xref: /llvm-project/llvm/lib/CodeGen/TargetLoweringBase.cpp (revision ab976a17121374ae3407374b2aa6306e95863eb3)
1 //===- TargetLoweringBase.cpp - Implement the TargetLoweringBase class ----===//
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 implements the TargetLoweringBase class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ADT/BitVector.h"
14 #include "llvm/ADT/STLExtras.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/ADT/StringExtras.h"
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/ADT/Twine.h"
19 #include "llvm/Analysis/Loads.h"
20 #include "llvm/Analysis/TargetTransformInfo.h"
21 #include "llvm/CodeGen/Analysis.h"
22 #include "llvm/CodeGen/ISDOpcodes.h"
23 #include "llvm/CodeGen/MachineBasicBlock.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineInstr.h"
27 #include "llvm/CodeGen/MachineInstrBuilder.h"
28 #include "llvm/CodeGen/MachineMemOperand.h"
29 #include "llvm/CodeGen/MachineOperand.h"
30 #include "llvm/CodeGen/MachineRegisterInfo.h"
31 #include "llvm/CodeGen/RuntimeLibcallUtil.h"
32 #include "llvm/CodeGen/StackMaps.h"
33 #include "llvm/CodeGen/TargetLowering.h"
34 #include "llvm/CodeGen/TargetOpcodes.h"
35 #include "llvm/CodeGen/TargetRegisterInfo.h"
36 #include "llvm/CodeGen/ValueTypes.h"
37 #include "llvm/CodeGenTypes/MachineValueType.h"
38 #include "llvm/IR/Attributes.h"
39 #include "llvm/IR/CallingConv.h"
40 #include "llvm/IR/DataLayout.h"
41 #include "llvm/IR/DerivedTypes.h"
42 #include "llvm/IR/Function.h"
43 #include "llvm/IR/GlobalValue.h"
44 #include "llvm/IR/GlobalVariable.h"
45 #include "llvm/IR/IRBuilder.h"
46 #include "llvm/IR/Module.h"
47 #include "llvm/IR/Type.h"
48 #include "llvm/Support/Casting.h"
49 #include "llvm/Support/CommandLine.h"
50 #include "llvm/Support/Compiler.h"
51 #include "llvm/Support/ErrorHandling.h"
52 #include "llvm/Support/MathExtras.h"
53 #include "llvm/Target/TargetMachine.h"
54 #include "llvm/Target/TargetOptions.h"
55 #include "llvm/TargetParser/Triple.h"
56 #include "llvm/Transforms/Utils/SizeOpts.h"
57 #include <algorithm>
58 #include <cassert>
59 #include <cstdint>
60 #include <cstring>
61 #include <iterator>
62 #include <string>
63 #include <tuple>
64 #include <utility>
65 
66 using namespace llvm;
67 
68 static cl::opt<bool> JumpIsExpensiveOverride(
69     "jump-is-expensive", cl::init(false),
70     cl::desc("Do not create extra branches to split comparison logic."),
71     cl::Hidden);
72 
73 static cl::opt<unsigned> MinimumJumpTableEntries
74   ("min-jump-table-entries", cl::init(4), cl::Hidden,
75    cl::desc("Set minimum number of entries to use a jump table."));
76 
77 static cl::opt<unsigned> MaximumJumpTableSize
78   ("max-jump-table-size", cl::init(UINT_MAX), cl::Hidden,
79    cl::desc("Set maximum size of jump tables."));
80 
81 /// Minimum jump table density for normal functions.
82 static cl::opt<unsigned>
83     JumpTableDensity("jump-table-density", cl::init(10), cl::Hidden,
84                      cl::desc("Minimum density for building a jump table in "
85                               "a normal function"));
86 
87 /// Minimum jump table density for -Os or -Oz functions.
88 static cl::opt<unsigned> OptsizeJumpTableDensity(
89     "optsize-jump-table-density", cl::init(40), cl::Hidden,
90     cl::desc("Minimum density for building a jump table in "
91              "an optsize function"));
92 
93 // FIXME: This option is only to test if the strict fp operation processed
94 // correctly by preventing mutating strict fp operation to normal fp operation
95 // during development. When the backend supports strict float operation, this
96 // option will be meaningless.
97 static cl::opt<bool> DisableStrictNodeMutation("disable-strictnode-mutation",
98        cl::desc("Don't mutate strict-float node to a legalize node"),
99        cl::init(false), cl::Hidden);
100 
101 /// GetFPLibCall - Helper to return the right libcall for the given floating
102 /// point type, or UNKNOWN_LIBCALL if there is none.
103 RTLIB::Libcall RTLIB::getFPLibCall(EVT VT,
104                                    RTLIB::Libcall Call_F32,
105                                    RTLIB::Libcall Call_F64,
106                                    RTLIB::Libcall Call_F80,
107                                    RTLIB::Libcall Call_F128,
108                                    RTLIB::Libcall Call_PPCF128) {
109   return
110     VT == MVT::f32 ? Call_F32 :
111     VT == MVT::f64 ? Call_F64 :
112     VT == MVT::f80 ? Call_F80 :
113     VT == MVT::f128 ? Call_F128 :
114     VT == MVT::ppcf128 ? Call_PPCF128 :
115     RTLIB::UNKNOWN_LIBCALL;
116 }
117 
118 /// getFPEXT - Return the FPEXT_*_* value for the given types, or
119 /// UNKNOWN_LIBCALL if there is none.
120 RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) {
121   if (OpVT == MVT::f16) {
122     if (RetVT == MVT::f32)
123       return FPEXT_F16_F32;
124     if (RetVT == MVT::f64)
125       return FPEXT_F16_F64;
126     if (RetVT == MVT::f80)
127       return FPEXT_F16_F80;
128     if (RetVT == MVT::f128)
129       return FPEXT_F16_F128;
130   } else if (OpVT == MVT::f32) {
131     if (RetVT == MVT::f64)
132       return FPEXT_F32_F64;
133     if (RetVT == MVT::f128)
134       return FPEXT_F32_F128;
135     if (RetVT == MVT::ppcf128)
136       return FPEXT_F32_PPCF128;
137   } else if (OpVT == MVT::f64) {
138     if (RetVT == MVT::f128)
139       return FPEXT_F64_F128;
140     else if (RetVT == MVT::ppcf128)
141       return FPEXT_F64_PPCF128;
142   } else if (OpVT == MVT::f80) {
143     if (RetVT == MVT::f128)
144       return FPEXT_F80_F128;
145   } else if (OpVT == MVT::bf16) {
146     if (RetVT == MVT::f32)
147       return FPEXT_BF16_F32;
148   }
149 
150   return UNKNOWN_LIBCALL;
151 }
152 
153 /// getFPROUND - Return the FPROUND_*_* value for the given types, or
154 /// UNKNOWN_LIBCALL if there is none.
155 RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) {
156   if (RetVT == MVT::f16) {
157     if (OpVT == MVT::f32)
158       return FPROUND_F32_F16;
159     if (OpVT == MVT::f64)
160       return FPROUND_F64_F16;
161     if (OpVT == MVT::f80)
162       return FPROUND_F80_F16;
163     if (OpVT == MVT::f128)
164       return FPROUND_F128_F16;
165     if (OpVT == MVT::ppcf128)
166       return FPROUND_PPCF128_F16;
167   } else if (RetVT == MVT::bf16) {
168     if (OpVT == MVT::f32)
169       return FPROUND_F32_BF16;
170     if (OpVT == MVT::f64)
171       return FPROUND_F64_BF16;
172     if (OpVT == MVT::f80)
173       return FPROUND_F80_BF16;
174     if (OpVT == MVT::f128)
175       return FPROUND_F128_BF16;
176   } else if (RetVT == MVT::f32) {
177     if (OpVT == MVT::f64)
178       return FPROUND_F64_F32;
179     if (OpVT == MVT::f80)
180       return FPROUND_F80_F32;
181     if (OpVT == MVT::f128)
182       return FPROUND_F128_F32;
183     if (OpVT == MVT::ppcf128)
184       return FPROUND_PPCF128_F32;
185   } else if (RetVT == MVT::f64) {
186     if (OpVT == MVT::f80)
187       return FPROUND_F80_F64;
188     if (OpVT == MVT::f128)
189       return FPROUND_F128_F64;
190     if (OpVT == MVT::ppcf128)
191       return FPROUND_PPCF128_F64;
192   } else if (RetVT == MVT::f80) {
193     if (OpVT == MVT::f128)
194       return FPROUND_F128_F80;
195   }
196 
197   return UNKNOWN_LIBCALL;
198 }
199 
200 /// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
201 /// UNKNOWN_LIBCALL if there is none.
202 RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
203   if (OpVT == MVT::f16) {
204     if (RetVT == MVT::i32)
205       return FPTOSINT_F16_I32;
206     if (RetVT == MVT::i64)
207       return FPTOSINT_F16_I64;
208     if (RetVT == MVT::i128)
209       return FPTOSINT_F16_I128;
210   } else if (OpVT == MVT::f32) {
211     if (RetVT == MVT::i32)
212       return FPTOSINT_F32_I32;
213     if (RetVT == MVT::i64)
214       return FPTOSINT_F32_I64;
215     if (RetVT == MVT::i128)
216       return FPTOSINT_F32_I128;
217   } else if (OpVT == MVT::f64) {
218     if (RetVT == MVT::i32)
219       return FPTOSINT_F64_I32;
220     if (RetVT == MVT::i64)
221       return FPTOSINT_F64_I64;
222     if (RetVT == MVT::i128)
223       return FPTOSINT_F64_I128;
224   } else if (OpVT == MVT::f80) {
225     if (RetVT == MVT::i32)
226       return FPTOSINT_F80_I32;
227     if (RetVT == MVT::i64)
228       return FPTOSINT_F80_I64;
229     if (RetVT == MVT::i128)
230       return FPTOSINT_F80_I128;
231   } else if (OpVT == MVT::f128) {
232     if (RetVT == MVT::i32)
233       return FPTOSINT_F128_I32;
234     if (RetVT == MVT::i64)
235       return FPTOSINT_F128_I64;
236     if (RetVT == MVT::i128)
237       return FPTOSINT_F128_I128;
238   } else if (OpVT == MVT::ppcf128) {
239     if (RetVT == MVT::i32)
240       return FPTOSINT_PPCF128_I32;
241     if (RetVT == MVT::i64)
242       return FPTOSINT_PPCF128_I64;
243     if (RetVT == MVT::i128)
244       return FPTOSINT_PPCF128_I128;
245   }
246   return UNKNOWN_LIBCALL;
247 }
248 
249 /// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
250 /// UNKNOWN_LIBCALL if there is none.
251 RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
252   if (OpVT == MVT::f16) {
253     if (RetVT == MVT::i32)
254       return FPTOUINT_F16_I32;
255     if (RetVT == MVT::i64)
256       return FPTOUINT_F16_I64;
257     if (RetVT == MVT::i128)
258       return FPTOUINT_F16_I128;
259   } else if (OpVT == MVT::f32) {
260     if (RetVT == MVT::i32)
261       return FPTOUINT_F32_I32;
262     if (RetVT == MVT::i64)
263       return FPTOUINT_F32_I64;
264     if (RetVT == MVT::i128)
265       return FPTOUINT_F32_I128;
266   } else if (OpVT == MVT::f64) {
267     if (RetVT == MVT::i32)
268       return FPTOUINT_F64_I32;
269     if (RetVT == MVT::i64)
270       return FPTOUINT_F64_I64;
271     if (RetVT == MVT::i128)
272       return FPTOUINT_F64_I128;
273   } else if (OpVT == MVT::f80) {
274     if (RetVT == MVT::i32)
275       return FPTOUINT_F80_I32;
276     if (RetVT == MVT::i64)
277       return FPTOUINT_F80_I64;
278     if (RetVT == MVT::i128)
279       return FPTOUINT_F80_I128;
280   } else if (OpVT == MVT::f128) {
281     if (RetVT == MVT::i32)
282       return FPTOUINT_F128_I32;
283     if (RetVT == MVT::i64)
284       return FPTOUINT_F128_I64;
285     if (RetVT == MVT::i128)
286       return FPTOUINT_F128_I128;
287   } else if (OpVT == MVT::ppcf128) {
288     if (RetVT == MVT::i32)
289       return FPTOUINT_PPCF128_I32;
290     if (RetVT == MVT::i64)
291       return FPTOUINT_PPCF128_I64;
292     if (RetVT == MVT::i128)
293       return FPTOUINT_PPCF128_I128;
294   }
295   return UNKNOWN_LIBCALL;
296 }
297 
298 /// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
299 /// UNKNOWN_LIBCALL if there is none.
