xref: /llvm-project/llvm/lib/CodeGen/TargetLoweringBase.cpp (revision c18be32185ca10e55bdef0f2d43629ccfb7e89eb)
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   } else if (RetVT == MVT::f32) {
175     if (OpVT == MVT::f64)
176       return FPROUND_F64_F32;
177     if (OpVT == MVT::f80)
178       return FPROUND_F80_F32;
179     if (OpVT == MVT::f128)
180       return FPROUND_F128_F32;
181     if (OpVT == MVT::ppcf128)
182       return FPROUND_PPCF128_F32;
183   } else if (RetVT == MVT::f64) {
184     if (OpVT == MVT::f80)
185       return FPROUND_F80_F64;
186     if (OpVT == MVT::f128)
187       return FPROUND_F128_F64;
188     if (OpVT == MVT::ppcf128)
189       return FPROUND_PPCF128_F64;
190   } else if (RetVT == MVT::f80) {
191     if (OpVT == MVT::f128)
192       return FPROUND_F128_F80;
193   }
194 
195   return UNKNOWN_LIBCALL;
196 }
197 
198 /// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
199 /// UNKNOWN_LIBCALL if there is none.
200 RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
201   if (OpVT == MVT::f16) {
202     if (RetVT == MVT::i32)
203       return FPTOSINT_F16_I32;
204     if (RetVT == MVT::i64)
205       return FPTOSINT_F16_I64;
206     if (RetVT == MVT::i128)
207       return FPTOSINT_F16_I128;
208   } else if (OpVT == MVT::f32) {
209     if (RetVT == MVT::i32)
210       return FPTOSINT_F32_I32;
211     if (RetVT == MVT::i64)
212       return FPTOSINT_F32_I64;
213     if (RetVT == MVT::i128)
214       return FPTOSINT_F32_I128;
215   } else if (OpVT == MVT::f64) {
216     if (RetVT == MVT::i32)
217       return FPTOSINT_F64_I32;
218     if (RetVT == MVT::i64)
219       return FPTOSINT_F64_I64;
220     if (RetVT == MVT::i128)
221       return FPTOSINT_F64_I128;
222   } else if (OpVT == MVT::f80) {
223     if (RetVT == MVT::i32)
224       return FPTOSINT_F80_I32;
225     if (RetVT == MVT::i64)
226       return FPTOSINT_F80_I64;
227     if (RetVT == MVT::i128)
228       return FPTOSINT_F80_I128;
229   } else if (OpVT == MVT::f128) {
230     if (RetVT == MVT::i32)
231       return FPTOSINT_F128_I32;
232     if (RetVT == MVT::i64)
233       return FPTOSINT_F128_I64;
234     if (RetVT == MVT::i128)
235       return FPTOSINT_F128_I128;
236   } else if (OpVT == MVT::ppcf128) {
237     if (RetVT == MVT::i32)
238       return FPTOSINT_PPCF128_I32;
239     if (RetVT == MVT::i64)
240       return FPTOSINT_PPCF128_I64;
241     if (RetVT == MVT::i128)
242       return FPTOSINT_PPCF128_I128;
243   }
244   return UNKNOWN_LIBCALL;
245 }
246 
247 /// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
248 /// UNKNOWN_LIBCALL if there is none.
249 RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
250   if (OpVT == MVT::f16) {
251     if (RetVT == MVT::i32)
252       return FPTOUINT_F16_I32;
253     if (RetVT == MVT::i64)
254       return FPTOUINT_F16_I64;
255     if (RetVT == MVT::i128)
256       return FPTOUINT_F16_I128;
257   } else if (OpVT == MVT::f32) {
258     if (RetVT == MVT::i32)
259       return FPTOUINT_F32_I32;
260     if (RetVT == MVT::i64)
261       return FPTOUINT_F32_I64;
262     if (RetVT == MVT::i128)
263       return FPTOUINT_F32_I128;
264   } else if (OpVT == MVT::f64) {
265     if (RetVT == MVT::i32)
266       return FPTOUINT_F64_I32;
267     if (RetVT == MVT::i64)
268       return FPTOUINT_F64_I64;
269     if (RetVT == MVT::i128)
270       return FPTOUINT_F64_I128;
271   } else if (OpVT == MVT::f80) {
272     if (RetVT == MVT::i32)
273       return FPTOUINT_F80_I32;
274     if (RetVT == MVT::i64)
275       return FPTOUINT_F80_I64;
276     if (RetVT == MVT::i128)
277       return FPTOUINT_F80_I128;
278   } else if (OpVT == MVT::f128) {
279     if (RetVT == MVT::i32)
280       return FPTOUINT_F128_I32;
281     if (RetVT == MVT::i64)
282       return FPTOUINT_F128_I64;
283     if (RetVT == MVT::i128)
284       return FPTOUINT_F128_I128;
285   } else if (OpVT == MVT::ppcf128) {
286     if (RetVT == MVT::i32)
287       return FPTOUINT_PPCF128_I32;
288     if (RetVT == MVT::i64)
289       return FPTOUINT_PPCF128_I64;
290     if (RetVT == MVT::i128)
291       return FPTOUINT_PPCF128_I128;
292   }
293   return UNKNOWN_LIBCALL;
294 }
295 
296 /// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
297 /// UNKNOWN_LIBCALL if there is none.
298 RTLIB::Libcall RTLIB::getSINTTOFP(EVT OpVT, EVT RetVT) {
299   if (OpVT == MVT::i32) {
300     if (RetVT == MVT::f16)
301       return SINTTOFP_I32_F16;
302     if (RetVT == MVT::f32)
303       return SINTTOFP_I32_F32;
304     if (RetVT == MVT::f64)
305       return SINTTOFP_I32_F64;
306     if (RetVT == MVT::f80)
307       return SINTTOFP_I32_F80;
308     if (RetVT == MVT::f128)
309       return SINTTOFP_I32_F128;
310     if (RetVT == MVT::ppcf128)
311       return SINTTOFP_I32_PPCF128;
312   } else if (OpVT == MVT::i64) {
313     if (RetVT == MVT::f16)
314       return SINTTOFP_I64_F16;
315     if (RetVT == MVT::f32)
316       return SINTTOFP_I64_F32;
317     if (RetVT == MVT::f64)
318       return SINTTOFP_I64_F64;
319     if (RetVT == MVT::f80)
320       return SINTTOFP_I64_F80;
321     if (RetVT == MVT::f128)
322       return SINTTOFP_I64_F128;
323     if (RetVT == MVT::ppcf128)
324       return SINTTOFP_I64_PPCF128;
325   } else if (OpVT == MVT::i128) {
326     if (RetVT == MVT::f16)
327       return SINTTOFP_I128_F16;
328     if (RetVT == MVT::f32)
329       return SINTTOFP_I128_F32;
330     if (RetVT == MVT::f64)
331       return SINTTOFP_I128_F64;
332     if (RetVT == MVT::f80)
333       return SINTTOFP_I128_F80;
334     if (RetVT == MVT::f128)
335       return SINTTOFP_I128_F128;
336     if (RetVT == MVT::ppcf128)
337       return SINTTOFP_I128_PPCF128;
338   }
339   return UNKNOWN_LIBCALL;
340 }
341 
342 /// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
343 /// UNKNOWN_LIBCALL if there is none.
344 RTLIB::Libcall RTLIB::getUINTTOFP(EVT OpVT, EVT RetVT) {
345   if (OpVT == MVT::i32) {
346     if (RetVT == MVT::f16)
347       return UINTTOFP_I32_F16;
348     if (RetVT == MVT::f32)
349       return UINTTOFP_I32_F32;
350     if (RetVT == MVT::f64)
351       return UINTTOFP_I32_F64;
352     if (RetVT == MVT::f80)
353       return UINTTOFP_I32_F80;
354     if (RetVT == MVT::f128)
355       return UINTTOFP_I32_F128;
356     if (RetVT == MVT::ppcf128)
357       return UINTTOFP_I32_PPCF128;
358   } else if (OpVT == MVT::i64) {
359     if (RetVT == MVT::f16)
360       return UINTTOFP_I64_F16;
361     if (RetVT == MVT::f32)
362       return UINTTOFP_I64_F32;
363     if (RetVT == MVT::f64)
364       return UINTTOFP_I64_F64;
365     if (RetVT == MVT::f80)
366       return UINTTOFP_I64_F80;
367     if (RetVT == MVT::f128)
368       return UINTTOFP_I64_F128;
369     if (RetVT == MVT::ppcf128)
370       return UINTTOFP_I64_PPCF128;
371   } else if (OpVT == MVT::i128) {
372     if (RetVT == MVT::f16)
373       return UINTTOFP_I128_F16;
374     if (RetVT == MVT::f32)
375       return UINTTOFP_I128_F32;
376     if (RetVT == MVT::f64)
377       return UINTTOFP_I128_F64;
378     if (RetVT == MVT::f80)
379       return UINTTOFP_I128_F80;
380     if (RetVT == MVT::f128)
381       return UINTTOFP_I128_F128;
382     if (RetVT == MVT::ppcf128)
383       return UINTTOFP_I128_PPCF128;
384   }
385   return UNKNOWN_LIBCALL;
386 }
387 
388 RTLIB::Libcall RTLIB::getPOWI(EVT RetVT) {
389   return getFPLibCall(RetVT, POWI_F32, POWI_F64, POWI_F80, POWI_F128,
390                       POWI_PPCF128);
391 }
392 
393 RTLIB::Libcall RTLIB::getLDEXP(EVT RetVT) {
394   return getFPLibCall(RetVT, LDEXP_F32, LDEXP_F64, LDEXP_F80, LDEXP_F128,
395                       LDEXP_PPCF128);
396 }
397 
398 RTLIB::Libcall RTLIB::getFREXP(EVT RetVT) {
399   return getFPLibCall(RetVT, FREXP_F32, FREXP_F64, FREXP_F80, FREXP_F128,
400                       FREXP_PPCF128);
401 }
402 
403 RTLIB::Libcall RTLIB::getOutlineAtomicHelper(const Libcall (&LC)[5][4],
404                                              AtomicOrdering Order,
405                                              uint64_t MemSize) {
406   unsigned ModeN, ModelN;
407   switch (MemSize) {
408   case 1:
409     ModeN = 0;
410     break;
411   case 2:
412     ModeN = 1;
413     break;
414   case 4:
415     ModeN = 2;
416     break;
417   case 8:
418     ModeN = 3;
419     break;
420   case 16:
421     ModeN = 4;
422     break;
423   default:
424     return RTLIB::UNKNOWN_LIBCALL;
425   }
426 
427   switch (Order) {
428   case AtomicOrdering::Monotonic:
429     ModelN = 0;
430     break;
431   case AtomicOrdering::Acquire:
432     ModelN = 1;
433     break;
434   case AtomicOrdering::Release:
435     ModelN = 2;
436     break;
437   case AtomicOrdering::AcquireRelease:
438   case AtomicOrdering::SequentiallyConsistent:
439     ModelN = 3;
440     break;
441   default:
442     return UNKNOWN_LIBCALL;
443   }
444 
445   return LC[ModeN][ModelN];
446 }
447 
448 RTLIB::Libcall RTLIB::getOUTLINE_ATOMIC(unsigned Opc, AtomicOrdering Order,
449                                         MVT VT) {
450   if (!VT.isScalarInteger())
451     return UNKNOWN_LIBCALL;
452   uint64_t MemSize = VT.getScalarSizeInBits() / 8;
453 
454 #define LCALLS(A, B)                                                           \
455   { A##B##_RELAX, A##B##_ACQ, A##B##_REL, A##B##_ACQ_REL }
456 #define LCALL5(A)                                                              \
457   LCALLS(A, 1), LCALLS(A, 2), LCALLS(A, 4), LCALLS(A, 8), LCALLS(A, 16)
458   switch (Opc) {
459   case ISD::ATOMIC_CMP_SWAP: {
460     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_CAS)};
461     return getOutlineAtomicHelper(LC, Order, MemSize);
462   }
463   case ISD::ATOMIC_SWAP: {
464     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_SWP)};
465     return getOutlineAtomicHelper(LC, Order, MemSize);
466   }
467   case ISD::ATOMIC_LOAD_ADD: {
468     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDADD)};
469     return getOutlineAtomicHelper(LC, Order, MemSize);
470   }
471   case ISD::ATOMIC_LOAD_OR: {
472     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDSET)};
473     return getOutlineAtomicHelper(LC, Order, MemSize);
474   }
475   case ISD::ATOMIC_LOAD_CLR: {
476     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDCLR)};
477     return getOutlineAtomicHelper(LC, Order, MemSize);
478   }
479   case ISD::ATOMIC_LOAD_XOR: {
480     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDEOR)};
