LegalizeTypes.h revision 4f069e6db1772a7e6cd8bfc360d819b56557badc
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  };
66
67  /// ValueTypeActions - This is a bitvector that contains two bits for each
68  /// simple value type, where the two bits correspond to the LegalizeAction
69  /// enum.  This can be queried with "getTypeAction(VT)".
70  TargetLowering::ValueTypeActionImpl ValueTypeActions;
71
72  /// getTypeAction - Return how we should legalize values of this type, either
73  /// it is already legal or we need to expand it into multiple registers of
74  /// smaller integer type, or we need to promote it to a larger type.
75  LegalizeAction getTypeAction(MVT::ValueType VT) const {
76    return (LegalizeAction)ValueTypeActions.getTypeAction(VT);
77  }
78
79  /// isTypeLegal - Return true if this type is legal on this target.
80  ///
81  bool isTypeLegal(MVT::ValueType VT) const {
82    return getTypeAction(VT) == Legal;
83  }
84
85  /// PromotedNodes - For nodes that are below legal width, this map indicates
86  /// what promoted value to use.
87  DenseMap<SDOperand, SDOperand> PromotedNodes;
88
89  /// ExpandedNodes - For nodes that need to be expanded this map indicates
90  /// which operands are the expanded version of the input.
91  DenseMap<SDOperand, std::pair<SDOperand, SDOperand> > ExpandedNodes;
92
93  /// ScalarizedNodes - For nodes that are <1 x ty>, this map indicates the
94  /// scalar value of type 'ty' to use.
95  DenseMap<SDOperand, SDOperand> ScalarizedNodes;
96
97  /// SplitNodes - For nodes that need to be split this map indicates
98  /// which operands are the expanded version of the input.
99  DenseMap<SDOperand, std::pair<SDOperand, SDOperand> > SplitNodes;
100
101  /// ReplacedNodes - For nodes that have been replaced with another,
102  /// indicates the replacement node to use.
103  DenseMap<SDOperand, SDOperand> ReplacedNodes;
104
105  /// Worklist - This defines a worklist of nodes to process.  In order to be
106  /// pushed onto this worklist, all operands of a node must have already been
107  /// processed.
108  SmallVector<SDNode*, 128> Worklist;
109
110public:
111  explicit DAGTypeLegalizer(SelectionDAG &dag)
112    : TLI(dag.getTargetLoweringInfo()), DAG(dag),
113    ValueTypeActions(TLI.getValueTypeActions()) {
114    assert(MVT::LAST_VALUETYPE <= 32 &&
115           "Too many value types for ValueTypeActions to hold!");
116  }
117
118  void run();
119
120  /// ReanalyzeNode - Recompute the NodeID and correct processed operands
121  /// for the specified node, adding it to the worklist if ready.
122  void ReanalyzeNode(SDNode *N) {
123    N->setNodeId(NewNode);
124    AnalyzeNewNode(N);
125  }
126
127private:
128  void AnalyzeNewNode(SDNode *&N);
129
130  void ReplaceValueWith(SDOperand From, SDOperand To);
131  void ReplaceNodeWith(SDNode *From, SDNode *To);
132
133  void RemapNode(SDOperand &N);
134
135  // Common routines.
136  SDOperand CreateStackStoreLoad(SDOperand Op, MVT::ValueType DestVT);
137  SDOperand HandleMemIntrinsic(SDNode *N);
138  void SplitOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
139
140  //===--------------------------------------------------------------------===//
141  // Promotion Support: LegalizeTypesPromote.cpp
142  //===--------------------------------------------------------------------===//
143
144  SDOperand GetPromotedOp(SDOperand Op) {
145    SDOperand &PromotedOp = PromotedNodes[Op];
146    RemapNode(PromotedOp);
147    assert(PromotedOp.Val && "Operand wasn't promoted?");
148    return PromotedOp;
149  }
150  void SetPromotedOp(SDOperand Op, SDOperand Result);
151
152  /// GetPromotedZExtOp - Get a promoted operand and zero extend it to the final
153  /// size.
