PPCISelLowering.h revision 022d9e1cef7586a80a96446ae8691a37def9bbf4
1//===-- PPCISelLowering.h - PPC32 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 PPC uses to lower LLVM code into a
11// selection DAG.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_TARGET_POWERPC_PPC32ISELLOWERING_H
16#define LLVM_TARGET_POWERPC_PPC32ISELLOWERING_H
17
18#include "llvm/Target/TargetLowering.h"
19#include "llvm/CodeGen/SelectionDAG.h"
20#include "PPC.h"
21#include "PPCSubtarget.h"
22
23namespace llvm {
24  namespace PPCISD {
25    enum NodeType {
26      // Start the numbering where the builtin ops and target ops leave off.
27      FIRST_NUMBER = ISD::BUILTIN_OP_END,
28
29      /// FSEL - Traditional three-operand fsel node.
30      ///
31      FSEL,
32
33      /// FCFID - The FCFID instruction, taking an f64 operand and producing
34      /// and f64 value containing the FP representation of the integer that
35      /// was temporarily in the f64 operand.
36      FCFID,
37
38      /// FCTI[D,W]Z - The FCTIDZ and FCTIWZ instructions, taking an f32 or f64
39      /// operand, producing an f64 value containing the integer representation
40      /// of that FP value.
41      FCTIDZ, FCTIWZ,
42
43      /// STFIWX - The STFIWX instruction.  The first operand is an input token
44      /// chain, then an f64 value to store, then an address to store it to.
45      STFIWX,
46
47      // VMADDFP, VNMSUBFP - The VMADDFP and VNMSUBFP instructions, taking
48      // three v4f32 operands and producing a v4f32 result.
49      VMADDFP, VNMSUBFP,
50
51      /// VPERM - The PPC VPERM Instruction.
52      ///
53      VPERM,
54
55      /// Hi/Lo - These represent the high and low 16-bit parts of a global
56      /// address respectively.  These nodes have two operands, the first of
57      /// which must be a TargetGlobalAddress, and the second of which must be a
58      /// Constant.  Selected naively, these turn into 'lis G+C' and 'li G+C',
59      /// though these are usually folded into other nodes.
60      Hi, Lo,
61
62      TOC_ENTRY,
63
64      /// The following three target-specific nodes are used for calls through
65      /// function pointers in the 64-bit SVR4 ABI.
66
67      /// Restore the TOC from the TOC save area of the current stack frame.
68      /// This is basically a hard coded load instruction which additionally
69      /// takes/produces a flag.
70      TOC_RESTORE,
71
72      /// Like a regular LOAD but additionally taking/producing a flag.
73      LOAD,
74
75      /// LOAD into r2 (also taking/producing a flag). Like TOC_RESTORE, this is
76      /// a hard coded load instruction.
77      LOAD_TOC,
78
79      /// OPRC, CHAIN = DYNALLOC(CHAIN, NEGSIZE, FRAME_INDEX)
80      /// This instruction is lowered in PPCRegisterInfo::eliminateFrameIndex to
81      /// compute an allocation on the stack.
82      DYNALLOC,
83
84      /// GlobalBaseReg - On Darwin, this node represents the result of the mflr
85      /// at function entry, used for PIC code.
86      GlobalBaseReg,
87
88      /// These nodes represent the 32-bit PPC shifts that operate on 6-bit
89      /// shift amounts.  These nodes are generated by the multi-precision shift
90      /// code.
91      SRL, SRA, SHL,
92
93      /// EXTSW_32 - This is the EXTSW instruction for use with "32-bit"
94      /// registers.
95      EXTSW_32,
96
97      /// CALL - A direct function call.
98      CALL_Darwin, CALL_SVR4,
99
100      /// NOP - Special NOP which follows 64-bit SVR4 calls.
101      NOP,
102
103      /// CHAIN,FLAG = MTCTR(VAL, CHAIN[, INFLAG]) - Directly corresponds to a
104      /// MTCTR instruction.
105      MTCTR,
106
107      /// CHAIN,FLAG = BCTRL(CHAIN, INFLAG) - Directly corresponds to a
108      /// BCTRL instruction.
109      BCTRL_Darwin, BCTRL_SVR4,
110
111      /// Return with a flag operand, matched by 'blr'
112      RET_FLAG,
113
114      /// R32 = MFCR(CRREG, INFLAG) - Represents the MFCR/MFOCRF instructions.
