDOperand &Lo, SDOperand &Hi);
383  void SplitRes_LOAD(LoadSDNode *N, SDOperand &Lo, SDOperand &Hi);
384  void SplitRes_BUILD_PAIR(SDNode *N, SDOperand &Lo, SDOperand &Hi);
385  void SplitRes_INSERT_VECTOR_ELT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
386  void SplitRes_VECTOR_SHUFFLE(SDNode *N, SDOperand &Lo, SDOperand &Hi);
387
388  void SplitRes_BUILD_VECTOR(SDNode *N, SDOperand &Lo, SDOperand &Hi);
389  void SplitRes_CONCAT_VECTORS(SDNode *N, SDOperand &Lo, SDOperand &Hi);
390  void SplitRes_BIT_CONVERT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
391  void SplitRes_UnOp(SDNode *N, SDOperand &Lo, SDOperand &Hi);
392  void SplitRes_BinOp(SDNode *N, SDOperand &Lo, SDOperand &Hi);
393  void SplitRes_FPOWI(SDNode *N, SDOperand &Lo, SDOperand &Hi);
394  void SplitRes_SELECT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
395
396  // Operand Vector Splitting: <128 x ty> -> 2 x <64 x ty>.
397  bool SplitOperand(SDNode *N, unsigned OpNo);
398
399  SDOperand SplitOp_BIT_CONVERT(SDNode *N);
400  SDOperand SplitOp_EXTRACT_SUBVECTOR(SDNode *N);
401  SDOperand SplitOp_EXTRACT_VECTOR_ELT(SDNode *N);
402  SDOperand SplitOp_RET(SDNode *N, unsigned OpNo);
403  SDOperand SplitOp_STORE(StoreSDNode *N, unsigned OpNo);
404  SDOperand SplitOp_VECTOR_SHUFFLE(SDNode *N, unsigned OpNo);
405};
406
407} // end namespace llvm.
408
409#endif
410