xref: /llvm-project/llvm/lib/CodeGen/TargetLoweringBase.cpp (revision 0d9fc1743378c73012828698122c46dc580d29eb)
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     // FP environment operations default to expand.
822     setOperationAction(ISD::GET_FPENV, VT, Expand);
823     setOperationAction(ISD::SET_FPENV, VT, Expand);
824     setOperationAction(ISD::RESET_FPENV, VT, Expand);
825   }
826 
827   // Most targets ignore the @llvm.prefetch intrinsic.
828   setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
829 
830   // Most targets also ignore the @llvm.readcyclecounter intrinsic.
831   setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Expand);
832 
833   // Most targets also ignore the @llvm.readsteadycounter intrinsic.
834   setOperationAction(ISD::READSTEADYCOUNTER, MVT::i64, Expand);
835 
836   // ConstantFP nodes default to expand.  Targets can either change this to
837   // Legal, in which case all fp constants are legal, or use isFPImmLegal()
838   // to optimize expansions for certain constants.
839   setOperationAction(ISD::ConstantFP,
840                      {MVT::bf16, MVT::f16, MVT::f32, MVT::f64, MVT::f80, MVT::f128},
841                      Expand);
842 
843   // These library functions default to expand.
844   setOperationAction({ISD::FCBRT,      ISD::FLOG,  ISD::FLOG2,  ISD::FLOG10,
845                       ISD::FEXP,       ISD::FEXP2, ISD::FEXP10, ISD::FFLOOR,
846                       ISD::FNEARBYINT, ISD::FCEIL, ISD::FRINT,  ISD::FTRUNC,
847                       ISD::FROUNDEVEN, ISD::FTAN,  ISD::FACOS,  ISD::FASIN,
848                       ISD::FATAN,      ISD::FCOSH, ISD::FSINH,  ISD::FTANH,
849                       ISD::FATAN2},
850                      {MVT::f32, MVT::f64, MVT::f128}, Expand);
851 
852   // FIXME: Query RuntimeLibCalls to make the decision.
853   setOperationAction({ISD::LRINT, ISD::LLRINT, ISD::LROUND, ISD::LLROUND},
854                      {MVT::f32, MVT::f64, MVT::f128}, LibCall);
855 
856   setOperationAction({ISD::FTAN, ISD::FACOS, ISD::FASIN, ISD::FATAN, ISD::FCOSH,
857                       ISD::FSINH, ISD::FTANH, ISD::FATAN2},
858                      MVT::f16, Promote);
859   // Default ISD::TRAP to expand (which turns it into abort).
860   setOperationAction(ISD::TRAP, MVT::Other, Expand);
861 
862   // On most systems, DEBUGTRAP and TRAP have no difference. The "Expand"
863   // here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP.
864   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand);
865 
866   setOperationAction(ISD::UBSANTRAP, MVT::Other, Expand);
867 
868   setOperationAction(ISD::GET_FPENV_MEM, MVT::Other, Expand);
869   setOperationAction(ISD::SET_FPENV_MEM, MVT::Other, Expand);
870 
871   for (MVT VT : {MVT::i8, MVT::i16, MVT::i32, MVT::i64}) {
872     setOperationAction(ISD::GET_FPMODE, VT, Expand);
873     setOperationAction(ISD::SET_FPMODE, VT, Expand);
874   }
875   setOperationAction(ISD::RESET_FPMODE, MVT::Other, Expand);
876 
877   // This one by default will call __clear_cache unless the target
878   // wants something different.
879   setOperationAction(ISD::CLEAR_CACHE, MVT::Other, LibCall);
880 }
881 
882 MVT TargetLoweringBase::getScalarShiftAmountTy(const DataLayout &DL,
883                                                EVT) const {
884   return MVT::getIntegerVT(DL.getPointerSizeInBits(0));
885 }
886 
887 EVT TargetLoweringBase::getShiftAmountTy(EVT LHSTy,
888                                          const DataLayout &DL) const {
889   assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
890   if (LHSTy.isVector())
891     return LHSTy;
892   MVT ShiftVT = getScalarShiftAmountTy(DL, LHSTy);
893   // If any possible shift value won't fit in the prefered type, just use
894   // something safe. Assume it will be legalized when the shift is expanded.
895   if (ShiftVT.getSizeInBits() < Log2_32_Ceil(LHSTy.getSizeInBits()))
896     ShiftVT = MVT::i32;
897   assert(ShiftVT.getSizeInBits() >= Log2_32_Ceil(LHSTy.getSizeInBits()) &&
898          "ShiftVT is still too small!");
899   return ShiftVT;
900 }
901 
902 bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
903   assert(isTypeLegal(VT));
904   switch (Op) {
905   default:
906     return false;
907   case ISD::SDIV:
908   case ISD::UDIV:
909   case ISD::SREM:
910   case ISD::UREM:
911     return true;
912   }
913 }
914 
915 bool TargetLoweringBase::isFreeAddrSpaceCast(unsigned SrcAS,
916                                              unsigned DestAS) const {
917   return TM.isNoopAddrSpaceCast(SrcAS, DestAS);
918 }
919 
920 unsigned TargetLoweringBase::getBitWidthForCttzElements(
921     Type *RetTy, ElementCount EC, bool ZeroIsPoison,
922     const ConstantRange *VScaleRange) const {
923   // Find the smallest "sensible" element type to use for the expansion.
924   ConstantRange CR(APInt(64, EC.getKnownMinValue()));
925   if (EC.isScalable())
926     CR = CR.umul_sat(*VScaleRange);
927 
928   if (ZeroIsPoison)
929     CR = CR.subtract(APInt(64, 1));
930 
931   unsigned EltWidth = RetTy->getScalarSizeInBits();
932   EltWidth = std::min(EltWidth, (unsigned)CR.getActiveBits());
933   EltWidth = std::max(llvm::bit_ceil(EltWidth), (unsigned)8);
934 
935   return EltWidth;
936 }
937 
938 void TargetLoweringBase::setJumpIsExpensive(bool isExpensive) {
939   // If the command-line option was specified, ignore this request.
940   if (!JumpIsExpensiveOverride.getNumOccurrences())
941     JumpIsExpensive = isExpensive;
942 }
943 
944 TargetLoweringBase::LegalizeKind
945 TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
946   // If this is a simple type, use the ComputeRegisterProp mechanism.
947   if (VT.isSimple()) {
948     MVT SVT = VT.getSimpleVT();
949     assert((unsigned)SVT.SimpleTy < std::size(TransformToType));
950     MVT NVT = TransformToType[SVT.SimpleTy];
951     LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
952 
953     assert((LA == TypeLegal || LA == TypeSoftenFloat ||
954             LA == TypeSoftPromoteHalf ||
955             (NVT.isVector() ||
956              ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger)) &&
957            "Promote may not follow Expand or Promote");
958 
959     if (LA == TypeSplitVector)
960       return LegalizeKind(LA, EVT(SVT).getHalfNumVectorElementsVT(Context));
961     if (LA == TypeScalarizeVector)
962       return LegalizeKind(LA, SVT.getVectorElementType());
963     return LegalizeKind(LA, NVT);
964   }
965 
966   // Handle Extended Scalar Types.
967   if (!VT.isVector()) {
968     assert(VT.isInteger() && "Float types must be simple");
969     unsigned BitSize = VT.getSizeInBits();
970     // First promote to a power-of-two size, then expand if necessary.
971     if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
972       EVT NVT = VT.getRoundIntegerType(Context);
973       assert(NVT != VT && "Unable to round integer VT");
974       LegalizeKind NextStep = getTypeConversion(Context, NVT);
975       // Avoid multi-step promotion.
976       if (NextStep.first == TypePromoteInteger)
977         return NextStep;
978       // Return rounded integer type.
979       return LegalizeKind(TypePromoteInteger, NVT);
980     }
981 
982     return LegalizeKind(TypeExpandInteger,
983                         EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
984   }
985 
986   // Handle vector types.
987   ElementCount NumElts = VT.getVectorElementCount();
988   EVT EltVT = VT.getVectorElementType();
989 
990   // Vectors with only one element are always scalarized.
991   if (NumElts.isScalar())
992     return LegalizeKind(TypeScalarizeVector, EltVT);
993 
994   // Try to widen vector elements until the element type is a power of two and
995   // promote it to a legal type later on, for example:
996   // <3 x i8> -> <4 x i8> -> <4 x i32>
997   if (EltVT.isInteger()) {
998     // Vectors with a number of elements that is not a power of two are always
999     // widened, for example <3 x i8> -> <4 x i8>.