154  SDOperand GetPromotedZExtOp(SDOperand Op) {
155    MVT::ValueType OldVT = Op.getValueType();
156    Op = GetPromotedOp(Op);
157    return DAG.getZeroExtendInReg(Op, OldVT);
158  }
159
160  // Result Promotion.
161  void PromoteResult(SDNode *N, unsigned ResNo);
162  SDOperand PromoteResult_BUILD_PAIR(SDNode *N);
163  SDOperand PromoteResult_Constant(SDNode *N);
164  SDOperand PromoteResult_CTLZ(SDNode *N);
165  SDOperand PromoteResult_CTPOP(SDNode *N);
166  SDOperand PromoteResult_CTTZ(SDNode *N);
167  SDOperand PromoteResult_FP_ROUND(SDNode *N);
168  SDOperand PromoteResult_FP_TO_XINT(SDNode *N);
169  SDOperand PromoteResult_INT_EXTEND(SDNode *N);
170  SDOperand PromoteResult_LOAD(LoadSDNode *N);
171  SDOperand PromoteResult_SDIV(SDNode *N);
172  SDOperand PromoteResult_SELECT   (SDNode *N);
173  SDOperand PromoteResult_SELECT_CC(SDNode *N);
174  SDOperand PromoteResult_SETCC(SDNode *N);
175  SDOperand PromoteResult_SHL(SDNode *N);
176  SDOperand PromoteResult_SimpleIntBinOp(SDNode *N);
177  SDOperand PromoteResult_SRA(SDNode *N);
178  SDOperand PromoteResult_SRL(SDNode *N);
179  SDOperand PromoteResult_TRUNCATE(SDNode *N);
180  SDOperand PromoteResult_UDIV(SDNode *N);
181  SDOperand PromoteResult_UNDEF(SDNode *N);
182
183  // Operand Promotion.
184  bool PromoteOperand(SDNode *N, unsigned OperandNo);
185  SDOperand PromoteOperand_ANY_EXTEND(SDNode *N);
186  SDOperand PromoteOperand_BUILD_PAIR(SDNode *N);
187  SDOperand PromoteOperand_BR_CC(SDNode *N, unsigned OpNo);
188  SDOperand PromoteOperand_BRCOND(SDNode *N, unsigned OpNo);
189  SDOperand PromoteOperand_BUILD_VECTOR(SDNode *N);
190  SDOperand PromoteOperand_FP_EXTEND(SDNode *N);
191  SDOperand PromoteOperand_FP_ROUND(SDNode *N);
192  SDOperand PromoteOperand_INT_TO_FP(SDNode *N);
193  SDOperand PromoteOperand_INSERT_VECTOR_ELT(SDNode *N, unsigned OpNo);
194  SDOperand PromoteOperand_MEMBARRIER(SDNode *N);
195  SDOperand PromoteOperand_RET(SDNode *N, unsigned OpNo);
196  SDOperand PromoteOperand_SELECT(SDNode *N, unsigned OpNo);
197  SDOperand PromoteOperand_SETCC(SDNode *N, unsigned OpNo);
198  SDOperand PromoteOperand_SIGN_EXTEND(SDNode *N);
199  SDOperand PromoteOperand_STORE(StoreSDNode *N, unsigned OpNo);
200  SDOperand PromoteOperand_TRUNCATE(SDNode *N);
201  SDOperand PromoteOperand_ZERO_EXTEND(SDNode *N);
202
203  void PromoteSetCCOperands(SDOperand &LHS,SDOperand &RHS, ISD::CondCode Code);
204
205  //===--------------------------------------------------------------------===//
206  // Expansion Support: LegalizeTypesExpand.cpp
207  //===--------------------------------------------------------------------===//
208
209  void GetExpandedOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
210  void SetExpandedOp(SDOperand Op, SDOperand Lo, SDOperand Hi);
211
212  // Result Expansion.