481     return getOutlineAtomicHelper(LC, Order, MemSize);
482   }
483   default:
484     return UNKNOWN_LIBCALL;
485   }
486 #undef LCALLS
487 #undef LCALL5
488 }
489 
490 RTLIB::Libcall RTLIB::getSYNC(unsigned Opc, MVT VT) {
491 #define OP_TO_LIBCALL(Name, Enum)                                              \
492   case Name:                                                                   \
493     switch (VT.SimpleTy) {                                                     \
494     default:                                                                   \
495       return UNKNOWN_LIBCALL;                                                  \
496     case MVT::i8:                                                              \
497       return Enum##_1;                                                         \
498     case MVT::i16:                                                             \
499       return Enum##_2;                                                         \
500     case MVT::i32:                                                             \
501       return Enum##_4;                                                         \
502     case MVT::i64:                                                             \
503       return Enum##_8;                                                         \
504     case MVT::i128:                                                            \
505       return Enum##_16;                                                        \
506     }
507 
508   switch (Opc) {
509     OP_TO_LIBCALL(ISD::ATOMIC_SWAP, SYNC_LOCK_TEST_AND_SET)
510     OP_TO_LIBCALL(ISD::ATOMIC_CMP_SWAP, SYNC_VAL_COMPARE_AND_SWAP)
511     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_ADD, SYNC_FETCH_AND_ADD)
512     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_SUB, SYNC_FETCH_AND_SUB)
513     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_AND, SYNC_FETCH_AND_AND)
514     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_OR, SYNC_FETCH_AND_OR)
515     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_XOR, SYNC_FETCH_AND_XOR)
516     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_NAND, SYNC_FETCH_AND_NAND)
517     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MAX, SYNC_FETCH_AND_MAX)
518     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMAX, SYNC_FETCH_AND_UMAX)
519     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MIN, SYNC_FETCH_AND_MIN)
520     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMIN, SYNC_FETCH_AND_UMIN)
521   }
522 
523 #undef OP_TO_LIBCALL
524 
525   return UNKNOWN_LIBCALL;
526 }
527 
528 RTLIB::Libcall RTLIB::getMEMCPY_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
529   switch (ElementSize) {
530   case 1:
531     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_1;
532   case 2:
533     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_2;
534   case 4:
535     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_4;
536   case 8:
537     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_8;
538   case 16:
539     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_16;
540   default:
541     return UNKNOWN_LIBCALL;
542   }
543 }
544 
545 RTLIB::Libcall RTLIB::getMEMMOVE_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
546   switch (ElementSize) {
547   case 1:
548     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_1;
549   case 2:
550     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_2;
551   case 4:
552     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_4;
553   case 8:
554     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_8;
555   case 16:
556     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_16;
557   default:
558     return UNKNOWN_LIBCALL;
559   }
560 }
561 
562 RTLIB::Libcall RTLIB::getMEMSET_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
563   switch (ElementSize) {
564   case 1:
565     return MEMSET_ELEMENT_UNORDERED_ATOMIC_1;
566   case 2:
567     return MEMSET_ELEMENT_UNORDERED_ATOMIC_2;
568   case 4:
569     return MEMSET_ELEMENT_UNORDERED_ATOMIC_4;
570   case 8:
571     return MEMSET_ELEMENT_UNORDERED_ATOMIC_8;
572   case 16:
573     return MEMSET_ELEMENT_UNORDERED_ATOMIC_16;
574   default:
575     return UNKNOWN_LIBCALL;
576   }
577 }
578 
579 void RTLIB::initCmpLibcallCCs(ISD::CondCode *CmpLibcallCCs) {
580   std::fill(CmpLibcallCCs, CmpLibcallCCs + RTLIB::UNKNOWN_LIBCALL,
581             ISD::SETCC_INVALID);
582   CmpLibcallCCs[RTLIB::OEQ_F32] = ISD::SETEQ;
583   CmpLibcallCCs[RTLIB::OEQ_F64] = ISD::SETEQ;
584   CmpLibcallCCs[RTLIB::OEQ_F128] = ISD::SETEQ;
585   CmpLibcallCCs[RTLIB::OEQ_PPCF128] = ISD::SETEQ;
586   CmpLibcallCCs[RTLIB::UNE_F32] = ISD::SETNE;
587   CmpLibcallCCs[RTLIB::UNE_F64] = ISD::SETNE;
588   CmpLibcallCCs[RTLIB::UNE_F128] = ISD::SETNE;
589   CmpLibcallCCs[RTLIB::UNE_PPCF128] = ISD::SETNE;
590   CmpLibcallCCs[RTLIB::OGE_F32] = ISD::SETGE;
591   CmpLibcallCCs[RTLIB::OGE_F64] = ISD::SETGE;
592   CmpLibcallCCs[RTLIB::OGE_F128] = ISD::SETGE;
593   CmpLibcallCCs[RTLIB::OGE_PPCF128] = ISD::SETGE;
594   CmpLibcallCCs[RTLIB::OLT_F32] = ISD::SETLT;
595   CmpLibcallCCs[RTLIB::OLT_F64] = ISD::SETLT;
596   CmpLibcallCCs[RTLIB::OLT_F128] = ISD::SETLT;
597   CmpLibcallCCs[RTLIB::OLT_PPCF128] = ISD::SETLT;
598   CmpLibcallCCs[RTLIB::OLE_F32] = ISD::SETLE;
599   CmpLibcallCCs[RTLIB::OLE_F64] = ISD::SETLE;
600   CmpLibcallCCs[RTLIB::OLE_F128] = ISD::SETLE;
601   CmpLibcallCCs[RTLIB::OLE_PPCF128] = ISD::SETLE;
602   CmpLibcallCCs[RTLIB::OGT_F32] = ISD::SETGT;
603   CmpLibcallCCs[RTLIB::OGT_F64] = ISD::SETGT;
604   CmpLibcallCCs[RTLIB::OGT_F128] = ISD::SETGT;
605   CmpLibcallCCs[RTLIB::OGT_PPCF128] = ISD::SETGT;
606   CmpLibcallCCs[RTLIB::UO_F32] = ISD::SETNE;
607   CmpLibcallCCs[RTLIB::UO_F64] = ISD::SETNE;
608   CmpLibcallCCs[RTLIB::UO_F128] = ISD::SETNE;
609   CmpLibcallCCs[RTLIB::UO_PPCF128] = ISD::SETNE;
610 }
611 
612 /// NOTE: The TargetMachine owns TLOF.
613 TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm)
614     : TM(tm), Libcalls(TM.getTargetTriple()) {
615   initActions();
616 
617   // Perform these initializations only once.
618   MaxStoresPerMemset = MaxStoresPerMemcpy = MaxStoresPerMemmove =
619       MaxLoadsPerMemcmp = 8;
620   MaxGluedStoresPerMemcpy = 0;
621   MaxStoresPerMemsetOptSize = MaxStoresPerMemcpyOptSize =
622       MaxStoresPerMemmoveOptSize = MaxLoadsPerMemcmpOptSize = 4;
623   HasMultipleConditionRegisters = false;
624   HasExtractBitsInsn = false;
625   JumpIsExpensive = JumpIsExpensiveOverride;
626   PredictableSelectIsExpensive = false;
627   EnableExtLdPromotion = false;
628   StackPointerRegisterToSaveRestore = 0;
629   BooleanContents = UndefinedBooleanContent;
630   BooleanFloatContents = UndefinedBooleanContent;
631   BooleanVectorContents = UndefinedBooleanContent;
632   SchedPreferenceInfo = Sched::ILP;
633   GatherAllAliasesMaxDepth = 18;
634   IsStrictFPEnabled = DisableStrictNodeMutation;
635   MaxBytesForAlignment = 0;
636   MaxAtomicSizeInBitsSupported = 0;
637 
638   // Assume that even with libcalls, no target supports wider than 128 bit
639   // division.
640   MaxDivRemBitWidthSupported = 128;
641 
642   MaxLargeFPConvertBitWidthSupported = llvm::IntegerType::MAX_INT_BITS;
643 
644   MinCmpXchgSizeInBits = 0;
645   SupportsUnalignedAtomics = false;
646 
647   RTLIB::initCmpLibcallCCs(CmpLibcallCCs);
648 }
649 
650 void TargetLoweringBase::initActions() {
651   // All operations default to being supported.
652   memset(OpActions, 0, sizeof(OpActions));
653   memset(LoadExtActions, 0, sizeof(LoadExtActions));
654   memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
655   memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
656   memset(CondCodeActions, 0, sizeof(CondCodeActions));
657   std::fill(std::begin(RegClassForVT), std::end(RegClassForVT), nullptr);
658   std::fill(std::begin(TargetDAGCombineArray),
659             std::end(TargetDAGCombineArray), 0);
660 
661   // Let extending atomic loads be unsupported by default.
662   for (MVT ValVT : MVT::all_valuetypes())
663     for (MVT MemVT : MVT::all_valuetypes())
664       setAtomicLoadExtAction({ISD::SEXTLOAD, ISD::ZEXTLOAD}, ValVT, MemVT,
665                              Expand);
666 
667   // We're somewhat special casing MVT::i2 and MVT::i4. Ideally we want to
668   // remove this and targets should individually set these types if not legal.
669   for (ISD::NodeType NT : enum_seq(ISD::DELETED_NODE, ISD::BUILTIN_OP_END,
670                                    force_iteration_on_noniterable_enum)) {
671     for (MVT VT : {MVT::i2, MVT::i4})
672       OpActions[(unsigned)VT.SimpleTy][NT] = Expand;
673   }
674   for (MVT AVT : MVT::all_valuetypes()) {
675     for (MVT VT : {MVT::i2, MVT::i4, MVT::v128i2, MVT::v64i4}) {
676       setTruncStoreAction(AVT, VT, Expand);
677       setLoadExtAction(ISD::EXTLOAD, AVT, VT, Expand);
678       setLoadExtAction(ISD::ZEXTLOAD, AVT, VT, Expand);
679     }
680   }
681   for (unsigned IM = (unsigned)ISD::PRE_INC;
682        IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
683     for (MVT VT : {MVT::i2, MVT::i4}) {
684       setIndexedLoadAction(IM, VT, Expand);
685       setIndexedStoreAction(IM, VT, Expand);
686       setIndexedMaskedLoadAction(IM, VT, Expand);
687       setIndexedMaskedStoreAction(IM, VT, Expand);
688     }
689   }
690 
691   for (MVT VT : MVT::fp_valuetypes()) {
692     MVT IntVT = MVT::getIntegerVT(VT.getFixedSizeInBits());
693     if (IntVT.isValid()) {
694       setOperationAction(ISD::ATOMIC_SWAP, VT, Promote);
695       AddPromotedToType(ISD::ATOMIC_SWAP, VT, IntVT);
696     }
697   }
698 
699   // Set default actions for various operations.
700   for (MVT VT : MVT::all_valuetypes()) {
701     // Default all indexed load / store to expand.
702     for (unsigned IM = (unsigned)ISD::PRE_INC;
703          IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
704       setIndexedLoadAction(IM, VT, Expand);
705       setIndexedStoreAction(IM, VT, Expand);
706       setIndexedMaskedLoadAction(IM, VT, Expand);
707       setIndexedMaskedStoreAction(IM, VT, Expand);
708     }
709 
710     // Most backends expect to see the node which just returns the value loaded.
711     setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, VT, Expand);
712 
713     // These operations default to expand.