300 RTLIB::Libcall RTLIB::getSINTTOFP(EVT OpVT, EVT RetVT) {
301   if (OpVT == MVT::i32) {
302     if (RetVT == MVT::f16)
303       return SINTTOFP_I32_F16;
304     if (RetVT == MVT::f32)
305       return SINTTOFP_I32_F32;
306     if (RetVT == MVT::f64)
307       return SINTTOFP_I32_F64;
308     if (RetVT == MVT::f80)
309       return SINTTOFP_I32_F80;
310     if (RetVT == MVT::f128)
311       return SINTTOFP_I32_F128;
312     if (RetVT == MVT::ppcf128)
313       return SINTTOFP_I32_PPCF128;
314   } else if (OpVT == MVT::i64) {
315     if (RetVT == MVT::f16)
316       return SINTTOFP_I64_F16;
317     if (RetVT == MVT::f32)
318       return SINTTOFP_I64_F32;
319     if (RetVT == MVT::f64)
320       return SINTTOFP_I64_F64;
321     if (RetVT == MVT::f80)
322       return SINTTOFP_I64_F80;
323     if (RetVT == MVT::f128)
324       return SINTTOFP_I64_F128;
325     if (RetVT == MVT::ppcf128)
326       return SINTTOFP_I64_PPCF128;
327   } else if (OpVT == MVT::i128) {
328     if (RetVT == MVT::f16)
329       return SINTTOFP_I128_F16;
330     if (RetVT == MVT::f32)
331       return SINTTOFP_I128_F32;
332     if (RetVT == MVT::f64)
333       return SINTTOFP_I128_F64;
334     if (RetVT == MVT::f80)
335       return SINTTOFP_I128_F80;
336     if (RetVT == MVT::f128)
337       return SINTTOFP_I128_F128;
338     if (RetVT == MVT::ppcf128)
339       return SINTTOFP_I128_PPCF128;
340   }
341   return UNKNOWN_LIBCALL;
342 }
343 
344 /// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
345 /// UNKNOWN_LIBCALL if there is none.
346 RTLIB::Libcall RTLIB::getUINTTOFP(EVT OpVT, EVT RetVT) {
347   if (OpVT == MVT::i32) {
348     if (RetVT == MVT::f16)
349       return UINTTOFP_I32_F16;
350     if (RetVT == MVT::f32)
351       return UINTTOFP_I32_F32;
352     if (RetVT == MVT::f64)
353       return UINTTOFP_I32_F64;
354     if (RetVT == MVT::f80)
355       return UINTTOFP_I32_F80;
356     if (RetVT == MVT::f128)
357       return UINTTOFP_I32_F128;
358     if (RetVT == MVT::ppcf128)
359       return UINTTOFP_I32_PPCF128;
360   } else if (OpVT == MVT::i64) {
361     if (RetVT == MVT::f16)
362       return UINTTOFP_I64_F16;
363     if (RetVT == MVT::f32)
364       return UINTTOFP_I64_F32;
365     if (RetVT == MVT::f64)
366       return UINTTOFP_I64_F64;
367     if (RetVT == MVT::f80)
368       return UINTTOFP_I64_F80;
369     if (RetVT == MVT::f128)
370       return UINTTOFP_I64_F128;
371     if (RetVT == MVT::ppcf128)
372       return UINTTOFP_I64_PPCF128;
373   } else if (OpVT == MVT::i128) {
374     if (RetVT == MVT::f16)
375       return UINTTOFP_I128_F16;
376     if (RetVT == MVT::f32)
377       return UINTTOFP_I128_F32;
378     if (RetVT == MVT::f64)
379       return UINTTOFP_I128_F64;
380     if (RetVT == MVT::f80)
381       return UINTTOFP_I128_F80;
382     if (RetVT == MVT::f128)
383       return UINTTOFP_I128_F128;
384     if (RetVT == MVT::ppcf128)
385       return UINTTOFP_I128_PPCF128;
386   }
387   return UNKNOWN_LIBCALL;
388 }
389 
390 RTLIB::Libcall RTLIB::getPOWI(EVT RetVT) {
391   return getFPLibCall(RetVT, POWI_F32, POWI_F64, POWI_F80, POWI_F128,
392                       POWI_PPCF128);
393 }
394 
395 RTLIB::Libcall RTLIB::getLDEXP(EVT RetVT) {
396   return getFPLibCall(RetVT, LDEXP_F32, LDEXP_F64, LDEXP_F80, LDEXP_F128,
397                       LDEXP_PPCF128);
398 }
399 
400 RTLIB::Libcall RTLIB::getFREXP(EVT RetVT) {
401   return getFPLibCall(RetVT, FREXP_F32, FREXP_F64, FREXP_F80, FREXP_F128,
402                       FREXP_PPCF128);
403 }
404 
405 RTLIB::Libcall RTLIB::getFSINCOS(EVT RetVT) {
406   return getFPLibCall(RetVT, SINCOS_F32, SINCOS_F64, SINCOS_F80, SINCOS_F128,
407                       SINCOS_PPCF128);
408 }
409 
410 RTLIB::Libcall RTLIB::getOutlineAtomicHelper(const Libcall (&LC)[5][4],
411                                              AtomicOrdering Order,
412                                              uint64_t MemSize) {
413   unsigned ModeN, ModelN;
414   switch (MemSize) {
415   case 1:
416     ModeN = 0;
417     break;
418   case 2:
419     ModeN = 1;
420     break;
421   case 4:
422     ModeN = 2;
423     break;
424   case 8:
425     ModeN = 3;
426     break;
427   case 16:
428     ModeN = 4;
429     break;
430   default:
431     return RTLIB::UNKNOWN_LIBCALL;
432   }
433 
434   switch (Order) {
435   case AtomicOrdering::Monotonic:
436     ModelN = 0;
437     break;
438   case AtomicOrdering::Acquire:
439     ModelN = 1;
440     break;
441   case AtomicOrdering::Release:
442     ModelN = 2;
443     break;
444   case AtomicOrdering::AcquireRelease:
445   case AtomicOrdering::SequentiallyConsistent:
446     ModelN = 3;
447     break;
448   default:
449     return UNKNOWN_LIBCALL;
450   }
451 
452   return LC[ModeN][ModelN];
453 }
454 
455 RTLIB::Libcall RTLIB::getOUTLINE_ATOMIC(unsigned Opc, AtomicOrdering Order,
456                                         MVT VT) {
457   if (!VT.isScalarInteger())
458     return UNKNOWN_LIBCALL;
459   uint64_t MemSize = VT.getScalarSizeInBits() / 8;
460 
461 #define LCALLS(A, B)                                                           \
462   { A##B##_RELAX, A##B##_ACQ, A##B##_REL, A##B##_ACQ_REL }
463 #define LCALL5(A)                                                              \
464   LCALLS(A, 1), LCALLS(A, 2), LCALLS(A, 4), LCALLS(A, 8), LCALLS(A, 16)
465   switch (Opc) {
466   case ISD::ATOMIC_CMP_SWAP: {
467     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_CAS)};
468     return getOutlineAtomicHelper(LC, Order, MemSize);
469   }
470   case ISD::ATOMIC_SWAP: {
471     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_SWP)};
472     return getOutlineAtomicHelper(LC, Order, MemSize);
473   }
474   case ISD::ATOMIC_LOAD_ADD: {
475     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDADD)};
476     return getOutlineAtomicHelper(LC, Order, MemSize);
477   }
478   case ISD::ATOMIC_LOAD_OR: {
479     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDSET)};
480     return getOutlineAtomicHelper(LC, Order, MemSize);
481   }
482   case ISD::ATOMIC_LOAD_CLR: {
483     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDCLR)};
484     return getOutlineAtomicHelper(LC, Order, MemSize);
485   }
486   case ISD::ATOMIC_LOAD_XOR: {
487     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDEOR)};
488     return getOutlineAtomicHelper(LC, Order, MemSize);
489   }
490   default:
491     return UNKNOWN_LIBCALL;
492   }
493 #undef LCALLS
494 #undef LCALL5
495 }
496 
497 RTLIB::Libcall RTLIB::getSYNC(unsigned Opc, MVT VT) {
498 #define OP_TO_LIBCALL(Name, Enum)                                              \
499   case Name:                                                                   \
500     switch (VT.SimpleTy) {                                                     \
501     default:                                                                   \
502       return UNKNOWN_LIBCALL;                                                  \
503     case MVT::i8:                                                              \
504       return Enum##_1;                                                         \
505     case MVT::i16:                                                             \
506       return Enum##_2;                                                         \
507     case MVT::i32:                                                             \
508       return Enum##_4;                                                         \
509     case MVT::i64:                                                             \
510       return Enum##_8;                                                         \
511     case MVT::i128:                                                            \
512       return Enum##_16;                                                        \
513     }
514 
515   switch (Opc) {
516     OP_TO_LIBCALL(ISD::ATOMIC_SWAP, SYNC_LOCK_TEST_AND_SET)
517     OP_TO_LIBCALL(ISD::ATOMIC_CMP_SWAP, SYNC_VAL_COMPARE_AND_SWAP)
518     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_ADD, SYNC_FETCH_AND_ADD)
519     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_SUB, SYNC_FETCH_AND_SUB)
520     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_AND, SYNC_FETCH_AND_AND)
521     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_OR, SYNC_FETCH_AND_OR)
522     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_XOR, SYNC_FETCH_AND_XOR)
523     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_NAND, SYNC_FETCH_AND_NAND)
524     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MAX, SYNC_FETCH_AND_MAX)
525     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMAX, SYNC_FETCH_AND_UMAX)
526     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MIN, SYNC_FETCH_AND_MIN)
527     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMIN, SYNC_FETCH_AND_UMIN)
528   }
529 
530 #undef OP_TO_LIBCALL
531 
532   return UNKNOWN_LIBCALL;
533 }
534 
535 RTLIB::Libcall RTLIB::getMEMCPY_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
536   switch (ElementSize) {
537   case 1:
538     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_1;
539   case 2:
540     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_2;
541   case 4:
542     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_4;
543   case 8:
544     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_8;
545   case 16:
546     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_16;
547   default:
548     return UNKNOWN_LIBCALL;
549   }
550 }
551 
552 RTLIB::Libcall RTLIB::getMEMMOVE_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
553   switch (ElementSize) {
554   case 1:
555     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_1;
556   case 2:
557     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_2;
558   case 4:
559     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_4;
560   case 8:
561     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_8;
562   case 16:
563     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_16;
564   default:
565     return UNKNOWN_LIBCALL;
566   }
567 }
568 
569 RTLIB::Libcall RTLIB::getMEMSET_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
570   switch (ElementSize) {
571   case 1:
572     return MEMSET_ELEMENT_UNORDERED_ATOMIC_1;
573   case 2:
574     return MEMSET_ELEMENT_UNORDERED_ATOMIC_2;
575   case 4:
576     return MEMSET_ELEMENT_UNORDERED_ATOMIC_4;
577   case 8:
578     return MEMSET_ELEMENT_UNORDERED_ATOMIC_8;
579   case 16:
580     return MEMSET_ELEMENT_UNORDERED_ATOMIC_16;
581   default:
582     return UNKNOWN_LIBCALL;
583   }
584 }
585 
586 void RTLIB::initCmpLibcallCCs(ISD::CondCode *CmpLibcallCCs) {
587   std::fill(CmpLibcallCCs, CmpLibcallCCs + RTLIB::UNKNOWN_LIBCALL,
588             ISD::SETCC_INVALID);
589   CmpLibcallCCs[RTLIB::OEQ_F32] = ISD::SETEQ;
590   CmpLibcallCCs[RTLIB::OEQ_F64] = ISD::SETEQ;
591   CmpLibcallCCs[RTLIB::OEQ_F128] = ISD::SETEQ;
592   CmpLibcallCCs[RTLIB::OEQ_PPCF128] = ISD::SETEQ;
593   CmpLibcallCCs[RTLIB::UNE_F32] = ISD::SETNE;
594   CmpLibcallCCs[RTLIB::UNE_F64] = ISD::SETNE;
595   CmpLibcallCCs[RTLIB::UNE_F128] = ISD::SETNE;
596   CmpLibcallCCs[RTLIB::UNE_PPCF128] = ISD::SETNE;
597   CmpLibcallCCs[RTLIB::OGE_F32] = ISD::SETGE;
598   CmpLibcallCCs[RTLIB::OGE_F64] = ISD::SETGE;
599   CmpLibcallCCs[RTLIB::OGE_F128] = ISD::SETGE;
600   CmpLibcallCCs[RTLIB::OGE_PPCF128] = ISD::SETGE;
601   CmpLibcallCCs[RTLIB::OLT_F32] = ISD::SETLT;
602   CmpLibcallCCs[RTLIB::OLT_F64] = ISD::SETLT;
603   CmpLibcallCCs[RTLIB::OLT_F128] = ISD::SETLT;
604   CmpLibcallCCs[RTLIB::OLT_PPCF128] = ISD::SETLT;
605   CmpLibcallCCs[RTLIB::OLE_F32] = ISD::SETLE;
606   CmpLibcallCCs[RTLIB::OLE_F64] = ISD::SETLE;
607   CmpLibcallCCs[RTLIB::OLE_F128] = ISD::SETLE;
608   CmpLibcallCCs[RTLIB::OLE_PPCF128] = ISD::SETLE;
609   CmpLibcallCCs[RTLIB::OGT_F32] = ISD::SETGT;
610   CmpLibcallCCs[RTLIB::OGT_F64] = ISD::SETGT;
611   CmpLibcallCCs[RTLIB::OGT_F128] = ISD::SETGT;
612   CmpLibcallCCs[RTLIB::OGT_PPCF128] = ISD::SETGT;
613   CmpLibcallCCs[RTLIB::UO_F32] = ISD::SETNE;
614   CmpLibcallCCs[RTLIB::UO_F64] = ISD::SETNE;
615   CmpLibcallCCs[RTLIB::UO_F128] = ISD::SETNE;
616   CmpLibcallCCs[RTLIB::UO_PPCF128] = ISD::SETNE;
617 }
618 
619 /// NOTE: The TargetMachine owns TLOF.