213  void ExpandResult(SDNode *N, unsigned ResNo);
214  void ExpandResult_ANY_EXTEND (SDNode *N, SDOperand &Lo, SDOperand &Hi);
215  void ExpandResult_AssertZext (SDNode *N, SDOperand &Lo, SDOperand &Hi);
216  void ExpandResult_BIT_CONVERT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
217  void ExpandResult_BUILD_PAIR (SDNode *N, SDOperand &Lo, SDOperand &Hi);
218  void ExpandResult_Constant   (SDNode *N, SDOperand &Lo, SDOperand &Hi);
219  void ExpandResult_CTLZ       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
220  void ExpandResult_CTPOP      (SDNode *N, SDOperand &Lo, SDOperand &Hi);
221  void ExpandResult_CTTZ       (SDNode *N, SDOperand &Lo, SDOperand &Hi);
222  void ExpandResult_LOAD       (LoadSDNode *N, SDOperand &Lo, SDOperand &Hi);
223  void ExpandResult_MERGE_VALUES(SDNode *N, SDOperand &Lo, SDOperand &Hi);
224  void ExpandResult_SIGN_EXTEND(SDNode *N, SDOperand &Lo, SDOperand &Hi);
225  void ExpandResult_SIGN_EXTEND_INREG(SDNode *N, SDOperand &Lo, SDOperand &Hi);
226  void ExpandResult_TRUNCATE   (SDNode *N, SDOperand &Lo, SDOperand &Hi);
227  void ExpandResult_UNDEF      (SDNode *N, SDOperand &Lo, SDOperand &Hi);
228  void ExpandResult_ZERO_EXTEND(SDNode *N, SDOperand &Lo, SDOperand &Hi);
229
230  void ExpandResult_Logical    (SDNode *N, SDOperand &Lo, SDOperand &Hi);
231  void ExpandResult_BSWAP      (SDNode *N, SDOperand &Lo, SDOperand &Hi);
232  void ExpandResult_ADDSUB     (SDNode *N, SDOperand &Lo, SDOperand &Hi);
233  void ExpandResult_ADDSUBC    (SDNode *N, SDOperand &Lo, SDOperand &Hi);
234  void ExpandResult_ADDSUBE    (SDNode *N, SDOperand &Lo, SDOperand &Hi);
235  void ExpandResult_SELECT     (SDNode *N, SDOperand &Lo, SDOperand &Hi);
236  void ExpandResult_SELECT_CC  (SDNode *N, SDOperand &Lo, SDOperand &Hi);
237  void ExpandResult_MUL        (SDNode *N, SDOperand &Lo, SDOperand &Hi);
238  void ExpandResult_Shift      (SDNode *N, SDOperand &Lo, SDOperand &Hi);
239
240  void ExpandShiftByConstant(SDNode *N, unsigned Amt,
241                             SDOperand &Lo, SDOperand &Hi);
242  bool ExpandShiftWithKnownAmountBit(SDNode *N, SDOperand &Lo, SDOperand &Hi);
243
244  // Operand Expansion.
245  bool ExpandOperand(SDNode *N, unsigned OperandNo);
246  SDOperand ExpandOperand_BIT_CONVERT(SDNode *N);
247  SDOperand ExpandOperand_BR_CC(SDNode *N);
248  SDOperand ExpandOperand_BUILD_VECTOR(SDNode *N);
249  SDOperand ExpandOperand_EXTRACT_ELEMENT(SDNode *N);
250  SDOperand ExpandOperand_SETCC(SDNode *N);
251  SDOperand ExpandOperand_SINT_TO_FP(SDOperand Source, MVT::ValueType DestTy);
252  SDOperand ExpandOperand_STORE(StoreSDNode *N, unsigned OpNo);
253  SDOperand ExpandOperand_TRUNCATE(SDNode *N);
254  SDOperand ExpandOperand_UINT_TO_FP(SDOperand Source, MVT::ValueType DestTy);
255
256  void ExpandSetCCOperands(SDOperand &NewLHS, SDOperand &NewRHS,
257                           ISD::CondCode &CCCode);
258
259  //===--------------------------------------------------------------------===//
260  // Scalarization Support: LegalizeTypesScalarize.cpp
261  //===--------------------------------------------------------------------===//
262
263  SDOperand GetScalarizedOp(SDOperand Op) {
264    SDOperand &ScalarOp = ScalarizedNodes[Op];
265    RemapNode(ScalarOp);
266    assert(ScalarOp.Val && "Operand wasn't scalarized?");
267    return ScalarOp;
268  }
269  void SetScalarizedOp(SDOperand Op, SDOperand Result);
270
271  // Result Vector Scalarization: <1 x ty> -> ty.