714     setOperationAction({ISD::FGETSIGN,       ISD::CONCAT_VECTORS,
715                         ISD::FMINNUM,        ISD::FMAXNUM,
716                         ISD::FMINNUM_IEEE,   ISD::FMAXNUM_IEEE,
717                         ISD::FMINIMUM,       ISD::FMAXIMUM,
718                         ISD::FMINIMUMNUM,    ISD::FMAXIMUMNUM,
719                         ISD::FMAD,           ISD::SMIN,
720                         ISD::SMAX,           ISD::UMIN,
721                         ISD::UMAX,           ISD::ABS,
722                         ISD::FSHL,           ISD::FSHR,
723                         ISD::SADDSAT,        ISD::UADDSAT,
724                         ISD::SSUBSAT,        ISD::USUBSAT,
725                         ISD::SSHLSAT,        ISD::USHLSAT,
726                         ISD::SMULFIX,        ISD::SMULFIXSAT,
727                         ISD::UMULFIX,        ISD::UMULFIXSAT,
728                         ISD::SDIVFIX,        ISD::SDIVFIXSAT,
729                         ISD::UDIVFIX,        ISD::UDIVFIXSAT,
730                         ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT,
731                         ISD::IS_FPCLASS},
732                        VT, Expand);
733 
734     // Overflow operations default to expand
735     setOperationAction({ISD::SADDO, ISD::SSUBO, ISD::UADDO, ISD::USUBO,
736                         ISD::SMULO, ISD::UMULO},
737                        VT, Expand);
738 
739     // Carry-using overflow operations default to expand.
740     setOperationAction({ISD::UADDO_CARRY, ISD::USUBO_CARRY, ISD::SETCCCARRY,
741                         ISD::SADDO_CARRY, ISD::SSUBO_CARRY},
742                        VT, Expand);
743 
744     // ADDC/ADDE/SUBC/SUBE default to expand.
745     setOperationAction({ISD::ADDC, ISD::ADDE, ISD::SUBC, ISD::SUBE}, VT,
746                        Expand);
747 
748     // [US]CMP default to expand
749     setOperationAction({ISD::UCMP, ISD::SCMP}, VT, Expand);
750 
751     // Halving adds
752     setOperationAction(
753         {ISD::AVGFLOORS, ISD::AVGFLOORU, ISD::AVGCEILS, ISD::AVGCEILU}, VT,
754         Expand);
755 
756     // Absolute difference
757     setOperationAction({ISD::ABDS, ISD::ABDU}, VT, Expand);
758 
759     // Saturated trunc
760     setOperationAction(ISD::TRUNCATE_SSAT_S, VT, Expand);
761     setOperationAction(ISD::TRUNCATE_SSAT_U, VT, Expand);
762     setOperationAction(ISD::TRUNCATE_USAT_U, VT, Expand);
763 
764     // These default to Expand so they will be expanded to CTLZ/CTTZ by default.
765     setOperationAction({ISD::CTLZ_ZERO_UNDEF, ISD::CTTZ_ZERO_UNDEF}, VT,
766                        Expand);
767 
768     setOperationAction({ISD::BITREVERSE, ISD::PARITY}, VT, Expand);
769 
770     // These library functions default to expand.
771     setOperationAction({ISD::FROUND, ISD::FPOWI, ISD::FLDEXP, ISD::FFREXP}, VT,
772                        Expand);
773 
774     // These operations default to expand for vector types.
775     if (VT.isVector())
776       setOperationAction(
777           {ISD::FCOPYSIGN, ISD::SIGN_EXTEND_INREG, ISD::ANY_EXTEND_VECTOR_INREG,
778            ISD::SIGN_EXTEND_VECTOR_INREG, ISD::ZERO_EXTEND_VECTOR_INREG,
779            ISD::SPLAT_VECTOR, ISD::LRINT, ISD::LLRINT, ISD::LROUND,
780            ISD::LLROUND, ISD::FTAN, ISD::FACOS, ISD::FASIN, ISD::FATAN,
781            ISD::FCOSH, ISD::FSINH, ISD::FTANH},
782           VT, Expand);
783 
784       // Constrained floating-point operations default to expand.
785 #define DAG_INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN)               \
786     setOperationAction(ISD::STRICT_##DAGN, VT, Expand);
787 #include "llvm/IR/ConstrainedOps.def"
788 
789     // For most targets @llvm.get.dynamic.area.offset just returns 0.
790     setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, VT, Expand);
791 
792     // Vector reduction default to expand.
793     setOperationAction(
794         {ISD::VECREDUCE_FADD, ISD::VECREDUCE_FMUL, ISD::VECREDUCE_ADD,
795          ISD::VECREDUCE_MUL, ISD::VECREDUCE_AND, ISD::VECREDUCE_OR,
796          ISD::VECREDUCE_XOR, ISD::VECREDUCE_SMAX, ISD::VECREDUCE_SMIN,
797          ISD::VECREDUCE_UMAX, ISD::VECREDUCE_UMIN, ISD::VECREDUCE_FMAX,
798          ISD::VECREDUCE_FMIN, ISD::VECREDUCE_FMAXIMUM, ISD::VECREDUCE_FMINIMUM,
799          ISD::VECREDUCE_SEQ_FADD, ISD::VECREDUCE_SEQ_FMUL},
800         VT, Expand);
801 
802     // Named vector shuffles default to expand.
803     setOperationAction(ISD::VECTOR_SPLICE, VT, Expand);
804 
805     // Only some target support this vector operation. Most need to expand it.
806     setOperationAction(ISD::VECTOR_COMPRESS, VT, Expand);
807 
808     // VP operations default to expand.
809 #define BEGIN_REGISTER_VP_SDNODE(SDOPC, ...)                                   \
810     setOperationAction(ISD::SDOPC, VT, Expand);
811 #include "llvm/IR/VPIntrinsics.def"
812 
813     // FP environment operations default to expand.
814     setOperationAction(ISD::GET_FPENV, VT, Expand);
815     setOperationAction(ISD::SET_FPENV, VT, Expand);
816     setOperationAction(ISD::RESET_FPENV, VT, Expand);
817   }
818 
819   // Most targets ignore the @llvm.prefetch intrinsic.
820   setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
821 
822   // Most targets also ignore the @llvm.readcyclecounter intrinsic.
823   setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Expand);
824 
825   // Most targets also ignore the @llvm.readsteadycounter intrinsic.
826   setOperationAction(ISD::READSTEADYCOUNTER, MVT::i64, Expand);
827 
828   // ConstantFP nodes default to expand.  Targets can either change this to
829   // Legal, in which case all fp constants are legal, or use isFPImmLegal()
830   // to optimize expansions for certain constants.
831   setOperationAction(ISD::ConstantFP,
832                      {MVT::bf16, MVT::f16, MVT::f32, MVT::f64, MVT::f80, MVT::f128},
833                      Expand);
834 
835   // These library functions default to expand.
836   setOperationAction({ISD::FCBRT,      ISD::FLOG,  ISD::FLOG2,  ISD::FLOG10,
837                       ISD::FEXP,       ISD::FEXP2, ISD::FEXP10, ISD::FFLOOR,
838                       ISD::FNEARBYINT, ISD::FCEIL, ISD::FRINT,  ISD::FTRUNC,
839                       ISD::FROUNDEVEN, ISD::FTAN,  ISD::FACOS,  ISD::FASIN,
840                       ISD::FATAN,      ISD::FCOSH, ISD::FSINH,  ISD::FTANH},
841                      {MVT::f32, MVT::f64, MVT::f128}, Expand);
842 
843   // FIXME: Query RuntimeLibCalls to make the decision.
844   setOperationAction({ISD::LRINT, ISD::LLRINT, ISD::LROUND, ISD::LLROUND},
845                      {MVT::f32, MVT::f64, MVT::f128}, LibCall);
846 
847   setOperationAction({ISD::FTAN, ISD::FACOS, ISD::FASIN, ISD::FATAN, ISD::FCOSH,
848                       ISD::FSINH, ISD::FTANH},
849                      MVT::f16, Promote);
850   // Default ISD::TRAP to expand (which turns it into abort).
851   setOperationAction(ISD::TRAP, MVT::Other, Expand);
852 
853   // On most systems, DEBUGTRAP and TRAP have no difference. The "Expand"
854   // here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP.
855   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand);
856 
857   setOperationAction(ISD::UBSANTRAP, MVT::Other, Expand);
858 
859   setOperationAction(ISD::GET_FPENV_MEM, MVT::Other, Expand);
860   setOperationAction(ISD::SET_FPENV_MEM, MVT::Other, Expand);
861 
862   for (MVT VT : {MVT::i8, MVT::i16, MVT::i32, MVT::i64}) {
863     setOperationAction(ISD::GET_FPMODE, VT, Expand);
864     setOperationAction(ISD::SET_FPMODE, VT, Expand);
865   }
866   setOperationAction(ISD::RESET_FPMODE, MVT::Other, Expand);
867 
868   // This one by default will call __clear_cache unless the target
869   // wants something different.
870   setOperationAction(ISD::CLEAR_CACHE, MVT::Other, LibCall);
871 }
872 
873 MVT TargetLoweringBase::getScalarShiftAmountTy(const DataLayout &DL,
874                                                EVT) const {
875   return MVT::getIntegerVT(DL.getPointerSizeInBits(0));
876 }
877 
878 EVT TargetLoweringBase::getShiftAmountTy(EVT LHSTy,
879                                          const DataLayout &DL) const {
880   assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
881   if (LHSTy.isVector())
882     return LHSTy;
883   MVT ShiftVT = getScalarShiftAmountTy(DL, LHSTy);
884   // If any possible shift value won't fit in the prefered type, just use
885   // something safe. Assume it will be legalized when the shift is expanded.
886   if (ShiftVT.getSizeInBits() < Log2_32_Ceil(LHSTy.getSizeInBits()))
887     ShiftVT = MVT::i32;
888   assert(ShiftVT.getSizeInBits() >= Log2_32_Ceil(LHSTy.getSizeInBits()) &&
889          "ShiftVT is still too small!");
890   return ShiftVT;
891 }
892 
893 bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
894   assert(isTypeLegal(VT));
895   switch (Op) {
896   default:
897     return false;
898   case ISD::SDIV:
899   case ISD::UDIV:
900   case ISD::SREM:
901   case ISD::UREM:
902     return true;
903   }
904 }
905 
906 bool TargetLoweringBase::isFreeAddrSpaceCast(unsigned SrcAS,
907                                              unsigned DestAS) const {
908   return TM.isNoopAddrSpaceCast(SrcAS, DestAS);
909 }
910 
911 unsigned TargetLoweringBase::getBitWidthForCttzElements(
912     Type *RetTy, ElementCount EC, bool ZeroIsPoison,
913     const ConstantRange *VScaleRange) const {
914   // Find the smallest "sensible" element type to use for the expansion.
915   ConstantRange CR(APInt(64, EC.getKnownMinValue()));
916   if (EC.isScalable())
917     CR = CR.umul_sat(*VScaleRange);
918 
919   if (ZeroIsPoison)
920     CR = CR.subtract(APInt(64, 1));
921 
922   unsigned EltWidth = RetTy->getScalarSizeInBits();
923   EltWidth = std::min(EltWidth, (unsigned)CR.getActiveBits());
924   EltWidth = std::max(llvm::bit_ceil(EltWidth), (unsigned)8);
925 
926   return EltWidth;
927 }
928 
929 void TargetLoweringBase::setJumpIsExpensive(bool isExpensive) {
930   // If the command-line option was specified, ignore this request.
931   if (!JumpIsExpensiveOverride.getNumOccurrences())
932     JumpIsExpensive = isExpensive;
933 }
934 
935 TargetLoweringBase::LegalizeKind
936 TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
937   // If this is a simple type, use the ComputeRegisterProp mechanism.
938   if (VT.isSimple()) {
939     MVT SVT = VT.getSimpleVT();
940     assert((unsigned)SVT.SimpleTy < std::size(TransformToType));
941     MVT NVT = TransformToType[SVT.SimpleTy];
942     LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
943 
944     assert((LA == TypeLegal || LA == TypeSoftenFloat ||
945             LA == TypeSoftPromoteHalf ||
946             (NVT.isVector() ||
947              ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger)) &&
948            "Promote may not follow Expand or Promote");
949 
950     if (LA == TypeSplitVector)
951       return LegalizeKind(LA, EVT(SVT).getHalfNumVectorElementsVT(Context));
952     if (LA == TypeScalarizeVector)
953       return LegalizeKind(LA, SVT.getVectorElementType());
954     return LegalizeKind(LA, NVT);
955   }
956 
957   // Handle Extended Scalar Types.
