ARMISelLowering.h revision 205218
1//===-- ARMISelLowering.h - ARM DAG Lowering Interface ----------*- 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 file defines the interfaces that ARM uses to lower LLVM code into a
11// selection DAG.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef ARMISELLOWERING_H
16#define ARMISELLOWERING_H
17
18#include "ARMSubtarget.h"
19#include "llvm/Target/TargetLowering.h"
20#include "llvm/CodeGen/SelectionDAG.h"
21#include "llvm/CodeGen/CallingConvLower.h"
22#include <vector>
23
24namespace llvm {
25  class ARMConstantPoolValue;
26
27  namespace ARMISD {
28    // ARM Specific DAG Nodes
29    enum NodeType {
30      // Start the numbering where the builtin ops and target ops leave off.
31      FIRST_NUMBER = ISD::BUILTIN_OP_END,
32
33      Wrapper,      // Wrapper - A wrapper node for TargetConstantPool,
34                    // TargetExternalSymbol, and TargetGlobalAddress.
35      WrapperJT,    // WrapperJT - A wrapper node for TargetJumpTable
36
37      CALL,         // Function call.
38      CALL_PRED,    // Function call that's predicable.
39      CALL_NOLINK,  // Function call with branch not branch-and-link.
40      tCALL,        // Thumb function call.