1000     if (!VT.isPow2VectorType()) {
1001       NumElts = NumElts.coefficientNextPowerOf2();
1002       EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
1003       return LegalizeKind(TypeWidenVector, NVT);
1004     }
1005 
1006     // Examine the element type.
1007     LegalizeKind LK = getTypeConversion(Context, EltVT);
1008 
1009     // If type is to be expanded, split the vector.
1010     //  <4 x i140> -> <2 x i140>
1011     if (LK.first == TypeExpandInteger) {
1012       if (VT.getVectorElementCount().isScalable())
1013         return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1014       return LegalizeKind(TypeSplitVector,
1015                           VT.getHalfNumVectorElementsVT(Context));
1016     }
1017 
1018     // Promote the integer element types until a legal vector type is found
1019     // or until the element integer type is too big. If a legal type was not
1020     // found, fallback to the usual mechanism of widening/splitting the
1021     // vector.
1022     EVT OldEltVT = EltVT;
1023     while (true) {
1024       // Increase the bitwidth of the element to the next pow-of-two
1025       // (which is greater than 8 bits).
1026       EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
1027                   .getRoundIntegerType(Context);
1028 
1029       // Stop trying when getting a non-simple element type.
1030       // Note that vector elements may be greater than legal vector element
1031       // types. Example: X86 XMM registers hold 64bit element on 32bit
1032       // systems.
1033       if (!EltVT.isSimple())
1034         break;
1035 
1036       // Build a new vector type and check if it is legal.
1037       MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1038       // Found a legal promoted vector type.
1039       if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
1040         return LegalizeKind(TypePromoteInteger,
1041                             EVT::getVectorVT(Context, EltVT, NumElts));
1042     }
1043 
1044     // Reset the type to the unexpanded type if we did not find a legal vector
1045     // type with a promoted vector element type.
1046     EltVT = OldEltVT;
1047   }
1048 
1049   // Try to widen the vector until a legal type is found.
1050   // If there is no wider legal type, split the vector.
1051   while (true) {
1052     // Round up to the next power of 2.
1053     NumElts = NumElts.coefficientNextPowerOf2();
1054 
1055     // If there is no simple vector type with this many elements then there
1056     // cannot be a larger legal vector type.  Note that this assumes that
1057     // there are no skipped intermediate vector types in the simple types.
1058     if (!EltVT.isSimple())
1059       break;
1060     MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1061     if (LargerVector == MVT())
1062       break;
1063 
1064     // If this type is legal then widen the vector.
1065     if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
1066       return LegalizeKind(TypeWidenVector, LargerVector);
1067   }
1068 
1069   // Widen odd vectors to next power of two.
1070   if (!VT.isPow2VectorType()) {
1071     EVT NVT = VT.getPow2VectorType(Context);
1072     return LegalizeKind(TypeWidenVector, NVT);
1073   }
1074 
1075   if (VT.getVectorElementCount() == ElementCount::getScalable(1))
1076     return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1077 
1078   // Vectors with illegal element types are expanded.
1079   EVT NVT = EVT::getVectorVT(Context, EltVT,
1080                              VT.getVectorElementCount().divideCoefficientBy(2));
1081   return LegalizeKind(TypeSplitVector, NVT);
1082 }
1083 
1084 static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
1085                                           unsigned &NumIntermediates,
1086                                           MVT &RegisterVT,
1087                                           TargetLoweringBase *TLI) {
1088   // Figure out the right, legal destination reg to copy into.
1089   ElementCount EC = VT.getVectorElementCount();
1090   MVT EltTy = VT.getVectorElementType();
1091 
1092   unsigned NumVectorRegs = 1;
1093 
1094   // Scalable vectors cannot be scalarized, so splitting or widening is
1095   // required.
1096   if (VT.isScalableVector() && !isPowerOf2_32(EC.getKnownMinValue()))
1097     llvm_unreachable(
1098         "Splitting or widening of non-power-of-2 MVTs is not implemented.");
1099 
1100   // FIXME: We don't support non-power-of-2-sized vectors for now.
1101   // Ideally we could break down into LHS/RHS like LegalizeDAG does.
1102   if (!isPowerOf2_32(EC.getKnownMinValue())) {
1103     // Split EC to unit size (scalable property is preserved).
1104     NumVectorRegs = EC.getKnownMinValue();
1105     EC = ElementCount::getFixed(1);
1106   }
1107 
1108   // Divide the input until we get to a supported size. This will
1109   // always end up with an EC that represent a scalar or a scalable
1110   // scalar.
1111   while (EC.getKnownMinValue() > 1 &&
1112          !TLI->isTypeLegal(MVT::getVectorVT(EltTy, EC))) {
1113     EC = EC.divideCoefficientBy(2);
1114     NumVectorRegs <<= 1;
1115   }
1116 
1117   NumIntermediates = NumVectorRegs;
1118 
1119   MVT NewVT = MVT::getVectorVT(EltTy, EC);
1120   if (!TLI->isTypeLegal(NewVT))
1121     NewVT = EltTy;
1122   IntermediateVT = NewVT;
1123 
1124   unsigned LaneSizeInBits = NewVT.getScalarSizeInBits();
1125 
1126   // Convert sizes such as i33 to i64.
1127   LaneSizeInBits = llvm::bit_ceil(LaneSizeInBits);
1128 
1129   MVT DestVT = TLI->getRegisterType(NewVT);
1130   RegisterVT = DestVT;
1131   if (EVT(DestVT).bitsLT(NewVT))    // Value is expanded, e.g. i64 -> i16.
1132     return NumVectorRegs * (LaneSizeInBits / DestVT.getScalarSizeInBits());
1133 
1134   // Otherwise, promotion or legal types use the same number of registers as
1135   // the vector decimated to the appropriate level.
1136   return NumVectorRegs;
1137 }
1138 
1139 /// isLegalRC - Return true if the value types that can be represented by the
1140 /// specified register class are all legal.
1141 bool TargetLoweringBase::isLegalRC(const TargetRegisterInfo &TRI,
1142                                    const TargetRegisterClass &RC) const {
1143   for (const auto *I = TRI.legalclasstypes_begin(RC); *I != MVT::Other; ++I)
1144     if (isTypeLegal(*I))
1145       return true;
1146   return false;
1147 }
1148 
1149 /// Replace/modify any TargetFrameIndex operands with a targte-dependent
1150 /// sequence of memory operands that is recognized by PrologEpilogInserter.
1151 MachineBasicBlock *
1152 TargetLoweringBase::emitPatchPoint(MachineInstr &InitialMI,
1153                                    MachineBasicBlock *MBB) const {
1154   MachineInstr *MI = &InitialMI;
1155   MachineFunction &MF = *MI->getMF();
1156   MachineFrameInfo &MFI = MF.getFrameInfo();
1157 
1158   // We're handling multiple types of operands here:
1159   // PATCHPOINT MetaArgs - live-in, read only, direct
1160   // STATEPOINT Deopt Spill - live-through, read only, indirect
1161   // STATEPOINT Deopt Alloca - live-through, read only, direct
1162   // (We're currently conservative and mark the deopt slots read/write in
1163   // practice.)
1164   // STATEPOINT GC Spill - live-through, read/write, indirect
1165   // STATEPOINT GC Alloca - live-through, read/write, direct
1166   // The live-in vs live-through is handled already (the live through ones are
1167   // all stack slots), but we need to handle the different type of stackmap
1168   // operands and memory effects here.
1169 
1170   if (llvm::none_of(MI->operands(),
1171                     [](MachineOperand &Operand) { return Operand.isFI(); }))
1172     return MBB;
1173 
1174   MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), MI->getDesc());
1175 
1176   // Inherit previous memory operands.
1177   MIB.cloneMemRefs(*MI);
1178 
1179   for (unsigned i = 0; i < MI->getNumOperands(); ++i) {
1180     MachineOperand &MO = MI->getOperand(i);
1181     if (!MO.isFI()) {
1182       // Index of Def operand this Use it tied to.
1183       // Since Defs are coming before Uses, if Use is tied, then
1184       // index of Def must be smaller that index of that Use.
1185       // Also, Defs preserve their position in new MI.
1186       unsigned TiedTo = i;
1187       if (MO.isReg() && MO.isTied())
1188         TiedTo = MI->findTiedOperandIdx(i);
1189       MIB.add(MO);
1190       if (TiedTo < i)
1191         MIB->tieOperands(TiedTo, MIB->getNumOperands() - 1);
1192       continue;
1193     }
1194 
1195     // foldMemoryOperand builds a new MI after replacing a single FI operand
1196     // with the canonical set of five x86 addressing-mode operands.
