PPCISelLowering.h revision 210299
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 MFCRpseud/MFOCRF
115      /// instructions.  This copies the bits corresponding to the specified
116      /// CRREG into the resultant GPR.  Bits corresponding to other CR regs
117      /// are undefined.
118      MFCR,
119
120      /// RESVEC = VCMP(LHS, RHS, OPC) - Represents one of the altivec VCMP*
121      /// instructions.  For lack of better number, we use the opcode number
122      /// encoding for the OPC field to identify the compare.  For example, 838
123      /// is VCMPGTSH.
124      VCMP,
125
126      /// RESVEC, OUTFLAG = VCMPo(LHS, RHS, OPC) - Represents one of the
127      /// altivec VCMP*o instructions.  For lack of better number, we use the
128      /// opcode number encoding for the OPC field to identify the compare.  For
129      /// example, 838 is VCMPGTSH.
130      VCMPo,
131
132      /// CHAIN = COND_BRANCH CHAIN, CRRC, OPC, DESTBB [, INFLAG] - This
133      /// corresponds to the COND_BRANCH pseudo instruction.  CRRC is the
134      /// condition register to branch on, OPC is the branch opcode to use (e.g.
135      /// PPC::BLE), DESTBB is the destination block to branch to, and INFLAG is
136      /// an optional input flag argument.
137      COND_BRANCH,
138
139      // The following 5 instructions are used only as part of the
140      // long double-to-int conversion sequence.
141
142      /// OUTFLAG = MFFS F8RC - This moves the FPSCR (not modelled) into the
143      /// register.
144      MFFS,
145
146      /// OUTFLAG = MTFSB0 INFLAG - This clears a bit in the FPSCR.
147      MTFSB0,
148
149      /// OUTFLAG = MTFSB1 INFLAG - This sets a bit in the FPSCR.
150      MTFSB1,
151
152      /// F8RC, OUTFLAG = FADDRTZ F8RC, F8RC, INFLAG - This is an FADD done with
153      /// rounding towards zero.  It has flags added so it won't move past the
154      /// FPSCR-setting instructions.
155      FADDRTZ,
156
157      /// MTFSF = F8RC, INFLAG - This moves the register into the FPSCR.
158      MTFSF,
159
160      /// LARX = This corresponds to PPC l{w|d}arx instrcution: load and
161      /// reserve indexed. This is used to implement atomic operations.
162      LARX,
163
164      /// STCX = This corresponds to PPC stcx. instrcution: store conditional
165      /// indexed. This is used to implement atomic operations.
166      STCX,
167
168      /// TC_RETURN - A tail call return.
169      ///   operand #0 chain
170      ///   operand #1 callee (register or absolute)
171      ///   operand #2 stack adjustment
172      ///   operand #3 optional in flag
173      TC_RETURN,
174
175      /// STD_32 - This is the STD instruction for use with "32-bit" registers.
176      STD_32 = ISD::FIRST_TARGET_MEMORY_OPCODE,
177
178      /// CHAIN = STBRX CHAIN, GPRC, Ptr, Type - This is a
179      /// byte-swapping store instruction.  It byte-swaps the low "Type" bits of
180      /// the GPRC input, then stores it through Ptr.  Type can be either i16 or
181      /// i32.
182      STBRX,
183
184      /// GPRC, CHAIN = LBRX CHAIN, Ptr, Type - This is a
185      /// byte-swapping load instruction.  It loads "Type" bits, byte swaps it,
186      /// then puts it in the bottom bits of the GPRC.  TYPE can be either i16
187      /// or i32.
188      LBRX
189    };
190  }
191
192  /// Define some predicates that are used for node matching.
193  namespace PPC {
194    /// isVPKUHUMShuffleMask - Return true if this is the shuffle mask for a
195    /// VPKUHUM instruction.
196    bool isVPKUHUMShuffleMask(ShuffleVectorSDNode *N, bool isUnary);
197
198    /// isVPKUWUMShuffleMask - Return true if this is the shuffle mask for a
199    /// VPKUWUM instruction.
200    bool isVPKUWUMShuffleMask(ShuffleVectorSDNode *N, bool isUnary);
201
202    /// isVMRGLShuffleMask - Return true if this is a shuffle mask suitable for
203    /// a VRGL* instruction with the specified unit size (1,2 or 4 bytes).
204    bool isVMRGLShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
205                            bool isUnary);
206
207    /// isVMRGHShuffleMask - Return true if this is a shuffle mask suitable for
208    /// a VRGH* instruction with the specified unit size (1,2 or 4 bytes).