620 TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm)
621     : TM(tm), Libcalls(TM.getTargetTriple()) {
622   initActions();
623 
624   // Perform these initializations only once.
625   MaxStoresPerMemset = MaxStoresPerMemcpy = MaxStoresPerMemmove =
626       MaxLoadsPerMemcmp = 8;
627   MaxGluedStoresPerMemcpy = 0;
628   MaxStoresPerMemsetOptSize = MaxStoresPerMemcpyOptSize =
629       MaxStoresPerMemmoveOptSize = MaxLoadsPerMemcmpOptSize = 4;
630   HasMultipleConditionRegisters = false;
631   HasExtractBitsInsn = false;
632   JumpIsExpensive = JumpIsExpensiveOverride;
633   PredictableSelectIsExpensive = false;
634   EnableExtLdPromotion = false;
635   StackPointerRegisterToSaveRestore = 0;
636   BooleanContents = UndefinedBooleanContent;
637   BooleanFloatContents = UndefinedBooleanContent;
638   BooleanVectorContents = UndefinedBooleanContent;
639   SchedPreferenceInfo = Sched::ILP;
640   GatherAllAliasesMaxDepth = 18;
641   IsStrictFPEnabled = DisableStrictNodeMutation;
642   MaxBytesForAlignment = 0;
643   MaxAtomicSizeInBitsSupported = 0;
644 
645   // Assume that even with libcalls, no target supports wider than 128 bit
646   // division.
647   MaxDivRemBitWidthSupported = 128;
648 
649   MaxLargeFPConvertBitWidthSupported = llvm::IntegerType::MAX_INT_BITS;
650 
651   MinCmpXchgSizeInBits = 0;
652   SupportsUnalignedAtomics = false;
653 
654   RTLIB::initCmpLibcallCCs(CmpLibcallCCs);
655 }
656 
657 void TargetLoweringBase::initActions() {
658   // All operations default to being supported.
659   memset(OpActions, 0, sizeof(OpActions));
660   memset(LoadExtActions, 0, sizeof(LoadExtActions));
661   memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
662   memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
663   memset(CondCodeActions, 0, sizeof(CondCodeActions));
664   std::fill(std::begin(RegClassForVT), std::end(RegClassForVT), nullptr);
665   std::fill(std::begin(TargetDAGCombineArray),
666             std::end(TargetDAGCombineArray), 0);
667 
668   // Let extending atomic loads be unsupported by default.
669   for (MVT ValVT : MVT::all_valuetypes())
670     for (MVT MemVT : MVT::all_valuetypes())
671       setAtomicLoadExtAction({ISD::SEXTLOAD, ISD::ZEXTLOAD}, ValVT, MemVT,
672                              Expand);
673 
674   // We're somewhat special casing MVT::i2 and MVT::i4. Ideally we want to
675   // remove this and targets should individually set these types if not legal.
676   for (ISD::NodeType NT : enum_seq(ISD::DELETED_NODE, ISD::BUILTIN_OP_END,
677                                    force_iteration_on_noniterable_enum)) {
678     for (MVT VT : {MVT::i2, MVT::i4})
679       OpActions[(unsigned)VT.SimpleTy][NT] = Expand;
680   }
681   for (MVT AVT : MVT::all_valuetypes()) {
682     for (MVT VT : {MVT::i2, MVT::i4, MVT::v128i2, MVT::v64i4}) {
683       setTruncStoreAction(AVT, VT, Expand);
684       setLoadExtAction(ISD::EXTLOAD, AVT, VT, Expand);
685       setLoadExtAction(ISD::ZEXTLOAD, AVT, VT, Expand);
686     }
687   }
688   for (unsigned IM = (unsigned)ISD::PRE_INC;
689        IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
690     for (MVT VT : {MVT::i2, MVT::i4}) {
691       setIndexedLoadAction(IM, VT, Expand);
692       setIndexedStoreAction(IM, VT, Expand);
693       setIndexedMaskedLoadAction(IM, VT, Expand);
694       setIndexedMaskedStoreAction(IM, VT, Expand);
695     }
696   }
697 
698   for (MVT VT : MVT::fp_valuetypes()) {
699     MVT IntVT = MVT::getIntegerVT(VT.getFixedSizeInBits());
700     if (IntVT.isValid()) {
701       setOperationAction(ISD::ATOMIC_SWAP, VT, Promote);
702       AddPromotedToType(ISD::ATOMIC_SWAP, VT, IntVT);
703     }
704   }
705 
706   // Set default actions for various operations.
707   for (MVT VT : MVT::all_valuetypes()) {
708     // Default all indexed load / store to expand.
709     for (unsigned IM = (unsigned)ISD::PRE_INC;
710          IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
711       setIndexedLoadAction(IM, VT, Expand);
712       setIndexedStoreAction(IM, VT, Expand);
713       setIndexedMaskedLoadAction(IM, VT, Expand);
714       setIndexedMaskedStoreAction(IM, VT, Expand);
715     }
716 
717     // Most backends expect to see the node which just returns the value loaded.
718     setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, VT, Expand);
719 
720     // These operations default to expand.
721     setOperationAction({ISD::FGETSIGN,       ISD::CONCAT_VECTORS,
722                         ISD::FMINNUM,        ISD::FMAXNUM,
723                         ISD::FMINNUM_IEEE,   ISD::FMAXNUM_IEEE,
724                         ISD::FMINIMUM,       ISD::FMAXIMUM,
725                         ISD::FMINIMUMNUM,    ISD::FMAXIMUMNUM,
726                         ISD::FMAD,           ISD::SMIN,
727                         ISD::SMAX,           ISD::UMIN,
728                         ISD::UMAX,           ISD::ABS,
729                         ISD::FSHL,           ISD::FSHR,
730                         ISD::SADDSAT,        ISD::UADDSAT,
731                         ISD::SSUBSAT,        ISD::USUBSAT,
732                         ISD::SSHLSAT,        ISD::USHLSAT,
733                         ISD::SMULFIX,        ISD::SMULFIXSAT,
734                         ISD::UMULFIX,        ISD::UMULFIXSAT,
735                         ISD::SDIVFIX,        ISD::SDIVFIXSAT,
736                         ISD::UDIVFIX,        ISD::UDIVFIXSAT,
737                         ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT,
738                         ISD::IS_FPCLASS},
739                        VT, Expand);
740 
741     // Overflow operations default to expand
742     setOperationAction({ISD::SADDO, ISD::SSUBO, ISD::UADDO, ISD::USUBO,
743                         ISD::SMULO, ISD::UMULO},
744                        VT, Expand);
745 
746     // Carry-using overflow operations default to expand.
747     setOperationAction({ISD::UADDO_CARRY, ISD::USUBO_CARRY, ISD::SETCCCARRY,
748                         ISD::SADDO_CARRY, ISD::SSUBO_CARRY},
749                        VT, Expand);
750 
751     // ADDC/ADDE/SUBC/SUBE default to expand.
752     setOperationAction({ISD::ADDC, ISD::ADDE, ISD::SUBC, ISD::SUBE}, VT,
753                        Expand);
754 
755     // [US]CMP default to expand
756     setOperationAction({ISD::UCMP, ISD::SCMP}, VT, Expand);
757 
758     // Halving adds
759     setOperationAction(
760         {ISD::AVGFLOORS, ISD::AVGFLOORU, ISD::AVGCEILS, ISD::AVGCEILU}, VT,
761         Expand);
762 
763     // Absolute difference
764     setOperationAction({ISD::ABDS, ISD::ABDU}, VT, Expand);
765 
766     // Saturated trunc
767     setOperationAction(ISD::TRUNCATE_SSAT_S, VT, Expand);
768     setOperationAction(ISD::TRUNCATE_SSAT_U, VT, Expand);
769     setOperationAction(ISD::TRUNCATE_USAT_U, VT, Expand);
770 
771     // These default to Expand so they will be expanded to CTLZ/CTTZ by default.
772     setOperationAction({ISD::CTLZ_ZERO_UNDEF, ISD::CTTZ_ZERO_UNDEF}, VT,
773                        Expand);
774 
775     setOperationAction({ISD::BITREVERSE, ISD::PARITY}, VT, Expand);
776 
777     // These library functions default to expand.
778     setOperationAction(
779         {ISD::FROUND, ISD::FPOWI, ISD::FLDEXP, ISD::FFREXP, ISD::FSINCOS}, VT,
780         Expand);
781 
782     // These operations default to expand for vector types.
783     if (VT.isVector())
784       setOperationAction(
785           {ISD::FCOPYSIGN, ISD::SIGN_EXTEND_INREG, ISD::ANY_EXTEND_VECTOR_INREG,
786            ISD::SIGN_EXTEND_VECTOR_INREG, ISD::ZERO_EXTEND_VECTOR_INREG,
787            ISD::SPLAT_VECTOR, ISD::LRINT, ISD::LLRINT, ISD::LROUND,
788            ISD::LLROUND, ISD::FTAN, ISD::FACOS, ISD::FASIN, ISD::FATAN,
789            ISD::FCOSH, ISD::FSINH, ISD::FTANH, ISD::FATAN2},
790           VT, Expand);
791 
792       // Constrained floating-point operations default to expand.
793 #define DAG_INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN)               \
794     setOperationAction(ISD::STRICT_##DAGN, VT, Expand);
795 #include "llvm/IR/ConstrainedOps.def"
796 
797     // For most targets @llvm.get.dynamic.area.offset just returns 0.
798     setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, VT, Expand);
799 
800     // Vector reduction default to expand.
801     setOperationAction(
802         {ISD::VECREDUCE_FADD, ISD::VECREDUCE_FMUL, ISD::VECREDUCE_ADD,
803          ISD::VECREDUCE_MUL, ISD::VECREDUCE_AND, ISD::VECREDUCE_OR,
804          ISD::VECREDUCE_XOR, ISD::VECREDUCE_SMAX, ISD::VECREDUCE_SMIN,
805          ISD::VECREDUCE_UMAX, ISD::VECREDUCE_UMIN, ISD::VECREDUCE_FMAX,
806          ISD::VECREDUCE_FMIN, ISD::VECREDUCE_FMAXIMUM, ISD::VECREDUCE_FMINIMUM,
807          ISD::VECREDUCE_SEQ_FADD, ISD::VECREDUCE_SEQ_FMUL},
808         VT, Expand);
809 
810     // Named vector shuffles default to expand.
811     setOperationAction(ISD::VECTOR_SPLICE, VT, Expand);
812 
813     // Only some target support this vector operation. Most need to expand it.
814     setOperationAction(ISD::VECTOR_COMPRESS, VT, Expand);
815 
816     // VP operations default to expand.
817 #define BEGIN_REGISTER_VP_SDNODE(SDOPC, ...)                                   \
818     setOperationAction(ISD::SDOPC, VT, Expand);
819 #include "llvm/IR/VPIntrinsics.def"
820 
821     // Masked vector extracts default to expand.
822     setOperationAction(ISD::VECTOR_FIND_LAST_ACTIVE, VT, Expand);
823 
824     // FP environment operations default to expand.
825     setOperationAction(ISD::GET_FPENV, VT, Expand);
826     setOperationAction(ISD::SET_FPENV, VT, Expand);
827     setOperationAction(ISD::RESET_FPENV, VT, Expand);
828   }
829 
830   // Most targets ignore the @llvm.prefetch intrinsic.
831   setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
832 
833   // Most targets also ignore the @llvm.readcyclecounter intrinsic.
834   setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Expand);
835 
836   // Most targets also ignore the @llvm.readsteadycounter intrinsic.
837   setOperationAction(ISD::READSTEADYCOUNTER, MVT::i64, Expand);
838 
839   // ConstantFP nodes default to expand.  Targets can either change this to
840   // Legal, in which case all fp constants are legal, or use isFPImmLegal()
841   // to optimize expansions for certain constants.
842   setOperationAction(ISD::ConstantFP,
843                      {MVT::bf16, MVT::f16, MVT::f32, MVT::f64, MVT::f80, MVT::f128},
844                      Expand);
845 
846   // These library functions default to expand.
847   setOperationAction({ISD::FCBRT,      ISD::FLOG,  ISD::FLOG2,  ISD::FLOG10,
848                       ISD::FEXP,       ISD::FEXP2, ISD::FEXP10, ISD::FFLOOR,
849                       ISD::FNEARBYINT, ISD::FCEIL, ISD::FRINT,  ISD::FTRUNC,
850                       ISD::FROUNDEVEN, ISD::FTAN,  ISD::FACOS,  ISD::FASIN,
851                       ISD::FATAN,      ISD::FCOSH, ISD::FSINH,  ISD::FTANH,
852                       ISD::FATAN2},
853                      {MVT::f32, MVT::f64, MVT::f128}, Expand);
854 
855   // FIXME: Query RuntimeLibCalls to make the decision.