1197     int FI = MO.getIndex();
1198 
1199     // Add frame index operands recognized by stackmaps.cpp
1200     if (MFI.isStatepointSpillSlotObjectIndex(FI)) {
1201       // indirect-mem-ref tag, size, #FI, offset.
1202       // Used for spills inserted by StatepointLowering.  This codepath is not
1203       // used for patchpoints/stackmaps at all, for these spilling is done via
1204       // foldMemoryOperand callback only.
1205       assert(MI->getOpcode() == TargetOpcode::STATEPOINT && "sanity");
1206       MIB.addImm(StackMaps::IndirectMemRefOp);
1207       MIB.addImm(MFI.getObjectSize(FI));
1208       MIB.add(MO);
1209       MIB.addImm(0);
1210     } else {
1211       // direct-mem-ref tag, #FI, offset.
1212       // Used by patchpoint, and direct alloca arguments to statepoints
1213       MIB.addImm(StackMaps::DirectMemRefOp);
1214       MIB.add(MO);
1215       MIB.addImm(0);
1216     }
1217 
1218     assert(MIB->mayLoad() && "Folded a stackmap use to a non-load!");
1219 
1220     // Add a new memory operand for this FI.
1221     assert(MFI.getObjectOffset(FI) != -1);
1222 
1223     // Note: STATEPOINT MMOs are added during SelectionDAG.  STACKMAP, and
1224     // PATCHPOINT should be updated to do the same. (TODO)
1225     if (MI->getOpcode() != TargetOpcode::STATEPOINT) {
1226       auto Flags = MachineMemOperand::MOLoad;
1227       MachineMemOperand *MMO = MF.getMachineMemOperand(
1228           MachinePointerInfo::getFixedStack(MF, FI), Flags,
1229           MF.getDataLayout().getPointerSize(), MFI.getObjectAlign(FI));
1230       MIB->addMemOperand(MF, MMO);
1231     }
1232   }
1233   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1234   MI->eraseFromParent();
1235   return MBB;
1236 }
1237 
1238 /// findRepresentativeClass - Return the largest legal super-reg register class
1239 /// of the register class for the specified type and its associated "cost".
1240 // This function is in TargetLowering because it uses RegClassForVT which would
1241 // need to be moved to TargetRegisterInfo and would necessitate moving
1242 // isTypeLegal over as well - a massive change that would just require
1243 // TargetLowering having a TargetRegisterInfo class member that it would use.
1244 std::pair<const TargetRegisterClass *, uint8_t>
1245 TargetLoweringBase::findRepresentativeClass(const TargetRegisterInfo *TRI,
1246                                             MVT VT) const {
1247   const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
1248   if (!RC)
1249     return std::make_pair(RC, 0);
1250 
1251   // Compute the set of all super-register classes.
1252   BitVector SuperRegRC(TRI->getNumRegClasses());
1253   for (SuperRegClassIterator RCI(RC, TRI); RCI.isValid(); ++RCI)
1254     SuperRegRC.setBitsInMask(RCI.getMask());
1255 
1256   // Find the first legal register class with the largest spill size.
1257   const TargetRegisterClass *BestRC = RC;
1258   for (unsigned i : SuperRegRC.set_bits()) {
1259     const TargetRegisterClass *SuperRC = TRI->getRegClass(i);
1260     // We want the largest possible spill size.
1261     if (TRI->getSpillSize(*SuperRC) <= TRI->getSpillSize(*BestRC))
1262       continue;
1263     if (!isLegalRC(*TRI, *SuperRC))
1264       continue;
1265     BestRC = SuperRC;
1266   }
1267   return std::make_pair(BestRC, 1);
1268 }
1269 
1270 /// computeRegisterProperties - Once all of the register classes are added,
1271 /// this allows us to compute derived properties we expose.
1272 void TargetLoweringBase::computeRegisterProperties(
1273     const TargetRegisterInfo *TRI) {
1274   // Everything defaults to needing one register.
1275   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1276     NumRegistersForVT[i] = 1;
1277     RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
1278   }
1279   // ...except isVoid, which doesn't need any registers.
1280   NumRegistersForVT[MVT::isVoid] = 0;
1281 
1282   // Find the largest integer register class.
1283   unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
1284   for (; RegClassForVT[LargestIntReg] == nullptr; --LargestIntReg)
1285     assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
1286 
1287   // Every integer value type larger than this largest register takes twice as
1288   // many registers to represent as the previous ValueType.
1289   for (unsigned ExpandedReg = LargestIntReg + 1;
1290        ExpandedReg <= MVT::LAST_INTEGER_VALUETYPE; ++ExpandedReg) {
1291     NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
1292     RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
1293     TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
1294     ValueTypeActions.setTypeAction((MVT::SimpleValueType)ExpandedReg,
1295                                    TypeExpandInteger);
1296   }
1297 
1298   // Inspect all of the ValueType's smaller than the largest integer
1299   // register to see which ones need promotion.
1300   unsigned LegalIntReg = LargestIntReg;
1301   for (unsigned IntReg = LargestIntReg - 1;
1302        IntReg >= (unsigned)MVT::i1; --IntReg) {
1303     MVT IVT = (MVT::SimpleValueType)IntReg;
1304     if (isTypeLegal(IVT)) {
1305       LegalIntReg = IntReg;
1306     } else {
1307       RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
1308         (MVT::SimpleValueType)LegalIntReg;
1309       ValueTypeActions.setTypeAction(IVT, TypePromoteInteger);
1310     }
1311   }
1312 
1313   // ppcf128 type is really two f64's.
1314   if (!isTypeLegal(MVT::ppcf128)) {
1315     if (isTypeLegal(MVT::f64)) {
1316       NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
1317       RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
1318       TransformToType[MVT::ppcf128] = MVT::f64;
1319       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat);
1320     } else {
1321       NumRegistersForVT[MVT::ppcf128] = NumRegistersForVT[MVT::i128];
1322       RegisterTypeForVT[MVT::ppcf128] = RegisterTypeForVT[MVT::i128];
1323       TransformToType[MVT::ppcf128] = MVT::i128;
1324       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeSoftenFloat);
1325     }
1326   }
1327 
1328   // Decide how to handle f128. If the target does not have native f128 support,
1329   // expand it to i128 and we will be generating soft float library calls.
1330   if (!isTypeLegal(MVT::f128)) {
1331     NumRegistersForVT[MVT::f128] = NumRegistersForVT[MVT::i128];
1332     RegisterTypeForVT[MVT::f128] = RegisterTypeForVT[MVT::i128];
1333     TransformToType[MVT::f128] = MVT::i128;
1334     ValueTypeActions.setTypeAction(MVT::f128, TypeSoftenFloat);
1335   }
1336 
1337   // Decide how to handle f80. If the target does not have native f80 support,
1338   // expand it to i96 and we will be generating soft float library calls.
1339   if (!isTypeLegal(MVT::f80)) {
1340     NumRegistersForVT[MVT::f80] = 3*NumRegistersForVT[MVT::i32];
1341     RegisterTypeForVT[MVT::f80] = RegisterTypeForVT[MVT::i32];
1342     TransformToType[MVT::f80] = MVT::i32;
1343     ValueTypeActions.setTypeAction(MVT::f80, TypeSoftenFloat);
1344   }
1345 
1346   // Decide how to handle f64. If the target does not have native f64 support,
1347   // expand it to i64 and we will be generating soft float library calls.
1348   if (!isTypeLegal(MVT::f64)) {
1349     NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
1350     RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
1351     TransformToType[MVT::f64] = MVT::i64;
1352     ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat);
1353   }
1354 
1355   // Decide how to handle f32. If the target does not have native f32 support,
1356   // expand it to i32 and we will be generating soft float library calls.
1357   if (!isTypeLegal(MVT::f32)) {
1358     NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
1359     RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
1360     TransformToType[MVT::f32] = MVT::i32;
1361     ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat);
1362   }
1363 
1364   // Decide how to handle f16. If the target does not have native f16 support,
1365   // promote it to f32, because there are no f16 library calls (except for
1366   // conversions).
1367   if (!isTypeLegal(MVT::f16)) {
1368     // Allow targets to control how we legalize half.
1369     bool SoftPromoteHalfType = softPromoteHalfType();
1370     bool UseFPRegsForHalfType = !SoftPromoteHalfType || useFPRegsForHalfType();
1371 
1372     if (!UseFPRegsForHalfType) {
1373       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::i16];
1374       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::i16];
1375     } else {
1376       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::f32];
1377       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::f32];
1378     }
1379     TransformToType[MVT::f16] = MVT::f32;
1380     if (SoftPromoteHalfType) {
1381       ValueTypeActions.setTypeAction(MVT::f16, TypeSoftPromoteHalf);
1382     } else {
1383       ValueTypeActions.setTypeAction(MVT::f16, TypePromoteFloat);
1384     }
1385   }
1386 
1387   // Decide how to handle bf16. If the target does not have native bf16 support,
1388   // promote it to f32, because there are no bf16 library calls (except for
1389   // converting from f32 to bf16).