41      BRCOND,       // Conditional branch.
42      BR_JT,        // Jumptable branch.
43      BR2_JT,       // Jumptable branch (2 level - jumptable entry is a jump).
44      RET_FLAG,     // Return with a flag operand.
45
46      PIC_ADD,      // Add with a PC operand and a PIC label.
47
48      CMP,          // ARM compare instructions.
49      CMPZ,         // ARM compare that sets only Z flag.
50      CMPFP,        // ARM VFP compare instruction, sets FPSCR.
51      CMPFPw0,      // ARM VFP compare against zero instruction, sets FPSCR.
52      FMSTAT,       // ARM fmstat instruction.
53      CMOV,         // ARM conditional move instructions.
54      CNEG,         // ARM conditional negate instructions.
55
56      RBIT,         // ARM bitreverse instruction
57
58      FTOSI,        // FP to sint within a FP register.
59      FTOUI,        // FP to uint within a FP register.
60      SITOF,        // sint to FP within a FP register.
61      UITOF,        // uint to FP within a FP register.
62      F16_TO_F32,   // Half FP to single FP within a FP register.
63      F32_TO_F16,   // Single FP to half FP within a FP register.
64
65      SRL_FLAG,     // V,Flag = srl_flag X -> srl X, 1 + save carry out.
66      SRA_FLAG,     // V,Flag = sra_flag X -> sra X, 1 + save carry out.
67      RRX,          // V = RRX X, Flag     -> srl X, 1 + shift in carry flag.
68
69      VMOVRRD,      // double to two gprs.
70      VMOVDRR,      // Two gprs to double.
71
72      EH_SJLJ_SETJMP,    // SjLj exception handling setjmp.
73      EH_SJLJ_LONGJMP,   // SjLj exception handling longjmp.
74
75      THREAD_POINTER,
76
77      DYN_ALLOC,    // Dynamic allocation on the stack.
78
79      MEMBARRIER,   // Memory barrier
80      SYNCBARRIER,  // Memory sync barrier
81
82      VCEQ,         // Vector compare equal.
83      VCGE,         // Vector compare greater than or equal.
84      VCGEU,        // Vector compare unsigned greater than or equal.
85      VCGT,         // Vector compare greater than.
86      VCGTU,        // Vector compare unsigned greater than.
87      VTST,         // Vector test bits.
88
89      // Vector shift by immediate:
90      VSHL,         // ...left
91      VSHRs,        // ...right (signed)
92      VSHRu,        // ...right (unsigned)
93      VSHLLs,       // ...left long (signed)
94      VSHLLu,       // ...left long (unsigned)
95      VSHLLi,       // ...left long (with maximum shift count)
96      VSHRN,        // ...right narrow
97
98      // Vector rounding shift by immediate:
99      VRSHRs,       // ...right (signed)
100      VRSHRu,       // ...right (unsigned)
101      VRSHRN,       // ...right narrow
102
103      // Vector saturating shift by immediate:
104      VQSHLs,       // ...left (signed)
105      VQSHLu,       // ...left (unsigned)
106      VQSHLsu,      // ...left (signed to unsigned)
107      VQSHRNs,      // ...right narrow (signed)
108      VQSHRNu,      // ...right narrow (unsigned)
109      VQSHRNsu,     // ...right narrow (signed to unsigned)
110
111      // Vector saturating rounding shift by immediate:
112      VQRSHRNs,     // ...right narrow (signed)
113      VQRSHRNu,     // ...right narrow (unsigned)
114      VQRSHRNsu,    // ...right narrow (signed to unsigned)
115
116      // Vector shift and insert:
117      VSLI,         // ...left
118      VSRI,         // ...right
119
120      // Vector get lane (VMOV scalar to ARM core register)
121      // (These are used for 8- and 16-bit element types only.)
122      VGETLANEu,    // zero-extend vector extract element
123      VGETLANEs,    // sign-extend vector extract element
124
125      // Vector duplicate:
126      VDUP,
127      VDUPLANE,
128
129      // Vector shuffles:
130      VEXT,         // extract
131      VREV64,       // reverse elements within 64-bit doublewords
132      VREV32,       // reverse elements within 32-bit words
133      VREV16,       // reverse elements within 16-bit halfwords
134      VZIP,         // zip (interleave)
135      VUZP,         // unzip (deinterleave)
136      VTRN,         // transpose
137
138      // Floating-point max and min:
139      FMAX,
140      FMIN
141    };
142  }
143
144  /// Define some predicates that are used for node matching.
145  namespace ARM {
146    /// getVMOVImm - If this is a build_vector of constants which can be
147    /// formed by using a VMOV instruction of the specified element size,
148    /// return the constant being splatted.  The ByteSize field indicates the
149    /// number of bytes of each element [1248].
150    SDValue getVMOVImm(SDNode *N, unsigned ByteSize, SelectionDAG &DAG);
151
152    /// getVFPf32Imm / getVFPf64Imm - If the given fp immediate can be
153    /// materialized with a VMOV.f32 / VMOV.f64 (i.e. fconsts / fconstd)
154    /// instruction, returns its 8-bit integer representation. Otherwise,
155    /// returns -1.
156    int getVFPf32Imm(const APFloat &FPImm);
157    int getVFPf64Imm(const APFloat &FPImm);
158  }
159
160  //===--------------------------------------------------------------------===//
161  //  ARMTargetLowering - ARM Implementation of the TargetLowering interface
162
163  class ARMTargetLowering : public TargetLowering {
164    int VarArgsFrameIndex;            // FrameIndex for start of varargs area.
165  public:
166    explicit ARMTargetLowering(TargetMachine &TM);
167
168    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG);
169
170    /// ReplaceNodeResults - Replace the results of node with an illegal result
171    /// type with new values built out of custom code.
172    ///
173    virtual void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
174                                    SelectionDAG &DAG);
175
176    virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
177
178    virtual const char *getTargetNodeName(unsigned Opcode) const;
179
180    virtual MachineBasicBlock *EmitInstrWithCustomInserter(MachineInstr *MI,
181                                                         MachineBasicBlock *MBB,
182                       DenseMap<MachineBasicBlock*, MachineBasicBlock*>*) const;
183
184    /// allowsUnalignedMemoryAccesses - Returns true if the target allows
185    /// unaligned memory accesses. of the specified type.
186    /// FIXME: Add getOptimalMemOpType to implement memcpy with NEON?