209    bool isVMRGHShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
210                            bool isUnary);
211
212    /// isVSLDOIShuffleMask - If this is a vsldoi shuffle mask, return the shift
213    /// amount, otherwise return -1.
214    int isVSLDOIShuffleMask(SDNode *N, bool isUnary);
215
216    /// isSplatShuffleMask - Return true if the specified VECTOR_SHUFFLE operand
217    /// specifies a splat of a single element that is suitable for input to
218    /// VSPLTB/VSPLTH/VSPLTW.
219    bool isSplatShuffleMask(ShuffleVectorSDNode *N, unsigned EltSize);
220
221    /// isAllNegativeZeroVector - Returns true if all elements of build_vector
222    /// are -0.0.
223    bool isAllNegativeZeroVector(SDNode *N);
224
225    /// getVSPLTImmediate - Return the appropriate VSPLT* immediate to splat the
226    /// specified isSplatShuffleMask VECTOR_SHUFFLE mask.
227    unsigned getVSPLTImmediate(SDNode *N, unsigned EltSize);
228
229    /// get_VSPLTI_elt - If this is a build_vector of constants which can be
230    /// formed by using a vspltis[bhw] instruction of the specified element
231    /// size, return the constant being splatted.  The ByteSize field indicates
232    /// the number of bytes of each element [124] -> [bhw].
233    SDValue get_VSPLTI_elt(SDNode *N, unsigned ByteSize, SelectionDAG &DAG);
234  }
235
236  class PPCTargetLowering : public TargetLowering {
237    const PPCSubtarget &PPCSubTarget;
238
239  public:
240    explicit PPCTargetLowering(PPCTargetMachine &TM);
241
242    /// getTargetNodeName() - This method returns the name of a target specific
243    /// DAG node.
244    virtual const char *getTargetNodeName(unsigned Opcode) const;
245
246    /// getSetCCResultType - Return the ISD::SETCC ValueType
247    virtual MVT::SimpleValueType getSetCCResultType(EVT VT) const;
248
249    /// getPreIndexedAddressParts - returns true by value, base pointer and
250    /// offset pointer and addressing mode by reference if the node's address
251    /// can be legally represented as pre-indexed load / store address.
252    virtual bool getPreIndexedAddressParts(SDNode *N, SDValue &Base,
253                                           SDValue &Offset,
254                                           ISD::MemIndexedMode &AM,
255                                           SelectionDAG &DAG) const;
256
257    /// SelectAddressRegReg - Given the specified addressed, check to see if it
258    /// can be represented as an indexed [r+r] operation.  Returns false if it
259    /// can be more efficiently represented with [r+imm].
260    bool SelectAddressRegReg(SDValue N, SDValue &Base, SDValue &Index,
261                             SelectionDAG &DAG) const;
262
263    /// SelectAddressRegImm - Returns true if the address N can be represented
264    /// by a base register plus a signed 16-bit displacement [r+imm], and if it
265    /// is not better represented as reg+reg.
266    bool SelectAddressRegImm(SDValue N, SDValue &Disp, SDValue &Base,
267                             SelectionDAG &DAG) const;
268
269    /// SelectAddressRegRegOnly - Given the specified addressed, force it to be
270    /// represented as an indexed [r+r] operation.
271    bool SelectAddressRegRegOnly(SDValue N, SDValue &Base, SDValue &Index,
272                                 SelectionDAG &DAG) const;
273
274    /// SelectAddressRegImmShift - Returns true if the address N can be
275    /// represented by a base register plus a signed 14-bit displacement
276    /// [r+imm*4].  Suitable for use by STD and friends.
277    bool SelectAddressRegImmShift(SDValue N, SDValue &Disp, SDValue &Base,
278                                  SelectionDAG &DAG) const;
279
280
281    /// LowerOperation - Provide custom lowering hooks for some operations.
282    ///
283    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
284
285    /// ReplaceNodeResults - Replace the results of node with an illegal result
286    /// type with new values built out of custom code.