1390   if (!isTypeLegal(MVT::bf16)) {
1391     NumRegistersForVT[MVT::bf16] = NumRegistersForVT[MVT::f32];
1392     RegisterTypeForVT[MVT::bf16] = RegisterTypeForVT[MVT::f32];
1393     TransformToType[MVT::bf16] = MVT::f32;
1394     ValueTypeActions.setTypeAction(MVT::bf16, TypeSoftPromoteHalf);
1395   }
1396 
1397   // Loop over all of the vector value types to see which need transformations.
1398   for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
1399        i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
1400     MVT VT = (MVT::SimpleValueType) i;
1401     if (isTypeLegal(VT))
1402       continue;
1403 
1404     MVT EltVT = VT.getVectorElementType();
1405     ElementCount EC = VT.getVectorElementCount();
1406     bool IsLegalWiderType = false;
1407     bool IsScalable = VT.isScalableVector();
1408     LegalizeTypeAction PreferredAction = getPreferredVectorAction(VT);
1409     switch (PreferredAction) {
1410     case TypePromoteInteger: {
1411       MVT::SimpleValueType EndVT = IsScalable ?
1412                                    MVT::LAST_INTEGER_SCALABLE_VECTOR_VALUETYPE :
1413                                    MVT::LAST_INTEGER_FIXEDLEN_VECTOR_VALUETYPE;
1414       // Try to promote the elements of integer vectors. If no legal
1415       // promotion was found, fall through to the widen-vector method.
1416       for (unsigned nVT = i + 1;
1417            (MVT::SimpleValueType)nVT <= EndVT; ++nVT) {
1418         MVT SVT = (MVT::SimpleValueType) nVT;
1419         // Promote vectors of integers to vectors with the same number
1420         // of elements, with a wider element type.
1421         if (SVT.getScalarSizeInBits() > EltVT.getFixedSizeInBits() &&
1422             SVT.getVectorElementCount() == EC && isTypeLegal(SVT)) {
1423           TransformToType[i] = SVT;
1424           RegisterTypeForVT[i] = SVT;
1425           NumRegistersForVT[i] = 1;
1426           ValueTypeActions.setTypeAction(VT, TypePromoteInteger);
1427           IsLegalWiderType = true;
1428           break;
1429         }
1430       }
1431       if (IsLegalWiderType)
1432         break;
1433       [[fallthrough]];
1434     }
1435 
1436     case TypeWidenVector:
1437       if (isPowerOf2_32(EC.getKnownMinValue())) {
1438         // Try to widen the vector.
1439         for (unsigned nVT = i + 1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
1440           MVT SVT = (MVT::SimpleValueType) nVT;
1441           if (SVT.getVectorElementType() == EltVT &&
1442               SVT.isScalableVector() == IsScalable &&
1443               SVT.getVectorElementCount().getKnownMinValue() >
1444                   EC.getKnownMinValue() &&
1445               isTypeLegal(SVT)) {
1446             TransformToType[i] = SVT;
1447             RegisterTypeForVT[i] = SVT;
1448             NumRegistersForVT[i] = 1;
1449             ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1450             IsLegalWiderType = true;
1451             break;
1452           }
1453         }
1454         if (IsLegalWiderType)
1455           break;
1456       } else {
1457         // Only widen to the next power of 2 to keep consistency with EVT.
1458         MVT NVT = VT.getPow2VectorType();
1459         if (isTypeLegal(NVT)) {
1460           TransformToType[i] = NVT;
1461           ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1462           RegisterTypeForVT[i] = NVT;
1463           NumRegistersForVT[i] = 1;
1464           break;
1465         }
1466       }
1467       [[fallthrough]];
1468 
1469     case TypeSplitVector:
1470     case TypeScalarizeVector: {
1471       MVT IntermediateVT;
1472       MVT RegisterVT;
1473       unsigned NumIntermediates;
1474       unsigned NumRegisters = getVectorTypeBreakdownMVT(VT, IntermediateVT,
1475           NumIntermediates, RegisterVT, this);
1476       NumRegistersForVT[i] = NumRegisters;
1477       assert(NumRegistersForVT[i] == NumRegisters &&
1478              "NumRegistersForVT size cannot represent NumRegisters!");
1479       RegisterTypeForVT[i] = RegisterVT;
1480 
1481       MVT NVT = VT.getPow2VectorType();
1482       if (NVT == VT) {
1483         // Type is already a power of 2.  The default action is to split.
1484         TransformToType[i] = MVT::Other;
1485         if (PreferredAction == TypeScalarizeVector)
1486           ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
1487         else if (PreferredAction == TypeSplitVector)
1488           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1489         else if (EC.getKnownMinValue() > 1)
1490           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1491         else
1492           ValueTypeActions.setTypeAction(VT, EC.isScalable()
1493                                                  ? TypeScalarizeScalableVector
1494                                                  : TypeScalarizeVector);
1495       } else {
1496         TransformToType[i] = NVT;
1497         ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1498       }
1499       break;
1500     }
1501     default:
1502       llvm_unreachable("Unknown vector legalization action!");
1503     }
1504   }
1505 
1506   // Determine the 'representative' register class for each value type.
1507   // An representative register class is the largest (meaning one which is
1508   // not a sub-register class / subreg register class) legal register class for
1509   // a group of value types. For example, on i386, i8, i16, and i32
1510   // representative would be GR32; while on x86_64 it's GR64.
1511   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1512     const TargetRegisterClass* RRC;
1513     uint8_t Cost;
1514     std::tie(RRC, Cost) = findRepresentativeClass(TRI, (MVT::SimpleValueType)i);
1515     RepRegClassForVT[i] = RRC;
1516     RepRegClassCostForVT[i] = Cost;
1517   }
1518 }
1519 
1520 EVT TargetLoweringBase::getSetCCResultType(const DataLayout &DL, LLVMContext &,
1521                                            EVT VT) const {
1522   assert(!VT.isVector() && "No default SetCC type for vectors!");
1523   return getPointerTy(DL).SimpleTy;
1524 }
1525 
1526 MVT::SimpleValueType TargetLoweringBase::getCmpLibcallReturnType() const {
1527   return MVT::i32; // return the default value
1528 }
1529 
1530 /// getVectorTypeBreakdown - Vector types are broken down into some number of
1531 /// legal first class types.  For example, MVT::v8f32 maps to 2 MVT::v4f32
1532 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
1533 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
1534 ///
1535 /// This method returns the number of registers needed, and the VT for each
1536 /// register.  It also returns the VT and quantity of the intermediate values
1537 /// before they are promoted/expanded.
1538 unsigned TargetLoweringBase::getVectorTypeBreakdown(LLVMContext &Context,
1539                                                     EVT VT, EVT &IntermediateVT,
1540                                                     unsigned &NumIntermediates,
1541                                                     MVT &RegisterVT) const {
1542   ElementCount EltCnt = VT.getVectorElementCount();
1543 
1544   // If there is a wider vector type with the same element type as this one,
1545   // or a promoted vector type that has the same number of elements which
1546   // are wider, then we should convert to that legal vector type.
1547   // This handles things like <2 x float> -> <4 x float> and
1548   // <4 x i1> -> <4 x i32>.
1549   LegalizeTypeAction TA = getTypeAction(Context, VT);
1550   if (!EltCnt.isScalar() &&
1551       (TA == TypeWidenVector || TA == TypePromoteInteger)) {
1552     EVT RegisterEVT = getTypeToTransformTo(Context, VT);
1553     if (isTypeLegal(RegisterEVT)) {
1554       IntermediateVT = RegisterEVT;
1555       RegisterVT = RegisterEVT.getSimpleVT();
1556       NumIntermediates = 1;
1557       return 1;
1558     }
1559   }
1560 
1561   // Figure out the right, legal destination reg to copy into.
1562   EVT EltTy = VT.getVectorElementType();
1563 
1564   unsigned NumVectorRegs = 1;
1565 
1566   // Scalable vectors cannot be scalarized, so handle the legalisation of the
1567   // types like done elsewhere in SelectionDAG.
1568   if (EltCnt.isScalable()) {
1569     LegalizeKind LK;
1570     EVT PartVT = VT;
1571     do {
1572       // Iterate until we've found a legal (part) type to hold VT.
