xref: /freebsd/contrib/llvm-project/llvm/lib/Target/SystemZ/SystemZISelLowering.h (revision 5036d9652a5701d00e9e40ea942c278e9f77d33d)
1 //===-- SystemZISelLowering.h - SystemZ DAG lowering interface --*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the interfaces that SystemZ uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZISELLOWERING_H
15 #define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZISELLOWERING_H
16 
17 #include "SystemZ.h"
18 #include "SystemZInstrInfo.h"
19 #include "llvm/CodeGen/MachineBasicBlock.h"
20 #include "llvm/CodeGen/SelectionDAG.h"
21 #include "llvm/CodeGen/TargetLowering.h"
22 #include <optional>
23 
24 namespace llvm {
25 namespace SystemZISD {
26 enum NodeType : unsigned {
27   FIRST_NUMBER = ISD::BUILTIN_OP_END,
28 
29   // Return with a glue operand.  Operand 0 is the chain operand.
30   RET_GLUE,
31 
32   // Calls a function.  Operand 0 is the chain operand and operand 1
33   // is the target address.  The arguments start at operand 2.
34   // There is an optional glue operand at the end.
35   CALL,
36   SIBCALL,
37 
38   // TLS calls.  Like regular calls, except operand 1 is the TLS symbol.
39   // (The call target is implicitly __tls_get_offset.)
40   TLS_GDCALL,
41   TLS_LDCALL,
42 
43   // Wraps a TargetGlobalAddress that should be loaded using PC-relative
44   // accesses (LARL).  Operand 0 is the address.
45   PCREL_WRAPPER,
46 
47   // Used in cases where an offset is applied to a TargetGlobalAddress.
48   // Operand 0 is the full TargetGlobalAddress and operand 1 is a
49   // PCREL_WRAPPER for an anchor point.  This is used so that we can
50   // cheaply refer to either the full address or the anchor point
51   // as a register base.
52   PCREL_OFFSET,
53 
54   // Integer comparisons.  There are three operands: the two values
55   // to compare, and an integer of type SystemZICMP.
56   ICMP,
57 
58   // Floating-point comparisons.  The two operands are the values to compare.
59   FCMP,
60 
61   // Test under mask.  The first operand is ANDed with the second operand
62   // and the condition codes are set on the result.  The third operand is
63   // a boolean that is true if the condition codes need to distinguish
64   // between CCMASK_TM_MIXED_MSB_0 and CCMASK_TM_MIXED_MSB_1 (which the
65   // register forms do but the memory forms don't).
66   TM,
67 
68   // Branches if a condition is true.  Operand 0 is the chain operand;
69   // operand 1 is the 4-bit condition-code mask, with bit N in
70   // big-endian order meaning "branch if CC=N"; operand 2 is the
71   // target block and operand 3 is the flag operand.
72   BR_CCMASK,
73 
74   // Selects between operand 0 and operand 1.  Operand 2 is the
75   // mask of condition-code values for which operand 0 should be
76   // chosen over operand 1; it has the same form as BR_CCMASK.
77   // Operand 3 is the flag operand.
78   SELECT_CCMASK,
79 
80   // Evaluates to the gap between the stack pointer and the
81   // base of the dynamically-allocatable area.
82   ADJDYNALLOC,
83 
84   // For allocating stack space when using stack clash protector.
85   // Allocation is performed by block, and each block is probed.
86   PROBED_ALLOCA,
87 
88   // Count number of bits set in operand 0 per byte.
89   POPCNT,
90 
91   // Wrappers around the ISD opcodes of the same name.  The output is GR128.
92   // Input operands may be GR64 or GR32, depending on the instruction.
93   SMUL_LOHI,
94   UMUL_LOHI,
95   SDIVREM,
96   UDIVREM,
97 
98   // Add/subtract with overflow/carry.  These have the same operands as
99   // the corresponding standard operations, except with the carry flag
100   // replaced by a condition code value.
101   SADDO, SSUBO, UADDO, USUBO, ADDCARRY, SUBCARRY,
102 
103   // Set the condition code from a boolean value in operand 0.
104   // Operand 1 is a mask of all condition-code values that may result of this
105   // operation, operand 2 is a mask of condition-code values that may result
106   // if the boolean is true.
107   // Note that this operation is always optimized away, we will never
108   // generate any code for it.
109   GET_CCMASK,
110 
111   // Use a series of MVCs to copy bytes from one memory location to another.
112   // The operands are:
113   // - the target address
114   // - the source address
115   // - the constant length
116   //
117   // This isn't a memory opcode because we'd need to attach two
118   // MachineMemOperands rather than one.
119   MVC,
120 
121   // Similar to MVC, but for logic operations (AND, OR, XOR).
122   NC,
123   OC,
124   XC,
125 
126   // Use CLC to compare two blocks of memory, with the same comments
127   // as for MVC.
128   CLC,
129 
130   // Use MVC to set a block of memory after storing the first byte.
