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/Triple.h"
19 #include "llvm/ADT/Twine.h"
20 #include "llvm/CodeGen/Analysis.h"
21 #include "llvm/CodeGen/ISDOpcodes.h"
22 #include "llvm/CodeGen/MachineBasicBlock.h"
23 #include "llvm/CodeGen/MachineFrameInfo.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/CodeGen/MachineInstr.h"
26 #include "llvm/CodeGen/MachineInstrBuilder.h"
27 #include "llvm/CodeGen/MachineMemOperand.h"
28 #include "llvm/CodeGen/MachineOperand.h"
29 #include "llvm/CodeGen/MachineRegisterInfo.h"
30 #include "llvm/CodeGen/RuntimeLibcalls.h"
31 #include "llvm/CodeGen/StackMaps.h"
32 #include "llvm/CodeGen/TargetLowering.h"
33 #include "llvm/CodeGen/TargetOpcodes.h"
34 #include "llvm/CodeGen/TargetRegisterInfo.h"
35 #include "llvm/CodeGen/ValueTypes.h"
36 #include "llvm/IR/Attributes.h"
37 #include "llvm/IR/CallingConv.h"
38 #include "llvm/IR/DataLayout.h"
39 #include "llvm/IR/DerivedTypes.h"
40 #include "llvm/IR/Function.h"
41 #include "llvm/IR/GlobalValue.h"
42 #include "llvm/IR/GlobalVariable.h"
43 #include "llvm/IR/IRBuilder.h"
44 #include "llvm/IR/Module.h"
45 #include "llvm/IR/Type.h"
46 #include "llvm/Support/BranchProbability.h"
47 #include "llvm/Support/Casting.h"
48 #include "llvm/Support/CommandLine.h"
49 #include "llvm/Support/Compiler.h"
50 #include "llvm/Support/ErrorHandling.h"
51 #include "llvm/Support/MachineValueType.h"
52 #include "llvm/Support/MathExtras.h"
53 #include "llvm/Target/TargetMachine.h"
54 #include <algorithm>
55 #include <cassert>
56 #include <cstddef>
57 #include <cstdint>
58 #include <cstring>
59 #include <iterator>
60 #include <string>
61 #include <tuple>
62 #include <utility>
63 
64 using namespace llvm;
65 
66 static cl::opt<bool> JumpIsExpensiveOverride(
67     "jump-is-expensive", cl::init(false),
68     cl::desc("Do not create extra branches to split comparison logic."),
69     cl::Hidden);
70 
71 static cl::opt<unsigned> MinimumJumpTableEntries
72   ("min-jump-table-entries", cl::init(4), cl::Hidden,
73    cl::desc("Set minimum number of entries to use a jump table."));
74 
75 static cl::opt<unsigned> MaximumJumpTableSize
76   ("max-jump-table-size", cl::init(UINT_MAX), cl::Hidden,
77    cl::desc("Set maximum size of jump tables."));
78 
79 /// Minimum jump table density for normal functions.
80 static cl::opt<unsigned>
81     JumpTableDensity("jump-table-density", cl::init(10), cl::Hidden,
82                      cl::desc("Minimum density for building a jump table in "
83                               "a normal function"));
84 
85 /// Minimum jump table density for -Os or -Oz functions.
86 static cl::opt<unsigned> OptsizeJumpTableDensity(
87     "optsize-jump-table-density", cl::init(40), cl::Hidden,
88     cl::desc("Minimum density for building a jump table in "
89              "an optsize function"));
90 
91 static bool darwinHasSinCos(const Triple &TT) {
92   assert(TT.isOSDarwin() && "should be called with darwin triple");
93   // Don't bother with 32 bit x86.
94   if (TT.getArch() == Triple::x86)
95     return false;
96   // Macos < 10.9 has no sincos_stret.
97   if (TT.isMacOSX())
98     return !TT.isMacOSXVersionLT(10, 9) && TT.isArch64Bit();
99   // iOS < 7.0 has no sincos_stret.
100   if (TT.isiOS())
101     return !TT.isOSVersionLT(7, 0);
102   // Any other darwin such as WatchOS/TvOS is new enough.
103   return true;
104 }
105 
106 // Although this default value is arbitrary, it is not random. It is assumed
107 // that a condition that evaluates the same way by a higher percentage than this
108 // is best represented as control flow. Therefore, the default value N should be
109 // set such that the win from N% correct executions is greater than the loss
110 // from (100 - N)% mispredicted executions for the majority of intended targets.