1573       LK = getTypeConversion(Context, PartVT);
1574       PartVT = LK.second;
1575     } while (LK.first != TypeLegal);
1576 
1577     if (!PartVT.isVector()) {
1578       report_fatal_error(
1579           "Don't know how to legalize this scalable vector type");
1580     }
1581 
1582     NumIntermediates =
1583         divideCeil(VT.getVectorElementCount().getKnownMinValue(),
1584                    PartVT.getVectorElementCount().getKnownMinValue());
1585     IntermediateVT = PartVT;
1586     RegisterVT = getRegisterType(Context, IntermediateVT);
1587     return NumIntermediates;
1588   }
1589 
1590   // FIXME: We don't support non-power-of-2-sized vectors for now.  Ideally
1591   // we could break down into LHS/RHS like LegalizeDAG does.
1592   if (!isPowerOf2_32(EltCnt.getKnownMinValue())) {
1593     NumVectorRegs = EltCnt.getKnownMinValue();
1594     EltCnt = ElementCount::getFixed(1);
1595   }
1596 
1597   // Divide the input until we get to a supported size.  This will always
1598   // end with a scalar if the target doesn't support vectors.
1599   while (EltCnt.getKnownMinValue() > 1 &&
1600          !isTypeLegal(EVT::getVectorVT(Context, EltTy, EltCnt))) {
1601     EltCnt = EltCnt.divideCoefficientBy(2);
1602     NumVectorRegs <<= 1;
1603   }
1604 
1605   NumIntermediates = NumVectorRegs;
1606 
1607   EVT NewVT = EVT::getVectorVT(Context, EltTy, EltCnt);
1608   if (!isTypeLegal(NewVT))
1609     NewVT = EltTy;
1610   IntermediateVT = NewVT;
1611 
1612   MVT DestVT = getRegisterType(Context, NewVT);
1613   RegisterVT = DestVT;
1614 
1615   if (EVT(DestVT).bitsLT(NewVT)) {  // Value is expanded, e.g. i64 -> i16.
1616     TypeSize NewVTSize = NewVT.getSizeInBits();
1617     // Convert sizes such as i33 to i64.
1618     if (!llvm::has_single_bit<uint32_t>(NewVTSize.getKnownMinValue()))
1619       NewVTSize = NewVTSize.coefficientNextPowerOf2();
1620     return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
1621   }
1622 
1623   // Otherwise, promotion or legal types use the same number of registers as
1624   // the vector decimated to the appropriate level.
1625   return NumVectorRegs;
1626 }
1627 
1628 bool TargetLoweringBase::isSuitableForJumpTable(const SwitchInst *SI,
1629                                                 uint64_t NumCases,
1630                                                 uint64_t Range,
1631                                                 ProfileSummaryInfo *PSI,
1632                                                 BlockFrequencyInfo *BFI) const {
1633   // FIXME: This function check the maximum table size and density, but the
1634   // minimum size is not checked. It would be nice if the minimum size is
1635   // also combined within this function. Currently, the minimum size check is
1636   // performed in findJumpTable() in SelectionDAGBuiler and
1637   // getEstimatedNumberOfCaseClusters() in BasicTTIImpl.
1638   const bool OptForSize =
1639       llvm::shouldOptimizeForSize(SI->getParent(), PSI, BFI);
1640   const unsigned MinDensity = getMinimumJumpTableDensity(OptForSize);
1641   const unsigned MaxJumpTableSize = getMaximumJumpTableSize();
1642 
1643   // Check whether the number of cases is small enough and
1644   // the range is dense enough for a jump table.
1645   return (OptForSize || Range <= MaxJumpTableSize) &&
1646          (NumCases * 100 >= Range * MinDensity);
1647 }
1648 
1649 MVT TargetLoweringBase::getPreferredSwitchConditionType(LLVMContext &Context,
1650                                                         EVT ConditionVT) const {
1651   return getRegisterType(Context, ConditionVT);
1652 }
1653 
1654 /// Get the EVTs and ArgFlags collections that represent the legalized return
1655 /// type of the given function.  This does not require a DAG or a return value,
1656 /// and is suitable for use before any DAGs for the function are constructed.
1657 /// TODO: Move this out of TargetLowering.cpp.
1658 void llvm::GetReturnInfo(CallingConv::ID CC, Type *ReturnType,
1659                          AttributeList attr,
1660                          SmallVectorImpl<ISD::OutputArg> &Outs,
1661                          const TargetLowering &TLI, const DataLayout &DL) {
1662   SmallVector<EVT, 4> ValueVTs;
1663   ComputeValueVTs(TLI, DL, ReturnType, ValueVTs);
1664   unsigned NumValues = ValueVTs.size();
1665   if (NumValues == 0) return;
1666 
1667   for (unsigned j = 0, f = NumValues; j != f; ++j) {
1668     EVT VT = ValueVTs[j];
1669     ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
1670 
1671     if (attr.hasRetAttr(Attribute::SExt))
1672       ExtendKind = ISD::SIGN_EXTEND;
1673     else if (attr.hasRetAttr(Attribute::ZExt))
1674       ExtendKind = ISD::ZERO_EXTEND;
1675 
1676     if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger())
1677       VT = TLI.getTypeForExtReturn(ReturnType->getContext(), VT, ExtendKind);
1678 
1679     unsigned NumParts =
1680         TLI.getNumRegistersForCallingConv(ReturnType->getContext(), CC, VT);
1681     MVT PartVT =
1682         TLI.getRegisterTypeForCallingConv(ReturnType->getContext(), CC, VT);
1683 
1684     // 'inreg' on function refers to return value
1685     ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
1686     if (attr.hasRetAttr(Attribute::InReg))
1687       Flags.setInReg();
1688 
1689     // Propagate extension type if any
1690     if (attr.hasRetAttr(Attribute::SExt))
1691       Flags.setSExt();
1692     else if (attr.hasRetAttr(Attribute::ZExt))
1693       Flags.setZExt();
1694 
1695     for (unsigned i = 0; i < NumParts; ++i)
1696       Outs.push_back(ISD::OutputArg(Flags, PartVT, VT, /*isfixed=*/true, 0, 0));
1697   }
1698 }
1699 
1700 Align TargetLoweringBase::getByValTypeAlignment(Type *Ty,
1701                                                 const DataLayout &DL) const {
1702   return DL.getABITypeAlign(Ty);
1703 }
1704 
1705 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1706     LLVMContext &Context, const DataLayout &DL, EVT VT, unsigned AddrSpace,
1707     Align Alignment, MachineMemOperand::Flags Flags, unsigned *Fast) const {
1708   // Check if the specified alignment is sufficient based on the data layout.
1709   // TODO: While using the data layout works in practice, a better solution
1710   // would be to implement this check directly (make this a virtual function).
1711   // For example, the ABI alignment may change based on software platform while
1712   // this function should only be affected by hardware implementation.
1713   Type *Ty = VT.getTypeForEVT(Context);
1714   if (VT.isZeroSized() || Alignment >= DL.getABITypeAlign(Ty)) {
1715     // Assume that an access that meets the ABI-specified alignment is fast.
1716     if (Fast != nullptr)
1717       *Fast = 1;
1718     return true;
1719   }
1720 
1721   // This is a misaligned access.