131   MEMSET_MVC,
132 
133   // Use an MVST-based sequence to implement stpcpy().
134   STPCPY,
135 
136   // Use a CLST-based sequence to implement strcmp().  The two input operands
137   // are the addresses of the strings to compare.
138   STRCMP,
139 
140   // Use an SRST-based sequence to search a block of memory.  The first
141   // operand is the end address, the second is the start, and the third
142   // is the character to search for.  CC is set to 1 on success and 2
143   // on failure.
144   SEARCH_STRING,
145 
146   // Store the CC value in bits 29 and 28 of an integer.
147   IPM,
148 
149   // Transaction begin.  The first operand is the chain, the second
150   // the TDB pointer, and the third the immediate control field.
151   // Returns CC value and chain.
152   TBEGIN,
153   TBEGIN_NOFLOAT,
154 
155   // Transaction end.  Just the chain operand.  Returns CC value and chain.
156   TEND,
157 
158   // Create a vector constant by filling byte N of the result with bit
159   // 15-N of the single operand.
160   BYTE_MASK,
161 
162   // Create a vector constant by replicating an element-sized RISBG-style mask.
163   // The first operand specifies the starting set bit and the second operand
164   // specifies the ending set bit.  Both operands count from the MSB of the
165   // element.
166   ROTATE_MASK,
167 
168   // Replicate a GPR scalar value into all elements of a vector.
169   REPLICATE,
170 
171   // Create a vector from two i64 GPRs.
172   JOIN_DWORDS,
173 
174   // Replicate one element of a vector into all elements.  The first operand
175   // is the vector and the second is the index of the element to replicate.
176   SPLAT,
177 
178   // Interleave elements from the high half of operand 0 and the high half
179   // of operand 1.
180   MERGE_HIGH,
181 
182   // Likewise for the low halves.
183   MERGE_LOW,
184 
185   // Concatenate the vectors in the first two operands, shift them left
186   // by the third operand, and take the first half of the result.
187   SHL_DOUBLE,
188 
189   // Take one element of the first v2i64 operand and the one element of
190   // the second v2i64 operand and concatenate them to form a v2i64 result.
191   // The third operand is a 4-bit value of the form 0A0B, where A and B
192   // are the element selectors for the first operand and second operands
193   // respectively.
194   PERMUTE_DWORDS,
195 
196   // Perform a general vector permute on vector operands 0 and 1.
197   // Each byte of operand 2 controls the corresponding byte of the result,
198   // in the same way as a byte-level VECTOR_SHUFFLE mask.
199   PERMUTE,
200 
201   // Pack vector operands 0 and 1 into a single vector with half-sized elements.
202   PACK,
203 
204   // Likewise, but saturate the result and set CC.  PACKS_CC does signed
205   // saturation and PACKLS_CC does unsigned saturation.
206   PACKS_CC,
207   PACKLS_CC,
208 
209   // Unpack the first half of vector operand 0 into double-sized elements.
210   // UNPACK_HIGH sign-extends and UNPACKL_HIGH zero-extends.
211   UNPACK_HIGH,
212   UNPACKL_HIGH,
213 
214   // Likewise for the second half.
215   UNPACK_LOW,
216   UNPACKL_LOW,
217 
218   // Shift/rotate each element of vector operand 0 by the number of bits
219   // specified by scalar operand 1.
220   VSHL_BY_SCALAR,
221   VSRL_BY_SCALAR,
222   VSRA_BY_SCALAR,
223   VROTL_BY_SCALAR,
224 
225   // For each element of the output type, sum across all sub-elements of
226   // operand 0 belonging to the corresponding element, and add in the
227   // rightmost sub-element of the corresponding element of operand 1.
228   VSUM,
229 
230   // Compute carry/borrow indication for add/subtract.
231   VACC, VSCBI,
232   // Add/subtract with carry/borrow.
233   VAC, VSBI,
234   // Compute carry/borrow indication for add/subtract with carry/borrow.
235   VACCC, VSBCBI,
236 
237   // Compare integer vector operands 0 and 1 to produce the usual 0/-1
238   // vector result.  VICMPE is for equality, VICMPH for "signed greater than"
239   // and VICMPHL for "unsigned greater than".
240   VICMPE,
241   VICMPH,
242   VICMPHL,
243 
244   // Likewise, but also set the condition codes on the result.
245   VICMPES,
246   VICMPHS,
247   VICMPHLS,
248 
249   // Compare floating-point vector operands 0 and 1 to produce the usual 0/-1
250   // vector result.  VFCMPE is for "ordered and equal", VFCMPH for "ordered and
251   // greater than" and VFCMPHE for "ordered and greater than or equal to".
252   VFCMPE,
253   VFCMPH,
254   VFCMPHE,
255 
256   // Likewise, but also set the condition codes on the result.
257   VFCMPES,
258   VFCMPHS,
259   VFCMPHES,
260 
261   // Test floating-point data class for vectors.