958   if (!VT.isVector()) {
959     assert(VT.isInteger() && "Float types must be simple");
960     unsigned BitSize = VT.getSizeInBits();
961     // First promote to a power-of-two size, then expand if necessary.
962     if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
963       EVT NVT = VT.getRoundIntegerType(Context);
964       assert(NVT != VT && "Unable to round integer VT");
965       LegalizeKind NextStep = getTypeConversion(Context, NVT);
966       // Avoid multi-step promotion.
967       if (NextStep.first == TypePromoteInteger)
968         return NextStep;
969       // Return rounded integer type.
970       return LegalizeKind(TypePromoteInteger, NVT);
971     }
972 
973     return LegalizeKind(TypeExpandInteger,
974                         EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
975   }
976 
977   // Handle vector types.
978   ElementCount NumElts = VT.getVectorElementCount();
979   EVT EltVT = VT.getVectorElementType();
980 
981   // Vectors with only one element are always scalarized.
982   if (NumElts.isScalar())
983     return LegalizeKind(TypeScalarizeVector, EltVT);
984 
985   // Try to widen vector elements until the element type is a power of two and
986   // promote it to a legal type later on, for example:
987   // <3 x i8> -> <4 x i8> -> <4 x i32>
988   if (EltVT.isInteger()) {
989     // Vectors with a number of elements that is not a power of two are always
990     // widened, for example <3 x i8> -> <4 x i8>.
991     if (!VT.isPow2VectorType()) {
992       NumElts = NumElts.coefficientNextPowerOf2();
993       EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
994       return LegalizeKind(TypeWidenVector, NVT);
995     }
996 
997     // Examine the element type.
998     LegalizeKind LK = getTypeConversion(Context, EltVT);
999 
1000     // If type is to be expanded, split the vector.
1001     //  <4 x i140> -> <2 x i140>
1002     if (LK.first == TypeExpandInteger) {
1003       if (VT.getVectorElementCount().isScalable())
1004         return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1005       return LegalizeKind(TypeSplitVector,
1006                           VT.getHalfNumVectorElementsVT(Context));
1007     }
1008 
1009     // Promote the integer element types until a legal vector type is found
1010     // or until the element integer type is too big. If a legal type was not
1011     // found, fallback to the usual mechanism of widening/splitting the
1012     // vector.
1013     EVT OldEltVT = EltVT;
1014     while (true) {
1015       // Increase the bitwidth of the element to the next pow-of-two
1016       // (which is greater than 8 bits).
1017       EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
1018                   .getRoundIntegerType(Context);
1019 
1020       // Stop trying when getting a non-simple element type.
1021       // Note that vector elements may be greater than legal vector element
1022       // types. Example: X86 XMM registers hold 64bit element on 32bit
1023       // systems.
1024       if (!EltVT.isSimple())
1025         break;
1026 
1027       // Build a new vector type and check if it is legal.
1028       MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1029       // Found a legal promoted vector type.
1030       if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
1031         return LegalizeKind(TypePromoteInteger,
1032                             EVT::getVectorVT(Context, EltVT, NumElts));
1033     }
1034 
1035     // Reset the type to the unexpanded type if we did not find a legal vector
1036     // type with a promoted vector element type.
1037     EltVT = OldEltVT;
1038   }
1039 
1040   // Try to widen the vector until a legal type is found.
1041   // If there is no wider legal type, split the vector.
1042   while (true) {
1043     // Round up to the next power of 2.
1044     NumElts = NumElts.coefficientNextPowerOf2();
1045 
1046     // If there is no simple vector type with this many elements then there
1047     // cannot be a larger legal vector type.  Note that this assumes that
1048     // there are no skipped intermediate vector types in the simple types.
1049     if (!EltVT.isSimple())
1050       break;
1051     MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1052     if (LargerVector == MVT())
1053       break;
1054 
1055     // If this type is legal then widen the vector.
1056     if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
1057       return LegalizeKind(TypeWidenVector, LargerVector);
1058   }
1059 
1060   // Widen odd vectors to next power of two.
1061   if (!VT.isPow2VectorType()) {
1062     EVT NVT = VT.getPow2VectorType(Context);
1063     return LegalizeKind(TypeWidenVector, NVT);
1064   }
1065 
1066   if (VT.getVectorElementCount() == ElementCount::getScalable(1))
1067     return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1068 
1069   // Vectors with illegal element types are expanded.
1070   EVT NVT = EVT::getVectorVT(Context, EltVT,
1071                              VT.getVectorElementCount().divideCoefficientBy(2));
1072   return LegalizeKind(TypeSplitVector, NVT);
1073 }
1074 
1075 static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
1076                                           unsigned &NumIntermediates,
1077                                           MVT &RegisterVT,
1078                                           TargetLoweringBase *TLI) {
1079   // Figure out the right, legal destination reg to copy into.
1080   ElementCount EC = VT.getVectorElementCount();
1081   MVT EltTy = VT.getVectorElementType();
1082 
1083   unsigned NumVectorRegs = 1;
1084 
1085   // Scalable vectors cannot be scalarized, so splitting or widening is
1086   // required.
1087   if (VT.isScalableVector() && !isPowerOf2_32(EC.getKnownMinValue()))
1088     llvm_unreachable(
1089         "Splitting or widening of non-power-of-2 MVTs is not implemented.");
1090 
1091   // FIXME: We don't support non-power-of-2-sized vectors for now.
1092   // Ideally we could break down into LHS/RHS like LegalizeDAG does.
1093   if (!isPowerOf2_32(EC.getKnownMinValue())) {
1094     // Split EC to unit size (scalable property is preserved).
1095     NumVectorRegs = EC.getKnownMinValue();
1096     EC = ElementCount::getFixed(1);
1097   }
1098 
1099   // Divide the input until we get to a supported size. This will
1100   // always end up with an EC that represent a scalar or a scalable
1101   // scalar.
1102   while (EC.getKnownMinValue() > 1 &&
1103          !TLI->isTypeLegal(MVT::getVectorVT(EltTy, EC))) {
1104     EC = EC.divideCoefficientBy(2);
1105     NumVectorRegs <<= 1;
1106   }
1107 
1108   NumIntermediates = NumVectorRegs;
1109 
1110   MVT NewVT = MVT::getVectorVT(EltTy, EC);
1111   if (!TLI->isTypeLegal(NewVT))
1112     NewVT = EltTy;
1113   IntermediateVT = NewVT;
1114 
1115   unsigned LaneSizeInBits = NewVT.getScalarSizeInBits();
1116 
1117   // Convert sizes such as i33 to i64.
1118   LaneSizeInBits = llvm::bit_ceil(LaneSizeInBits);
1119 
1120   MVT DestVT = TLI->getRegisterType(NewVT);
1121   RegisterVT = DestVT;
1122   if (EVT(DestVT).bitsLT(NewVT))    // Value is expanded, e.g. i64 -> i16.
1123     return NumVectorRegs * (LaneSizeInBits / DestVT.getScalarSizeInBits());
1124 
1125   // Otherwise, promotion or legal types use the same number of registers as
1126   // the vector decimated to the appropriate level.
1127   return NumVectorRegs;
1128 }
1129 
1130 /// isLegalRC - Return true if the value types that can be represented by the
1131 /// specified register class are all legal.
1132 bool TargetLoweringBase::isLegalRC(const TargetRegisterInfo &TRI,
1133                                    const TargetRegisterClass &RC) const {
1134   for (const auto *I = TRI.legalclasstypes_begin(RC); *I != MVT::Other; ++I)
1135     if (isTypeLegal(*I))
1136       return true;
1137   return false;
1138 }
1139 
1140 /// Replace/modify any TargetFrameIndex operands with a targte-dependent
1141 /// sequence of memory operands that is recognized by PrologEpilogInserter.
1142 MachineBasicBlock *
1143 TargetLoweringBase::emitPatchPoint(MachineInstr &InitialMI,
1144                                    MachineBasicBlock *MBB) const {
1145   MachineInstr *MI = &InitialMI;
1146   MachineFunction &MF = *MI->getMF();
1147   MachineFrameInfo &MFI = MF.getFrameInfo();
1148 
1149   // We're handling multiple types of operands here:
1150   // PATCHPOINT MetaArgs - live-in, read only, direct
1151   // STATEPOINT Deopt Spill - live-through, read only, indirect
1152   // STATEPOINT Deopt Alloca - live-through, read only, direct
1153   // (We're currently conservative and mark the deopt slots read/write in
1154   // practice.)
1155   // STATEPOINT GC Spill - live-through, read/write, indirect
1156   // STATEPOINT GC Alloca - live-through, read/write, direct
1157   // The live-in vs live-through is handled already (the live through ones are
1158   // all stack slots), but we need to handle the different type of stackmap
1159   // operands and memory effects here.
1160 
1161   if (llvm::none_of(MI->operands(),
1162                     [](MachineOperand &Operand) { return Operand.isFI(); }))
1163     return MBB;
1164 
1165   MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), MI->getDesc());
1166 
1167   // Inherit previous memory operands.
1168   MIB.cloneMemRefs(*MI);
1169 
1170   for (unsigned i = 0; i < MI->getNumOperands(); ++i) {
1171     MachineOperand &MO = MI->getOperand(i);
1172     if (!MO.isFI()) {
1173       // Index of Def operand this Use it tied to.
1174       // Since Defs are coming before Uses, if Use is tied, then
1175       // index of Def must be smaller that index of that Use.
1176       // Also, Defs preserve their position in new MI.
1177       unsigned TiedTo = i;
1178       if (MO.isReg() && MO.isTied())
1179         TiedTo = MI->findTiedOperandIdx(i);
1180       MIB.add(MO);
1181       if (TiedTo < i)
1182         MIB->tieOperands(TiedTo, MIB->getNumOperands() - 1);
1183       continue;
1184     }
1185 
1186     // foldMemoryOperand builds a new MI after replacing a single FI operand
1187     // with the canonical set of five x86 addressing-mode operands.
1188     int FI = MO.getIndex();
1189 
1190     // Add frame index operands recognized by stackmaps.cpp
1191     if (MFI.isStatepointSpillSlotObjectIndex(FI)) {
1192       // indirect-mem-ref tag, size, #FI, offset.
1193       // Used for spills inserted by StatepointLowering.  This codepath is not
1194       // used for patchpoints/stackmaps at all, for these spilling is done via
1195       // foldMemoryOperand callback only.
1196       assert(MI->getOpcode() == TargetOpcode::STATEPOINT && "sanity");
1197       MIB.addImm(StackMaps::IndirectMemRefOp);
1198       MIB.addImm(MFI.getObjectSize(FI));
1199       MIB.add(MO);
1200       MIB.addImm(0);
1201     } else {
1202       // direct-mem-ref tag, #FI, offset.
1203       // Used by patchpoint, and direct alloca arguments to statepoints
1204       MIB.addImm(StackMaps::DirectMemRefOp);
1205       MIB.add(MO);
1206       MIB.addImm(0);
1207     }
1208 
1209     assert(MIB->mayLoad() && "Folded a stackmap use to a non-load!");
1210 
1211     // Add a new memory operand for this FI.
1212     assert(MFI.getObjectOffset(FI) != -1);
1213 
1214     // Note: STATEPOINT MMOs are added during SelectionDAG.  STACKMAP, and
1215     // PATCHPOINT should be updated to do the same. (TODO)
1216     if (MI->getOpcode() != TargetOpcode::STATEPOINT) {
1217       auto Flags = MachineMemOperand::MOLoad;
1218       MachineMemOperand *MMO = MF.getMachineMemOperand(
1219           MachinePointerInfo::getFixedStack(MF, FI), Flags,
1220           MF.getDataLayout().getPointerSize(), MFI.getObjectAlign(FI));
1221       MIB->addMemOperand(MF, MMO);
1222     }
1223   }
1224   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1225   MI->eraseFromParent();
1226   return MBB;
1227 }
1228 
1229 /// findRepresentativeClass - Return the largest legal super-reg register class
1230 /// of the register class for the specified type and its associated "cost".
1231 // This function is in TargetLowering because it uses RegClassForVT which would
1232 // need to be moved to TargetRegisterInfo and would necessitate moving
1233 // isTypeLegal over as well - a massive change that would just require
1234 // TargetLowering having a TargetRegisterInfo class member that it would use.