1722   return allowsMisalignedMemoryAccesses(VT, AddrSpace, Alignment, Flags, Fast);
1723 }
1724 
1725 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1726     LLVMContext &Context, const DataLayout &DL, EVT VT,
1727     const MachineMemOperand &MMO, unsigned *Fast) const {
1728   return allowsMemoryAccessForAlignment(Context, DL, VT, MMO.getAddrSpace(),
1729                                         MMO.getAlign(), MMO.getFlags(), Fast);
1730 }
1731 
1732 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1733                                             const DataLayout &DL, EVT VT,
1734                                             unsigned AddrSpace, Align Alignment,
1735                                             MachineMemOperand::Flags Flags,
1736                                             unsigned *Fast) const {
1737   return allowsMemoryAccessForAlignment(Context, DL, VT, AddrSpace, Alignment,
1738                                         Flags, Fast);
1739 }
1740 
1741 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1742                                             const DataLayout &DL, EVT VT,
1743                                             const MachineMemOperand &MMO,
1744                                             unsigned *Fast) const {
1745   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1746                             MMO.getFlags(), Fast);
1747 }
1748 
1749 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1750                                             const DataLayout &DL, LLT Ty,
1751                                             const MachineMemOperand &MMO,
1752                                             unsigned *Fast) const {
1753   EVT VT = getApproximateEVTForLLT(Ty, Context);
1754   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1755                             MMO.getFlags(), Fast);
1756 }
1757 
1758 //===----------------------------------------------------------------------===//
1759 //  TargetTransformInfo Helpers
1760 //===----------------------------------------------------------------------===//
1761 
1762 int TargetLoweringBase::InstructionOpcodeToISD(unsigned Opcode) const {
1763   enum InstructionOpcodes {
1764 #define HANDLE_INST(NUM, OPCODE, CLASS) OPCODE = NUM,
1765 #define LAST_OTHER_INST(NUM) InstructionOpcodesCount = NUM
1766 #include "llvm/IR/Instruction.def"
1767   };
1768   switch (static_cast<InstructionOpcodes>(Opcode)) {
1769   case Ret:            return 0;
1770   case Br:             return 0;
1771   case Switch:         return 0;
1772   case IndirectBr:     return 0;
1773   case Invoke:         return 0;
1774   case CallBr:         return 0;
1775   case Resume:         return 0;
1776   case Unreachable:    return 0;
1777   case CleanupRet:     return 0;
1778   case CatchRet:       return 0;
1779   case CatchPad:       return 0;
1780   case CatchSwitch:    return 0;
1781   case CleanupPad:     return 0;
1782   case FNeg:           return ISD::FNEG;
1783   case Add:            return ISD::ADD;
1784   case FAdd:           return ISD::FADD;
1785   case Sub:            return ISD::SUB;
1786   case FSub:           return ISD::FSUB;
1787   case Mul:            return ISD::MUL;
1788   case FMul:           return ISD::FMUL;
1789   case UDiv:           return ISD::UDIV;
1790   case SDiv:           return ISD::SDIV;
1791   case FDiv:           return ISD::FDIV;
1792   case URem:           return ISD::UREM;
1793   case SRem:           return ISD::SREM;
1794   case FRem:           return ISD::FREM;
1795   case Shl:            return ISD::SHL;
1796   case LShr:           return ISD::SRL;
1797   case AShr:           return ISD::SRA;
1798   case And:            return ISD::AND;
1799   case Or:             return ISD::OR;
1800   case Xor:            return ISD::XOR;
1801   case Alloca:         return 0;
1802   case Load:           return ISD::LOAD;
1803   case Store:          return ISD::STORE;
1804   case GetElementPtr:  return 0;
1805   case Fence:          return 0;
1806   case AtomicCmpXchg:  return 0;
1807   case AtomicRMW:      return 0;
1808   case Trunc:          return ISD::TRUNCATE;
1809   case ZExt:           return ISD::ZERO_EXTEND;
1810   case SExt:           return ISD::SIGN_EXTEND;
1811   case FPToUI:         return ISD::FP_TO_UINT;
1812   case FPToSI:         return ISD::FP_TO_SINT;
1813   case UIToFP:         return ISD::UINT_TO_FP;
1814   case SIToFP:         return ISD::SINT_TO_FP;
1815   case FPTrunc:        return ISD::FP_ROUND;
1816   case FPExt:          return ISD::FP_EXTEND;
1817   case PtrToInt:       return ISD::BITCAST;
1818   case IntToPtr:       return ISD::BITCAST;
1819   case BitCast:        return ISD::BITCAST;
1820   case AddrSpaceCast:  return ISD::ADDRSPACECAST;
1821   case ICmp:           return ISD::SETCC;
1822   case FCmp:           return ISD::SETCC;
1823   case PHI:            return 0;
1824   case Call:           return 0;
1825   case Select:         return ISD::SELECT;
1826   case UserOp1:        return 0;
1827   case UserOp2:        return 0;
1828   case VAArg:          return 0;
1829   case ExtractElement: return ISD::EXTRACT_VECTOR_ELT;
1830   case InsertElement:  return ISD::INSERT_VECTOR_ELT;
1831   case ShuffleVector:  return ISD::VECTOR_SHUFFLE;
1832   case ExtractValue:   return ISD::MERGE_VALUES;
1833   case InsertValue:    return ISD::MERGE_VALUES;
1834   case LandingPad:     return 0;
1835   case Freeze:         return ISD::FREEZE;
1836   }
1837 
1838   llvm_unreachable("Unknown instruction type encountered!");
1839 }
1840 
1841 Value *
1842 TargetLoweringBase::getDefaultSafeStackPointerLocation(IRBuilderBase &IRB,
1843                                                        bool UseTLS) const {
1844   // compiler-rt provides a variable with a magic name.  Targets that do not
1845   // link with compiler-rt may also provide such a variable.
1846   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1847   const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
1848   auto UnsafeStackPtr =
1849       dyn_cast_or_null<GlobalVariable>(M->getNamedValue(UnsafeStackPtrVar));
1850 
1851   const DataLayout &DL = M->getDataLayout();
1852   PointerType *StackPtrTy = DL.getAllocaPtrType(M->getContext());
1853 
1854   if (!UnsafeStackPtr) {
1855     auto TLSModel = UseTLS ?
1856         GlobalValue::InitialExecTLSModel :
1857         GlobalValue::NotThreadLocal;
1858     // The global variable is not defined yet, define it ourselves.
1859     // We use the initial-exec TLS model because we do not support the
1860     // variable living anywhere other than in the main executable.
1861     UnsafeStackPtr = new GlobalVariable(
1862         *M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
1863         UnsafeStackPtrVar, nullptr, TLSModel);
1864   } else {
1865     // The variable exists, check its type and attributes.
1866     //
1867     // FIXME: Move to IR verifier.
1868     if (UnsafeStackPtr->getValueType() != StackPtrTy)
1869       report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
1870     if (UseTLS != UnsafeStackPtr->isThreadLocal())
1871       report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
1872                          (UseTLS ? "" : "not ") + "be thread-local");
1873   }
1874   return UnsafeStackPtr;
1875 }
1876 
1877 Value *
1878 TargetLoweringBase::getSafeStackPointerLocation(IRBuilderBase &IRB) const {
1879   if (!TM.getTargetTriple().isAndroid())
1880     return getDefaultSafeStackPointerLocation(IRB, true);
1881 
1882   // Android provides a libc function to retrieve the address of the current
1883   // thread's unsafe stack pointer.
1884   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1885   auto *PtrTy = PointerType::getUnqual(M->getContext());
1886   FunctionCallee Fn =
1887       M->getOrInsertFunction("__safestack_pointer_address", PtrTy);
1888   return IRB.CreateCall(Fn);
1889 }
1890 
1891 //===----------------------------------------------------------------------===//
1892 //  Loop Strength Reduction hooks
1893 //===----------------------------------------------------------------------===//
1894 
1895 /// isLegalAddressingMode - Return true if the addressing mode represented
1896 /// by AM is legal for this target, for a load/store of the specified type.
1897 bool TargetLoweringBase::isLegalAddressingMode(const DataLayout &DL,
1898                                                const AddrMode &AM, Type *Ty,
1899                                                unsigned AS, Instruction *I) const {
1900   // The default implementation of this implements a conservative RISCy, r+r and
1901   // r+i addr mode.
1902 
1903   // Scalable offsets not supported
1904   if (AM.ScalableOffset)
1905     return false;
1906 
1907   // Allows a sign-extended 16-bit immediate field.
1908   if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
1909     return false;
1910 
1911   // No global is ever allowed as a base.
1912   if (AM.BaseGV)
1913     return false;
1914 
1915   // Only support r+r,
1916   switch (AM.Scale) {
1917   case 0:  // "r+i" or just "i", depending on HasBaseReg.
1918     break;
1919   case 1:
1920     if (AM.HasBaseReg && AM.BaseOffs)  // "r+r+i" is not allowed.
1921       return false;
1922     // Otherwise we have r+r or r+i.
1923     break;
1924   case 2:
1925     if (AM.HasBaseReg || AM.BaseOffs)  // 2*r+r  or  2*r+i is not allowed.
1926       return false;
1927     // Allow 2*r as r+r.
1928     break;
1929   default: // Don't allow n * r
1930     return false;
1931   }
1932 
1933   return true;
1934 }
1935 
1936 //===----------------------------------------------------------------------===//
1937 //  Stack Protector
1938 //===----------------------------------------------------------------------===//
1939 
1940 // For OpenBSD return its special guard variable. Otherwise return nullptr,
1941 // so that SelectionDAG handle SSP.