115      /// This copies the bits corresponding to the specified CRREG into the
116      /// resultant GPR.  Bits corresponding to other CR regs are undefined.
117      MFCR,
118
119      /// RESVEC = VCMP(LHS, RHS, OPC) - Represents one of the altivec VCMP*
120      /// instructions.  For lack of better number, we use the opcode number
121      /// encoding for the OPC field to identify the compare.  For example, 838
122      /// is VCMPGTSH.
123      VCMP,
124
125      /// RESVEC, OUTFLAG = VCMPo(LHS, RHS, OPC) - Represents one of the
126      /// altivec VCMP*o instructions.  For lack of better number, we use the
127      /// opcode number encoding for the OPC field to identify the compare.  For
128      /// example, 838 is VCMPGTSH.
129      VCMPo,
130
131      /// CHAIN = COND_BRANCH CHAIN, CRRC, OPC, DESTBB [, INFLAG] - This
132      /// corresponds to the COND_BRANCH pseudo instruction.  CRRC is the
133      /// condition register to branch on, OPC is the branch opcode to use (e.g.
134      /// PPC::BLE), DESTBB is the destination block to branch to, and INFLAG is
135      /// an optional input flag argument.
136      COND_BRANCH,
137
138      // The following 5 instructions are used only as part of the
139      // long double-to-int conversion sequence.
140
141      /// OUTFLAG = MFFS F8RC - This moves the FPSCR (not modelled) into the
142      /// register.
143      MFFS,
144
145      /// OUTFLAG = MTFSB0 INFLAG - This clears a bit in the FPSCR.
146      MTFSB0,
147
148      /// OUTFLAG = MTFSB1 INFLAG - This sets a bit in the FPSCR.
149      MTFSB1,
150
151      /// F8RC, OUTFLAG = FADDRTZ F8RC, F8RC, INFLAG - This is an FADD done with
152      /// rounding towards zero.  It has flags added so it won't move past the
153      /// FPSCR-setting instructions.
154      FADDRTZ,
155
156      /// MTFSF = F8RC, INFLAG - This moves the register into the FPSCR.
157      MTFSF,
158
159      /// LARX = This corresponds to PPC l{w|d}arx instrcution: load and
160      /// reserve indexed. This is used to implement atomic operations.
161      LARX,
162
163      /// STCX = This corresponds to PPC stcx. instrcution: store conditional
164      /// indexed. This is used to implement atomic operations.
165      STCX,
166
167      /// TC_RETURN - A tail call return.
168      ///   operand #0 chain
169      ///   operand #1 callee (register or absolute)
170      ///   operand #2 stack adjustment
171      ///   operand #3 optional in flag
172      TC_RETURN,
173
174      /// STD_32 - This is the STD instruction for use with "32-bit" registers.
175      STD_32 = ISD::FIRST_TARGET_MEMORY_OPCODE,
176
177      /// CHAIN = STBRX CHAIN, GPRC, Ptr, Type - This is a
178      /// byte-swapping store instruction.  It byte-swaps the low "Type" bits of
179      /// the GPRC input, then stores it through Ptr.  Type can be either i16 or
180      /// i32.
181      STBRX,
182
183      /// GPRC, CHAIN = LBRX CHAIN, Ptr, Type - This is a
184      /// byte-swapping load instruction.  It loads "Type" bits, byte swaps it,
185      /// then puts it in the bottom bits of the GPRC.  TYPE can be either i16
186      /// or i32.
187      LBRX
188    };
189  }
190
191  /// Define some predicates that are used for node matching.
192  namespace PPC {
193    /// isVPKUHUMShuffleMask - Return true if this is the shuffle mask for a
194    /// VPKUHUM instruction.
195    bool isVPKUHUMShuffleMask(ShuffleVectorSDNode *N, bool isUnary);
196
197    /// isVPKUWUMShuffleMask - Return true if this is the shuffle mask for a
198    /// VPKUWUM instruction.
199    bool isVPKUWUMShuffleMask(ShuffleVectorSDNode *N, bool isUnary);
200
201    /// isVMRGLShuffleMask - Return true if this is a shuffle mask suitable for
202    /// a VRGL* instruction with the specified unit size (1,2 or 4 bytes).
203    bool isVMRGLShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
204                            bool isUnary);
205
206    /// isVMRGHShuffleMask - Return true if this is a shuffle mask suitable for
207    /// a VRGH* instruction with the specified unit size (1,2 or 4 bytes).