111 static cl::opt<int> MinPercentageForPredictableBranch(
112     "min-predictable-branch", cl::init(99),
113     cl::desc("Minimum percentage (0-100) that a condition must be either true "
114              "or false to assume that the condition is predictable"),
115     cl::Hidden);
116 
117 void TargetLoweringBase::InitLibcalls(const Triple &TT) {
118 #define HANDLE_LIBCALL(code, name) \
119   setLibcallName(RTLIB::code, name);
120 #include "llvm/IR/RuntimeLibcalls.def"
121 #undef HANDLE_LIBCALL
122   // Initialize calling conventions to their default.
123   for (int LC = 0; LC < RTLIB::UNKNOWN_LIBCALL; ++LC)
124     setLibcallCallingConv((RTLIB::Libcall)LC, CallingConv::C);
125 
126   // A few names are different on particular architectures or environments.
127   if (TT.isOSDarwin()) {
128     // For f16/f32 conversions, Darwin uses the standard naming scheme, instead
129     // of the gnueabi-style __gnu_*_ieee.
130     // FIXME: What about other targets?
131     setLibcallName(RTLIB::FPEXT_F16_F32, "__extendhfsf2");
132     setLibcallName(RTLIB::FPROUND_F32_F16, "__truncsfhf2");
133 
134     // Some darwins have an optimized __bzero/bzero function.
135     switch (TT.getArch()) {
136     case Triple::x86:
137     case Triple::x86_64:
138       if (TT.isMacOSX() && !TT.isMacOSXVersionLT(10, 6))
139         setLibcallName(RTLIB::BZERO, "__bzero");
140       break;
141     case Triple::aarch64:
142       setLibcallName(RTLIB::BZERO, "bzero");
143       break;
144     default:
145       break;
146     }
147 
148     if (darwinHasSinCos(TT)) {
149       setLibcallName(RTLIB::SINCOS_STRET_F32, "__sincosf_stret");
150       setLibcallName(RTLIB::SINCOS_STRET_F64, "__sincos_stret");
151       if (TT.isWatchABI()) {
152         setLibcallCallingConv(RTLIB::SINCOS_STRET_F32,
153                               CallingConv::ARM_AAPCS_VFP);
154         setLibcallCallingConv(RTLIB::SINCOS_STRET_F64,
155                               CallingConv::ARM_AAPCS_VFP);
156       }
157     }
158   } else {
159     setLibcallName(RTLIB::FPEXT_F16_F32, "__gnu_h2f_ieee");
160     setLibcallName(RTLIB::FPROUND_F32_F16, "__gnu_f2h_ieee");
161   }
162 
163   if (TT.isGNUEnvironment() || TT.isOSFuchsia() ||
164       (TT.isAndroid() && !TT.isAndroidVersionLT(9))) {
165     setLibcallName(RTLIB::SINCOS_F32, "sincosf");
166     setLibcallName(RTLIB::SINCOS_F64, "sincos");
167     setLibcallName(RTLIB::SINCOS_F80, "sincosl");
168     setLibcallName(RTLIB::SINCOS_F128, "sincosl");
169     setLibcallName(RTLIB::SINCOS_PPCF128, "sincosl");
170   }
171 
172   if (TT.isOSOpenBSD()) {
173     setLibcallName(RTLIB::STACKPROTECTOR_CHECK_FAIL, nullptr);
174   }
175 }
176 
177 /// getFPEXT - Return the FPEXT_*_* value for the given types, or
178 /// UNKNOWN_LIBCALL if there is none.
179 RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) {
180   if (OpVT == MVT::f16) {
181     if (RetVT == MVT::f32)
182       return FPEXT_F16_F32;
183   } else if (OpVT == MVT::f32) {
184     if (RetVT == MVT::f64)
185       return FPEXT_F32_F64;
186     if (RetVT == MVT::f128)
187       return FPEXT_F32_F128;
188     if (RetVT == MVT::ppcf128)
189       return FPEXT_F32_PPCF128;
190   } else if (OpVT == MVT::f64) {
191     if (RetVT == MVT::f128)
192       return FPEXT_F64_F128;
193     else if (RetVT == MVT::ppcf128)
194       return FPEXT_F64_PPCF128;
195   } else if (OpVT == MVT::f80) {
196     if (RetVT == MVT::f128)
197       return FPEXT_F80_F128;
198   }
199 
200   return UNKNOWN_LIBCALL;
201 }
202 
203 /// getFPROUND - Return the FPROUND_*_* value for the given types, or
204 /// UNKNOWN_LIBCALL if there is none.