1942 Value *TargetLoweringBase::getIRStackGuard(IRBuilderBase &IRB) const {
1943   if (getTargetMachine().getTargetTriple().isOSOpenBSD()) {
1944     Module &M = *IRB.GetInsertBlock()->getParent()->getParent();
1945     PointerType *PtrTy = PointerType::getUnqual(M.getContext());
1946     Constant *C = M.getOrInsertGlobal("__guard_local", PtrTy);
1947     if (GlobalVariable *G = dyn_cast_or_null<GlobalVariable>(C))
1948       G->setVisibility(GlobalValue::HiddenVisibility);
1949     return C;
1950   }
1951   return nullptr;
1952 }
1953 
1954 // Currently only support "standard" __stack_chk_guard.
1955 // TODO: add LOAD_STACK_GUARD support.
1956 void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
1957   if (!M.getNamedValue("__stack_chk_guard")) {
1958     auto *GV = new GlobalVariable(M, PointerType::getUnqual(M.getContext()),
1959                                   false, GlobalVariable::ExternalLinkage,
1960                                   nullptr, "__stack_chk_guard");
1961 
1962     // FreeBSD has "__stack_chk_guard" defined externally on libc.so
1963     if (M.getDirectAccessExternalData() &&
1964         !TM.getTargetTriple().isWindowsGNUEnvironment() &&
1965         !(TM.getTargetTriple().isPPC64() &&
1966           TM.getTargetTriple().isOSFreeBSD()) &&
1967         (!TM.getTargetTriple().isOSDarwin() ||
1968          TM.getRelocationModel() == Reloc::Static))
1969       GV->setDSOLocal(true);
1970   }
1971 }
1972 
1973 // Currently only support "standard" __stack_chk_guard.
1974 // TODO: add LOAD_STACK_GUARD support.
1975 Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
1976   return M.getNamedValue("__stack_chk_guard");
1977 }
1978 
1979 Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
1980   return nullptr;
1981 }
1982 
1983 unsigned TargetLoweringBase::getMinimumJumpTableEntries() const {
1984   return MinimumJumpTableEntries;
1985 }
1986 
1987 void TargetLoweringBase::setMinimumJumpTableEntries(unsigned Val) {
1988   MinimumJumpTableEntries = Val;
1989 }
1990 
1991 unsigned TargetLoweringBase::getMinimumJumpTableDensity(bool OptForSize) const {
1992   return OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
1993 }
1994 
1995 unsigned TargetLoweringBase::getMaximumJumpTableSize() const {
1996   return MaximumJumpTableSize;
1997 }
1998 
1999 void TargetLoweringBase::setMaximumJumpTableSize(unsigned Val) {
2000   MaximumJumpTableSize = Val;
2001 }
2002 
2003 bool TargetLoweringBase::isJumpTableRelative() const {
2004   return getTargetMachine().isPositionIndependent();
2005 }
2006 
2007 Align TargetLoweringBase::getPrefLoopAlignment(MachineLoop *ML) const {
2008   if (TM.Options.LoopAlignment)
2009     return Align(TM.Options.LoopAlignment);
2010   return PrefLoopAlignment;
2011 }
2012 
2013 unsigned TargetLoweringBase::getMaxPermittedBytesForAlignment(
2014     MachineBasicBlock *MBB) const {
2015   return MaxBytesForAlignment;
2016 }
2017 
2018 //===----------------------------------------------------------------------===//
2019 //  Reciprocal Estimates
2020 //===----------------------------------------------------------------------===//
2021 
2022 /// Get the reciprocal estimate attribute string for a function that will
2023 /// override the target defaults.
2024 static StringRef getRecipEstimateForFunc(MachineFunction &MF) {
2025   const Function &F = MF.getFunction();
2026   return F.getFnAttribute("reciprocal-estimates").getValueAsString();
2027 }
2028 
2029 /// Construct a string for the given reciprocal operation of the given type.
2030 /// This string should match the corresponding option to the front-end's
2031 /// "-mrecip" flag assuming those strings have been passed through in an
2032 /// attribute string. For example, "vec-divf" for a division of a vXf32.
2033 static std::string getReciprocalOpName(bool IsSqrt, EVT VT) {
2034   std::string Name = VT.isVector() ? "vec-" : "";
2035 
2036   Name += IsSqrt ? "sqrt" : "div";
2037 
2038   // TODO: Handle other float types?
2039   if (VT.getScalarType() == MVT::f64) {
2040     Name += "d";
2041   } else if (VT.getScalarType() == MVT::f16) {
2042     Name += "h";
2043   } else {
2044     assert(VT.getScalarType() == MVT::f32 &&
2045            "Unexpected FP type for reciprocal estimate");
2046     Name += "f";
2047   }
2048 
2049   return Name;
2050 }
2051 
2052 /// Return the character position and value (a single numeric character) of a
2053 /// customized refinement operation in the input string if it exists. Return
2054 /// false if there is no customized refinement step count.
2055 static bool parseRefinementStep(StringRef In, size_t &Position,
2056                                 uint8_t &Value) {
2057   const char RefStepToken = ':';
2058   Position = In.find(RefStepToken);
2059   if (Position == StringRef::npos)
2060     return false;
2061 
2062   StringRef RefStepString = In.substr(Position + 1);
2063   // Allow exactly one numeric character for the additional refinement
2064   // step parameter.
2065   if (RefStepString.size() == 1) {
2066     char RefStepChar = RefStepString[0];
2067     if (isDigit(RefStepChar)) {
2068       Value = RefStepChar - '0';
2069       return true;
2070     }
2071   }
2072   report_fatal_error("Invalid refinement step for -recip.");
2073 }
2074 
2075 /// For the input attribute string, return one of the ReciprocalEstimate enum
2076 /// status values (enabled, disabled, or not specified) for this operation on
2077 /// the specified data type.
2078 static int getOpEnabled(bool IsSqrt, EVT VT, StringRef Override) {
2079   if (Override.empty())
2080     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2081 
2082   SmallVector<StringRef, 4> OverrideVector;
2083   Override.split(OverrideVector, ',');
2084   unsigned NumArgs = OverrideVector.size();
2085 
2086   // Check if "all", "none", or "default" was specified.
2087   if (NumArgs == 1) {
2088     // Look for an optional setting of the number of refinement steps needed
2089     // for this type of reciprocal operation.
2090     size_t RefPos;
2091     uint8_t RefSteps;
2092     if (parseRefinementStep(Override, RefPos, RefSteps)) {
2093       // Split the string for further processing.
2094       Override = Override.substr(0, RefPos);
2095     }
2096 
2097     // All reciprocal types are enabled.
2098     if (Override == "all")
2099       return TargetLoweringBase::ReciprocalEstimate::Enabled;
2100 
2101     // All reciprocal types are disabled.
2102     if (Override == "none")
2103       return TargetLoweringBase::ReciprocalEstimate::Disabled;
2104 
2105     // Target defaults for enablement are used.
2106     if (Override == "default")
2107       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2108   }
2109 
2110   // The attribute string may omit the size suffix ('f'/'d').
2111   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2112   std::string VTNameNoSize = VTName;
2113   VTNameNoSize.pop_back();
2114   static const char DisabledPrefix = '!';
2115 
2116   for (StringRef RecipType : OverrideVector) {
2117     size_t RefPos;
2118     uint8_t RefSteps;
2119     if (parseRefinementStep(RecipType, RefPos, RefSteps))
2120       RecipType = RecipType.substr(0, RefPos);
2121 
2122     // Ignore the disablement token for string matching.
2123     bool IsDisabled = RecipType[0] == DisabledPrefix;
2124     if (IsDisabled)
2125       RecipType = RecipType.substr(1);
2126 
2127     if (RecipType == VTName || RecipType == VTNameNoSize)
2128       return IsDisabled ? TargetLoweringBase::ReciprocalEstimate::Disabled
2129                         : TargetLoweringBase::ReciprocalEstimate::Enabled;
2130   }
2131 
2132   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2133 }
2134 
2135 /// For the input attribute string, return the customized refinement step count
2136 /// for this operation on the specified data type. If the step count does not
2137 /// exist, return the ReciprocalEstimate enum value for unspecified.
2138 static int getOpRefinementSteps(bool IsSqrt, EVT VT, StringRef Override) {
2139   if (Override.empty())
2140     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2141 
2142   SmallVector<StringRef, 4> OverrideVector;
2143   Override.split(OverrideVector, ',');
2144   unsigned NumArgs = OverrideVector.size();
2145 
2146   // Check if "all", "default", or "none" was specified.
2147   if (NumArgs == 1) {
2148     // Look for an optional setting of the number of refinement steps needed
2149     // for this type of reciprocal operation.
2150     size_t RefPos;
2151     uint8_t RefSteps;
2152     if (!parseRefinementStep(Override, RefPos, RefSteps))
2153       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2154 
2155     // Split the string for further processing.