208    bool isVMRGHShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
209                            bool isUnary);
210
211    /// isVSLDOIShuffleMask - If this is a vsldoi shuffle mask, return the shift
212    /// amount, otherwise return -1.
213    int isVSLDOIShuffleMask(SDNode *N, bool isUnary);
214
215    /// isSplatShuffleMask - Return true if the specified VECTOR_SHUFFLE operand
216    /// specifies a splat of a single element that is suitable for input to
217    /// VSPLTB/VSPLTH/VSPLTW.
218    bool isSplatShuffleMask(ShuffleVectorSDNode *N, unsigned EltSize);
219
220    /// isAllNegativeZeroVector - Returns true if all elements of build_vector
221    /// are -0.0.
222    bool isAllNegativeZeroVector(SDNode *N);
223
224    /// getVSPLTImmediate - Return the appropriate VSPLT* immediate to splat the
225    /// specified isSplatShuffleMask VECTOR_SHUFFLE mask.
226    unsigned getVSPLTImmediate(SDNode *N, unsigned EltSize);
227
228    /// get_VSPLTI_elt - If this is a build_vector of constants which can be
229    /// formed by using a vspltis[bhw] instruction of the specified element
230    /// size, return the constant being splatted.  The ByteSize field indicates
231    /// the number of bytes of each element [124] -> [bhw].
232    SDValue get_VSPLTI_elt(SDNode *N, unsigned ByteSize, SelectionDAG &DAG);
233  }
234
235  class PPCTargetLowering : public TargetLowering {
236    int VarArgsFrameIndex;            // FrameIndex for start of varargs area.
237    int VarArgsStackOffset;           // StackOffset for start of stack
238                                      // arguments.
239    unsigned VarArgsNumGPR;           // Index of the first unused integer
240                                      // register for parameter passing.
241    unsigned VarArgsNumFPR;           // Index of the first unused double
242                                      // register for parameter passing.
243    const PPCSubtarget &PPCSubTarget;
244  public:
245    explicit PPCTargetLowering(PPCTargetMachine &TM);
246
247    /// getTargetNodeName() - This method returns the name of a target specific
248    /// DAG node.
249    virtual const char *getTargetNodeName(unsigned Opcode) const;
250
251    /// getSetCCResultType - Return the ISD::SETCC ValueType
252    virtual MVT::SimpleValueType getSetCCResultType(EVT VT) const;
253
254    /// getPreIndexedAddressParts - returns true by value, base pointer and
255    /// offset pointer and addressing mode by reference if the node's address
256    /// can be legally represented as pre-indexed load / store address.
257    virtual bool getPreIndexedAddressParts(SDNode *N, SDValue &Base,
258                                           SDValue &Offset,
259                                           ISD::MemIndexedMode &AM,
260                                           SelectionDAG &DAG) const;
261
262    /// SelectAddressRegReg - Given the specified addressed, check to see if it
263    /// can be represented as an indexed [r+r] operation.  Returns false if it
264    /// can be more efficiently represented with [r+imm].
265    bool SelectAddressRegReg(SDValue N, SDValue &Base, SDValue &Index,
266                             SelectionDAG &DAG) const;
267
268    /// SelectAddressRegImm - Returns true if the address N can be represented
269    /// by a base register plus a signed 16-bit displacement [r+imm], and if it
270    /// is not better represented as reg+reg.
271    bool SelectAddressRegImm(SDValue N, SDValue &Disp, SDValue &Base,
272                             SelectionDAG &DAG) const;
273
274    /// SelectAddressRegRegOnly - Given the specified addressed, force it to be
275    /// represented as an indexed [r+r] operation.
276    bool SelectAddressRegRegOnly(SDValue N, SDValue &Base, SDValue &Index,
277                                 SelectionDAG &DAG) const;
278
279    /// SelectAddressRegImmShift - Returns true if the address N can be
280    /// represented by a base register plus a signed 14-bit displacement
281    /// [r+imm*4].  Suitable for use by STD and friends.
282    bool SelectAddressRegImmShift(SDValue N, SDValue &Disp, SDValue &Base,
283                                  SelectionDAG &DAG) const;
284
285
286    /// LowerOperation - Provide custom lowering hooks for some operations.
287    ///
288    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG);
289
290    /// ReplaceNodeResults - Replace the results of node with an illegal result
291    /// type with new values built out of custom code.