262   VFTCI,
263 
264   // Extend the even f32 elements of vector operand 0 to produce a vector
265   // of f64 elements.
266   VEXTEND,
267 
268   // Round the f64 elements of vector operand 0 to f32s and store them in the
269   // even elements of the result.
270   VROUND,
271 
272   // AND the two vector operands together and set CC based on the result.
273   VTM,
274 
275   // i128 high integer comparisons.
276   SCMP128HI,
277   UCMP128HI,
278 
279   // String operations that set CC as a side-effect.
280   VFAE_CC,
281   VFAEZ_CC,
282   VFEE_CC,
283   VFEEZ_CC,
284   VFENE_CC,
285   VFENEZ_CC,
286   VISTR_CC,
287   VSTRC_CC,
288   VSTRCZ_CC,
289   VSTRS_CC,
290   VSTRSZ_CC,
291 
292   // Test Data Class.
293   //
294   // Operand 0: the value to test
295   // Operand 1: the bit mask
296   TDC,
297 
298   // z/OS XPLINK ADA Entry
299   // Wraps a TargetGlobalAddress that should be loaded from a function's
300   // AssociatedData Area (ADA). Tha ADA is passed to the function by the
301   // caller in the XPLink ABI defined register R5.
302   // Operand 0: the GlobalValue/External Symbol
303   // Operand 1: the ADA register
304   // Operand 2: the offset (0 for the first and 8 for the second element in the
305   // function descriptor)
306   ADA_ENTRY,
307 
308   // Strict variants of scalar floating-point comparisons.
309   // Quiet and signaling versions.
310   STRICT_FCMP = ISD::FIRST_TARGET_STRICTFP_OPCODE,
311   STRICT_FCMPS,
312 
313   // Strict variants of vector floating-point comparisons.
314   // Quiet and signaling versions.
315   STRICT_VFCMPE,
316   STRICT_VFCMPH,
317   STRICT_VFCMPHE,
318   STRICT_VFCMPES,
319   STRICT_VFCMPHS,
320   STRICT_VFCMPHES,
321 
322   // Strict variants of VEXTEND and VROUND.
323   STRICT_VEXTEND,
324   STRICT_VROUND,
325 
326   // Wrappers around the inner loop of an 8- or 16-bit ATOMIC_SWAP or
327   // ATOMIC_LOAD_<op>.
328   //
329   // Operand 0: the address of the containing 32-bit-aligned field
330   // Operand 1: the second operand of <op>, in the high bits of an i32
331   //            for everything except ATOMIC_SWAPW
332   // Operand 2: how many bits to rotate the i32 left to bring the first
333   //            operand into the high bits
334   // Operand 3: the negative of operand 2, for rotating the other way
335   // Operand 4: the width of the field in bits (8 or 16)
336   ATOMIC_SWAPW = ISD::FIRST_TARGET_MEMORY_OPCODE,
337   ATOMIC_LOADW_ADD,
338   ATOMIC_LOADW_SUB,
339   ATOMIC_LOADW_AND,
340   ATOMIC_LOADW_OR,
341   ATOMIC_LOADW_XOR,
342   ATOMIC_LOADW_NAND,
343   ATOMIC_LOADW_MIN,
344   ATOMIC_LOADW_MAX,
345   ATOMIC_LOADW_UMIN,
346   ATOMIC_LOADW_UMAX,
347 
348   // A wrapper around the inner loop of an ATOMIC_CMP_SWAP.
349   //
350   // Operand 0: the address of the containing 32-bit-aligned field
351   // Operand 1: the compare value, in the low bits of an i32
352   // Operand 2: the swap value, in the low bits of an i32
353   // Operand 3: how many bits to rotate the i32 left to bring the first
354   //            operand into the high bits
355   // Operand 4: the negative of operand 2, for rotating the other way
356   // Operand 5: the width of the field in bits (8 or 16)
357   ATOMIC_CMP_SWAPW,
358 
359   // Atomic compare-and-swap returning CC value.
360   // Val, CC, OUTCHAIN = ATOMIC_CMP_SWAP(INCHAIN, ptr, cmp, swap)
361   ATOMIC_CMP_SWAP,
362 
363   // 128-bit atomic load.
364   // Val, OUTCHAIN = ATOMIC_LOAD_128(INCHAIN, ptr)
365   ATOMIC_LOAD_128,
366 
367   // 128-bit atomic store.
368   // OUTCHAIN = ATOMIC_STORE_128(INCHAIN, val, ptr)
369   ATOMIC_STORE_128,
370 
371   // 128-bit atomic compare-and-swap.
372   // Val, CC, OUTCHAIN = ATOMIC_CMP_SWAP(INCHAIN, ptr, cmp, swap)
373   ATOMIC_CMP_SWAP_128,
374 
375   // Byte swapping load/store.  Same operands as regular load/store.
376   LRV, STRV,
377 
378   // Element swapping load/store.  Same operands as regular load/store.