856   setOperationAction({ISD::LRINT, ISD::LLRINT, ISD::LROUND, ISD::LLROUND},
857                      {MVT::f32, MVT::f64, MVT::f128}, LibCall);
858 
859   setOperationAction({ISD::FTAN, ISD::FACOS, ISD::FASIN, ISD::FATAN, ISD::FCOSH,
860                       ISD::FSINH, ISD::FTANH, ISD::FATAN2},
861                      MVT::f16, Promote);
862   // Default ISD::TRAP to expand (which turns it into abort).
863   setOperationAction(ISD::TRAP, MVT::Other, Expand);
864 
865   // On most systems, DEBUGTRAP and TRAP have no difference. The "Expand"
866   // here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP.
867   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand);
868 
869   setOperationAction(ISD::UBSANTRAP, MVT::Other, Expand);
870 
871   setOperationAction(ISD::GET_FPENV_MEM, MVT::Other, Expand);
872   setOperationAction(ISD::SET_FPENV_MEM, MVT::Other, Expand);
873 
874   for (MVT VT : {MVT::i8, MVT::i16, MVT::i32, MVT::i64}) {
875     setOperationAction(ISD::GET_FPMODE, VT, Expand);
876     setOperationAction(ISD::SET_FPMODE, VT, Expand);
877   }
878   setOperationAction(ISD::RESET_FPMODE, MVT::Other, Expand);
879 
880   // This one by default will call __clear_cache unless the target
881   // wants something different.
882   setOperationAction(ISD::CLEAR_CACHE, MVT::Other, LibCall);
883 }
884 
885 MVT TargetLoweringBase::getScalarShiftAmountTy(const DataLayout &DL,
886                                                EVT) const {
887   return MVT::getIntegerVT(DL.getPointerSizeInBits(0));
888 }
889 
890 EVT TargetLoweringBase::getShiftAmountTy(EVT LHSTy,
891                                          const DataLayout &DL) const {
892   assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
893   if (LHSTy.isVector())
894     return LHSTy;
895   MVT ShiftVT = getScalarShiftAmountTy(DL, LHSTy);
896   // If any possible shift value won't fit in the prefered type, just use
897   // something safe. Assume it will be legalized when the shift is expanded.
898   if (ShiftVT.getSizeInBits() < Log2_32_Ceil(LHSTy.getSizeInBits()))
899     ShiftVT = MVT::i32;
900   assert(ShiftVT.getSizeInBits() >= Log2_32_Ceil(LHSTy.getSizeInBits()) &&
901          "ShiftVT is still too small!");
902   return ShiftVT;
903 }
904 
905 bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
906   assert(isTypeLegal(VT));
907   switch (Op) {
908   default:
909     return false;
910   case ISD::SDIV:
911   case ISD::UDIV:
912   case ISD::SREM:
913   case ISD::UREM:
914     return true;
915   }
916 }
917 
918 bool TargetLoweringBase::isFreeAddrSpaceCast(unsigned SrcAS,
919                                              unsigned DestAS) const {
920   return TM.isNoopAddrSpaceCast(SrcAS, DestAS);
921 }
922 
923 unsigned TargetLoweringBase::getBitWidthForCttzElements(
924     Type *RetTy, ElementCount EC, bool ZeroIsPoison,
925     const ConstantRange *VScaleRange) const {
926   // Find the smallest "sensible" element type to use for the expansion.
927   ConstantRange CR(APInt(64, EC.getKnownMinValue()));
928   if (EC.isScalable())
929     CR = CR.umul_sat(*VScaleRange);
930 
931   if (ZeroIsPoison)
932     CR = CR.subtract(APInt(64, 1));
933 
934   unsigned EltWidth = RetTy->getScalarSizeInBits();
935   EltWidth = std::min(EltWidth, (unsigned)CR.getActiveBits());
936   EltWidth = std::max(llvm::bit_ceil(EltWidth), (unsigned)8);
937 
938   return EltWidth;
939 }
940 
941 void TargetLoweringBase::setJumpIsExpensive(bool isExpensive) {
942   // If the command-line option was specified, ignore this request.
943   if (!JumpIsExpensiveOverride.getNumOccurrences())
944     JumpIsExpensive = isExpensive;
945 }
946 
947 TargetLoweringBase::LegalizeKind
948 TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
949   // If this is a simple type, use the ComputeRegisterProp mechanism.
950   if (VT.isSimple()) {
951     MVT SVT = VT.getSimpleVT();
952     assert((unsigned)SVT.SimpleTy < std::size(TransformToType));
953     MVT NVT = TransformToType[SVT.SimpleTy];
954     LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
955 
956     assert((LA == TypeLegal || LA == TypeSoftenFloat ||
957             LA == TypeSoftPromoteHalf ||
958             (NVT.isVector() ||
959              ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger)) &&
960            "Promote may not follow Expand or Promote");
961 
962     if (LA == TypeSplitVector)
963       return LegalizeKind(LA, EVT(SVT).getHalfNumVectorElementsVT(Context));
964     if (LA == TypeScalarizeVector)
965       return LegalizeKind(LA, SVT.getVectorElementType());
966     return LegalizeKind(LA, NVT);
967   }
968 
969   // Handle Extended Scalar Types.
970   if (!VT.isVector()) {
971     assert(VT.isInteger() && "Float types must be simple");
972     unsigned BitSize = VT.getSizeInBits();
973     // First promote to a power-of-two size, then expand if necessary.
974     if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
975       EVT NVT = VT.getRoundIntegerType(Context);
976       assert(NVT != VT && "Unable to round integer VT");
977       LegalizeKind NextStep = getTypeConversion(Context, NVT);
978       // Avoid multi-step promotion.
979       if (NextStep.first == TypePromoteInteger)
980         return NextStep;
981       // Return rounded integer type.
982       return LegalizeKind(TypePromoteInteger, NVT);
983     }
984 
985     return LegalizeKind(TypeExpandInteger,
986                         EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
987   }
988 
989   // Handle vector types.
990   ElementCount NumElts = VT.getVectorElementCount();
991   EVT EltVT = VT.getVectorElementType();
992 
993   // Vectors with only one element are always scalarized.
994   if (NumElts.isScalar())
995     return LegalizeKind(TypeScalarizeVector, EltVT);
996 
997   // Try to widen vector elements until the element type is a power of two and
998   // promote it to a legal type later on, for example:
999   // <3 x i8> -> <4 x i8> -> <4 x i32>
1000   if (EltVT.isInteger()) {
1001     // Vectors with a number of elements that is not a power of two are always
1002     // widened, for example <3 x i8> -> <4 x i8>.
1003     if (!VT.isPow2VectorType()) {
1004       NumElts = NumElts.coefficientNextPowerOf2();
1005       EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
1006       return LegalizeKind(TypeWidenVector, NVT);
1007     }
1008 
1009     // Examine the element type.
1010     LegalizeKind LK = getTypeConversion(Context, EltVT);
1011 
1012     // If type is to be expanded, split the vector.
1013     //  <4 x i140> -> <2 x i140>
1014     if (LK.first == TypeExpandInteger) {
1015       if (VT.getVectorElementCount().isScalable())
1016         return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1017       return LegalizeKind(TypeSplitVector,
1018                           VT.getHalfNumVectorElementsVT(Context));
1019     }
1020 
1021     // Promote the integer element types until a legal vector type is found
1022     // or until the element integer type is too big. If a legal type was not
1023     // found, fallback to the usual mechanism of widening/splitting the
1024     // vector.
1025     EVT OldEltVT = EltVT;
1026     while (true) {
1027       // Increase the bitwidth of the element to the next pow-of-two
1028       // (which is greater than 8 bits).
1029       EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
1030                   .getRoundIntegerType(Context);
1031 
1032       // Stop trying when getting a non-simple element type.
1033       // Note that vector elements may be greater than legal vector element
1034       // types. Example: X86 XMM registers hold 64bit element on 32bit
1035       // systems.
1036       if (!EltVT.isSimple())
1037         break;
1038 
1039       // Build a new vector type and check if it is legal.
1040       MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1041       // Found a legal promoted vector type.
1042       if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
1043         return LegalizeKind(TypePromoteInteger,
1044                             EVT::getVectorVT(Context, EltVT, NumElts));
1045     }
1046 
1047     // Reset the type to the unexpanded type if we did not find a legal vector
1048     // type with a promoted vector element type.
1049     EltVT = OldEltVT;
1050   }
1051 
1052   // Try to widen the vector until a legal type is found.
1053   // If there is no wider legal type, split the vector.
1054   while (true) {
1055     // Round up to the next power of 2.
1056     NumElts = NumElts.coefficientNextPowerOf2();
1057 
1058     // If there is no simple vector type with this many elements then there
1059     // cannot be a larger legal vector type.  Note that this assumes that
1060     // there are no skipped intermediate vector types in the simple types.
1061     if (!EltVT.isSimple())
1062       break;
1063     MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1064     if (LargerVector == MVT())
1065       break;
1066 
1067     // If this type is legal then widen the vector.
1068     if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
1069       return LegalizeKind(TypeWidenVector, LargerVector);
1070   }
1071 
1072   // Widen odd vectors to next power of two.
1073   if (!VT.isPow2VectorType()) {
1074     EVT NVT = VT.getPow2VectorType(Context);
1075     return LegalizeKind(TypeWidenVector, NVT);
1076   }
1077 
1078   if (VT.getVectorElementCount() == ElementCount::getScalable(1))
1079     return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1080 
1081   // Vectors with illegal element types are expanded.
1082   EVT NVT = EVT::getVectorVT(Context, EltVT,
1083                              VT.getVectorElementCount().divideCoefficientBy(2));
1084   return LegalizeKind(TypeSplitVector, NVT);
1085 }
1086 
1087 static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
1088                                           unsigned &NumIntermediates,
1089                                           MVT &RegisterVT,
1090                                           TargetLoweringBase *TLI) {
1091   // Figure out the right, legal destination reg to copy into.
1092   ElementCount EC = VT.getVectorElementCount();
1093   MVT EltTy = VT.getVectorElementType();
1094 
1095   unsigned NumVectorRegs = 1;
1096 
1097   // Scalable vectors cannot be scalarized, so splitting or widening is
1098   // required.
1099   if (VT.isScalableVector() && !isPowerOf2_32(EC.getKnownMinValue()))
1100     llvm_unreachable(
1101         "Splitting or widening of non-power-of-2 MVTs is not implemented.");
1102 
1103   // FIXME: We don't support non-power-of-2-sized vectors for now.
1104   // Ideally we could break down into LHS/RHS like LegalizeDAG does.
1105   if (!isPowerOf2_32(EC.getKnownMinValue())) {
1106     // Split EC to unit size (scalable property is preserved).
1107     NumVectorRegs = EC.getKnownMinValue();
1108     EC = ElementCount::getFixed(1);
1109   }
1110 
1111   // Divide the input until we get to a supported size. This will
1112   // always end up with an EC that represent a scalar or a scalable
1113   // scalar.
1114   while (EC.getKnownMinValue() > 1 &&
1115          !TLI->isTypeLegal(MVT::getVectorVT(EltTy, EC))) {
1116     EC = EC.divideCoefficientBy(2);
1117     NumVectorRegs <<= 1;
1118   }
1119 
1120   NumIntermediates = NumVectorRegs;
1121 
1122   MVT NewVT = MVT::getVectorVT(EltTy, EC);
1123   if (!TLI->isTypeLegal(NewVT))
1124     NewVT = EltTy;
1125   IntermediateVT = NewVT;
1126 
1127   unsigned LaneSizeInBits = NewVT.getScalarSizeInBits();
1128 
1129   // Convert sizes such as i33 to i64.
1130   LaneSizeInBits = llvm::bit_ceil(LaneSizeInBits);
1131 
1132   MVT DestVT = TLI->getRegisterType(NewVT);
1133   RegisterVT = DestVT;
1134   if (EVT(DestVT).bitsLT(NewVT))    // Value is expanded, e.g. i64 -> i16.
1135     return NumVectorRegs * (LaneSizeInBits / DestVT.getScalarSizeInBits());
1136 
1137   // Otherwise, promotion or legal types use the same number of registers as
1138   // the vector decimated to the appropriate level.
1139   return NumVectorRegs;
1140 }
1141 
1142 /// isLegalRC - Return true if the value types that can be represented by the
1143 /// specified register class are all legal.
1144 bool TargetLoweringBase::isLegalRC(const TargetRegisterInfo &TRI,
1145                                    const TargetRegisterClass &RC) const {
1146   for (const auto *I = TRI.legalclasstypes_begin(RC); *I != MVT::Other; ++I)
1147     if (isTypeLegal(*I))
1148       return true;
1149   return false;
1150 }
1151 
1152 /// Replace/modify any TargetFrameIndex operands with a targte-dependent
1153 /// sequence of memory operands that is recognized by PrologEpilogInserter.
1154 MachineBasicBlock *
1155 TargetLoweringBase::emitPatchPoint(MachineInstr &InitialMI,
1156                                    MachineBasicBlock *MBB) const {
1157   MachineInstr *MI = &InitialMI;
1158   MachineFunction &MF = *MI->getMF();
1159   MachineFrameInfo &MFI = MF.getFrameInfo();
1160 
1161   // We're handling multiple types of operands here:
1162   // PATCHPOINT MetaArgs - live-in, read only, direct
1163   // STATEPOINT Deopt Spill - live-through, read only, indirect
1164   // STATEPOINT Deopt Alloca - live-through, read only, direct
1165   // (We're currently conservative and mark the deopt slots read/write in
1166   // practice.)