205 RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) {
206   if (RetVT == MVT::f16) {
207     if (OpVT == MVT::f32)
208       return FPROUND_F32_F16;
209     if (OpVT == MVT::f64)
210       return FPROUND_F64_F16;
211     if (OpVT == MVT::f80)
212       return FPROUND_F80_F16;
213     if (OpVT == MVT::f128)
214       return FPROUND_F128_F16;
215     if (OpVT == MVT::ppcf128)
216       return FPROUND_PPCF128_F16;
217   } else if (RetVT == MVT::f32) {
218     if (OpVT == MVT::f64)
219       return FPROUND_F64_F32;
220     if (OpVT == MVT::f80)
221       return FPROUND_F80_F32;
222     if (OpVT == MVT::f128)
223       return FPROUND_F128_F32;
224     if (OpVT == MVT::ppcf128)
225       return FPROUND_PPCF128_F32;
226   } else if (RetVT == MVT::f64) {
227     if (OpVT == MVT::f80)
228       return FPROUND_F80_F64;
229     if (OpVT == MVT::f128)
230       return FPROUND_F128_F64;
231     if (OpVT == MVT::ppcf128)
232       return FPROUND_PPCF128_F64;
233   } else if (RetVT == MVT::f80) {
234     if (OpVT == MVT::f128)
235       return FPROUND_F128_F80;
236   }
237 
238   return UNKNOWN_LIBCALL;
239 }
240 
241 /// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
242 /// UNKNOWN_LIBCALL if there is none.
243 RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
244   if (OpVT == MVT::f32) {
245     if (RetVT == MVT::i32)
246       return FPTOSINT_F32_I32;
247     if (RetVT == MVT::i64)
248       return FPTOSINT_F32_I64;
249     if (RetVT == MVT::i128)
250       return FPTOSINT_F32_I128;
251   } else if (OpVT == MVT::f64) {
252     if (RetVT == MVT::i32)
253       return FPTOSINT_F64_I32;
254     if (RetVT == MVT::i64)
255       return FPTOSINT_F64_I64;
256     if (RetVT == MVT::i128)
257       return FPTOSINT_F64_I128;
258   } else if (OpVT == MVT::f80) {
259     if (RetVT == MVT::i32)
260       return FPTOSINT_F80_I32;
261     if (RetVT == MVT::i64)
262       return FPTOSINT_F80_I64;
263     if (RetVT == MVT::i128)
264       return FPTOSINT_F80_I128;
265   } else if (OpVT == MVT::f128) {
266     if (RetVT == MVT::i32)
267       return FPTOSINT_F128_I32;
268     if (RetVT == MVT::i64)
269       return FPTOSINT_F128_I64;
270     if (RetVT == MVT::i128)
271       return FPTOSINT_F128_I128;
272   } else if (OpVT == MVT::ppcf128) {
273     if (RetVT == MVT::i32)
274       return FPTOSINT_PPCF128_I32;
275     if (RetVT == MVT::i64)
276       return FPTOSINT_PPCF128_I64;
277     if (RetVT == MVT::i128)
278       return FPTOSINT_PPCF128_I128;
279   }
280   return UNKNOWN_LIBCALL;
281 }
282 
283 /// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
284 /// UNKNOWN_LIBCALL if there is none.
285 RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
286   if (OpVT == MVT::f32) {
287     if (RetVT == MVT::i32)
288       return FPTOUINT_F32_I32;
289     if (RetVT == MVT::i64)
290       return FPTOUINT_F32_I64;
291     if (RetVT == MVT::i128)
292       return FPTOUINT_F32_I128;
293   } else if (OpVT == MVT::f64) {
294     if (RetVT == MVT::i32)
295       return FPTOUINT_F64_I32;
296     if (RetVT == MVT::i64)
297       return FPTOUINT_F64_I64;
298     if (RetVT == MVT::i128)
299       return FPTOUINT_F64_I128;
300   } else if (OpVT == MVT::f80) {
301     if (RetVT == MVT::i32)
302       return FPTOUINT_F80_I32;
303     if (RetVT == MVT::i64)
304       return FPTOUINT_F80_I64;
305     if (RetVT == MVT::i128)
306       return FPTOUINT_F80_I128;
307   } else if (OpVT == MVT::f128) {
308     if (RetVT == MVT::i32)
309       return FPTOUINT_F128_I32;
310     if (RetVT == MVT::i64)
311       return FPTOUINT_F128_I64;
312     if (RetVT == MVT::i128)
313       return FPTOUINT_F128_I128;
314   } else if (OpVT == MVT::ppcf128) {
315     if (RetVT == MVT::i32)
316       return FPTOUINT_PPCF128_I32;
317     if (RetVT == MVT::i64)
318       return FPTOUINT_PPCF128_I64;
319     if (RetVT == MVT::i128)
320       return FPTOUINT_PPCF128_I128;
321   }
322   return UNKNOWN_LIBCALL;
323 }
324 
325 /// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
326 /// UNKNOWN_LIBCALL if there is none.