287    ///
288    virtual void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
289                                    SelectionDAG &DAG) const;
290
291    virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
292
293    virtual void computeMaskedBitsForTargetNode(const SDValue Op,
294                                                const APInt &Mask,
295                                                APInt &KnownZero,
296                                                APInt &KnownOne,
297                                                const SelectionDAG &DAG,
298                                                unsigned Depth = 0) const;
299
300    virtual MachineBasicBlock *
301      EmitInstrWithCustomInserter(MachineInstr *MI,
302                                  MachineBasicBlock *MBB) const;
303    MachineBasicBlock *EmitAtomicBinary(MachineInstr *MI,
304                                        MachineBasicBlock *MBB, bool is64Bit,
305                                        unsigned BinOpcode) const;
306    MachineBasicBlock *EmitPartwordAtomicBinary(MachineInstr *MI,
307                                                MachineBasicBlock *MBB,
308                                            bool is8bit, unsigned Opcode) const;
309
310    ConstraintType getConstraintType(const std::string &Constraint) const;
311    std::pair<unsigned, const TargetRegisterClass*>
312      getRegForInlineAsmConstraint(const std::string &Constraint,
313                                   EVT VT) const;
314
315    /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
316    /// function arguments in the caller parameter area.  This is the actual
317    /// alignment, not its logarithm.
318    unsigned getByValTypeAlignment(const Type *Ty) const;
319
320    /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
321    /// vector.  If it is invalid, don't add anything to Ops.
322    virtual void LowerAsmOperandForConstraint(SDValue Op,
323                                              char ConstraintLetter,
324                                              std::vector<SDValue> &Ops,
325                                              SelectionDAG &DAG) const;
326
327    /// isLegalAddressingMode - Return true if the addressing mode represented
328    /// by AM is legal for this target, for a load/store of the specified type.
329    virtual bool isLegalAddressingMode(const AddrMode &AM, const Type *Ty)const;
330
331    /// isLegalAddressImmediate - Return true if the integer value can be used
332    /// as the offset of the target addressing mode for load / store of the
333    /// given type.
334    virtual bool isLegalAddressImmediate(int64_t V, const Type *Ty) const;
335
336    /// isLegalAddressImmediate - Return true if the GlobalValue can be used as
337    /// the offset of the target addressing mode.
338    virtual bool isLegalAddressImmediate(GlobalValue *GV) const;
339
340    virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
341
342    /// getOptimalMemOpType - Returns the target specific optimal type for load
343    /// and store operations as a result of memset, memcpy, and memmove
344    /// lowering. If DstAlign is zero that means it's safe to destination
345    /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
346    /// means there isn't a need to check it against alignment requirement,
347    /// probably because the source does not need to be loaded. If
348    /// 'NonScalarIntSafe' is true, that means it's safe to return a
349    /// non-scalar-integer type, e.g. empty string source, constant, or loaded
350    /// from memory. 'MemcpyStrSrc' indicates whether the memcpy source is
351    /// constant so it does not need to be loaded.
352    /// It returns EVT::Other if the type should be determined using generic
353    /// target-independent logic.
354    virtual EVT
355    getOptimalMemOpType(uint64_t Size, unsigned DstAlign, unsigned SrcAlign,
356                        bool NonScalarIntSafe, bool MemcpyStrSrc,
357                        MachineFunction &MF) const;
358
359    /// getFunctionAlignment - Return the Log2 alignment of this function.
360    virtual unsigned getFunctionAlignment(const Function *F) const;
361
362  private:
363    SDValue getFramePointerFrameIndex(SelectionDAG & DAG) const;
364    SDValue getReturnAddrFrameIndex(SelectionDAG & DAG) const;
365
366    bool
367    IsEligibleForTailCallOptimization(SDValue Callee,
368                                      CallingConv::ID CalleeCC,
369                                      bool isVarArg,
370                                      const SmallVectorImpl<ISD::InputArg> &Ins,
371                                      SelectionDAG& DAG) const;
372
373    SDValue EmitTailCallLoadFPAndRetAddr(SelectionDAG & DAG,
374                                         int SPDiff,
375                                         SDValue Chain,
376                                         SDValue &LROpOut,
377                                         SDValue &FPOpOut,
378                                         bool isDarwinABI,
379                                         DebugLoc dl) const;
380
381    SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
382    SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
383    SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
384    SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
385    SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