187    virtual bool allowsUnalignedMemoryAccesses(EVT VT) const;
188
189    /// isLegalAddressingMode - Return true if the addressing mode represented
190    /// by AM is legal for this target, for a load/store of the specified type.
191    virtual bool isLegalAddressingMode(const AddrMode &AM, const Type *Ty)const;
192    bool isLegalT2ScaledAddressingMode(const AddrMode &AM, EVT VT) const;
193
194    /// isLegalICmpImmediate - Return true if the specified immediate is legal
195    /// icmp immediate, that is the target has icmp instructions which can compare
196    /// a register against the immediate without having to materialize the
197    /// immediate into a register.
198    virtual bool isLegalICmpImmediate(int64_t Imm) const;
199
200    /// getPreIndexedAddressParts - returns true by value, base pointer and
201    /// offset pointer and addressing mode by reference if the node's address
202    /// can be legally represented as pre-indexed load / store address.
203    virtual bool getPreIndexedAddressParts(SDNode *N, SDValue &Base,
204                                           SDValue &Offset,
205                                           ISD::MemIndexedMode &AM,
206                                           SelectionDAG &DAG) const;
207
208    /// getPostIndexedAddressParts - returns true by value, base pointer and
209    /// offset pointer and addressing mode by reference if this node can be
210    /// combined with a load / store to form a post-indexed load / store.
211    virtual bool getPostIndexedAddressParts(SDNode *N, SDNode *Op,
212                                            SDValue &Base, SDValue &Offset,
213                                            ISD::MemIndexedMode &AM,
214                                            SelectionDAG &DAG) const;
215
216    virtual void computeMaskedBitsForTargetNode(const SDValue Op,
217                                                const APInt &Mask,
218                                                APInt &KnownZero,
219                                                APInt &KnownOne,
220                                                const SelectionDAG &DAG,
221                                                unsigned Depth) const;
222
223
224    ConstraintType getConstraintType(const std::string &Constraint) const;
225    std::pair<unsigned, const TargetRegisterClass*>
226      getRegForInlineAsmConstraint(const std::string &Constraint,
227                                   EVT VT) const;
228    std::vector<unsigned>
229    getRegClassForInlineAsmConstraint(const std::string &Constraint,
230                                      EVT VT) const;
231
232    /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
233    /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
234    /// true it means one of the asm constraint of the inline asm instruction
235    /// being processed is 'm'.
236    virtual void LowerAsmOperandForConstraint(SDValue Op,
237                                              char ConstraintLetter,
238                                              bool hasMemory,
239                                              std::vector<SDValue> &Ops,
240                                              SelectionDAG &DAG) const;
241
242    virtual const ARMSubtarget* getSubtarget() {
243      return Subtarget;
244    }
245
246    /// getFunctionAlignment - Return the Log2 alignment of this function.
247    virtual unsigned getFunctionAlignment(const Function *F) const;
248
249    bool isShuffleMaskLegal(const SmallVectorImpl<int> &M, EVT VT) const;
250    bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
251
252    /// isFPImmLegal - Returns true if the target can instruction select the
253    /// specified FP immediate natively. If false, the legalizer will
254    /// materialize the FP immediate as a load from a constant pool.
255    virtual bool isFPImmLegal(const APFloat &Imm, EVT VT) const;
256
257  private:
258    /// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
259    /// make the right decision when generating code for different targets.
260    const ARMSubtarget *Subtarget;
261
262    /// ARMPCLabelIndex - Keep track of the number of ARM PC labels created.