379   VLER, VSTER,
380 
381   // Use STORE CLOCK FAST to store current TOD clock value.
382   STCKF,
383 
384   // Prefetch from the second operand using the 4-bit control code in
385   // the first operand.  The code is 1 for a load prefetch and 2 for
386   // a store prefetch.
387   PREFETCH
388 };
389 
390 // Return true if OPCODE is some kind of PC-relative address.
391 inline bool isPCREL(unsigned Opcode) {
392   return Opcode == PCREL_WRAPPER || Opcode == PCREL_OFFSET;
393 }
394 } // end namespace SystemZISD
395 
396 namespace SystemZICMP {
397 // Describes whether an integer comparison needs to be signed or unsigned,
398 // or whether either type is OK.
399 enum {
400   Any,
401   UnsignedOnly,
402   SignedOnly
403 };
404 } // end namespace SystemZICMP
405 
406 class SystemZSubtarget;
407 
408 class SystemZTargetLowering : public TargetLowering {
409 public:
410   explicit SystemZTargetLowering(const TargetMachine &TM,
411                                  const SystemZSubtarget &STI);
412 
413   bool useSoftFloat() const override;
414 
415   // Override TargetLowering.
416   MVT getScalarShiftAmountTy(const DataLayout &, EVT) const override {
417     return MVT::i32;
418   }
419   MVT getVectorIdxTy(const DataLayout &DL) const override {
420     // Only the lower 12 bits of an element index are used, so we don't
421     // want to clobber the upper 32 bits of a GPR unnecessarily.
422     return MVT::i32;
423   }
424   TargetLoweringBase::LegalizeTypeAction getPreferredVectorAction(MVT VT)
425     const override {
426     // Widen subvectors to the full width rather than promoting integer
427     // elements.  This is better because:
428     //
429     // (a) it means that we can handle the ABI for passing and returning
430     //     sub-128 vectors without having to handle them as legal types.
431     //
432     // (b) we don't have instructions to extend on load and truncate on store,
433     //     so promoting the integers is less efficient.
434     //
435     // (c) there are no multiplication instructions for the widest integer
436     //     type (v2i64).
437     if (VT.getScalarSizeInBits() % 8 == 0)
438       return TypeWidenVector;
439     return TargetLoweringBase::getPreferredVectorAction(VT);
440   }
441   unsigned
442   getNumRegisters(LLVMContext &Context, EVT VT,
443                   std::optional<MVT> RegisterVT) const override {
444     // i128 inline assembly operand.
445     if (VT == MVT::i128 && RegisterVT && *RegisterVT == MVT::Untyped)
446       return 1;
447     return TargetLowering::getNumRegisters(Context, VT);
448   }
449   MVT getRegisterTypeForCallingConv(LLVMContext &Context, CallingConv::ID CC,
450                                     EVT VT) const override {
451     // 128-bit single-element vector types are passed like other vectors,
452     // not like their element type.
453     if (VT.isVector() && VT.getSizeInBits() == 128 &&
454         VT.getVectorNumElements() == 1)
455       return MVT::v16i8;
456     return TargetLowering::getRegisterTypeForCallingConv(Context, CC, VT);
457   }
458   bool isCheapToSpeculateCtlz(Type *) const override { return true; }
459   bool isCheapToSpeculateCttz(Type *) const override { return true; }
460   bool preferZeroCompareBranch() const override { return true; }
461   bool isMaskAndCmp0FoldingBeneficial(const Instruction &AndI) const override {
462     ConstantInt* Mask = dyn_cast<ConstantInt>(AndI.getOperand(1));
463     return Mask && Mask->getValue().isIntN(16);
464   }
465   bool convertSetCCLogicToBitwiseLogic(EVT VT) const override {
466     return VT.isScalarInteger();
467   }
468   EVT getSetCCResultType(const DataLayout &DL, LLVMContext &,
469                          EVT) const override;
470   bool isFMAFasterThanFMulAndFAdd(const MachineFunction &MF,
471                                   EVT VT) const override;
472   bool isFPImmLegal(const APFloat &Imm, EVT VT,
473                     bool ForCodeSize) const override;
474   bool ShouldShrinkFPConstant(EVT VT) const override {
475     // Do not shrink 64-bit FP constpool entries since LDEB is slower than
476     // LD, and having the full constant in memory enables reg/mem opcodes.