386    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
387    SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
388    SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
389    SDValue LowerTRAMPOLINE(SDValue Op, SelectionDAG &DAG) const;
390    SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG,
391                         const PPCSubtarget &Subtarget) const;
392    SDValue LowerVAARG(SDValue Op, SelectionDAG &DAG,
393                       const PPCSubtarget &Subtarget) const;
394    SDValue LowerSTACKRESTORE(SDValue Op, SelectionDAG &DAG,
395                                const PPCSubtarget &Subtarget) const;
396    SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG,
397                                      const PPCSubtarget &Subtarget) const;
398    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
399    SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG, DebugLoc dl) const;
400    SDValue LowerSINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
401    SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
402    SDValue LowerSHL_PARTS(SDValue Op, SelectionDAG &DAG) const;
403    SDValue LowerSRL_PARTS(SDValue Op, SelectionDAG &DAG) const;
404    SDValue LowerSRA_PARTS(SDValue Op, SelectionDAG &DAG) const;
405    SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const;
406    SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
407    SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
408    SDValue LowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG) const;
409    SDValue LowerMUL(SDValue Op, SelectionDAG &DAG) const;
410
411    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
412                            CallingConv::ID CallConv, bool isVarArg,
413                            const SmallVectorImpl<ISD::InputArg> &Ins,
414                            DebugLoc dl, SelectionDAG &DAG,
415                            SmallVectorImpl<SDValue> &InVals) const;
416    SDValue FinishCall(CallingConv::ID CallConv, DebugLoc dl, bool isTailCall,
417                       bool isVarArg,
418                       SelectionDAG &DAG,
419                       SmallVector<std::pair<unsigned, SDValue>, 8>
420                         &RegsToPass,
421                       SDValue InFlag, SDValue Chain,
422                       SDValue &Callee,
423                       int SPDiff, unsigned NumBytes,
424                       const SmallVectorImpl<ISD::InputArg> &Ins,
425                       SmallVectorImpl<SDValue> &InVals) const;
426
427    virtual SDValue
428      LowerFormalArguments(SDValue Chain,
429                           CallingConv::ID CallConv, bool isVarArg,
430                           const SmallVectorImpl<ISD::InputArg> &Ins,
431                           DebugLoc dl, SelectionDAG &DAG,
432                           SmallVectorImpl<SDValue> &InVals) const;
433
434    virtual SDValue
435      LowerCall(SDValue Chain, SDValue Callee,
436                CallingConv::ID CallConv, bool isVarArg, bool &isTailCall,
437                const SmallVectorImpl<ISD::OutputArg> &Outs,
438                const SmallVectorImpl<SDValue> &OutVals,
439                const SmallVectorImpl<ISD::InputArg> &Ins,
440                DebugLoc dl, SelectionDAG &DAG,
441                SmallVectorImpl<SDValue> &InVals) const;
442
443    virtual SDValue
444      LowerReturn(SDValue Chain,
445                  CallingConv::ID CallConv, bool isVarArg,
446                  const SmallVectorImpl<ISD::OutputArg> &Outs,
447                  const SmallVectorImpl<SDValue> &OutVals,
448                  DebugLoc dl, SelectionDAG &DAG) const;
449
450    SDValue
451      LowerFormalArguments_Darwin(SDValue Chain,
452                                  CallingConv::ID CallConv, bool isVarArg,
453                                  const SmallVectorImpl<ISD::InputArg> &Ins,
454                                  DebugLoc dl, SelectionDAG &DAG,
455                                  SmallVectorImpl<SDValue> &InVals) const;
456    SDValue
457      LowerFormalArguments_SVR4(SDValue Chain,
458                                CallingConv::ID CallConv, bool isVarArg,
459                                const SmallVectorImpl<ISD::InputArg> &Ins,
460                                DebugLoc dl, SelectionDAG &DAG,
461                                SmallVectorImpl<SDValue> &InVals) const;
462
463    SDValue
464      LowerCall_Darwin(SDValue Chain, SDValue Callee,
465                       CallingConv::ID CallConv, bool isVarArg, bool isTailCall,
466                       const SmallVectorImpl<ISD::OutputArg> &Outs,
467                       const SmallVectorImpl<SDValue> &OutVals,
468                       const SmallVectorImpl<ISD::InputArg> &Ins,
469                       DebugLoc dl, SelectionDAG &DAG,
470                       SmallVectorImpl<SDValue> &InVals) const;
471    SDValue
472      LowerCall_SVR4(SDValue Chain, SDValue Callee,
473                     CallingConv::ID CallConv, bool isVarArg, bool isTailCall,
474                     const SmallVectorImpl<ISD::OutputArg> &Outs,
475                     const SmallVectorImpl<SDValue> &OutVals,
476                     const SmallVectorImpl<ISD::InputArg> &Ins,
477                     DebugLoc dl, SelectionDAG &DAG,
478                     SmallVectorImpl<SDValue> &InVals) const;
479  };
480}
481
482#endif   // LLVM_TARGET_POWERPC_PPC32ISELLOWERING_H
483