1235 std::pair<const TargetRegisterClass *, uint8_t>
1236 TargetLoweringBase::findRepresentativeClass(const TargetRegisterInfo *TRI,
1237                                             MVT VT) const {
1238   const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
1239   if (!RC)
1240     return std::make_pair(RC, 0);
1241 
1242   // Compute the set of all super-register classes.
1243   BitVector SuperRegRC(TRI->getNumRegClasses());
1244   for (SuperRegClassIterator RCI(RC, TRI); RCI.isValid(); ++RCI)
1245     SuperRegRC.setBitsInMask(RCI.getMask());
1246 
1247   // Find the first legal register class with the largest spill size.
1248   const TargetRegisterClass *BestRC = RC;
1249   for (unsigned i : SuperRegRC.set_bits()) {
1250     const TargetRegisterClass *SuperRC = TRI->getRegClass(i);
1251     // We want the largest possible spill size.
1252     if (TRI->getSpillSize(*SuperRC) <= TRI->getSpillSize(*BestRC))
1253       continue;
1254     if (!isLegalRC(*TRI, *SuperRC))
1255       continue;
1256     BestRC = SuperRC;
1257   }
1258   return std::make_pair(BestRC, 1);
1259 }
1260 
1261 /// computeRegisterProperties - Once all of the register classes are added,
1262 /// this allows us to compute derived properties we expose.
1263 void TargetLoweringBase::computeRegisterProperties(
1264     const TargetRegisterInfo *TRI) {
1265   // Everything defaults to needing one register.
1266   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1267     NumRegistersForVT[i] = 1;
1268     RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
1269   }
1270   // ...except isVoid, which doesn't need any registers.
1271   NumRegistersForVT[MVT::isVoid] = 0;
1272 
1273   // Find the largest integer register class.
1274   unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
1275   for (; RegClassForVT[LargestIntReg] == nullptr; --LargestIntReg)
1276     assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
1277 
1278   // Every integer value type larger than this largest register takes twice as
1279   // many registers to represent as the previous ValueType.
1280   for (unsigned ExpandedReg = LargestIntReg + 1;
1281        ExpandedReg <= MVT::LAST_INTEGER_VALUETYPE; ++ExpandedReg) {
1282     NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
1283     RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
1284     TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
1285     ValueTypeActions.setTypeAction((MVT::SimpleValueType)ExpandedReg,
1286                                    TypeExpandInteger);
1287   }
1288 
1289   // Inspect all of the ValueType's smaller than the largest integer
1290   // register to see which ones need promotion.
1291   unsigned LegalIntReg = LargestIntReg;
1292   for (unsigned IntReg = LargestIntReg - 1;
1293        IntReg >= (unsigned)MVT::i1; --IntReg) {
1294     MVT IVT = (MVT::SimpleValueType)IntReg;
1295     if (isTypeLegal(IVT)) {
1296       LegalIntReg = IntReg;
1297     } else {
1298       RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
1299         (MVT::SimpleValueType)LegalIntReg;
1300       ValueTypeActions.setTypeAction(IVT, TypePromoteInteger);
1301     }
1302   }
1303 
1304   // ppcf128 type is really two f64's.
1305   if (!isTypeLegal(MVT::ppcf128)) {
1306     if (isTypeLegal(MVT::f64)) {
1307       NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
1308       RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
1309       TransformToType[MVT::ppcf128] = MVT::f64;
1310       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat);
1311     } else {
1312       NumRegistersForVT[MVT::ppcf128] = NumRegistersForVT[MVT::i128];
1313       RegisterTypeForVT[MVT::ppcf128] = RegisterTypeForVT[MVT::i128];
1314       TransformToType[MVT::ppcf128] = MVT::i128;
1315       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeSoftenFloat);
1316     }
1317   }
1318 
1319   // Decide how to handle f128. If the target does not have native f128 support,
1320   // expand it to i128 and we will be generating soft float library calls.
1321   if (!isTypeLegal(MVT::f128)) {
1322     NumRegistersForVT[MVT::f128] = NumRegistersForVT[MVT::i128];
1323     RegisterTypeForVT[MVT::f128] = RegisterTypeForVT[MVT::i128];
1324     TransformToType[MVT::f128] = MVT::i128;
1325     ValueTypeActions.setTypeAction(MVT::f128, TypeSoftenFloat);
1326   }
1327 
1328   // Decide how to handle f80. If the target does not have native f80 support,
1329   // expand it to i96 and we will be generating soft float library calls.
1330   if (!isTypeLegal(MVT::f80)) {
1331     NumRegistersForVT[MVT::f80] = 3*NumRegistersForVT[MVT::i32];
1332     RegisterTypeForVT[MVT::f80] = RegisterTypeForVT[MVT::i32];
1333     TransformToType[MVT::f80] = MVT::i32;
1334     ValueTypeActions.setTypeAction(MVT::f80, TypeSoftenFloat);
1335   }
1336 
1337   // Decide how to handle f64. If the target does not have native f64 support,
1338   // expand it to i64 and we will be generating soft float library calls.
1339   if (!isTypeLegal(MVT::f64)) {
1340     NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
1341     RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
1342     TransformToType[MVT::f64] = MVT::i64;
1343     ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat);
1344   }
1345 
1346   // Decide how to handle f32. If the target does not have native f32 support,
1347   // expand it to i32 and we will be generating soft float library calls.
1348   if (!isTypeLegal(MVT::f32)) {
1349     NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
1350     RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
1351     TransformToType[MVT::f32] = MVT::i32;
1352     ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat);
1353   }
1354 
1355   // Decide how to handle f16. If the target does not have native f16 support,
1356   // promote it to f32, because there are no f16 library calls (except for
1357   // conversions).
1358   if (!isTypeLegal(MVT::f16)) {
1359     // Allow targets to control how we legalize half.
1360     bool SoftPromoteHalfType = softPromoteHalfType();
1361     bool UseFPRegsForHalfType = !SoftPromoteHalfType || useFPRegsForHalfType();
1362 
1363     if (!UseFPRegsForHalfType) {
1364       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::i16];
1365       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::i16];
1366     } else {
1367       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::f32];
1368       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::f32];
1369     }
1370     TransformToType[MVT::f16] = MVT::f32;
1371     if (SoftPromoteHalfType) {
1372       ValueTypeActions.setTypeAction(MVT::f16, TypeSoftPromoteHalf);
1373     } else {
1374       ValueTypeActions.setTypeAction(MVT::f16, TypePromoteFloat);
1375     }
1376   }
1377 
1378   // Decide how to handle bf16. If the target does not have native bf16 support,
1379   // promote it to f32, because there are no bf16 library calls (except for
1380   // converting from f32 to bf16).
1381   if (!isTypeLegal(MVT::bf16)) {
1382     NumRegistersForVT[MVT::bf16] = NumRegistersForVT[MVT::f32];
1383     RegisterTypeForVT[MVT::bf16] = RegisterTypeForVT[MVT::f32];
1384     TransformToType[MVT::bf16] = MVT::f32;
1385     ValueTypeActions.setTypeAction(MVT::bf16, TypeSoftPromoteHalf);
1386   }
1387 
1388   // Loop over all of the vector value types to see which need transformations.
1389   for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
1390        i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
1391     MVT VT = (MVT::SimpleValueType) i;
1392     if (isTypeLegal(VT))
1393       continue;
1394 
1395     MVT EltVT = VT.getVectorElementType();
1396     ElementCount EC = VT.getVectorElementCount();
1397     bool IsLegalWiderType = false;
1398     bool IsScalable = VT.isScalableVector();
1399     LegalizeTypeAction PreferredAction = getPreferredVectorAction(VT);
1400     switch (PreferredAction) {
1401     case TypePromoteInteger: {
1402       MVT::SimpleValueType EndVT = IsScalable ?
1403                                    MVT::LAST_INTEGER_SCALABLE_VECTOR_VALUETYPE :
1404                                    MVT::LAST_INTEGER_FIXEDLEN_VECTOR_VALUETYPE;
1405       // Try to promote the elements of integer vectors. If no legal
1406       // promotion was found, fall through to the widen-vector method.
1407       for (unsigned nVT = i + 1;
1408            (MVT::SimpleValueType)nVT <= EndVT; ++nVT) {
1409         MVT SVT = (MVT::SimpleValueType) nVT;
1410         // Promote vectors of integers to vectors with the same number
1411         // of elements, with a wider element type.
1412         if (SVT.getScalarSizeInBits() > EltVT.getFixedSizeInBits() &&
1413             SVT.getVectorElementCount() == EC && isTypeLegal(SVT)) {
1414           TransformToType[i] = SVT;
1415           RegisterTypeForVT[i] = SVT;
1416           NumRegistersForVT[i] = 1;
1417           ValueTypeActions.setTypeAction(VT, TypePromoteInteger);
1418           IsLegalWiderType = true;
1419           break;
1420         }
1421       }
1422       if (IsLegalWiderType)
1423         break;
1424       [[fallthrough]];
1425     }
1426 
1427     case TypeWidenVector:
1428       if (isPowerOf2_32(EC.getKnownMinValue())) {
1429         // Try to widen the vector.
1430         for (unsigned nVT = i + 1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
1431           MVT SVT = (MVT::SimpleValueType) nVT;
1432           if (SVT.getVectorElementType() == EltVT &&
1433               SVT.isScalableVector() == IsScalable &&
1434               SVT.getVectorElementCount().getKnownMinValue() >
1435                   EC.getKnownMinValue() &&
1436               isTypeLegal(SVT)) {
1437             TransformToType[i] = SVT;
1438             RegisterTypeForVT[i] = SVT;
1439             NumRegistersForVT[i] = 1;
1440             ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1441             IsLegalWiderType = true;
1442             break;
1443           }
1444         }
1445         if (IsLegalWiderType)
1446           break;
1447       } else {
1448         // Only widen to the next power of 2 to keep consistency with EVT.
1449         MVT NVT = VT.getPow2VectorType();
1450         if (isTypeLegal(NVT)) {
1451           TransformToType[i] = NVT;
1452           ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1453           RegisterTypeForVT[i] = NVT;
1454           NumRegistersForVT[i] = 1;
1455           break;
1456         }
1457       }
1458       [[fallthrough]];
1459 
1460     case TypeSplitVector:
1461     case TypeScalarizeVector: {
1462       MVT IntermediateVT;
1463       MVT RegisterVT;
1464       unsigned NumIntermediates;
1465       unsigned NumRegisters = getVectorTypeBreakdownMVT(VT, IntermediateVT,
1466           NumIntermediates, RegisterVT, this);
1467       NumRegistersForVT[i] = NumRegisters;
1468       assert(NumRegistersForVT[i] == NumRegisters &&
1469              "NumRegistersForVT size cannot represent NumRegisters!");
1470       RegisterTypeForVT[i] = RegisterVT;
1471 
1472       MVT NVT = VT.getPow2VectorType();
1473       if (NVT == VT) {
1474         // Type is already a power of 2.  The default action is to split.
1475         TransformToType[i] = MVT::Other;
1476         if (PreferredAction == TypeScalarizeVector)
1477           ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
1478         else if (PreferredAction == TypeSplitVector)
1479           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1480         else if (EC.getKnownMinValue() > 1)
1481           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1482         else
1483           ValueTypeActions.setTypeAction(VT, EC.isScalable()
1484                                                  ? TypeScalarizeScalableVector
1485                                                  : TypeScalarizeVector);
1486       } else {
1487         TransformToType[i] = NVT;
1488         ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1489       }
1490       break;
1491     }
1492     default:
1493       llvm_unreachable("Unknown vector legalization action!");
1494     }
1495   }
1496 
1497   // Determine the 'representative' register class for each value type.
1498   // An representative register class is the largest (meaning one which is
1499   // not a sub-register class / subreg register class) legal register class for
1500   // a group of value types. For example, on i386, i8, i16, and i32
1501   // representative would be GR32; while on x86_64 it's GR64.