1167   // STATEPOINT GC Spill - live-through, read/write, indirect
1168   // STATEPOINT GC Alloca - live-through, read/write, direct
1169   // The live-in vs live-through is handled already (the live through ones are
1170   // all stack slots), but we need to handle the different type of stackmap
1171   // operands and memory effects here.
1172 
1173   if (llvm::none_of(MI->operands(),
1174                     [](MachineOperand &Operand) { return Operand.isFI(); }))
1175     return MBB;
1176 
1177   MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), MI->getDesc());
1178 
1179   // Inherit previous memory operands.
1180   MIB.cloneMemRefs(*MI);
1181 
1182   for (unsigned i = 0; i < MI->getNumOperands(); ++i) {
1183     MachineOperand &MO = MI->getOperand(i);
1184     if (!MO.isFI()) {
1185       // Index of Def operand this Use it tied to.
1186       // Since Defs are coming before Uses, if Use is tied, then
1187       // index of Def must be smaller that index of that Use.
1188       // Also, Defs preserve their position in new MI.
1189       unsigned TiedTo = i;
1190       if (MO.isReg() && MO.isTied())
1191         TiedTo = MI->findTiedOperandIdx(i);
1192       MIB.add(MO);
1193       if (TiedTo < i)
1194         MIB->tieOperands(TiedTo, MIB->getNumOperands() - 1);
1195       continue;
1196     }
1197 
1198     // foldMemoryOperand builds a new MI after replacing a single FI operand
1199     // with the canonical set of five x86 addressing-mode operands.
1200     int FI = MO.getIndex();
1201 
1202     // Add frame index operands recognized by stackmaps.cpp
1203     if (MFI.isStatepointSpillSlotObjectIndex(FI)) {
1204       // indirect-mem-ref tag, size, #FI, offset.
1205       // Used for spills inserted by StatepointLowering.  This codepath is not
1206       // used for patchpoints/stackmaps at all, for these spilling is done via
1207       // foldMemoryOperand callback only.
1208       assert(MI->getOpcode() == TargetOpcode::STATEPOINT && "sanity");
1209       MIB.addImm(StackMaps::IndirectMemRefOp);
1210       MIB.addImm(MFI.getObjectSize(FI));
1211       MIB.add(MO);
1212       MIB.addImm(0);
1213     } else {
1214       // direct-mem-ref tag, #FI, offset.
1215       // Used by patchpoint, and direct alloca arguments to statepoints
1216       MIB.addImm(StackMaps::DirectMemRefOp);
1217       MIB.add(MO);
1218       MIB.addImm(0);
1219     }
1220 
1221     assert(MIB->mayLoad() && "Folded a stackmap use to a non-load!");
1222 
1223     // Add a new memory operand for this FI.
1224     assert(MFI.getObjectOffset(FI) != -1);
1225 
1226     // Note: STATEPOINT MMOs are added during SelectionDAG.  STACKMAP, and
1227     // PATCHPOINT should be updated to do the same. (TODO)
1228     if (MI->getOpcode() != TargetOpcode::STATEPOINT) {
1229       auto Flags = MachineMemOperand::MOLoad;
1230       MachineMemOperand *MMO = MF.getMachineMemOperand(
1231           MachinePointerInfo::getFixedStack(MF, FI), Flags,
1232           MF.getDataLayout().getPointerSize(), MFI.getObjectAlign(FI));
1233       MIB->addMemOperand(MF, MMO);
1234     }
1235   }
1236   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1237   MI->eraseFromParent();
1238   return MBB;
1239 }
1240 
1241 /// findRepresentativeClass - Return the largest legal super-reg register class
1242 /// of the register class for the specified type and its associated "cost".
1243 // This function is in TargetLowering because it uses RegClassForVT which would
1244 // need to be moved to TargetRegisterInfo and would necessitate moving
1245 // isTypeLegal over as well - a massive change that would just require
1246 // TargetLowering having a TargetRegisterInfo class member that it would use.
1247 std::pair<const TargetRegisterClass *, uint8_t>
1248 TargetLoweringBase::findRepresentativeClass(const TargetRegisterInfo *TRI,
1249                                             MVT VT) const {
1250   const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
1251   if (!RC)
1252     return std::make_pair(RC, 0);
1253 
1254   // Compute the set of all super-register classes.
1255   BitVector SuperRegRC(TRI->getNumRegClasses());
1256   for (SuperRegClassIterator RCI(RC, TRI); RCI.isValid(); ++RCI)
1257     SuperRegRC.setBitsInMask(RCI.getMask());
1258 
1259   // Find the first legal register class with the largest spill size.
1260   const TargetRegisterClass *BestRC = RC;
1261   for (unsigned i : SuperRegRC.set_bits()) {
1262     const TargetRegisterClass *SuperRC = TRI->getRegClass(i);
1263     // We want the largest possible spill size.
1264     if (TRI->getSpillSize(*SuperRC) <= TRI->getSpillSize(*BestRC))
1265       continue;
1266     if (!isLegalRC(*TRI, *SuperRC))
1267       continue;
1268     BestRC = SuperRC;
1269   }
1270   return std::make_pair(BestRC, 1);
1271 }
1272 
1273 /// computeRegisterProperties - Once all of the register classes are added,
1274 /// this allows us to compute derived properties we expose.
1275 void TargetLoweringBase::computeRegisterProperties(
1276     const TargetRegisterInfo *TRI) {
1277   // Everything defaults to needing one register.
1278   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1279     NumRegistersForVT[i] = 1;
1280     RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
1281   }
1282   // ...except isVoid, which doesn't need any registers.
1283   NumRegistersForVT[MVT::isVoid] = 0;
1284 
1285   // Find the largest integer register class.
1286   unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
1287   for (; RegClassForVT[LargestIntReg] == nullptr; --LargestIntReg)
1288     assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
1289 
1290   // Every integer value type larger than this largest register takes twice as
1291   // many registers to represent as the previous ValueType.
1292   for (unsigned ExpandedReg = LargestIntReg + 1;
1293        ExpandedReg <= MVT::LAST_INTEGER_VALUETYPE; ++ExpandedReg) {
1294     NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
1295     RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
1296     TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
1297     ValueTypeActions.setTypeAction((MVT::SimpleValueType)ExpandedReg,
1298                                    TypeExpandInteger);
1299   }
1300 
1301   // Inspect all of the ValueType's smaller than the largest integer
1302   // register to see which ones need promotion.
1303   unsigned LegalIntReg = LargestIntReg;
1304   for (unsigned IntReg = LargestIntReg - 1;
1305        IntReg >= (unsigned)MVT::i1; --IntReg) {
1306     MVT IVT = (MVT::SimpleValueType)IntReg;
1307     if (isTypeLegal(IVT)) {
1308       LegalIntReg = IntReg;
1309     } else {
1310       RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
1311         (MVT::SimpleValueType)LegalIntReg;
1312       ValueTypeActions.setTypeAction(IVT, TypePromoteInteger);
1313     }
1314   }
1315 
1316   // ppcf128 type is really two f64's.
1317   if (!isTypeLegal(MVT::ppcf128)) {
1318     if (isTypeLegal(MVT::f64)) {
1319       NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
1320       RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
1321       TransformToType[MVT::ppcf128] = MVT::f64;
1322       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat);
1323     } else {
1324       NumRegistersForVT[MVT::ppcf128] = NumRegistersForVT[MVT::i128];
1325       RegisterTypeForVT[MVT::ppcf128] = RegisterTypeForVT[MVT::i128];
1326       TransformToType[MVT::ppcf128] = MVT::i128;
1327       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeSoftenFloat);
1328     }
1329   }
1330 
1331   // Decide how to handle f128. If the target does not have native f128 support,
1332   // expand it to i128 and we will be generating soft float library calls.
1333   if (!isTypeLegal(MVT::f128)) {
1334     NumRegistersForVT[MVT::f128] = NumRegistersForVT[MVT::i128];
1335     RegisterTypeForVT[MVT::f128] = RegisterTypeForVT[MVT::i128];
1336     TransformToType[MVT::f128] = MVT::i128;
1337     ValueTypeActions.setTypeAction(MVT::f128, TypeSoftenFloat);
1338   }
1339 
1340   // Decide how to handle f80. If the target does not have native f80 support,
1341   // expand it to i96 and we will be generating soft float library calls.
1342   if (!isTypeLegal(MVT::f80)) {
1343     NumRegistersForVT[MVT::f80] = 3*NumRegistersForVT[MVT::i32];
1344     RegisterTypeForVT[MVT::f80] = RegisterTypeForVT[MVT::i32];
1345     TransformToType[MVT::f80] = MVT::i32;
1346     ValueTypeActions.setTypeAction(MVT::f80, TypeSoftenFloat);
1347   }
1348 
1349   // Decide how to handle f64. If the target does not have native f64 support,
1350   // expand it to i64 and we will be generating soft float library calls.
1351   if (!isTypeLegal(MVT::f64)) {
1352     NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
1353     RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
1354     TransformToType[MVT::f64] = MVT::i64;
1355     ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat);
1356   }
1357 
1358   // Decide how to handle f32. If the target does not have native f32 support,
1359   // expand it to i32 and we will be generating soft float library calls.
1360   if (!isTypeLegal(MVT::f32)) {
1361     NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
1362     RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
1363     TransformToType[MVT::f32] = MVT::i32;
1364     ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat);
1365   }
1366 
1367   // Decide how to handle f16. If the target does not have native f16 support,
1368   // promote it to f32, because there are no f16 library calls (except for
1369   // conversions).
1370   if (!isTypeLegal(MVT::f16)) {
1371     // Allow targets to control how we legalize half.
1372     bool SoftPromoteHalfType = softPromoteHalfType();
1373     bool UseFPRegsForHalfType = !SoftPromoteHalfType || useFPRegsForHalfType();
1374 
1375     if (!UseFPRegsForHalfType) {
1376       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::i16];
1377       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::i16];
1378     } else {
1379       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::f32];
1380       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::f32];
1381     }
1382     TransformToType[MVT::f16] = MVT::f32;
1383     if (SoftPromoteHalfType) {
1384       ValueTypeActions.setTypeAction(MVT::f16, TypeSoftPromoteHalf);
1385     } else {
1386       ValueTypeActions.setTypeAction(MVT::f16, TypePromoteFloat);
1387     }
1388   }
1389 
1390   // Decide how to handle bf16. If the target does not have native bf16 support,
1391   // promote it to f32, because there are no bf16 library calls (except for
1392   // converting from f32 to bf16).
1393   if (!isTypeLegal(MVT::bf16)) {
1394     NumRegistersForVT[MVT::bf16] = NumRegistersForVT[MVT::f32];
1395     RegisterTypeForVT[MVT::bf16] = RegisterTypeForVT[MVT::f32];
1396     TransformToType[MVT::bf16] = MVT::f32;
1397     ValueTypeActions.setTypeAction(MVT::bf16, TypeSoftPromoteHalf);
1398   }
1399 
1400   // Loop over all of the vector value types to see which need transformations.
1401   for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
1402        i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
1403     MVT VT = (MVT::SimpleValueType) i;
1404     if (isTypeLegal(VT))
1405       continue;
1406 
1407     MVT EltVT = VT.getVectorElementType();
1408     ElementCount EC = VT.getVectorElementCount();
1409     bool IsLegalWiderType = false;
1410     bool IsScalable = VT.isScalableVector();
1411     LegalizeTypeAction PreferredAction = getPreferredVectorAction(VT);
1412     switch (PreferredAction) {
1413     case TypePromoteInteger: {
1414       MVT::SimpleValueType EndVT = IsScalable ?
1415                                    MVT::LAST_INTEGER_SCALABLE_VECTOR_VALUETYPE :
1416                                    MVT::LAST_INTEGER_FIXEDLEN_VECTOR_VALUETYPE;
1417       // Try to promote the elements of integer vectors. If no legal
1418       // promotion was found, fall through to the widen-vector method.
1419       for (unsigned nVT = i + 1;
1420            (MVT::SimpleValueType)nVT <= EndVT; ++nVT) {
1421         MVT SVT = (MVT::SimpleValueType) nVT;
1422         // Promote vectors of integers to vectors with the same number
1423         // of elements, with a wider element type.
1424         if (SVT.getScalarSizeInBits() > EltVT.getFixedSizeInBits() &&
1425             SVT.getVectorElementCount() == EC && isTypeLegal(SVT)) {
1426           TransformToType[i] = SVT;
1427           RegisterTypeForVT[i] = SVT;
1428           NumRegistersForVT[i] = 1;
1429           ValueTypeActions.setTypeAction(VT, TypePromoteInteger);
1430           IsLegalWiderType = true;
1431           break;
1432         }
1433       }
1434       if (IsLegalWiderType)
1435         break;
1436       [[fallthrough]];
1437     }
1438 
1439     case TypeWidenVector:
1440       if (isPowerOf2_32(EC.getKnownMinValue())) {
1441         // Try to widen the vector.