477     return VT != MVT::f64;
478   }
479   bool hasInlineStackProbe(const MachineFunction &MF) const override;
480   AtomicExpansionKind shouldCastAtomicLoadInIR(LoadInst *LI) const override;
481   AtomicExpansionKind shouldCastAtomicStoreInIR(StoreInst *SI) const override;
482   AtomicExpansionKind
483   shouldExpandAtomicRMWInIR(AtomicRMWInst *RMW) const override;
484   bool isLegalICmpImmediate(int64_t Imm) const override;
485   bool isLegalAddImmediate(int64_t Imm) const override;
486   bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
487                              unsigned AS,
488                              Instruction *I = nullptr) const override;
489   bool allowsMisalignedMemoryAccesses(EVT VT, unsigned AS, Align Alignment,
490                                       MachineMemOperand::Flags Flags,
491                                       unsigned *Fast) const override;
492   bool
493   findOptimalMemOpLowering(std::vector<EVT> &MemOps, unsigned Limit,
494                            const MemOp &Op, unsigned DstAS, unsigned SrcAS,
495                            const AttributeList &FuncAttributes) const override;
496   EVT getOptimalMemOpType(const MemOp &Op,
497                           const AttributeList &FuncAttributes) const override;
498   bool isTruncateFree(Type *, Type *) const override;
499   bool isTruncateFree(EVT, EVT) const override;
500 
501   bool shouldFormOverflowOp(unsigned Opcode, EVT VT,
502                             bool MathUsed) const override {
503     // Form add and sub with overflow intrinsics regardless of any extra
504     // users of the math result.
505     return VT == MVT::i32 || VT == MVT::i64;
506   }
507 
508   bool shouldConsiderGEPOffsetSplit() const override { return true; }
509 
510   bool shouldExpandCmpUsingSelects() const override { return true; }
511 
512   const char *getTargetNodeName(unsigned Opcode) const override;
513   std::pair<unsigned, const TargetRegisterClass *>
514   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
515                                StringRef Constraint, MVT VT) const override;
516   TargetLowering::ConstraintType
517   getConstraintType(StringRef Constraint) const override;
518   TargetLowering::ConstraintWeight
519     getSingleConstraintMatchWeight(AsmOperandInfo &info,
520                                    const char *constraint) const override;
521   void LowerAsmOperandForConstraint(SDValue Op, StringRef Constraint,
522                                     std::vector<SDValue> &Ops,
523                                     SelectionDAG &DAG) const override;
524 
525   InlineAsm::ConstraintCode
526   getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
527     if (ConstraintCode.size() == 1) {
528       switch(ConstraintCode[0]) {
529       default:
530         break;
531       case 'o':
532         return InlineAsm::ConstraintCode::o;
533       case 'Q':
534         return InlineAsm::ConstraintCode::Q;
535       case 'R':
536         return InlineAsm::ConstraintCode::R;
537       case 'S':
538         return InlineAsm::ConstraintCode::S;
539       case 'T':
540         return InlineAsm::ConstraintCode::T;
541       }
542     } else if (ConstraintCode.size() == 2 && ConstraintCode[0] == 'Z') {
543       switch (ConstraintCode[1]) {
544       default:
545         break;
546       case 'Q':
547         return InlineAsm::ConstraintCode::ZQ;
548       case 'R':
549         return InlineAsm::ConstraintCode::ZR;
550       case 'S':
551         return InlineAsm::ConstraintCode::ZS;
552       case 'T':
553         return InlineAsm::ConstraintCode::ZT;
554       }
555     }
556     return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
557   }
558 
559   Register getRegisterByName(const char *RegName, LLT VT,
560                              const MachineFunction &MF) const override;
561 
562   /// If a physical register, this returns the register that receives the
563   /// exception address on entry to an EH pad.
564   Register
565   getExceptionPointerRegister(const Constant *PersonalityFn) const override;
566 
567   /// If a physical register, this returns the register that receives the
568   /// exception typeid on entry to a landing pad.
569   Register
570   getExceptionSelectorRegister(const Constant *PersonalityFn) const override;
571 
572   /// Override to support customized stack guard loading.
573   bool useLoadStackGuardNode() const override {
574     return true;
575   }
576   void insertSSPDeclarations(Module &M) const override {
577   }
578 
579   MachineBasicBlock *
580   EmitInstrWithCustomInserter(MachineInstr &MI,
581                               MachineBasicBlock *BB) const override;
582   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
583   void LowerOperationWrapper(SDNode *N, SmallVectorImpl<SDValue> &Results,
584                              SelectionDAG &DAG) const override;
585   void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
586                           SelectionDAG &DAG) const override;
587   const MCPhysReg *getScratchRegisters(CallingConv::ID CC) const override;
588   bool allowTruncateForTailCall(Type *, Type *) const override;
589   bool mayBeEmittedAsTailCall(const CallInst *CI) const override;
590   bool splitValueIntoRegisterParts(
591       SelectionDAG & DAG, const SDLoc &DL, SDValue Val, SDValue *Parts,
592       unsigned NumParts, MVT PartVT, std::optional<CallingConv::ID> CC)
593       const override;
594   SDValue joinRegisterPartsIntoValue(
595       SelectionDAG & DAG, const SDLoc &DL, const SDValue *Parts,
596       unsigned NumParts, MVT PartVT, EVT ValueVT,
597       std::optional<CallingConv::ID> CC) const override;
598   SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
599                                bool isVarArg,
600                                const SmallVectorImpl<ISD::InputArg> &Ins,
601                                const SDLoc &DL, SelectionDAG &DAG,
602                                SmallVectorImpl<SDValue> &InVals) const override;
603   SDValue LowerCall(CallLoweringInfo &CLI,
604                     SmallVectorImpl<SDValue> &InVals) const override;
605 
606   std::pair<SDValue, SDValue>
607   makeExternalCall(SDValue Chain, SelectionDAG &DAG, const char *CalleeName,
608                    EVT RetVT, ArrayRef<SDValue> Ops, CallingConv::ID CallConv,
609                    bool IsSigned, SDLoc DL, bool DoesNotReturn,
610                    bool IsReturnValueUsed) const;
611 
612   bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
613                       bool isVarArg,
614                       const SmallVectorImpl<ISD::OutputArg> &Outs,
615                       LLVMContext &Context) const override;
616   SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
617                       const SmallVectorImpl<ISD::OutputArg> &Outs,
618                       const SmallVectorImpl<SDValue> &OutVals, const SDLoc &DL,
619                       SelectionDAG &DAG) const override;
620   SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
621 
622   /// Determine which of the bits specified in Mask are known to be either
623   /// zero or one and return them in the KnownZero/KnownOne bitsets.