1502   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1503     const TargetRegisterClass* RRC;
1504     uint8_t Cost;
1505     std::tie(RRC, Cost) = findRepresentativeClass(TRI, (MVT::SimpleValueType)i);
1506     RepRegClassForVT[i] = RRC;
1507     RepRegClassCostForVT[i] = Cost;
1508   }
1509 }
1510 
1511 EVT TargetLoweringBase::getSetCCResultType(const DataLayout &DL, LLVMContext &,
1512                                            EVT VT) const {
1513   assert(!VT.isVector() && "No default SetCC type for vectors!");
1514   return getPointerTy(DL).SimpleTy;
1515 }
1516 
1517 MVT::SimpleValueType TargetLoweringBase::getCmpLibcallReturnType() const {
1518   return MVT::i32; // return the default value
1519 }
1520 
1521 /// getVectorTypeBreakdown - Vector types are broken down into some number of
1522 /// legal first class types.  For example, MVT::v8f32 maps to 2 MVT::v4f32
1523 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
1524 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
1525 ///
1526 /// This method returns the number of registers needed, and the VT for each
1527 /// register.  It also returns the VT and quantity of the intermediate values
1528 /// before they are promoted/expanded.
1529 unsigned TargetLoweringBase::getVectorTypeBreakdown(LLVMContext &Context,
1530                                                     EVT VT, EVT &IntermediateVT,
1531                                                     unsigned &NumIntermediates,
1532                                                     MVT &RegisterVT) const {
1533   ElementCount EltCnt = VT.getVectorElementCount();
1534 
1535   // If there is a wider vector type with the same element type as this one,
1536   // or a promoted vector type that has the same number of elements which
1537   // are wider, then we should convert to that legal vector type.
1538   // This handles things like <2 x float> -> <4 x float> and
1539   // <4 x i1> -> <4 x i32>.
1540   LegalizeTypeAction TA = getTypeAction(Context, VT);
1541   if (!EltCnt.isScalar() &&
1542       (TA == TypeWidenVector || TA == TypePromoteInteger)) {
1543     EVT RegisterEVT = getTypeToTransformTo(Context, VT);
1544     if (isTypeLegal(RegisterEVT)) {
1545       IntermediateVT = RegisterEVT;
1546       RegisterVT = RegisterEVT.getSimpleVT();
1547       NumIntermediates = 1;
1548       return 1;
1549     }
1550   }
1551 
1552   // Figure out the right, legal destination reg to copy into.
1553   EVT EltTy = VT.getVectorElementType();
1554 
1555   unsigned NumVectorRegs = 1;
1556 
1557   // Scalable vectors cannot be scalarized, so handle the legalisation of the
1558   // types like done elsewhere in SelectionDAG.
1559   if (EltCnt.isScalable()) {
1560     LegalizeKind LK;
1561     EVT PartVT = VT;
1562     do {
1563       // Iterate until we've found a legal (part) type to hold VT.
1564       LK = getTypeConversion(Context, PartVT);
1565       PartVT = LK.second;
1566     } while (LK.first != TypeLegal);
1567 
1568     if (!PartVT.isVector()) {
1569       report_fatal_error(
1570           "Don't know how to legalize this scalable vector type");
1571     }
1572 
1573     NumIntermediates =
1574         divideCeil(VT.getVectorElementCount().getKnownMinValue(),
1575                    PartVT.getVectorElementCount().getKnownMinValue());
1576     IntermediateVT = PartVT;
1577     RegisterVT = getRegisterType(Context, IntermediateVT);
1578     return NumIntermediates;
1579   }
1580 
1581   // FIXME: We don't support non-power-of-2-sized vectors for now.  Ideally
1582   // we could break down into LHS/RHS like LegalizeDAG does.
1583   if (!isPowerOf2_32(EltCnt.getKnownMinValue())) {
1584     NumVectorRegs = EltCnt.getKnownMinValue();
1585     EltCnt = ElementCount::getFixed(1);
1586   }
1587 
1588   // Divide the input until we get to a supported size.  This will always
1589   // end with a scalar if the target doesn't support vectors.
1590   while (EltCnt.getKnownMinValue() > 1 &&
1591          !isTypeLegal(EVT::getVectorVT(Context, EltTy, EltCnt))) {
1592     EltCnt = EltCnt.divideCoefficientBy(2);
1593     NumVectorRegs <<= 1;
1594   }
1595 
1596   NumIntermediates = NumVectorRegs;
1597 
1598   EVT NewVT = EVT::getVectorVT(Context, EltTy, EltCnt);
1599   if (!isTypeLegal(NewVT))
1600     NewVT = EltTy;
1601   IntermediateVT = NewVT;
1602 
1603   MVT DestVT = getRegisterType(Context, NewVT);
1604   RegisterVT = DestVT;
1605 
1606   if (EVT(DestVT).bitsLT(NewVT)) {  // Value is expanded, e.g. i64 -> i16.
1607     TypeSize NewVTSize = NewVT.getSizeInBits();
1608     // Convert sizes such as i33 to i64.
1609     if (!llvm::has_single_bit<uint32_t>(NewVTSize.getKnownMinValue()))
1610       NewVTSize = NewVTSize.coefficientNextPowerOf2();
1611     return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
1612   }
1613 
1614   // Otherwise, promotion or legal types use the same number of registers as
1615   // the vector decimated to the appropriate level.
1616   return NumVectorRegs;
1617 }
1618 
1619 bool TargetLoweringBase::isSuitableForJumpTable(const SwitchInst *SI,
1620                                                 uint64_t NumCases,
1621                                                 uint64_t Range,
1622                                                 ProfileSummaryInfo *PSI,
1623                                                 BlockFrequencyInfo *BFI) const {
1624   // FIXME: This function check the maximum table size and density, but the
1625   // minimum size is not checked. It would be nice if the minimum size is
1626   // also combined within this function. Currently, the minimum size check is
1627   // performed in findJumpTable() in SelectionDAGBuiler and
1628   // getEstimatedNumberOfCaseClusters() in BasicTTIImpl.
1629   const bool OptForSize =
1630       SI->getParent()->getParent()->hasOptSize() ||
1631       llvm::shouldOptimizeForSize(SI->getParent(), PSI, BFI);
1632   const unsigned MinDensity = getMinimumJumpTableDensity(OptForSize);
1633   const unsigned MaxJumpTableSize = getMaximumJumpTableSize();
1634 
1635   // Check whether the number of cases is small enough and
1636   // the range is dense enough for a jump table.
1637   return (OptForSize || Range <= MaxJumpTableSize) &&
1638          (NumCases * 100 >= Range * MinDensity);
1639 }
1640 
1641 MVT TargetLoweringBase::getPreferredSwitchConditionType(LLVMContext &Context,
1642                                                         EVT ConditionVT) const {
1643   return getRegisterType(Context, ConditionVT);
1644 }
1645 
1646 /// Get the EVTs and ArgFlags collections that represent the legalized return
1647 /// type of the given function.  This does not require a DAG or a return value,
1648 /// and is suitable for use before any DAGs for the function are constructed.
1649 /// TODO: Move this out of TargetLowering.cpp.
1650 void llvm::GetReturnInfo(CallingConv::ID CC, Type *ReturnType,
1651                          AttributeList attr,
1652                          SmallVectorImpl<ISD::OutputArg> &Outs,
1653                          const TargetLowering &TLI, const DataLayout &DL) {
1654   SmallVector<EVT, 4> ValueVTs;
1655   ComputeValueVTs(TLI, DL, ReturnType, ValueVTs);
1656   unsigned NumValues = ValueVTs.size();
1657   if (NumValues == 0) return;
1658 
1659   for (unsigned j = 0, f = NumValues; j != f; ++j) {
1660     EVT VT = ValueVTs[j];
1661     ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
1662 
1663     if (attr.hasRetAttr(Attribute::SExt))
1664       ExtendKind = ISD::SIGN_EXTEND;
1665     else if (attr.hasRetAttr(Attribute::ZExt))
1666       ExtendKind = ISD::ZERO_EXTEND;
1667 
1668     if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger())
1669       VT = TLI.getTypeForExtReturn(ReturnType->getContext(), VT, ExtendKind);
1670 
1671     unsigned NumParts =
1672         TLI.getNumRegistersForCallingConv(ReturnType->getContext(), CC, VT);
1673     MVT PartVT =
1674         TLI.getRegisterTypeForCallingConv(ReturnType->getContext(), CC, VT);
1675 
1676     // 'inreg' on function refers to return value
1677     ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
1678     if (attr.hasRetAttr(Attribute::InReg))
1679       Flags.setInReg();
1680 
1681     // Propagate extension type if any
1682     if (attr.hasRetAttr(Attribute::SExt))
1683       Flags.setSExt();
1684     else if (attr.hasRetAttr(Attribute::ZExt))
1685       Flags.setZExt();
1686 
1687     for (unsigned i = 0; i < NumParts; ++i)
1688       Outs.push_back(ISD::OutputArg(Flags, PartVT, VT, /*isfixed=*/true, 0, 0));
1689   }
1690 }
1691 
1692 /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
1693 /// function arguments in the caller parameter area.  This is the actual
1694 /// alignment, not its logarithm.
1695 uint64_t TargetLoweringBase::getByValTypeAlignment(Type *Ty,
1696                                                    const DataLayout &DL) const {
1697   return DL.getABITypeAlign(Ty).value();
1698 }
1699 
1700 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1701     LLVMContext &Context, const DataLayout &DL, EVT VT, unsigned AddrSpace,
1702     Align Alignment, MachineMemOperand::Flags Flags, unsigned *Fast) const {
1703   // Check if the specified alignment is sufficient based on the data layout.
1704   // TODO: While using the data layout works in practice, a better solution
1705   // would be to implement this check directly (make this a virtual function).
1706   // For example, the ABI alignment may change based on software platform while
1707   // this function should only be affected by hardware implementation.
1708   Type *Ty = VT.getTypeForEVT(Context);
1709   if (VT.isZeroSized() || Alignment >= DL.getABITypeAlign(Ty)) {
1710     // Assume that an access that meets the ABI-specified alignment is fast.
1711     if (Fast != nullptr)
1712       *Fast = 1;
1713     return true;
1714   }
1715 
1716   // This is a misaligned access.