2156     Override = Override.substr(0, RefPos);
2157     assert(Override != "none" &&
2158            "Disabled reciprocals, but specifed refinement steps?");
2159 
2160     // If this is a general override, return the specified number of steps.
2161     if (Override == "all" || Override == "default")
2162       return RefSteps;
2163   }
2164 
2165   // The attribute string may omit the size suffix ('f'/'d').
2166   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2167   std::string VTNameNoSize = VTName;
2168   VTNameNoSize.pop_back();
2169 
2170   for (StringRef RecipType : OverrideVector) {
2171     size_t RefPos;
2172     uint8_t RefSteps;
2173     if (!parseRefinementStep(RecipType, RefPos, RefSteps))
2174       continue;
2175 
2176     RecipType = RecipType.substr(0, RefPos);
2177     if (RecipType == VTName || RecipType == VTNameNoSize)
2178       return RefSteps;
2179   }
2180 
2181   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2182 }
2183 
2184 int TargetLoweringBase::getRecipEstimateSqrtEnabled(EVT VT,
2185                                                     MachineFunction &MF) const {
2186   return getOpEnabled(true, VT, getRecipEstimateForFunc(MF));
2187 }
2188 
2189 int TargetLoweringBase::getRecipEstimateDivEnabled(EVT VT,
2190                                                    MachineFunction &MF) const {
2191   return getOpEnabled(false, VT, getRecipEstimateForFunc(MF));
2192 }
2193 
2194 int TargetLoweringBase::getSqrtRefinementSteps(EVT VT,
2195                                                MachineFunction &MF) const {
2196   return getOpRefinementSteps(true, VT, getRecipEstimateForFunc(MF));
2197 }
2198 
2199 int TargetLoweringBase::getDivRefinementSteps(EVT VT,
2200                                               MachineFunction &MF) const {
2201   return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
2202 }
2203 
2204 bool TargetLoweringBase::isLoadBitCastBeneficial(
2205     EVT LoadVT, EVT BitcastVT, const SelectionDAG &DAG,
2206     const MachineMemOperand &MMO) const {
2207   // Single-element vectors are scalarized, so we should generally avoid having
2208   // any memory operations on such types, as they would get scalarized too.
2209   if (LoadVT.isFixedLengthVector() && BitcastVT.isFixedLengthVector() &&
2210       BitcastVT.getVectorNumElements() == 1)
2211     return false;
2212 
2213   // Don't do if we could do an indexed load on the original type, but not on
2214   // the new one.
2215   if (!LoadVT.isSimple() || !BitcastVT.isSimple())
2216     return true;
2217 
2218   MVT LoadMVT = LoadVT.getSimpleVT();
2219 
2220   // Don't bother doing this if it's just going to be promoted again later, as
2221   // doing so might interfere with other combines.
2222   if (getOperationAction(ISD::LOAD, LoadMVT) == Promote &&
2223       getTypeToPromoteTo(ISD::LOAD, LoadMVT) == BitcastVT.getSimpleVT())
2224     return false;
2225 
2226   unsigned Fast = 0;
2227   return allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), BitcastVT,
2228                             MMO, &Fast) &&
2229          Fast;
2230 }
2231 
2232 void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
2233   MF.getRegInfo().freezeReservedRegs();
2234 }
2235 
2236 MachineMemOperand::Flags TargetLoweringBase::getLoadMemOperandFlags(
2237     const LoadInst &LI, const DataLayout &DL, AssumptionCache *AC,
2238     const TargetLibraryInfo *LibInfo) const {
2239   MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad;
2240   if (LI.isVolatile())
2241     Flags |= MachineMemOperand::MOVolatile;
2242 
2243   if (LI.hasMetadata(LLVMContext::MD_nontemporal))
2244     Flags |= MachineMemOperand::MONonTemporal;
2245 
2246   if (LI.hasMetadata(LLVMContext::MD_invariant_load))
2247     Flags |= MachineMemOperand::MOInvariant;
2248 
2249   if (isDereferenceableAndAlignedPointer(LI.getPointerOperand(), LI.getType(),
2250                                          LI.getAlign(), DL, &LI, AC,
2251                                          /*DT=*/nullptr, LibInfo))
2252     Flags |= MachineMemOperand::MODereferenceable;
2253 
2254   Flags |= getTargetMMOFlags(LI);
2255   return Flags;
2256 }
2257 
2258 MachineMemOperand::Flags
2259 TargetLoweringBase::getStoreMemOperandFlags(const StoreInst &SI,
2260                                             const DataLayout &DL) const {
2261   MachineMemOperand::Flags Flags = MachineMemOperand::MOStore;
2262 
2263   if (SI.isVolatile())
2264     Flags |= MachineMemOperand::MOVolatile;
2265 
2266   if (SI.hasMetadata(LLVMContext::MD_nontemporal))
2267     Flags |= MachineMemOperand::MONonTemporal;
2268 
2269   // FIXME: Not preserving dereferenceable
2270   Flags |= getTargetMMOFlags(SI);
2271   return Flags;
2272 }
2273 
2274 MachineMemOperand::Flags
2275 TargetLoweringBase::getAtomicMemOperandFlags(const Instruction &AI,
2276                                              const DataLayout &DL) const {
2277   auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
2278 
2279   if (const AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(&AI)) {
2280     if (RMW->isVolatile())
2281       Flags |= MachineMemOperand::MOVolatile;
2282   } else if (const AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(&AI)) {
2283     if (CmpX->isVolatile())
2284       Flags |= MachineMemOperand::MOVolatile;
2285   } else
2286     llvm_unreachable("not an atomic instruction");
2287 
2288   // FIXME: Not preserving dereferenceable
2289   Flags |= getTargetMMOFlags(AI);
2290   return Flags;
2291 }
2292 
2293 Instruction *TargetLoweringBase::emitLeadingFence(IRBuilderBase &Builder,
2294                                                   Instruction *Inst,
2295                                                   AtomicOrdering Ord) const {
2296   if (isReleaseOrStronger(Ord) && Inst->hasAtomicStore())
2297     return Builder.CreateFence(Ord);
2298   else
2299     return nullptr;
2300 }
2301 
2302 Instruction *TargetLoweringBase::emitTrailingFence(IRBuilderBase &Builder,
2303                                                    Instruction *Inst,
2304                                                    AtomicOrdering Ord) const {
2305   if (isAcquireOrStronger(Ord))
2306     return Builder.CreateFence(Ord);
2307   else
2308     return nullptr;
2309 }
2310 
2311 //===----------------------------------------------------------------------===//
2312 //  GlobalISel Hooks
2313 //===----------------------------------------------------------------------===//
2314 
2315 bool TargetLoweringBase::shouldLocalize(const MachineInstr &MI,
2316                                         const TargetTransformInfo *TTI) const {
2317   auto &MF = *MI.getMF();
2318   auto &MRI = MF.getRegInfo();
2319   // Assuming a spill and reload of a value has a cost of 1 instruction each,
2320   // this helper function computes the maximum number of uses we should consider
2321   // for remat. E.g. on arm64 global addresses take 2 insts to materialize. We
2322   // break even in terms of code size when the original MI has 2 users vs
2323   // choosing to potentially spill. Any more than 2 users we we have a net code
2324   // size increase. This doesn't take into account register pressure though.
2325   auto maxUses = [](unsigned RematCost) {
2326     // A cost of 1 means remats are basically free.
2327     if (RematCost == 1)
2328       return std::numeric_limits<unsigned>::max();
2329     if (RematCost == 2)
2330       return 2U;
2331 
2332     // Remat is too expensive, only sink if there's one user.
2333     if (RematCost > 2)
2334       return 1U;
2335     llvm_unreachable("Unexpected remat cost");
2336   };
2337 
2338   switch (MI.getOpcode()) {
2339   default:
2340     return false;
2341   // Constants-like instructions should be close to their users.
2342   // We don't want long live-ranges for them.
2343   case TargetOpcode::G_CONSTANT:
2344   case TargetOpcode::G_FCONSTANT:
2345   case TargetOpcode::G_FRAME_INDEX:
2346   case TargetOpcode::G_INTTOPTR:
2347     return true;
2348   case TargetOpcode::G_GLOBAL_VALUE: {
2349     unsigned RematCost = TTI->getGISelRematGlobalCost();
2350     Register Reg = MI.getOperand(0).getReg();
2351     unsigned MaxUses = maxUses(RematCost);
2352     if (MaxUses == UINT_MAX)
2353       return true; // Remats are "free" so always localize.
2354     return MRI.hasAtMostUserInstrs(Reg, MaxUses);
2355   }
2356   }
2357 }
2358