624   void computeKnownBitsForTargetNode(const SDValue Op,
625                                      KnownBits &Known,
626                                      const APInt &DemandedElts,
627                                      const SelectionDAG &DAG,
628                                      unsigned Depth = 0) const override;
629 
630   /// Determine the number of bits in the operation that are sign bits.
631   unsigned ComputeNumSignBitsForTargetNode(SDValue Op,
632                                            const APInt &DemandedElts,
633                                            const SelectionDAG &DAG,
634                                            unsigned Depth) const override;
635 
636   bool isGuaranteedNotToBeUndefOrPoisonForTargetNode(
637       SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
638       bool PoisonOnly, unsigned Depth) const override;
639 
640   ISD::NodeType getExtendForAtomicOps() const override {
641     return ISD::ANY_EXTEND;
642   }
643   ISD::NodeType getExtendForAtomicCmpSwapArg() const override {
644     return ISD::ZERO_EXTEND;
645   }
646 
647   bool supportSwiftError() const override {
648     return true;
649   }
650 
651   unsigned getStackProbeSize(const MachineFunction &MF) const;
652 
653 private:
654   const SystemZSubtarget &Subtarget;
655 
656   // Implement LowerOperation for individual opcodes.
657   SDValue getVectorCmp(SelectionDAG &DAG, unsigned Opcode,
658                        const SDLoc &DL, EVT VT,
659                        SDValue CmpOp0, SDValue CmpOp1, SDValue Chain) const;
660   SDValue lowerVectorSETCC(SelectionDAG &DAG, const SDLoc &DL,
661                            EVT VT, ISD::CondCode CC,
662                            SDValue CmpOp0, SDValue CmpOp1,
663                            SDValue Chain = SDValue(),
664                            bool IsSignaling = false) const;
665   SDValue lowerSETCC(SDValue Op, SelectionDAG &DAG) const;
666   SDValue lowerSTRICT_FSETCC(SDValue Op, SelectionDAG &DAG,
667                              bool IsSignaling) const;
668   SDValue lowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
669   SDValue lowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
670   SDValue lowerGlobalAddress(GlobalAddressSDNode *Node,
671                              SelectionDAG &DAG) const;
672   SDValue lowerTLSGetOffset(GlobalAddressSDNode *Node,
673                             SelectionDAG &DAG, unsigned Opcode,
674                             SDValue GOTOffset) const;
675   SDValue lowerThreadPointer(const SDLoc &DL, SelectionDAG &DAG) const;
676   SDValue lowerGlobalTLSAddress(GlobalAddressSDNode *Node,
677                                 SelectionDAG &DAG) const;
678   SDValue lowerBlockAddress(BlockAddressSDNode *Node,
679                             SelectionDAG &DAG) const;
680   SDValue lowerJumpTable(JumpTableSDNode *JT, SelectionDAG &DAG) const;
681   SDValue lowerConstantPool(ConstantPoolSDNode *CP, SelectionDAG &DAG) const;
682   SDValue lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
683   SDValue lowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
684   SDValue lowerVASTART(SDValue Op, SelectionDAG &DAG) const;
685   SDValue lowerVASTART_ELF(SDValue Op, SelectionDAG &DAG) const;
686   SDValue lowerVASTART_XPLINK(SDValue Op, SelectionDAG &DAG) const;
687   SDValue lowerVACOPY(SDValue Op, SelectionDAG &DAG) const;
688   SDValue lowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const;
689   SDValue lowerDYNAMIC_STACKALLOC_ELF(SDValue Op, SelectionDAG &DAG) const;
690   SDValue lowerDYNAMIC_STACKALLOC_XPLINK(SDValue Op, SelectionDAG &DAG) const;
691   SDValue lowerGET_DYNAMIC_AREA_OFFSET(SDValue Op, SelectionDAG &DAG) const;
692   SDValue lowerSMUL_LOHI(SDValue Op, SelectionDAG &DAG) const;
693   SDValue lowerUMUL_LOHI(SDValue Op, SelectionDAG &DAG) const;
694   SDValue lowerSDIVREM(SDValue Op, SelectionDAG &DAG) const;
695   SDValue lowerUDIVREM(SDValue Op, SelectionDAG &DAG) const;
696   SDValue lowerXALUO(SDValue Op, SelectionDAG &DAG) const;