1442         for (unsigned nVT = i + 1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
1443           MVT SVT = (MVT::SimpleValueType) nVT;
1444           if (SVT.getVectorElementType() == EltVT &&
1445               SVT.isScalableVector() == IsScalable &&
1446               SVT.getVectorElementCount().getKnownMinValue() >
1447                   EC.getKnownMinValue() &&
1448               isTypeLegal(SVT)) {
1449             TransformToType[i] = SVT;
1450             RegisterTypeForVT[i] = SVT;
1451             NumRegistersForVT[i] = 1;
1452             ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1453             IsLegalWiderType = true;
1454             break;
1455           }
1456         }
1457         if (IsLegalWiderType)
1458           break;
1459       } else {
1460         // Only widen to the next power of 2 to keep consistency with EVT.
1461         MVT NVT = VT.getPow2VectorType();
1462         if (isTypeLegal(NVT)) {
1463           TransformToType[i] = NVT;
1464           ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1465           RegisterTypeForVT[i] = NVT;
1466           NumRegistersForVT[i] = 1;
1467           break;
1468         }
1469       }
1470       [[fallthrough]];
1471 
1472     case TypeSplitVector:
1473     case TypeScalarizeVector: {
1474       MVT IntermediateVT;
1475       MVT RegisterVT;
1476       unsigned NumIntermediates;
1477       unsigned NumRegisters = getVectorTypeBreakdownMVT(VT, IntermediateVT,
1478           NumIntermediates, RegisterVT, this);
1479       NumRegistersForVT[i] = NumRegisters;
1480       assert(NumRegistersForVT[i] == NumRegisters &&
1481              "NumRegistersForVT size cannot represent NumRegisters!");
1482       RegisterTypeForVT[i] = RegisterVT;
1483 
1484       MVT NVT = VT.getPow2VectorType();
1485       if (NVT == VT) {
1486         // Type is already a power of 2.  The default action is to split.
1487         TransformToType[i] = MVT::Other;
1488         if (PreferredAction == TypeScalarizeVector)
1489           ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
1490         else if (PreferredAction == TypeSplitVector)
1491           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1492         else if (EC.getKnownMinValue() > 1)
1493           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1494         else
1495           ValueTypeActions.setTypeAction(VT, EC.isScalable()
1496                                                  ? TypeScalarizeScalableVector
1497                                                  : TypeScalarizeVector);
1498       } else {
1499         TransformToType[i] = NVT;
1500         ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1501       }
1502       break;
1503     }
1504     default:
1505       llvm_unreachable("Unknown vector legalization action!");
1506     }
1507   }
1508 
1509   // Determine the 'representative' register class for each value type.
1510   // An representative register class is the largest (meaning one which is
1511   // not a sub-register class / subreg register class) legal register class for
1512   // a group of value types. For example, on i386, i8, i16, and i32
1513   // representative would be GR32; while on x86_64 it's GR64.
1514   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1515     const TargetRegisterClass* RRC;
1516     uint8_t Cost;
1517     std::tie(RRC, Cost) = findRepresentativeClass(TRI, (MVT::SimpleValueType)i);
1518     RepRegClassForVT[i] = RRC;
1519     RepRegClassCostForVT[i] = Cost;
1520   }
1521 }
1522 
1523 EVT TargetLoweringBase::getSetCCResultType(const DataLayout &DL, LLVMContext &,
1524                                            EVT VT) const {
1525   assert(!VT.isVector() && "No default SetCC type for vectors!");
1526   return getPointerTy(DL).SimpleTy;
1527 }
1528 
1529 MVT::SimpleValueType TargetLoweringBase::getCmpLibcallReturnType() const {
1530   return MVT::i32; // return the default value
1531 }
1532 
1533 /// getVectorTypeBreakdown - Vector types are broken down into some number of
1534 /// legal first class types.  For example, MVT::v8f32 maps to 2 MVT::v4f32
1535 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
1536 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
1537 ///
1538 /// This method returns the number of registers needed, and the VT for each
1539 /// register.  It also returns the VT and quantity of the intermediate values
1540 /// before they are promoted/expanded.
1541 unsigned TargetLoweringBase::getVectorTypeBreakdown(LLVMContext &Context,
1542                                                     EVT VT, EVT &IntermediateVT,
1543                                                     unsigned &NumIntermediates,
1544                                                     MVT &RegisterVT) const {
1545   ElementCount EltCnt = VT.getVectorElementCount();
1546 
1547   // If there is a wider vector type with the same element type as this one,
1548   // or a promoted vector type that has the same number of elements which
1549   // are wider, then we should convert to that legal vector type.
1550   // This handles things like <2 x float> -> <4 x float> and
1551   // <4 x i1> -> <4 x i32>.
1552   LegalizeTypeAction TA = getTypeAction(Context, VT);
1553   if (!EltCnt.isScalar() &&
1554       (TA == TypeWidenVector || TA == TypePromoteInteger)) {
1555     EVT RegisterEVT = getTypeToTransformTo(Context, VT);
1556     if (isTypeLegal(RegisterEVT)) {
1557       IntermediateVT = RegisterEVT;
1558       RegisterVT = RegisterEVT.getSimpleVT();
1559       NumIntermediates = 1;
1560       return 1;
1561     }
1562   }
1563 
1564   // Figure out the right, legal destination reg to copy into.
1565   EVT EltTy = VT.getVectorElementType();
1566 
1567   unsigned NumVectorRegs = 1;
1568 
1569   // Scalable vectors cannot be scalarized, so handle the legalisation of the
1570   // types like done elsewhere in SelectionDAG.
1571   if (EltCnt.isScalable()) {
1572     LegalizeKind LK;
1573     EVT PartVT = VT;
1574     do {
1575       // Iterate until we've found a legal (part) type to hold VT.
1576       LK = getTypeConversion(Context, PartVT);
1577       PartVT = LK.second;
1578     } while (LK.first != TypeLegal);
1579 
1580     if (!PartVT.isVector()) {
1581       report_fatal_error(
1582           "Don't know how to legalize this scalable vector type");
1583     }
1584 
1585     NumIntermediates =
1586         divideCeil(VT.getVectorElementCount().getKnownMinValue(),
1587                    PartVT.getVectorElementCount().getKnownMinValue());
1588     IntermediateVT = PartVT;
1589     RegisterVT = getRegisterType(Context, IntermediateVT);
1590     return NumIntermediates;
1591   }
1592 
1593   // FIXME: We don't support non-power-of-2-sized vectors for now.  Ideally
1594   // we could break down into LHS/RHS like LegalizeDAG does.
1595   if (!isPowerOf2_32(EltCnt.getKnownMinValue())) {
1596     NumVectorRegs = EltCnt.getKnownMinValue();
1597     EltCnt = ElementCount::getFixed(1);
1598   }
1599 
1600   // Divide the input until we get to a supported size.  This will always
1601   // end with a scalar if the target doesn't support vectors.
1602   while (EltCnt.getKnownMinValue() > 1 &&
1603          !isTypeLegal(EVT::getVectorVT(Context, EltTy, EltCnt))) {
1604     EltCnt = EltCnt.divideCoefficientBy(2);
1605     NumVectorRegs <<= 1;
1606   }
1607 
1608   NumIntermediates = NumVectorRegs;
1609 
1610   EVT NewVT = EVT::getVectorVT(Context, EltTy, EltCnt);
1611   if (!isTypeLegal(NewVT))
1612     NewVT = EltTy;
1613   IntermediateVT = NewVT;
1614 
1615   MVT DestVT = getRegisterType(Context, NewVT);
1616   RegisterVT = DestVT;
1617 
1618   if (EVT(DestVT).bitsLT(NewVT)) {  // Value is expanded, e.g. i64 -> i16.
1619     TypeSize NewVTSize = NewVT.getSizeInBits();
1620     // Convert sizes such as i33 to i64.
1621     if (!llvm::has_single_bit<uint32_t>(NewVTSize.getKnownMinValue()))
1622       NewVTSize = NewVTSize.coefficientNextPowerOf2();
1623     return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
1624   }
1625 
1626   // Otherwise, promotion or legal types use the same number of registers as
1627   // the vector decimated to the appropriate level.
1628   return NumVectorRegs;
1629 }
1630 
1631 bool TargetLoweringBase::isSuitableForJumpTable(const SwitchInst *SI,
1632                                                 uint64_t NumCases,
1633                                                 uint64_t Range,
1634                                                 ProfileSummaryInfo *PSI,
1635                                                 BlockFrequencyInfo *BFI) const {
1636   // FIXME: This function check the maximum table size and density, but the
1637   // minimum size is not checked. It would be nice if the minimum size is
1638   // also combined within this function. Currently, the minimum size check is
1639   // performed in findJumpTable() in SelectionDAGBuiler and
1640   // getEstimatedNumberOfCaseClusters() in BasicTTIImpl.
1641   const bool OptForSize =
1642       llvm::shouldOptimizeForSize(SI->getParent(), PSI, BFI);
1643   const unsigned MinDensity = getMinimumJumpTableDensity(OptForSize);
1644   const unsigned MaxJumpTableSize = getMaximumJumpTableSize();
1645 
1646   // Check whether the number of cases is small enough and
1647   // the range is dense enough for a jump table.
1648   return (OptForSize || Range <= MaxJumpTableSize) &&
1649          (NumCases * 100 >= Range * MinDensity);
1650 }
1651 
1652 MVT TargetLoweringBase::getPreferredSwitchConditionType(LLVMContext &Context,
1653                                                         EVT ConditionVT) const {
1654   return getRegisterType(Context, ConditionVT);
1655 }
1656 
1657 /// Get the EVTs and ArgFlags collections that represent the legalized return
1658 /// type of the given function.  This does not require a DAG or a return value,
1659 /// and is suitable for use before any DAGs for the function are constructed.
1660 /// TODO: Move this out of TargetLowering.cpp.
1661 void llvm::GetReturnInfo(CallingConv::ID CC, Type *ReturnType,
1662                          AttributeList attr,
1663                          SmallVectorImpl<ISD::OutputArg> &Outs,
1664                          const TargetLowering &TLI, const DataLayout &DL) {
1665   SmallVector<EVT, 4> ValueVTs;
1666   ComputeValueVTs(TLI, DL, ReturnType, ValueVTs);
1667   unsigned NumValues = ValueVTs.size();
1668   if (NumValues == 0) return;
1669 
1670   for (unsigned j = 0, f = NumValues; j != f; ++j) {
1671     EVT VT = ValueVTs[j];
1672     ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
1673 
1674     if (attr.hasRetAttr(Attribute::SExt))
1675       ExtendKind = ISD::SIGN_EXTEND;
1676     else if (attr.hasRetAttr(Attribute::ZExt))
1677       ExtendKind = ISD::ZERO_EXTEND;
1678 
1679     if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger())
1680       VT = TLI.getTypeForExtReturn(ReturnType->getContext(), VT, ExtendKind);
1681 
1682     unsigned NumParts =
1683         TLI.getNumRegistersForCallingConv(ReturnType->getContext(), CC, VT);
1684     MVT PartVT =
1685         TLI.getRegisterTypeForCallingConv(ReturnType->getContext(), CC, VT);
1686 
1687     // 'inreg' on function refers to return value
1688     ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
1689     if (attr.hasRetAttr(Attribute::InReg))
1690       Flags.setInReg();
1691 
1692     // Propagate extension type if any
1693     if (attr.hasRetAttr(Attribute::SExt))
1694       Flags.setSExt();
1695     else if (attr.hasRetAttr(Attribute::ZExt))
1696       Flags.setZExt();
1697 
1698     for (unsigned i = 0; i < NumParts; ++i)
1699       Outs.push_back(ISD::OutputArg(Flags, PartVT, VT, /*isfixed=*/true, 0, 0));
1700   }
1701 }
1702 
1703 Align TargetLoweringBase::getByValTypeAlignment(Type *Ty,
1704                                                 const DataLayout &DL) const {
1705   return DL.getABITypeAlign(Ty);
1706 }
1707 
1708 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1709     LLVMContext &Context, const DataLayout &DL, EVT VT, unsigned AddrSpace,
1710     Align Alignment, MachineMemOperand::Flags Flags, unsigned *Fast) const {
1711   // Check if the specified alignment is sufficient based on the data layout.
1712   // TODO: While using the data layout works in practice, a better solution
1713   // would be to implement this check directly (make this a virtual function).
1714   // For example, the ABI alignment may change based on software platform while
1715   // this function should only be affected by hardware implementation.
1716   Type *Ty = VT.getTypeForEVT(Context);
1717   if (VT.isZeroSized() || Alignment >= DL.getABITypeAlign(Ty)) {
1718     // Assume that an access that meets the ABI-specified alignment is fast.
1719     if (Fast != nullptr)
1720       *Fast = 1;
1721     return true;
1722   }
1723 
1724   // This is a misaligned access.