1717   return allowsMisalignedMemoryAccesses(VT, AddrSpace, Alignment, Flags, Fast);
1718 }
1719 
1720 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1721     LLVMContext &Context, const DataLayout &DL, EVT VT,
1722     const MachineMemOperand &MMO, unsigned *Fast) const {
1723   return allowsMemoryAccessForAlignment(Context, DL, VT, MMO.getAddrSpace(),
1724                                         MMO.getAlign(), MMO.getFlags(), Fast);
1725 }
1726 
1727 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1728                                             const DataLayout &DL, EVT VT,
1729                                             unsigned AddrSpace, Align Alignment,
1730                                             MachineMemOperand::Flags Flags,
1731                                             unsigned *Fast) const {
1732   return allowsMemoryAccessForAlignment(Context, DL, VT, AddrSpace, Alignment,
1733                                         Flags, Fast);
1734 }
1735 
1736 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1737                                             const DataLayout &DL, EVT VT,
1738                                             const MachineMemOperand &MMO,
1739                                             unsigned *Fast) const {
1740   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1741                             MMO.getFlags(), Fast);
1742 }
1743 
1744 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1745                                             const DataLayout &DL, LLT Ty,
1746                                             const MachineMemOperand &MMO,
1747                                             unsigned *Fast) const {
1748   EVT VT = getApproximateEVTForLLT(Ty, DL, Context);
1749   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1750                             MMO.getFlags(), Fast);
1751 }
1752 
1753 //===----------------------------------------------------------------------===//
1754 //  TargetTransformInfo Helpers
1755 //===----------------------------------------------------------------------===//
1756 
1757 int TargetLoweringBase::InstructionOpcodeToISD(unsigned Opcode) const {
1758   enum InstructionOpcodes {
1759 #define HANDLE_INST(NUM, OPCODE, CLASS) OPCODE = NUM,
1760 #define LAST_OTHER_INST(NUM) InstructionOpcodesCount = NUM
1761 #include "llvm/IR/Instruction.def"
1762   };
1763   switch (static_cast<InstructionOpcodes>(Opcode)) {
1764   case Ret:            return 0;
1765   case Br:             return 0;
1766   case Switch:         return 0;
1767   case IndirectBr:     return 0;
1768   case Invoke:         return 0;
1769   case CallBr:         return 0;
1770   case Resume:         return 0;
1771   case Unreachable:    return 0;
1772   case CleanupRet:     return 0;
1773   case CatchRet:       return 0;
1774   case CatchPad:       return 0;
1775   case CatchSwitch:    return 0;
1776   case CleanupPad:     return 0;
1777   case FNeg:           return ISD::FNEG;
1778   case Add:            return ISD::ADD;
1779   case FAdd:           return ISD::FADD;
1780   case Sub:            return ISD::SUB;
1781   case FSub:           return ISD::FSUB;
1782   case Mul:            return ISD::MUL;
1783   case FMul:           return ISD::FMUL;
1784   case UDiv:           return ISD::UDIV;
1785   case SDiv:           return ISD::SDIV;
1786   case FDiv:           return ISD::FDIV;
1787   case URem:           return ISD::UREM;
1788   case SRem:           return ISD::SREM;
1789   case FRem:           return ISD::FREM;
1790   case Shl:            return ISD::SHL;
1791   case LShr:           return ISD::SRL;
1792   case AShr:           return ISD::SRA;
1793   case And:            return ISD::AND;
1794   case Or:             return ISD::OR;
1795   case Xor:            return ISD::XOR;
1796   case Alloca:         return 0;
1797   case Load:           return ISD::LOAD;
1798   case Store:          return ISD::STORE;
1799   case GetElementPtr:  return 0;
1800   case Fence:          return 0;
1801   case AtomicCmpXchg:  return 0;
1802   case AtomicRMW:      return 0;
1803   case Trunc:          return ISD::TRUNCATE;
1804   case ZExt:           return ISD::ZERO_EXTEND;
1805   case SExt:           return ISD::SIGN_EXTEND;
1806   case FPToUI:         return ISD::FP_TO_UINT;
1807   case FPToSI:         return ISD::FP_TO_SINT;
1808   case UIToFP:         return ISD::UINT_TO_FP;
1809   case SIToFP:         return ISD::SINT_TO_FP;
1810   case FPTrunc:        return ISD::FP_ROUND;
1811   case FPExt:          return ISD::FP_EXTEND;
1812   case PtrToInt:       return ISD::BITCAST;
1813   case IntToPtr:       return ISD::BITCAST;
1814   case BitCast:        return ISD::BITCAST;
1815   case AddrSpaceCast:  return ISD::ADDRSPACECAST;
1816   case ICmp:           return ISD::SETCC;
1817   case FCmp:           return ISD::SETCC;
1818   case PHI:            return 0;
1819   case Call:           return 0;
1820   case Select:         return ISD::SELECT;
1821   case UserOp1:        return 0;
1822   case UserOp2:        return 0;
1823   case VAArg:          return 0;
1824   case ExtractElement: return ISD::EXTRACT_VECTOR_ELT;
1825   case InsertElement:  return ISD::INSERT_VECTOR_ELT;
1826   case ShuffleVector:  return ISD::VECTOR_SHUFFLE;
1827   case ExtractValue:   return ISD::MERGE_VALUES;
1828   case InsertValue:    return ISD::MERGE_VALUES;
1829   case LandingPad:     return 0;
1830   case Freeze:         return ISD::FREEZE;
1831   }
1832 
1833   llvm_unreachable("Unknown instruction type encountered!");
1834 }
1835 
1836 Value *
1837 TargetLoweringBase::getDefaultSafeStackPointerLocation(IRBuilderBase &IRB,
1838                                                        bool UseTLS) const {
1839   // compiler-rt provides a variable with a magic name.  Targets that do not
1840   // link with compiler-rt may also provide such a variable.
1841   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1842   const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
1843   auto UnsafeStackPtr =
1844       dyn_cast_or_null<GlobalVariable>(M->getNamedValue(UnsafeStackPtrVar));
1845 
1846   Type *StackPtrTy = PointerType::getUnqual(M->getContext());
1847 
1848   if (!UnsafeStackPtr) {
1849     auto TLSModel = UseTLS ?
1850         GlobalValue::InitialExecTLSModel :
1851         GlobalValue::NotThreadLocal;
1852     // The global variable is not defined yet, define it ourselves.
1853     // We use the initial-exec TLS model because we do not support the
1854     // variable living anywhere other than in the main executable.
1855     UnsafeStackPtr = new GlobalVariable(
1856         *M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
1857         UnsafeStackPtrVar, nullptr, TLSModel);
1858   } else {
1859     // The variable exists, check its type and attributes.
1860     if (UnsafeStackPtr->getValueType() != StackPtrTy)
1861       report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
1862     if (UseTLS != UnsafeStackPtr->isThreadLocal())
1863       report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
1864                          (UseTLS ? "" : "not ") + "be thread-local");
1865   }
1866   return UnsafeStackPtr;
1867 }
1868 
1869 Value *
1870 TargetLoweringBase::getSafeStackPointerLocation(IRBuilderBase &IRB) const {
1871   if (!TM.getTargetTriple().isAndroid())
1872     return getDefaultSafeStackPointerLocation(IRB, true);
1873 
1874   // Android provides a libc function to retrieve the address of the current
1875   // thread's unsafe stack pointer.
1876   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1877   auto *PtrTy = PointerType::getUnqual(M->getContext());
1878   FunctionCallee Fn =
1879       M->getOrInsertFunction("__safestack_pointer_address", PtrTy);
1880   return IRB.CreateCall(Fn);
1881 }
1882 
1883 //===----------------------------------------------------------------------===//
1884 //  Loop Strength Reduction hooks
1885 //===----------------------------------------------------------------------===//
1886 
1887 /// isLegalAddressingMode - Return true if the addressing mode represented
1888 /// by AM is legal for this target, for a load/store of the specified type.
1889 bool TargetLoweringBase::isLegalAddressingMode(const DataLayout &DL,
1890                                                const AddrMode &AM, Type *Ty,
1891                                                unsigned AS, Instruction *I) const {
1892   // The default implementation of this implements a conservative RISCy, r+r and
1893   // r+i addr mode.
1894 
1895   // Scalable offsets not supported
1896   if (AM.ScalableOffset)
1897     return false;
1898 
1899   // Allows a sign-extended 16-bit immediate field.
1900   if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
1901     return false;
1902 
1903   // No global is ever allowed as a base.
1904   if (AM.BaseGV)
1905     return false;
1906 
1907   // Only support r+r,
1908   switch (AM.Scale) {
1909   case 0:  // "r+i" or just "i", depending on HasBaseReg.
1910     break;
1911   case 1:
1912     if (AM.HasBaseReg && AM.BaseOffs)  // "r+r+i" is not allowed.
1913       return false;
1914     // Otherwise we have r+r or r+i.
1915     break;
1916   case 2:
1917     if (AM.HasBaseReg || AM.BaseOffs)  // 2*r+r  or  2*r+i is not allowed.
1918       return false;
1919     // Allow 2*r as r+r.
1920     break;
1921   default: // Don't allow n * r
1922     return false;
1923   }
1924 
1925   return true;
1926 }
1927 
1928 //===----------------------------------------------------------------------===//
1929 //  Stack Protector
1930 //===----------------------------------------------------------------------===//
1931 
1932 // For OpenBSD return its special guard variable. Otherwise return nullptr,
1933 // so that SelectionDAG handle SSP.
1934 Value *TargetLoweringBase::getIRStackGuard(IRBuilderBase &IRB) const {
1935   if (getTargetMachine().getTargetTriple().isOSOpenBSD()) {
1936     Module &M = *IRB.GetInsertBlock()->getParent()->getParent();
1937     PointerType *PtrTy = PointerType::getUnqual(M.getContext());
1938     Constant *C = M.getOrInsertGlobal("__guard_local", PtrTy);
1939     if (GlobalVariable *G = dyn_cast_or_null<GlobalVariable>(C))
1940       G->setVisibility(GlobalValue::HiddenVisibility);
1941     return C;
1942   }
1943   return nullptr;
1944 }
1945 
1946 // Currently only support "standard" __stack_chk_guard.
1947 // TODO: add LOAD_STACK_GUARD support.
1948 void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
1949   if (!M.getNamedValue("__stack_chk_guard")) {
1950     auto *GV = new GlobalVariable(M, PointerType::getUnqual(M.getContext()),
1951                                   false, GlobalVariable::ExternalLinkage,
1952                                   nullptr, "__stack_chk_guard");
1953 
1954     // FreeBSD has "__stack_chk_guard" defined externally on libc.so
1955     if (M.getDirectAccessExternalData() &&
1956         !TM.getTargetTriple().isWindowsGNUEnvironment() &&
1957         !(TM.getTargetTriple().isPPC64() &&
1958           TM.getTargetTriple().isOSFreeBSD()) &&
1959         (!TM.getTargetTriple().isOSDarwin() ||
1960          TM.getRelocationModel() == Reloc::Static))
1961       GV->setDSOLocal(true);
1962   }
1963 }
1964 
1965 // Currently only support "standard" __stack_chk_guard.
1966 // TODO: add LOAD_STACK_GUARD support.
1967 Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
1968   return M.getNamedValue("__stack_chk_guard");
1969 }
1970 
1971 Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
1972   return nullptr;
1973 }
1974 
1975 unsigned TargetLoweringBase::getMinimumJumpTableEntries() const {
1976   return MinimumJumpTableEntries;
1977 }
1978 
1979 void TargetLoweringBase::setMinimumJumpTableEntries(unsigned Val) {
1980   MinimumJumpTableEntries = Val;
1981 }
1982 
1983 unsigned TargetLoweringBase::getMinimumJumpTableDensity(bool OptForSize) const {
1984   return OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
1985 }
1986 
1987 unsigned TargetLoweringBase::getMaximumJumpTableSize() const {
1988   return MaximumJumpTableSize;
1989 }
1990 
1991 void TargetLoweringBase::setMaximumJumpTableSize(unsigned Val) {
1992   MaximumJumpTableSize = Val;
1993 }
1994 
1995 bool TargetLoweringBase::isJumpTableRelative() const {
1996   return getTargetMachine().isPositionIndependent();
1997 }
1998 
1999 Align TargetLoweringBase::getPrefLoopAlignment(MachineLoop *ML) const {
2000   if (TM.Options.LoopAlignment)
2001     return Align(TM.Options.LoopAlignment);
2002   return PrefLoopAlignment;
2003 }
2004 
2005 unsigned TargetLoweringBase::getMaxPermittedBytesForAlignment(
2006     MachineBasicBlock *MBB) const {
2007   return MaxBytesForAlignment;
2008 }
2009 
2010 //===----------------------------------------------------------------------===//
2011 //  Reciprocal Estimates
2012 //===----------------------------------------------------------------------===//
2013 
2014 /// Get the reciprocal estimate attribute string for a function that will
2015 /// override the target defaults.
2016 static StringRef getRecipEstimateForFunc(MachineFunction &MF) {
2017   const Function &F = MF.getFunction();
2018   return F.getFnAttribute("reciprocal-estimates").getValueAsString();
2019 }
2020 
2021 /// Construct a string for the given reciprocal operation of the given type.
2022 /// This string should match the corresponding option to the front-end's
2023 /// "-mrecip" flag assuming those strings have been passed through in an
2024 /// attribute string. For example, "vec-divf" for a division of a vXf32.
2025 static std::string getReciprocalOpName(bool IsSqrt, EVT VT) {
2026   std::string Name = VT.isVector() ? "vec-" : "";
2027 
2028   Name += IsSqrt ? "sqrt" : "div";
2029 
2030   // TODO: Handle other float types?
2031   if (VT.getScalarType() == MVT::f64) {
2032     Name += "d";
2033   } else if (VT.getScalarType() == MVT::f16) {
2034     Name += "h";
2035   } else {
2036     assert(VT.getScalarType() == MVT::f32 &&
2037            "Unexpected FP type for reciprocal estimate");
2038     Name += "f";
2039   }
2040 
2041   return Name;
2042 }
2043 
2044 /// Return the character position and value (a single numeric character) of a
2045 /// customized refinement operation in the input string if it exists. Return
2046 /// false if there is no customized refinement step count.
2047 static bool parseRefinementStep(StringRef In, size_t &Position,
2048                                 uint8_t &Value) {
2049   const char RefStepToken = ':';
2050   Position = In.find(RefStepToken);
2051   if (Position == StringRef::npos)
2052     return false;
2053 
2054   StringRef RefStepString = In.substr(Position + 1);
2055   // Allow exactly one numeric character for the additional refinement
2056   // step parameter.