263    ///
264    unsigned ARMPCLabelIndex;
265
266    void addTypeForNEON(EVT VT, EVT PromotedLdStVT, EVT PromotedBitwiseVT);
267    void addDRTypeForNEON(EVT VT);
268    void addQRTypeForNEON(EVT VT);
269
270    typedef SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPassVector;
271    void PassF64ArgInRegs(DebugLoc dl, SelectionDAG &DAG,
272                          SDValue Chain, SDValue &Arg,
273                          RegsToPassVector &RegsToPass,
274                          CCValAssign &VA, CCValAssign &NextVA,
275                          SDValue &StackPtr,
276                          SmallVector<SDValue, 8> &MemOpChains,
277                          ISD::ArgFlagsTy Flags);
278    SDValue GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
279                                 SDValue &Root, SelectionDAG &DAG, DebugLoc dl);
280
281    CCAssignFn *CCAssignFnForNode(CallingConv::ID CC, bool Return, bool isVarArg) const;
282    SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
283                             DebugLoc dl, SelectionDAG &DAG,
284                             const CCValAssign &VA,
285                             ISD::ArgFlagsTy Flags);
286    SDValue LowerINTRINSIC_W_CHAIN(SDValue Op, SelectionDAG &DAG);
287    SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
288                                    const ARMSubtarget *Subtarget);
289    SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG);
290    SDValue LowerGlobalAddressDarwin(SDValue Op, SelectionDAG &DAG);
291    SDValue LowerGlobalAddressELF(SDValue Op, SelectionDAG &DAG);
292    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG);
293    SDValue LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
294                                            SelectionDAG &DAG);
295    SDValue LowerToTLSExecModels(GlobalAddressSDNode *GA,
296                                   SelectionDAG &DAG);
297    SDValue LowerGLOBAL_OFFSET_TABLE(SDValue Op, SelectionDAG &DAG);
298    SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG);
299    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG);
300    SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG);
301    SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG);
302    SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG);
303    SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG);
304    SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG);
305
306    SDValue EmitTargetCodeForMemcpy(SelectionDAG &DAG, DebugLoc dl,
307                                      SDValue Chain,
308                                      SDValue Dst, SDValue Src,
309                                      SDValue Size, unsigned Align,
310                                      bool AlwaysInline,
311                                      const Value *DstSV, uint64_t DstSVOff,
312                                      const Value *SrcSV, uint64_t SrcSVOff);
313    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
314                            CallingConv::ID CallConv, bool isVarArg,
315                            const SmallVectorImpl<ISD::InputArg> &Ins,
316                            DebugLoc dl, SelectionDAG &DAG,
317                            SmallVectorImpl<SDValue> &InVals);
318
319    virtual SDValue
320      LowerFormalArguments(SDValue Chain,
321                           CallingConv::ID CallConv, bool isVarArg,
322                           const SmallVectorImpl<ISD::InputArg> &Ins,
323                           DebugLoc dl, SelectionDAG &DAG,
324                           SmallVectorImpl<SDValue> &InVals);
325
326    virtual SDValue
327      LowerCall(SDValue Chain, SDValue Callee,
328                CallingConv::ID CallConv, bool isVarArg,
329                bool &isTailCall,
330                const SmallVectorImpl<ISD::OutputArg> &Outs,
331                const SmallVectorImpl<ISD::InputArg> &Ins,
332                DebugLoc dl, SelectionDAG &DAG,
333                SmallVectorImpl<SDValue> &InVals);
334
335    virtual SDValue
336      LowerReturn(SDValue Chain,
337                  CallingConv::ID CallConv, bool isVarArg,
338                  const SmallVectorImpl<ISD::OutputArg> &Outs,
339                  DebugLoc dl, SelectionDAG &DAG);
340
341    SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
342                      SDValue &ARMCC, SelectionDAG &DAG, DebugLoc dl);
343
344    MachineBasicBlock *EmitAtomicCmpSwap(MachineInstr *MI,
345                                         MachineBasicBlock *BB,
346                                         unsigned Size) const;
347    MachineBasicBlock *EmitAtomicBinary(MachineInstr *MI,
348                                        MachineBasicBlock *BB,
349                                        unsigned Size,
350                                        unsigned BinOpcode) const;
351
352  };
353}
354
355#endif  // ARMISELLOWERING_H
356