697   SDValue lowerUADDSUBO_CARRY(SDValue Op, SelectionDAG &DAG) const;
698   SDValue lowerBITCAST(SDValue Op, SelectionDAG &DAG) const;
699   SDValue lowerOR(SDValue Op, SelectionDAG &DAG) const;
700   SDValue lowerCTPOP(SDValue Op, SelectionDAG &DAG) const;
701   SDValue lowerVECREDUCE_ADD(SDValue Op, SelectionDAG &DAG) const;
702   SDValue lowerATOMIC_FENCE(SDValue Op, SelectionDAG &DAG) const;
703   SDValue lowerATOMIC_LDST_I128(SDValue Op, SelectionDAG &DAG) const;
704   SDValue lowerATOMIC_LOAD_OP(SDValue Op, SelectionDAG &DAG,
705                               unsigned Opcode) const;
706   SDValue lowerATOMIC_LOAD_SUB(SDValue Op, SelectionDAG &DAG) const;
707   SDValue lowerATOMIC_CMP_SWAP(SDValue Op, SelectionDAG &DAG) const;
708   SDValue lowerSTACKSAVE(SDValue Op, SelectionDAG &DAG) const;
709   SDValue lowerSTACKRESTORE(SDValue Op, SelectionDAG &DAG) const;
710   SDValue lowerPREFETCH(SDValue Op, SelectionDAG &DAG) const;
711   SDValue lowerINTRINSIC_W_CHAIN(SDValue Op, SelectionDAG &DAG) const;
712   SDValue lowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
713   bool isVectorElementLoad(SDValue Op) const;
714   SDValue buildVector(SelectionDAG &DAG, const SDLoc &DL, EVT VT,
715                       SmallVectorImpl<SDValue> &Elems) const;
716   SDValue lowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const;
717   SDValue lowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
718   SDValue lowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG) const;
719   SDValue lowerINSERT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
720   SDValue lowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
721   SDValue lowerSIGN_EXTEND_VECTOR_INREG(SDValue Op, SelectionDAG &DAG) const;
722   SDValue lowerZERO_EXTEND_VECTOR_INREG(SDValue Op, SelectionDAG &DAG) const;
723   SDValue lowerShift(SDValue Op, SelectionDAG &DAG, unsigned ByScalar) const;
724   SDValue lowerIS_FPCLASS(SDValue Op, SelectionDAG &DAG) const;
725   SDValue lowerGET_ROUNDING(SDValue Op, SelectionDAG &DAG) const;
726   SDValue lowerREADCYCLECOUNTER(SDValue Op, SelectionDAG &DAG) const;
727 
728   bool canTreatAsByteVector(EVT VT) const;
729   SDValue combineExtract(const SDLoc &DL, EVT ElemVT, EVT VecVT, SDValue OrigOp,
730                          unsigned Index, DAGCombinerInfo &DCI,
731                          bool Force) const;
732   SDValue combineTruncateExtract(const SDLoc &DL, EVT TruncVT, SDValue Op,
733                                  DAGCombinerInfo &DCI) const;
734   SDValue combineZERO_EXTEND(SDNode *N, DAGCombinerInfo &DCI) const;
735   SDValue combineSIGN_EXTEND(SDNode *N, DAGCombinerInfo &DCI) const;
736   SDValue combineSIGN_EXTEND_INREG(SDNode *N, DAGCombinerInfo &DCI) const;
737   SDValue combineMERGE(SDNode *N, DAGCombinerInfo &DCI) const;
738   bool canLoadStoreByteSwapped(EVT VT) const;
739   SDValue combineLOAD(SDNode *N, DAGCombinerInfo &DCI) const;
740   SDValue combineSTORE(SDNode *N, DAGCombinerInfo &DCI) const;
741   SDValue combineVECTOR_SHUFFLE(SDNode *N, DAGCombinerInfo &DCI) const;
742   SDValue combineEXTRACT_VECTOR_ELT(SDNode *N, DAGCombinerInfo &DCI) const;
743   SDValue combineJOIN_DWORDS(SDNode *N, DAGCombinerInfo &DCI) const;
744   SDValue combineFP_ROUND(SDNode *N, DAGCombinerInfo &DCI) const;
745   SDValue combineFP_EXTEND(SDNode *N, DAGCombinerInfo &DCI) const;
746   SDValue combineINT_TO_FP(SDNode *N, DAGCombinerInfo &DCI) const;
747   SDValue combineBSWAP(SDNode *N, DAGCombinerInfo &DCI) const;
748   SDValue combineBR_CCMASK(SDNode *N, DAGCombinerInfo &DCI) const;
749   SDValue combineSELECT_CCMASK(SDNode *N, DAGCombinerInfo &DCI) const;
750   SDValue combineGET_CCMASK(SDNode *N, DAGCombinerInfo &DCI) const;
751   SDValue combineIntDIVREM(SDNode *N, DAGCombinerInfo &DCI) const;
752   SDValue combineINTRINSIC(SDNode *N, DAGCombinerInfo &DCI) const;
753 
754   SDValue unwrapAddress(SDValue N) const override;
755 
756   // If the last instruction before MBBI in MBB was some form of COMPARE,
757   // try to replace it with a COMPARE AND BRANCH just before MBBI.