327 RTLIB::Libcall RTLIB::getSINTTOFP(EVT OpVT, EVT RetVT) {
328   if (OpVT == MVT::i32) {
329     if (RetVT == MVT::f32)
330       return SINTTOFP_I32_F32;
331     if (RetVT == MVT::f64)
332       return SINTTOFP_I32_F64;
333     if (RetVT == MVT::f80)
334       return SINTTOFP_I32_F80;
335     if (RetVT == MVT::f128)
336       return SINTTOFP_I32_F128;
337     if (RetVT == MVT::ppcf128)
338       return SINTTOFP_I32_PPCF128;
339   } else if (OpVT == MVT::i64) {
340     if (RetVT == MVT::f32)
341       return SINTTOFP_I64_F32;
342     if (RetVT == MVT::f64)
343       return SINTTOFP_I64_F64;
344     if (RetVT == MVT::f80)
345       return SINTTOFP_I64_F80;
346     if (RetVT == MVT::f128)
347       return SINTTOFP_I64_F128;
348     if (RetVT == MVT::ppcf128)
349       return SINTTOFP_I64_PPCF128;
350   } else if (OpVT == MVT::i128) {
351     if (RetVT == MVT::f32)
352       return SINTTOFP_I128_F32;
353     if (RetVT == MVT::f64)
354       return SINTTOFP_I128_F64;
355     if (RetVT == MVT::f80)
356       return SINTTOFP_I128_F80;
357     if (RetVT == MVT::f128)
358       return SINTTOFP_I128_F128;
359     if (RetVT == MVT::ppcf128)
360       return SINTTOFP_I128_PPCF128;
361   }
362   return UNKNOWN_LIBCALL;
363 }
364 
365 /// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
366 /// UNKNOWN_LIBCALL if there is none.
367 RTLIB::Libcall RTLIB::getUINTTOFP(EVT OpVT, EVT RetVT) {
368   if (OpVT == MVT::i32) {
369     if (RetVT == MVT::f32)
370       return UINTTOFP_I32_F32;
371     if (RetVT == MVT::f64)
372       return UINTTOFP_I32_F64;
373     if (RetVT == MVT::f80)
374       return UINTTOFP_I32_F80;
375     if (RetVT == MVT::f128)
376       return UINTTOFP_I32_F128;
377     if (RetVT == MVT::ppcf128)
378       return UINTTOFP_I32_PPCF128;
379   } else if (OpVT == MVT::i64) {
380     if (RetVT == MVT::f32)
381       return UINTTOFP_I64_F32;
382     if (RetVT == MVT::f64)
383       return UINTTOFP_I64_F64;
384     if (RetVT == MVT::f80)
385       return UINTTOFP_I64_F80;
386     if (RetVT == MVT::f128)
387       return UINTTOFP_I64_F128;
388     if (RetVT == MVT::ppcf128)
389       return UINTTOFP_I64_PPCF128;
390   } else if (OpVT == MVT::i128) {
391     if (RetVT == MVT::f32)
392       return UINTTOFP_I128_F32;
393     if (RetVT == MVT::f64)
394       return UINTTOFP_I128_F64;
395     if (RetVT == MVT::f80)
396       return UINTTOFP_I128_F80;
397     if (RetVT == MVT::f128)
398       return UINTTOFP_I128_F128;
399     if (RetVT == MVT::ppcf128)
400       return UINTTOFP_I128_PPCF128;
401   }
402   return UNKNOWN_LIBCALL;
403 }
404 
405 RTLIB::Libcall RTLIB::getSYNC(unsigned Opc, MVT VT) {
406 #define OP_TO_LIBCALL(Name, Enum)                                              \
407   case Name:                                                                   \
408     switch (VT.SimpleTy) {                                                     \
409     default:                                                                   \
410       return UNKNOWN_LIBCALL;                                                  \
411     case MVT::i8:                                                              \
412       return Enum##_1;                                                         \
413     case MVT::i16:                                                             \
414       return Enum##_2;                                                         \