272  void ScalarizeResult(SDNode *N, unsigned OpNo);
273  SDOperand ScalarizeRes_BinOp(SDNode *N);
274  SDOperand ScalarizeRes_UnaryOp(SDNode *N);
275
276  SDOperand ScalarizeRes_BIT_CONVERT(SDNode *N);
277  SDOperand ScalarizeRes_FPOWI(SDNode *N);
278  SDOperand ScalarizeRes_INSERT_VECTOR_ELT(SDNode *N);
279  SDOperand ScalarizeRes_LOAD(LoadSDNode *N);
280  SDOperand ScalarizeRes_SELECT(SDNode *N);
281  SDOperand ScalarizeRes_UNDEF(SDNode *N);
282  SDOperand ScalarizeRes_VECTOR_SHUFFLE(SDNode *N);
283
284  // Operand Vector Scalarization: <1 x ty> -> ty.
285  bool ScalarizeOperand(SDNode *N, unsigned OpNo);
286  SDOperand ScalarizeOp_EXTRACT_VECTOR_ELT(SDNode *N);
287  SDOperand ScalarizeOp_STORE(StoreSDNode *N, unsigned OpNo);
288
289  //===--------------------------------------------------------------------===//
290  // Vector Splitting Support: LegalizeTypesSplit.cpp
291  //===--------------------------------------------------------------------===//
292
293  void GetSplitOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi);
294  void SetSplitOp(SDOperand Op, SDOperand Lo, SDOperand Hi);
295
296  // Result Vector Splitting: <128 x ty> -> 2 x <64 x ty>.
297  void SplitResult(SDNode *N, unsigned OpNo);
298
299  void SplitRes_UNDEF(SDNode *N, SDOperand &Lo, SDOperand &Hi);
300  void SplitRes_LOAD(LoadSDNode *N, SDOperand &Lo, SDOperand &Hi);
301  void SplitRes_BUILD_PAIR(SDNode *N, SDOperand &Lo, SDOperand &Hi);
302  void SplitRes_INSERT_VECTOR_ELT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
303  void SplitRes_VECTOR_SHUFFLE(SDNode *N, SDOperand &Lo, SDOperand &Hi);
304
305  void SplitRes_BUILD_VECTOR(SDNode *N, SDOperand &Lo, SDOperand &Hi);
306  void SplitRes_CONCAT_VECTORS(SDNode *N, SDOperand &Lo, SDOperand &Hi);
307  void SplitRes_BIT_CONVERT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
308  void SplitRes_UnOp(SDNode *N, SDOperand &Lo, SDOperand &Hi);
309  void SplitRes_BinOp(SDNode *N, SDOperand &Lo, SDOperand &Hi);
310  void SplitRes_FPOWI(SDNode *N, SDOperand &Lo, SDOperand &Hi);
311  void SplitRes_SELECT(SDNode *N, SDOperand &Lo, SDOperand &Hi);
312
313  // Operand Vector Scalarization: <128 x ty> -> 2 x <64 x ty>.
314  bool SplitOperand(SDNode *N, unsigned OpNo);
315
316  SDOperand SplitOp_EXTRACT_SUBVECTOR(SDNode *N);
317  SDOperand SplitOp_RET(SDNode *N, unsigned OpNo);
318  SDOperand SplitOp_STORE(StoreSDNode *N, unsigned OpNo);
319};
320
321} // end namespace llvm.
322
323#endif
324