1725   return allowsMisalignedMemoryAccesses(VT, AddrSpace, Alignment, Flags, Fast);
1726 }
1727 
1728 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1729     LLVMContext &Context, const DataLayout &DL, EVT VT,
1730     const MachineMemOperand &MMO, unsigned *Fast) const {
1731   return allowsMemoryAccessForAlignment(Context, DL, VT, MMO.getAddrSpace(),
1732                                         MMO.getAlign(), MMO.getFlags(), Fast);
1733 }
1734 
1735 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1736                                             const DataLayout &DL, EVT VT,
1737                                             unsigned AddrSpace, Align Alignment,
1738                                             MachineMemOperand::Flags Flags,
1739                                             unsigned *Fast) const {
1740   return allowsMemoryAccessForAlignment(Context, DL, VT, AddrSpace, Alignment,
1741                                         Flags, Fast);
1742 }
1743 
1744 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1745                                             const DataLayout &DL, EVT VT,
1746                                             const MachineMemOperand &MMO,
1747                                             unsigned *Fast) const {
1748   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1749                             MMO.getFlags(), Fast);
1750 }
1751 
1752 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1753                                             const DataLayout &DL, LLT Ty,
1754                                             const MachineMemOperand &MMO,
1755                                             unsigned *Fast) const {
1756   EVT VT = getApproximateEVTForLLT(Ty, Context);
1757   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1758                             MMO.getFlags(), Fast);
1759 }
1760 
1761 //===----------------------------------------------------------------------===//
1762 //  TargetTransformInfo Helpers
1763 //===----------------------------------------------------------------------===//
1764 
1765 int TargetLoweringBase::InstructionOpcodeToISD(unsigned Opcode) const {
1766   enum InstructionOpcodes {
1767 #define HANDLE_INST(NUM, OPCODE, CLASS) OPCODE = NUM,
1768 #define LAST_OTHER_INST(NUM) InstructionOpcodesCount = NUM
1769 #include "llvm/IR/Instruction.def"
1770   };
1771   switch (static_cast<InstructionOpcodes>(Opcode)) {
1772   case Ret:            return 0;
1773   case Br:             return 0;
1774   case Switch:         return 0;
1775   case IndirectBr:     return 0;
1776   case Invoke:         return 0;
1777   case CallBr:         return 0;
1778   case Resume:         return 0;
1779   case Unreachable:    return 0;
1780   case CleanupRet:     return 0;
1781   case CatchRet:       return 0;
1782   case CatchPad:       return 0;
1783   case CatchSwitch:    return 0;
1784   case CleanupPad:     return 0;
1785   case FNeg:           return ISD::FNEG;
1786   case Add:            return ISD::ADD;
1787   case FAdd:           return ISD::FADD;
1788   case Sub:            return ISD::SUB;
1789   case FSub:           return ISD::FSUB;
1790   case Mul:            return ISD::MUL;
1791   case FMul:           return ISD::FMUL;
1792   case UDiv:           return ISD::UDIV;
1793   case SDiv:           return ISD::SDIV;
1794   case FDiv:           return ISD::FDIV;
1795   case URem:           return ISD::UREM;
1796   case SRem:           return ISD::SREM;
1797   case FRem:           return ISD::FREM;
1798   case Shl:            return ISD::SHL;
1799   case LShr:           return ISD::SRL;
1800   case AShr:           return ISD::SRA;
1801   case And:            return ISD::AND;
1802   case Or:             return ISD::OR;
1803   case Xor:            return ISD::XOR;
1804   case Alloca:         return 0;
1805   case Load:           return ISD::LOAD;
1806   case Store:          return ISD::STORE;
1807   case GetElementPtr:  return 0;
1808   case Fence:          return 0;
1809   case AtomicCmpXchg:  return 0;
1810   case AtomicRMW:      return 0;
1811   case Trunc:          return ISD::TRUNCATE;
1812   case ZExt:           return ISD::ZERO_EXTEND;
1813   case SExt:           return ISD::SIGN_EXTEND;
1814   case FPToUI:         return ISD::FP_TO_UINT;
1815   case FPToSI:         return ISD::FP_TO_SINT;
1816   case UIToFP:         return ISD::UINT_TO_FP;
1817   case SIToFP:         return ISD::SINT_TO_FP;
1818   case FPTrunc:        return ISD::FP_ROUND;
1819   case FPExt:          return ISD::FP_EXTEND;
1820   case PtrToInt:       return ISD::BITCAST;
1821   case IntToPtr:       return ISD::BITCAST;
1822   case BitCast:        return ISD::BITCAST;
1823   case AddrSpaceCast:  return ISD::ADDRSPACECAST;
1824   case ICmp:           return ISD::SETCC;
1825   case FCmp:           return ISD::SETCC;
1826   case PHI:            return 0;
1827   case Call:           return 0;
1828   case Select:         return ISD::SELECT;
1829   case UserOp1:        return 0;
1830   case UserOp2:        return 0;
1831   case VAArg:          return 0;
1832   case ExtractElement: return ISD::EXTRACT_VECTOR_ELT;
1833   case InsertElement:  return ISD::INSERT_VECTOR_ELT;
1834   case ShuffleVector:  return ISD::VECTOR_SHUFFLE;
1835   case ExtractValue:   return ISD::MERGE_VALUES;
1836   case InsertValue:    return ISD::MERGE_VALUES;
1837   case LandingPad:     return 0;
1838   case Freeze:         return ISD::FREEZE;
1839   }
1840 
1841   llvm_unreachable("Unknown instruction type encountered!");
1842 }
1843 
1844 int TargetLoweringBase::IntrinsicIDToISD(Intrinsic::ID ID) const {
1845   switch (ID) {
1846   case Intrinsic::exp:
1847     return ISD::FEXP;
1848   case Intrinsic::exp2:
1849     return ISD::FEXP2;
1850   default:
1851     return ISD::DELETED_NODE;
1852   }
1853 }
1854 
1855 Value *
1856 TargetLoweringBase::getDefaultSafeStackPointerLocation(IRBuilderBase &IRB,
1857                                                        bool UseTLS) const {
1858   // compiler-rt provides a variable with a magic name.  Targets that do not
1859   // link with compiler-rt may also provide such a variable.
1860   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1861   const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
1862   auto UnsafeStackPtr =
1863       dyn_cast_or_null<GlobalVariable>(M->getNamedValue(UnsafeStackPtrVar));
1864 
1865   const DataLayout &DL = M->getDataLayout();
1866   PointerType *StackPtrTy = DL.getAllocaPtrType(M->getContext());
1867 
1868   if (!UnsafeStackPtr) {
1869     auto TLSModel = UseTLS ?
1870         GlobalValue::InitialExecTLSModel :
1871         GlobalValue::NotThreadLocal;
1872     // The global variable is not defined yet, define it ourselves.
1873     // We use the initial-exec TLS model because we do not support the
1874     // variable living anywhere other than in the main executable.
1875     UnsafeStackPtr = new GlobalVariable(
1876         *M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
1877         UnsafeStackPtrVar, nullptr, TLSModel);
1878   } else {
1879     // The variable exists, check its type and attributes.
1880     //
1881     // FIXME: Move to IR verifier.
1882     if (UnsafeStackPtr->getValueType() != StackPtrTy)
1883       report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
1884     if (UseTLS != UnsafeStackPtr->isThreadLocal())
1885       report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
1886                          (UseTLS ? "" : "not ") + "be thread-local");
1887   }
1888   return UnsafeStackPtr;
1889 }
1890 
1891 Value *
1892 TargetLoweringBase::getSafeStackPointerLocation(IRBuilderBase &IRB) const {
1893   if (!TM.getTargetTriple().isAndroid())
1894     return getDefaultSafeStackPointerLocation(IRB, true);
1895 
1896   // Android provides a libc function to retrieve the address of the current
1897   // thread's unsafe stack pointer.
1898   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1899   auto *PtrTy = PointerType::getUnqual(M->getContext());
1900   FunctionCallee Fn =
1901       M->getOrInsertFunction("__safestack_pointer_address", PtrTy);
1902   return IRB.CreateCall(Fn);
1903 }
1904 
1905 //===----------------------------------------------------------------------===//
1906 //  Loop Strength Reduction hooks
1907 //===----------------------------------------------------------------------===//
1908 
1909 /// isLegalAddressingMode - Return true if the addressing mode represented
1910 /// by AM is legal for this target, for a load/store of the specified type.
1911 bool TargetLoweringBase::isLegalAddressingMode(const DataLayout &DL,
1912                                                const AddrMode &AM, Type *Ty,
1913                                                unsigned AS, Instruction *I) const {
1914   // The default implementation of this implements a conservative RISCy, r+r and
1915   // r+i addr mode.
1916 
1917   // Scalable offsets not supported
1918   if (AM.ScalableOffset)
1919     return false;
1920 
1921   // Allows a sign-extended 16-bit immediate field.
1922   if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
1923     return false;
1924 
1925   // No global is ever allowed as a base.
1926   if (AM.BaseGV)
1927     return false;
1928 
1929   // Only support r+r,
1930   switch (AM.Scale) {
1931   case 0:  // "r+i" or just "i", depending on HasBaseReg.
1932     break;
1933   case 1:
1934     if (AM.HasBaseReg && AM.BaseOffs)  // "r+r+i" is not allowed.
1935       return false;
1936     // Otherwise we have r+r or r+i.
1937     break;
1938   case 2:
1939     if (AM.HasBaseReg || AM.BaseOffs)  // 2*r+r  or  2*r+i is not allowed.
1940       return false;
1941     // Allow 2*r as r+r.
1942     break;
1943   default: // Don't allow n * r
1944     return false;
1945   }
1946 
1947   return true;
1948 }
1949 
1950 //===----------------------------------------------------------------------===//
1951 //  Stack Protector
1952 //===----------------------------------------------------------------------===//
1953 
1954 // For OpenBSD return its special guard variable. Otherwise return nullptr,
1955 // so that SelectionDAG handle SSP.
1956 Value *TargetLoweringBase::getIRStackGuard(IRBuilderBase &IRB) const {
1957   if (getTargetMachine().getTargetTriple().isOSOpenBSD()) {
1958     Module &M = *IRB.GetInsertBlock()->getParent()->getParent();
1959     PointerType *PtrTy = PointerType::getUnqual(M.getContext());
1960     Constant *C = M.getOrInsertGlobal("__guard_local", PtrTy);
1961     if (GlobalVariable *G = dyn_cast_or_null<GlobalVariable>(C))
1962       G->setVisibility(GlobalValue::HiddenVisibility);
1963     return C;
1964   }
1965   return nullptr;
1966 }
1967 
1968 // Currently only support "standard" __stack_chk_guard.
1969 // TODO: add LOAD_STACK_GUARD support.
1970 void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
1971   if (!M.getNamedValue("__stack_chk_guard")) {
1972     auto *GV = new GlobalVariable(M, PointerType::getUnqual(M.getContext()),
1973                                   false, GlobalVariable::ExternalLinkage,
1974                                   nullptr, "__stack_chk_guard");
1975 
1976     // FreeBSD has "__stack_chk_guard" defined externally on libc.so
1977     if (M.getDirectAccessExternalData() &&
1978         !TM.getTargetTriple().isWindowsGNUEnvironment() &&
1979         !(TM.getTargetTriple().isPPC64() &&
1980           TM.getTargetTriple().isOSFreeBSD()) &&
1981         (!TM.getTargetTriple().isOSDarwin() ||
1982          TM.getRelocationModel() == Reloc::Static))
1983       GV->setDSOLocal(true);
1984   }
1985 }
1986 
1987 // Currently only support "standard" __stack_chk_guard.
1988 // TODO: add LOAD_STACK_GUARD support.
1989 Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
1990   return M.getNamedValue("__stack_chk_guard");
1991 }
1992 
1993 Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
1994   return nullptr;
1995 }
1996 
1997 unsigned TargetLoweringBase::getMinimumJumpTableEntries() const {
1998   return MinimumJumpTableEntries;
1999 }
2000 
2001 void TargetLoweringBase::setMinimumJumpTableEntries(unsigned Val) {
2002   MinimumJumpTableEntries = Val;
2003 }
2004 
2005 unsigned TargetLoweringBase::getMinimumJumpTableDensity(bool OptForSize) const {
2006   return OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
2007 }
2008 
2009 unsigned TargetLoweringBase::getMaximumJumpTableSize() const {
2010   return MaximumJumpTableSize;
2011 }
2012 
2013 void TargetLoweringBase::setMaximumJumpTableSize(unsigned Val) {
2014   MaximumJumpTableSize = Val;
2015 }
2016 
2017 bool TargetLoweringBase::isJumpTableRelative() const {
2018   return getTargetMachine().isPositionIndependent();
2019 }
2020 
2021 Align TargetLoweringBase::getPrefLoopAlignment(MachineLoop *ML) const {
2022   if (TM.Options.LoopAlignment)
2023     return Align(TM.Options.LoopAlignment);
2024   return PrefLoopAlignment;
2025 }
2026 
2027 unsigned TargetLoweringBase::getMaxPermittedBytesForAlignment(
2028     MachineBasicBlock *MBB) const {
2029   return MaxBytesForAlignment;
2030 }
2031 
2032 //===----------------------------------------------------------------------===//
2033 //  Reciprocal Estimates
2034 //===----------------------------------------------------------------------===//
2035 
2036 /// Get the reciprocal estimate attribute string for a function that will
2037 /// override the target defaults.
2038 static StringRef getRecipEstimateForFunc(MachineFunction &MF) {
2039   const Function &F = MF.getFunction();
2040   return F.getFnAttribute("reciprocal-estimates").getValueAsString();
2041 }
2042 
2043 /// Construct a string for the given reciprocal operation of the given type.
2044 /// This string should match the corresponding option to the front-end's
2045 /// "-mrecip" flag assuming those strings have been passed through in an
2046 /// attribute string. For example, "vec-divf" for a division of a vXf32.