415     case MVT::i32:                                                             \
416       return Enum##_4;                                                         \
417     case MVT::i64:                                                             \
418       return Enum##_8;                                                         \
419     case MVT::i128:                                                            \
420       return Enum##_16;                                                        \
421     }
422 
423   switch (Opc) {
424     OP_TO_LIBCALL(ISD::ATOMIC_SWAP, SYNC_LOCK_TEST_AND_SET)
425     OP_TO_LIBCALL(ISD::ATOMIC_CMP_SWAP, SYNC_VAL_COMPARE_AND_SWAP)
426     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_ADD, SYNC_FETCH_AND_ADD)
427     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_SUB, SYNC_FETCH_AND_SUB)
428     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_AND, SYNC_FETCH_AND_AND)
429     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_OR, SYNC_FETCH_AND_OR)
430     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_XOR, SYNC_FETCH_AND_XOR)
431     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_NAND, SYNC_FETCH_AND_NAND)
432     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MAX, SYNC_FETCH_AND_MAX)
433     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMAX, SYNC_FETCH_AND_UMAX)
434     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MIN, SYNC_FETCH_AND_MIN)
435     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMIN, SYNC_FETCH_AND_UMIN)
436   }
437 
438 #undef OP_TO_LIBCALL
439 
440   return UNKNOWN_LIBCALL;
441 }
442 
443 RTLIB::Libcall RTLIB::getMEMCPY_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
444   switch (ElementSize) {
445   case 1:
446     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_1;
447   case 2:
448     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_2;
449   case 4:
450     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_4;
451   case 8:
452     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_8;
453   case 16:
454     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_16;
455   default:
456     return UNKNOWN_LIBCALL;
457   }
458 }
459 
460 RTLIB::Libcall RTLIB::getMEMMOVE_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
461   switch (ElementSize) {
462   case 1:
463     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_1;
464   case 2:
465     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_2;
466   case 4:
467     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_4;
468   case 8:
469     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_8;
470   case 16:
471     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_16;
472   default:
473     return UNKNOWN_LIBCALL;
474   }
475 }
476 
477 RTLIB::Libcall RTLIB::getMEMSET_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
478   switch (ElementSize) {
479   case 1:
480     return MEMSET_ELEMENT_UNORDERED_ATOMIC_1;
481   case 2:
482     return MEMSET_ELEMENT_UNORDERED_ATOMIC_2;
483   case 4:
484     return MEMSET_ELEMENT_UNORDERED_ATOMIC_4;
485   case 8:
486     return MEMSET_ELEMENT_UNORDERED_ATOMIC_8;
487   case 16:
488     return MEMSET_ELEMENT_UNORDERED_ATOMIC_16;
489   default:
490     return UNKNOWN_LIBCALL;
491   }
492 }
493 
494 /// InitCmpLibcallCCs - Set default comparison libcall CC.