758   // CCMask and Target are the BRC-like operands for the branch.
759   // Return true if the change was made.
760   bool convertPrevCompareToBranch(MachineBasicBlock *MBB,
761                                   MachineBasicBlock::iterator MBBI,
762                                   unsigned CCMask,
763                                   MachineBasicBlock *Target) const;
764 
765   // Implement EmitInstrWithCustomInserter for individual operation types.
766   MachineBasicBlock *emitAdjCallStack(MachineInstr &MI,
767                                       MachineBasicBlock *BB) const;
768   MachineBasicBlock *emitSelect(MachineInstr &MI, MachineBasicBlock *BB) const;
769   MachineBasicBlock *emitCondStore(MachineInstr &MI, MachineBasicBlock *BB,
770                                    unsigned StoreOpcode, unsigned STOCOpcode,
771                                    bool Invert) const;
772   MachineBasicBlock *emitICmp128Hi(MachineInstr &MI, MachineBasicBlock *BB,
773                                    bool Unsigned) const;
774   MachineBasicBlock *emitPair128(MachineInstr &MI,
775                                  MachineBasicBlock *MBB) const;
776   MachineBasicBlock *emitExt128(MachineInstr &MI, MachineBasicBlock *MBB,
777                                 bool ClearEven) const;
778   MachineBasicBlock *emitAtomicLoadBinary(MachineInstr &MI,
779                                           MachineBasicBlock *BB,
780                                           unsigned BinOpcode,
781                                           bool Invert = false) const;
782   MachineBasicBlock *emitAtomicLoadMinMax(MachineInstr &MI,
783                                           MachineBasicBlock *MBB,
784                                           unsigned CompareOpcode,
785                                           unsigned KeepOldMask) const;
786   MachineBasicBlock *emitAtomicCmpSwapW(MachineInstr &MI,
787                                         MachineBasicBlock *BB) const;
788   MachineBasicBlock *emitMemMemWrapper(MachineInstr &MI, MachineBasicBlock *BB,
789                                        unsigned Opcode,
790                                        bool IsMemset = false) const;
791   MachineBasicBlock *emitStringWrapper(MachineInstr &MI, MachineBasicBlock *BB,
792                                        unsigned Opcode) const;
793   MachineBasicBlock *emitTransactionBegin(MachineInstr &MI,
794                                           MachineBasicBlock *MBB,
795                                           unsigned Opcode, bool NoFloat) const;
796   MachineBasicBlock *emitLoadAndTestCmp0(MachineInstr &MI,
797                                          MachineBasicBlock *MBB,
798                                          unsigned Opcode) const;
799   MachineBasicBlock *emitProbedAlloca(MachineInstr &MI,
800                                       MachineBasicBlock *MBB) const;
801 
802   SDValue getBackchainAddress(SDValue SP, SelectionDAG &DAG) const;
803 
804   MachineMemOperand::Flags
805   getTargetMMOFlags(const Instruction &I) const override;
806   const TargetRegisterClass *getRepRegClassFor(MVT VT) const override;
807 };
808 
809 struct SystemZVectorConstantInfo {
810 private:
811   APInt IntBits;             // The 128 bits as an integer.
812   APInt SplatBits;           // Smallest splat value.
813   APInt SplatUndef;          // Bits correspoding to undef operands of the BVN.
814   unsigned SplatBitSize = 0;
815   bool isFP128 = false;
816 public:
817   unsigned Opcode = 0;
818   SmallVector<unsigned, 2> OpVals;
819   MVT VecVT;
820   SystemZVectorConstantInfo(APInt IntImm);
821   SystemZVectorConstantInfo(APFloat FPImm)
822       : SystemZVectorConstantInfo(FPImm.bitcastToAPInt()) {
823     isFP128 = (&FPImm.getSemantics() == &APFloat::IEEEquad());
824   }
825   SystemZVectorConstantInfo(BuildVectorSDNode *BVN);
826   bool isVectorConstantLegal(const SystemZSubtarget &Subtarget);
827 };
828 
829 } // end namespace llvm
830 
831 #endif
832