2047 static std::string getReciprocalOpName(bool IsSqrt, EVT VT) {
2048   std::string Name = VT.isVector() ? "vec-" : "";
2049 
2050   Name += IsSqrt ? "sqrt" : "div";
2051 
2052   // TODO: Handle other float types?
2053   if (VT.getScalarType() == MVT::f64) {
2054     Name += "d";
2055   } else if (VT.getScalarType() == MVT::f16) {
2056     Name += "h";
2057   } else {
2058     assert(VT.getScalarType() == MVT::f32 &&
2059            "Unexpected FP type for reciprocal estimate");
2060     Name += "f";
2061   }
2062 
2063   return Name;
2064 }
2065 
2066 /// Return the character position and value (a single numeric character) of a
2067 /// customized refinement operation in the input string if it exists. Return
2068 /// false if there is no customized refinement step count.
2069 static bool parseRefinementStep(StringRef In, size_t &Position,
2070                                 uint8_t &Value) {
2071   const char RefStepToken = ':';
2072   Position = In.find(RefStepToken);
2073   if (Position == StringRef::npos)
2074     return false;
2075 
2076   StringRef RefStepString = In.substr(Position + 1);
2077   // Allow exactly one numeric character for the additional refinement
2078   // step parameter.
2079   if (RefStepString.size() == 1) {
2080     char RefStepChar = RefStepString[0];
2081     if (isDigit(RefStepChar)) {
2082       Value = RefStepChar - '0';
2083       return true;
2084     }
2085   }
2086   report_fatal_error("Invalid refinement step for -recip.");
2087 }
2088 
2089 /// For the input attribute string, return one of the ReciprocalEstimate enum
2090 /// status values (enabled, disabled, or not specified) for this operation on
2091 /// the specified data type.
2092 static int getOpEnabled(bool IsSqrt, EVT VT, StringRef Override) {
2093   if (Override.empty())
2094     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2095 
2096   SmallVector<StringRef, 4> OverrideVector;
2097   Override.split(OverrideVector, ',');
2098   unsigned NumArgs = OverrideVector.size();
2099 
2100   // Check if "all", "none", or "default" was specified.
2101   if (NumArgs == 1) {
2102     // Look for an optional setting of the number of refinement steps needed
2103     // for this type of reciprocal operation.
2104     size_t RefPos;
2105     uint8_t RefSteps;
2106     if (parseRefinementStep(Override, RefPos, RefSteps)) {
2107       // Split the string for further processing.
2108       Override = Override.substr(0, RefPos);
2109     }
2110 
2111     // All reciprocal types are enabled.
2112     if (Override == "all")
2113       return TargetLoweringBase::ReciprocalEstimate::Enabled;
2114 
2115     // All reciprocal types are disabled.
2116     if (Override == "none")
2117       return TargetLoweringBase::ReciprocalEstimate::Disabled;
2118 
2119     // Target defaults for enablement are used.
2120     if (Override == "default")
2121       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2122   }
2123 
2124   // The attribute string may omit the size suffix ('f'/'d').
2125   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2126   std::string VTNameNoSize = VTName;
2127   VTNameNoSize.pop_back();
2128   static const char DisabledPrefix = '!';
2129 
2130   for (StringRef RecipType : OverrideVector) {
2131     size_t RefPos;
2132     uint8_t RefSteps;
2133     if (parseRefinementStep(RecipType, RefPos, RefSteps))
2134       RecipType = RecipType.substr(0, RefPos);
2135 
2136     // Ignore the disablement token for string matching.
2137     bool IsDisabled = RecipType[0] == DisabledPrefix;
2138     if (IsDisabled)
2139       RecipType = RecipType.substr(1);
2140 
2141     if (RecipType == VTName || RecipType == VTNameNoSize)
2142       return IsDisabled ? TargetLoweringBase::ReciprocalEstimate::Disabled
2143                         : TargetLoweringBase::ReciprocalEstimate::Enabled;
2144   }
2145 
2146   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2147 }
2148 
2149 /// For the input attribute string, return the customized refinement step count
2150 /// for this operation on the specified data type. If the step count does not
2151 /// exist, return the ReciprocalEstimate enum value for unspecified.
2152 static int getOpRefinementSteps(bool IsSqrt, EVT VT, StringRef Override) {
2153   if (Override.empty())
2154     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2155 
2156   SmallVector<StringRef, 4> OverrideVector;
2157   Override.split(OverrideVector, ',');
2158   unsigned NumArgs = OverrideVector.size();
2159 
2160   // Check if "all", "default", or "none" was specified.
2161   if (NumArgs == 1) {
2162     // Look for an optional setting of the number of refinement steps needed
2163     // for this type of reciprocal operation.
2164     size_t RefPos;
2165     uint8_t RefSteps;
2166     if (!parseRefinementStep(Override, RefPos, RefSteps))
2167       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2168 
2169     // Split the string for further processing.
2170     Override = Override.substr(0, RefPos);
2171     assert(Override != "none" &&
2172            "Disabled reciprocals, but specifed refinement steps?");
2173 
2174     // If this is a general override, return the specified number of steps.
2175     if (Override == "all" || Override == "default")
2176       return RefSteps;
2177   }
2178 
2179   // The attribute string may omit the size suffix ('f'/'d').
2180   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2181   std::string VTNameNoSize = VTName;
2182   VTNameNoSize.pop_back();
2183 
2184   for (StringRef RecipType : OverrideVector) {
2185     size_t RefPos;
2186     uint8_t RefSteps;
2187     if (!parseRefinementStep(RecipType, RefPos, RefSteps))
2188       continue;
2189 
2190     RecipType = RecipType.substr(0, RefPos);
2191     if (RecipType == VTName || RecipType == VTNameNoSize)
2192       return RefSteps;
2193   }
2194 
2195   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2196 }
2197 
2198 int TargetLoweringBase::getRecipEstimateSqrtEnabled(EVT VT,
2199                                                     MachineFunction &MF) const {
2200   return getOpEnabled(true, VT, getRecipEstimateForFunc(MF));
2201 }
2202 
2203 int TargetLoweringBase::getRecipEstimateDivEnabled(EVT VT,
2204                                                    MachineFunction &MF) const {
2205   return getOpEnabled(false, VT, getRecipEstimateForFunc(MF));
2206 }
2207 
2208 int TargetLoweringBase::getSqrtRefinementSteps(EVT VT,
2209                                                MachineFunction &MF) const {
2210   return getOpRefinementSteps(true, VT, getRecipEstimateForFunc(MF));
2211 }
2212 
2213 int TargetLoweringBase::getDivRefinementSteps(EVT VT,
2214                                               MachineFunction &MF) const {
2215   return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
2216 }
2217 
2218 bool TargetLoweringBase::isLoadBitCastBeneficial(
2219     EVT LoadVT, EVT BitcastVT, const SelectionDAG &DAG,
2220     const MachineMemOperand &MMO) const {
2221   // Single-element vectors are scalarized, so we should generally avoid having
2222   // any memory operations on such types, as they would get scalarized too.
2223   if (LoadVT.isFixedLengthVector() && BitcastVT.isFixedLengthVector() &&
2224       BitcastVT.getVectorNumElements() == 1)
2225     return false;
2226 
2227   // Don't do if we could do an indexed load on the original type, but not on
2228   // the new one.
2229   if (!LoadVT.isSimple() || !BitcastVT.isSimple())
2230     return true;
2231 
2232   MVT LoadMVT = LoadVT.getSimpleVT();
2233 
2234   // Don't bother doing this if it's just going to be promoted again later, as
2235   // doing so might interfere with other combines.
2236   if (getOperationAction(ISD::LOAD, LoadMVT) == Promote &&
2237       getTypeToPromoteTo(ISD::LOAD, LoadMVT) == BitcastVT.getSimpleVT())
2238     return false;
2239 
2240   unsigned Fast = 0;
2241   return allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), BitcastVT,
2242                             MMO, &Fast) &&
2243          Fast;
2244 }
2245 
2246 void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
2247   MF.getRegInfo().freezeReservedRegs();
2248 }
2249 
2250 MachineMemOperand::Flags TargetLoweringBase::getLoadMemOperandFlags(
2251     const LoadInst &LI, const DataLayout &DL, AssumptionCache *AC,
2252     const TargetLibraryInfo *LibInfo) const {
2253   MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad;
2254   if (LI.isVolatile())
2255     Flags |= MachineMemOperand::MOVolatile;
2256 
2257   if (LI.hasMetadata(LLVMContext::MD_nontemporal))
2258     Flags |= MachineMemOperand::MONonTemporal;
2259 
2260   if (LI.hasMetadata(LLVMContext::MD_invariant_load))
2261     Flags |= MachineMemOperand::MOInvariant;
2262 
2263   if (isDereferenceableAndAlignedPointer(LI.getPointerOperand(), LI.getType(),
2264                                          LI.getAlign(), DL, &LI, AC,
2265                                          /*DT=*/nullptr, LibInfo))
2266     Flags |= MachineMemOperand::MODereferenceable;
2267 
2268   Flags |= getTargetMMOFlags(LI);
2269   return Flags;
2270 }
2271 
2272 MachineMemOperand::Flags
2273 TargetLoweringBase::getStoreMemOperandFlags(const StoreInst &SI,
2274                                             const DataLayout &DL) const {
2275   MachineMemOperand::Flags Flags = MachineMemOperand::MOStore;
2276 
2277   if (SI.isVolatile())
2278     Flags |= MachineMemOperand::MOVolatile;
2279 
2280   if (SI.hasMetadata(LLVMContext::MD_nontemporal))
2281     Flags |= MachineMemOperand::MONonTemporal;
2282 
2283   // FIXME: Not preserving dereferenceable
2284   Flags |= getTargetMMOFlags(SI);
2285   return Flags;
2286 }
2287 
2288 MachineMemOperand::Flags
2289 TargetLoweringBase::getAtomicMemOperandFlags(const Instruction &AI,
2290                                              const DataLayout &DL) const {
2291   auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
2292 
2293   if (const AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(&AI)) {
2294     if (RMW->isVolatile())
2295       Flags |= MachineMemOperand::MOVolatile;
2296   } else if (const AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(&AI)) {
2297     if (CmpX->isVolatile())
2298       Flags |= MachineMemOperand::MOVolatile;
2299   } else
2300     llvm_unreachable("not an atomic instruction");
2301 
2302   // FIXME: Not preserving dereferenceable
2303   Flags |= getTargetMMOFlags(AI);
2304   return Flags;
2305 }
2306 
2307 Instruction *TargetLoweringBase::emitLeadingFence(IRBuilderBase &Builder,
2308                                                   Instruction *Inst,
2309                                                   AtomicOrdering Ord) const {
2310   if (isReleaseOrStronger(Ord) && Inst->hasAtomicStore())
2311     return Builder.CreateFence(Ord);
2312   else
2313     return nullptr;
2314 }
2315 
2316 Instruction *TargetLoweringBase::emitTrailingFence(IRBuilderBase &Builder,
2317                                                    Instruction *Inst,
2318                                                    AtomicOrdering Ord) const {
2319   if (isAcquireOrStronger(Ord))
2320     return Builder.CreateFence(Ord);
2321   else
2322     return nullptr;
2323 }
2324 
2325 //===----------------------------------------------------------------------===//
2326 //  GlobalISel Hooks
2327 //===----------------------------------------------------------------------===//
2328 
2329 bool TargetLoweringBase::shouldLocalize(const MachineInstr &MI,
2330                                         const TargetTransformInfo *TTI) const {
2331   auto &MF = *MI.getMF();
2332   auto &MRI = MF.getRegInfo();
2333   // Assuming a spill and reload of a value has a cost of 1 instruction each,
2334   // this helper function computes the maximum number of uses we should consider
2335   // for remat. E.g. on arm64 global addresses take 2 insts to materialize. We
2336   // break even in terms of code size when the original MI has 2 users vs
2337   // choosing to potentially spill. Any more than 2 users we we have a net code
2338   // size increase. This doesn't take into account register pressure though.
2339   auto maxUses = [](unsigned RematCost) {
2340     // A cost of 1 means remats are basically free.
2341     if (RematCost == 1)
2342       return std::numeric_limits<unsigned>::max();
2343     if (RematCost == 2)
2344       return 2U;
2345 
2346     // Remat is too expensive, only sink if there's one user.
2347     if (RematCost > 2)
2348       return 1U;
2349     llvm_unreachable("Unexpected remat cost");
2350   };
2351 
2352   switch (MI.getOpcode()) {
2353   default:
2354     return false;
2355   // Constants-like instructions should be close to their users.
2356   // We don't want long live-ranges for them.
2357   case TargetOpcode::G_CONSTANT:
2358   case TargetOpcode::G_FCONSTANT:
2359   case TargetOpcode::G_FRAME_INDEX:
2360   case TargetOpcode::G_INTTOPTR:
2361     return true;
2362   case TargetOpcode::G_GLOBAL_VALUE: {
2363     unsigned RematCost = TTI->getGISelRematGlobalCost();
2364     Register Reg = MI.getOperand(0).getReg();
2365     unsigned MaxUses = maxUses(RematCost);
2366     if (MaxUses == UINT_MAX)
2367       return true; // Remats are "free" so always localize.
2368     return MRI.hasAtMostUserInstrs(Reg, MaxUses);
2369   }
2370   }
2371 }
2372