2057   if (RefStepString.size() == 1) {
2058     char RefStepChar = RefStepString[0];
2059     if (isDigit(RefStepChar)) {
2060       Value = RefStepChar - '0';
2061       return true;
2062     }
2063   }
2064   report_fatal_error("Invalid refinement step for -recip.");
2065 }
2066 
2067 /// For the input attribute string, return one of the ReciprocalEstimate enum
2068 /// status values (enabled, disabled, or not specified) for this operation on
2069 /// the specified data type.
2070 static int getOpEnabled(bool IsSqrt, EVT VT, StringRef Override) {
2071   if (Override.empty())
2072     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2073 
2074   SmallVector<StringRef, 4> OverrideVector;
2075   Override.split(OverrideVector, ',');
2076   unsigned NumArgs = OverrideVector.size();
2077 
2078   // Check if "all", "none", or "default" was specified.
2079   if (NumArgs == 1) {
2080     // Look for an optional setting of the number of refinement steps needed
2081     // for this type of reciprocal operation.
2082     size_t RefPos;
2083     uint8_t RefSteps;
2084     if (parseRefinementStep(Override, RefPos, RefSteps)) {
2085       // Split the string for further processing.
2086       Override = Override.substr(0, RefPos);
2087     }
2088 
2089     // All reciprocal types are enabled.
2090     if (Override == "all")
2091       return TargetLoweringBase::ReciprocalEstimate::Enabled;
2092 
2093     // All reciprocal types are disabled.
2094     if (Override == "none")
2095       return TargetLoweringBase::ReciprocalEstimate::Disabled;
2096 
2097     // Target defaults for enablement are used.
2098     if (Override == "default")
2099       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2100   }
2101 
2102   // The attribute string may omit the size suffix ('f'/'d').
2103   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2104   std::string VTNameNoSize = VTName;
2105   VTNameNoSize.pop_back();
2106   static const char DisabledPrefix = '!';
2107 
2108   for (StringRef RecipType : OverrideVector) {
2109     size_t RefPos;
2110     uint8_t RefSteps;
2111     if (parseRefinementStep(RecipType, RefPos, RefSteps))
2112       RecipType = RecipType.substr(0, RefPos);
2113 
2114     // Ignore the disablement token for string matching.
2115     bool IsDisabled = RecipType[0] == DisabledPrefix;
2116     if (IsDisabled)
2117       RecipType = RecipType.substr(1);
2118 
2119     if (RecipType == VTName || RecipType == VTNameNoSize)
2120       return IsDisabled ? TargetLoweringBase::ReciprocalEstimate::Disabled
2121                         : TargetLoweringBase::ReciprocalEstimate::Enabled;
2122   }
2123 
2124   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2125 }
2126 
2127 /// For the input attribute string, return the customized refinement step count
2128 /// for this operation on the specified data type. If the step count does not
2129 /// exist, return the ReciprocalEstimate enum value for unspecified.
2130 static int getOpRefinementSteps(bool IsSqrt, EVT VT, StringRef Override) {
2131   if (Override.empty())
2132     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2133 
2134   SmallVector<StringRef, 4> OverrideVector;
2135   Override.split(OverrideVector, ',');
2136   unsigned NumArgs = OverrideVector.size();
2137 
2138   // Check if "all", "default", or "none" was specified.
2139   if (NumArgs == 1) {
2140     // Look for an optional setting of the number of refinement steps needed
2141     // for this type of reciprocal operation.
2142     size_t RefPos;
2143     uint8_t RefSteps;
2144     if (!parseRefinementStep(Override, RefPos, RefSteps))
2145       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2146 
2147     // Split the string for further processing.
2148     Override = Override.substr(0, RefPos);
2149     assert(Override != "none" &&
2150            "Disabled reciprocals, but specifed refinement steps?");
2151 
2152     // If this is a general override, return the specified number of steps.
2153     if (Override == "all" || Override == "default")
2154       return RefSteps;
2155   }
2156 
2157   // The attribute string may omit the size suffix ('f'/'d').
2158   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2159   std::string VTNameNoSize = VTName;
2160   VTNameNoSize.pop_back();
2161 
2162   for (StringRef RecipType : OverrideVector) {
2163     size_t RefPos;
2164     uint8_t RefSteps;
2165     if (!parseRefinementStep(RecipType, RefPos, RefSteps))
2166       continue;
2167 
2168     RecipType = RecipType.substr(0, RefPos);
2169     if (RecipType == VTName || RecipType == VTNameNoSize)
2170       return RefSteps;
2171   }
2172 
2173   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2174 }
2175 
2176 int TargetLoweringBase::getRecipEstimateSqrtEnabled(EVT VT,
2177                                                     MachineFunction &MF) const {
2178   return getOpEnabled(true, VT, getRecipEstimateForFunc(MF));
2179 }
2180 
2181 int TargetLoweringBase::getRecipEstimateDivEnabled(EVT VT,
2182                                                    MachineFunction &MF) const {
2183   return getOpEnabled(false, VT, getRecipEstimateForFunc(MF));
2184 }
2185 
2186 int TargetLoweringBase::getSqrtRefinementSteps(EVT VT,
2187                                                MachineFunction &MF) const {
2188   return getOpRefinementSteps(true, VT, getRecipEstimateForFunc(MF));
2189 }
2190 
2191 int TargetLoweringBase::getDivRefinementSteps(EVT VT,
2192                                               MachineFunction &MF) const {
2193   return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
2194 }
2195 
2196 bool TargetLoweringBase::isLoadBitCastBeneficial(
2197     EVT LoadVT, EVT BitcastVT, const SelectionDAG &DAG,
2198     const MachineMemOperand &MMO) const {
2199   // Single-element vectors are scalarized, so we should generally avoid having
2200   // any memory operations on such types, as they would get scalarized too.
2201   if (LoadVT.isFixedLengthVector() && BitcastVT.isFixedLengthVector() &&
2202       BitcastVT.getVectorNumElements() == 1)
2203     return false;
2204 
2205   // Don't do if we could do an indexed load on the original type, but not on
2206   // the new one.
2207   if (!LoadVT.isSimple() || !BitcastVT.isSimple())
2208     return true;
2209 
2210   MVT LoadMVT = LoadVT.getSimpleVT();
2211 
2212   // Don't bother doing this if it's just going to be promoted again later, as
2213   // doing so might interfere with other combines.
2214   if (getOperationAction(ISD::LOAD, LoadMVT) == Promote &&
2215       getTypeToPromoteTo(ISD::LOAD, LoadMVT) == BitcastVT.getSimpleVT())
2216     return false;
2217 
2218   unsigned Fast = 0;
2219   return allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), BitcastVT,
2220                             MMO, &Fast) &&
2221          Fast;
2222 }
2223 
2224 void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
2225   MF.getRegInfo().freezeReservedRegs();
2226 }
2227 
2228 MachineMemOperand::Flags TargetLoweringBase::getLoadMemOperandFlags(
2229     const LoadInst &LI, const DataLayout &DL, AssumptionCache *AC,
2230     const TargetLibraryInfo *LibInfo) const {
2231   MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad;
2232   if (LI.isVolatile())
2233     Flags |= MachineMemOperand::MOVolatile;
2234 
2235   if (LI.hasMetadata(LLVMContext::MD_nontemporal))
2236     Flags |= MachineMemOperand::MONonTemporal;
2237 
2238   if (LI.hasMetadata(LLVMContext::MD_invariant_load))
2239     Flags |= MachineMemOperand::MOInvariant;
2240 
2241   if (isDereferenceableAndAlignedPointer(LI.getPointerOperand(), LI.getType(),
2242                                          LI.getAlign(), DL, &LI, AC,
2243                                          /*DT=*/nullptr, LibInfo))
2244     Flags |= MachineMemOperand::MODereferenceable;
2245 
2246   Flags |= getTargetMMOFlags(LI);
2247   return Flags;
2248 }
2249 
2250 MachineMemOperand::Flags
2251 TargetLoweringBase::getStoreMemOperandFlags(const StoreInst &SI,
2252                                             const DataLayout &DL) const {
2253   MachineMemOperand::Flags Flags = MachineMemOperand::MOStore;
2254 
2255   if (SI.isVolatile())
2256     Flags |= MachineMemOperand::MOVolatile;
2257 
2258   if (SI.hasMetadata(LLVMContext::MD_nontemporal))
2259     Flags |= MachineMemOperand::MONonTemporal;
2260 
2261   // FIXME: Not preserving dereferenceable
2262   Flags |= getTargetMMOFlags(SI);
2263   return Flags;
2264 }
2265 
2266 MachineMemOperand::Flags
2267 TargetLoweringBase::getAtomicMemOperandFlags(const Instruction &AI,
2268                                              const DataLayout &DL) const {
2269   auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
2270 
2271   if (const AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(&AI)) {
2272     if (RMW->isVolatile())
2273       Flags |= MachineMemOperand::MOVolatile;
2274   } else if (const AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(&AI)) {
2275     if (CmpX->isVolatile())
2276       Flags |= MachineMemOperand::MOVolatile;
2277   } else
2278     llvm_unreachable("not an atomic instruction");
2279 
2280   // FIXME: Not preserving dereferenceable
2281   Flags |= getTargetMMOFlags(AI);
2282   return Flags;
2283 }
2284 
2285 Instruction *TargetLoweringBase::emitLeadingFence(IRBuilderBase &Builder,
2286                                                   Instruction *Inst,
2287                                                   AtomicOrdering Ord) const {
2288   if (isReleaseOrStronger(Ord) && Inst->hasAtomicStore())
2289     return Builder.CreateFence(Ord);
2290   else
2291     return nullptr;
2292 }
2293 
2294 Instruction *TargetLoweringBase::emitTrailingFence(IRBuilderBase &Builder,
2295                                                    Instruction *Inst,
2296                                                    AtomicOrdering Ord) const {
2297   if (isAcquireOrStronger(Ord))
2298     return Builder.CreateFence(Ord);
2299   else
2300     return nullptr;
2301 }
2302 
2303 //===----------------------------------------------------------------------===//
2304 //  GlobalISel Hooks
2305 //===----------------------------------------------------------------------===//
2306 
2307 bool TargetLoweringBase::shouldLocalize(const MachineInstr &MI,
2308                                         const TargetTransformInfo *TTI) const {
2309   auto &MF = *MI.getMF();
2310   auto &MRI = MF.getRegInfo();
2311   // Assuming a spill and reload of a value has a cost of 1 instruction each,
2312   // this helper function computes the maximum number of uses we should consider
2313   // for remat. E.g. on arm64 global addresses take 2 insts to materialize. We
2314   // break even in terms of code size when the original MI has 2 users vs
2315   // choosing to potentially spill. Any more than 2 users we we have a net code
2316   // size increase. This doesn't take into account register pressure though.
2317   auto maxUses = [](unsigned RematCost) {
2318     // A cost of 1 means remats are basically free.
2319     if (RematCost == 1)
2320       return std::numeric_limits<unsigned>::max();
2321     if (RematCost == 2)
2322       return 2U;
2323 
2324     // Remat is too expensive, only sink if there's one user.
2325     if (RematCost > 2)
2326       return 1U;
2327     llvm_unreachable("Unexpected remat cost");
2328   };
2329 
2330   switch (MI.getOpcode()) {
2331   default:
2332     return false;
2333   // Constants-like instructions should be close to their users.
2334   // We don't want long live-ranges for them.
2335   case TargetOpcode::G_CONSTANT:
2336   case TargetOpcode::G_FCONSTANT:
2337   case TargetOpcode::G_FRAME_INDEX:
2338   case TargetOpcode::G_INTTOPTR:
2339     return true;
2340   case TargetOpcode::G_GLOBAL_VALUE: {
2341     unsigned RematCost = TTI->getGISelRematGlobalCost();
2342     Register Reg = MI.getOperand(0).getReg();
2343     unsigned MaxUses = maxUses(RematCost);
2344     if (MaxUses == UINT_MAX)
2345       return true; // Remats are "free" so always localize.
2346     return MRI.hasAtMostUserInstrs(Reg, MaxUses);
2347   }
2348   }
2349 }
2350