292    ///
293    virtual void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
294                                    SelectionDAG &DAG);
295
296    virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
297
298    virtual void computeMaskedBitsForTargetNode(const SDValue Op,
299                                                const APInt &Mask,
300                                                APInt &KnownZero,
301                                                APInt &KnownOne,
302                                                const SelectionDAG &DAG,
303                                                unsigned Depth = 0) const;
304
305    virtual MachineBasicBlock *EmitInstrWithCustomInserter(MachineInstr *MI,
306                                                         MachineBasicBlock *MBB,
307                    DenseMap<MachineBasicBlock*, MachineBasicBlock*> *EM) const;
308    MachineBasicBlock *EmitAtomicBinary(MachineInstr *MI,
309                                        MachineBasicBlock *MBB, bool is64Bit,
310                                        unsigned BinOpcode) const;
311    MachineBasicBlock *EmitPartwordAtomicBinary(MachineInstr *MI,
312                                                MachineBasicBlock *MBB,
313                                            bool is8bit, unsigned Opcode) const;
314
315    ConstraintType getConstraintType(const std::string &Constraint) const;
316    std::pair<unsigned, const TargetRegisterClass*>
317      getRegForInlineAsmConstraint(const std::string &Constraint,
318                                   EVT VT) const;
319
320    /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
321    /// function arguments in the caller parameter area.  This is the actual
322    /// alignment, not its logarithm.
323    unsigned getByValTypeAlignment(const Type *Ty) const;
324
325    /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
326    /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
327    /// true it means one of the asm constraint of the inline asm instruction
328    /// being processed is 'm'.
329    virtual void LowerAsmOperandForConstraint(SDValue Op,
330                                              char ConstraintLetter,
331                                              bool hasMemory,
332                                              std::vector<SDValue> &Ops,
333                                              SelectionDAG &DAG) const;
334
335    /// isLegalAddressingMode - Return true if the addressing mode represented
336    /// by AM is legal for this target, for a load/store of the specified type.
337    virtual bool isLegalAddressingMode(const AddrMode &AM, const Type *Ty)const;
338
339    /// isLegalAddressImmediate - Return true if the integer value can be used
340    /// as the offset of the target addressing mode for load / store of the
341    /// given type.
342    virtual bool isLegalAddressImmediate(int64_t V, const Type *Ty) const;
343
344    /// isLegalAddressImmediate - Return true if the GlobalValue can be used as
345    /// the offset of the target addressing mode.
346    virtual bool isLegalAddressImmediate(GlobalValue *GV) const;
347
348    virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
349
350    virtual EVT getOptimalMemOpType(uint64_t Size, unsigned Align,
351                                    bool isSrcConst, bool isSrcStr,
352                                    SelectionDAG &DAG) const;
353
354    /// getFunctionAlignment - Return the Log2 alignment of this function.
355    virtual unsigned getFunctionAlignment(const Function *F) const;
356
357  private:
358    SDValue getFramePointerFrameIndex(SelectionDAG & DAG) const;
359    SDValue getReturnAddrFrameIndex(SelectionDAG & DAG) const;
360
361    bool
362    IsEligibleForTailCallOptimization(SDValue Callee,
363                                      CallingConv::ID CalleeCC,
364                                      bool isVarArg,
365                                      const SmallVectorImpl<ISD::InputArg> &Ins,
366                                      SelectionDAG& DAG) const;
367
368    SDValue EmitTailCallLoadFPAndRetAddr(SelectionDAG & DAG,
369                                         int SPDiff,
370                                         SDValue Chain,
371                                         SDValue &LROpOut,
372                                         SDValue &FPOpOut,
373                                         bool isDarwinABI,
374                                         DebugLoc dl);
375
376    SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG);
377    SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG);
378    SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG);
379    SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG);
380    SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG);
381    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG);
382    SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG);
383    SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG);
384    SDValue LowerTRAMPOLINE(SDValue Op, SelectionDAG &DAG);
385    SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG,
386                           int VarArgsFrameIndex, int VarArgsStackOffset,
387                           unsigned VarArgsNumGPR, unsigned VarArgsNumFPR,
388                           const PPCSubtarget &Subtarget);
389    SDValue LowerVAARG(SDValue Op, SelectionDAG &DAG, int VarArgsFrameIndex,
390                         int VarArgsStackOffset, unsigned VarArgsNumGPR,
391                         unsigned VarArgsNumFPR, const PPCSubtarget &Subtarget);
392    SDValue LowerSTACKRESTORE(SDValue Op, SelectionDAG &DAG,
393                                const PPCSubtarget &Subtarget);
394    SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG,
395                                      const PPCSubtarget &Subtarget);
396    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG);
397    SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG, DebugLoc dl);
398    SDValue LowerSINT_TO_FP(SDValue Op, SelectionDAG &DAG);
399    SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG);
400    SDValue LowerSHL_PARTS(SDValue Op, SelectionDAG &DAG);
401    SDValue LowerSRL_PARTS(SDValue Op, SelectionDAG &DAG);
402    SDValue LowerSRA_PARTS(SDValue Op, SelectionDAG &DAG);
403    SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG);
404    SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG);
405    SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG);
406    SDValue LowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG);
407    SDValue LowerMUL(SDValue Op, SelectionDAG &DAG);
408
409    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
410                            CallingConv::ID CallConv, bool isVarArg,
411                            const SmallVectorImpl<ISD::InputArg> &Ins,
412                            DebugLoc dl, SelectionDAG &DAG,
413                            SmallVectorImpl<SDValue> &InVals);
414    SDValue FinishCall(CallingConv::ID CallConv, DebugLoc dl, bool isTailCall,
415                       bool isVarArg,
416                       SelectionDAG &DAG,
417                       SmallVector<std::pair<unsigned, SDValue>, 8>
418                         &RegsToPass,
419                       SDValue InFlag, SDValue Chain,
420                       SDValue &Callee,
421                       int SPDiff, unsigned NumBytes,
422                       const SmallVectorImpl<ISD::InputArg> &Ins,
423                       SmallVectorImpl<SDValue> &InVals);
424
425    virtual SDValue
426      LowerFormalArguments(SDValue Chain,
427                           CallingConv::ID CallConv, bool isVarArg,
428                           const SmallVectorImpl<ISD::InputArg> &Ins,
429                           DebugLoc dl, SelectionDAG &DAG,
430                           SmallVectorImpl<SDValue> &InVals);
431
432    virtual SDValue
433      LowerCall(SDValue Chain, SDValue Callee,
434                CallingConv::ID CallConv, bool isVarArg, bool &isTailCall,
435                const SmallVectorImpl<ISD::OutputArg> &Outs,
436                const SmallVectorImpl<ISD::InputArg> &Ins,
437                DebugLoc dl, SelectionDAG &DAG,
438                SmallVectorImpl<SDValue> &InVals);
439
440    virtual SDValue
441      LowerReturn(SDValue Chain,
442                  CallingConv::ID CallConv, bool isVarArg,
443                  const SmallVectorImpl<ISD::OutputArg> &Outs,
444                  DebugLoc dl, SelectionDAG &DAG);
445
446    SDValue
447      LowerFormalArguments_Darwin(SDValue Chain,
448                                  CallingConv::ID CallConv, bool isVarArg,
449                                  const SmallVectorImpl<ISD::InputArg> &Ins,
450                                  DebugLoc dl, SelectionDAG &DAG,
451                                  SmallVectorImpl<SDValue> &InVals);
452    SDValue
453      LowerFormalArguments_SVR4(SDValue Chain,
454                                CallingConv::ID CallConv, bool isVarArg,
455                                const SmallVectorImpl<ISD::InputArg> &Ins,
456                                DebugLoc dl, SelectionDAG &DAG,
457                                SmallVectorImpl<SDValue> &InVals);
458
459    SDValue
460      LowerCall_Darwin(SDValue Chain, SDValue Callee,
461                       CallingConv::ID CallConv, bool isVarArg, bool isTailCall,
462                       const SmallVectorImpl<ISD::OutputArg> &Outs,
463                       const SmallVectorImpl<ISD::InputArg> &Ins,
464                       DebugLoc dl, SelectionDAG &DAG,
465                       SmallVectorImpl<SDValue> &InVals);
466    SDValue
467      LowerCall_SVR4(SDValue Chain, SDValue Callee,
468                     CallingConv::ID CallConv, bool isVarArg, bool isTailCall,
469                     const SmallVectorImpl<ISD::OutputArg> &Outs,
470                     const SmallVectorImpl<ISD::InputArg> &Ins,
471                     DebugLoc dl, SelectionDAG &DAG,
472                     SmallVectorImpl<SDValue> &InVals);
473  };
474}
475
476#endif   // LLVM_TARGET_POWERPC_PPC32ISELLOWERING_H
477