495 static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
496   memset(CCs, ISD::SETCC_INVALID, sizeof(ISD::CondCode)*RTLIB::UNKNOWN_LIBCALL);
497   CCs[RTLIB::OEQ_F32] = ISD::SETEQ;
498   CCs[RTLIB::OEQ_F64] = ISD::SETEQ;
499   CCs[RTLIB::OEQ_F128] = ISD::SETEQ;
500   CCs[RTLIB::OEQ_PPCF128] = ISD::SETEQ;
501   CCs[RTLIB::UNE_F32] = ISD::SETNE;
502   CCs[RTLIB::UNE_F64] = ISD::SETNE;
503   CCs[RTLIB::UNE_F128] = ISD::SETNE;
504   CCs[RTLIB::UNE_PPCF128] = ISD::SETNE;
505   CCs[RTLIB::OGE_F32] = ISD::SETGE;
506   CCs[RTLIB::OGE_F64] = ISD::SETGE;
507   CCs[RTLIB::OGE_F128] = ISD::SETGE;
508   CCs[RTLIB::OGE_PPCF128] = ISD::SETGE;
509   CCs[RTLIB::OLT_F32] = ISD::SETLT;
510   CCs[RTLIB::OLT_F64] = ISD::SETLT;
511   CCs[RTLIB::OLT_F128] = ISD::SETLT;
512   CCs[RTLIB::OLT_PPCF128] = ISD::SETLT;
513   CCs[RTLIB::OLE_F32] = ISD::SETLE;
514   CCs[RTLIB::OLE_F64] = ISD::SETLE;
515   CCs[RTLIB::OLE_F128] = ISD::SETLE;
516   CCs[RTLIB::OLE_PPCF128] = ISD::SETLE;
517   CCs[RTLIB::OGT_F32] = ISD::SETGT;
518   CCs[RTLIB::OGT_F64] = ISD::SETGT;
519   CCs[RTLIB::OGT_F128] = ISD::SETGT;
520   CCs[RTLIB::OGT_PPCF128] = ISD::SETGT;
521   CCs[RTLIB::UO_F32] = ISD::SETNE;
522   CCs[RTLIB::UO_F64] = ISD::SETNE;
523   CCs[RTLIB::UO_F128] = ISD::SETNE;
524   CCs[RTLIB::UO_PPCF128] = ISD::SETNE;
525   CCs[RTLIB::O_F32] = ISD::SETEQ;
526   CCs[RTLIB::O_F64] = ISD::SETEQ;
527   CCs[RTLIB::O_F128] = ISD::SETEQ;
528   CCs[RTLIB::O_PPCF128] = ISD::SETEQ;
529 }
530 
531 /// NOTE: The TargetMachine owns TLOF.
532 TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm) : TM(tm) {
533   initActions();
534 
535   // Perform these initializations only once.
536   MaxStoresPerMemset = MaxStoresPerMemcpy = MaxStoresPerMemmove =
537       MaxLoadsPerMemcmp = 8;
538   MaxGluedStoresPerMemcpy = 0;
539   MaxStoresPerMemsetOptSize = MaxStoresPerMemcpyOptSize =
540       MaxStoresPerMemmoveOptSize = MaxLoadsPerMemcmpOptSize = 4;
541   UseUnderscoreSetJmp = false;
542   UseUnderscoreLongJmp = false;
543   HasMultipleConditionRegisters = false;
544   HasExtractBitsInsn = false;
545   JumpIsExpensive = JumpIsExpensiveOverride;
546   PredictableSelectIsExpensive = false;
547   EnableExtLdPromotion = false;
548   StackPointerRegisterToSaveRestore = 0;
549   BooleanContents = UndefinedBooleanContent;
550   BooleanFloatContents = UndefinedBooleanContent;
551   BooleanVectorContents = UndefinedBooleanContent;
552   SchedPreferenceInfo = Sched::ILP;
553   JumpBufSize = 0;
554   JumpBufAlignment = 0;
555   MinFunctionAlignment = 0;
556   PrefFunctionAlignment = 0;
557   PrefLoopAlignment = 0;
558   GatherAllAliasesMaxDepth = 18;
559   MinStackArgumentAlignment = 1;
560   // TODO: the default will be switched to 0 in the next commit, along
561   // with the Target-specific changes necessary.
562   MaxAtomicSizeInBitsSupported = 1024;
563 
564   MinCmpXchgSizeInBits = 0;
565   SupportsUnalignedAtomics = false;
566 
567   std::fill(std::begin(LibcallRoutineNames), std::end(LibcallRoutineNames), nullptr);
568 
569   InitLibcalls(TM.getTargetTriple());
570   InitCmpLibcallCCs(CmpLibcallCCs);
571 }
572 
573 void TargetLoweringBase::initActions() {
574   // All operations default to being supported.
575   memset(OpActions, 0, sizeof(OpActions));
576   memset(LoadExtActions, 0, sizeof(LoadExtActions));
577   memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
578   memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
579   memset(CondCodeActions, 0, sizeof(CondCodeActions));
580   std::fill(std::begin(RegClassForVT), std::end(RegClassForVT), nullptr);
581   std::fill(std::begin(TargetDAGCombineArray),
582             std::end(TargetDAGCombineArray), 0);
583 
584   for (MVT VT : MVT::fp_valuetypes()) {
585     MVT IntVT = MVT::getIntegerVT(VT.getSizeInBits());
586     if (IntVT.isValid()) {
587       setOperationAction(ISD::ATOMIC_SWAP, VT, Promote);
588       AddPromotedToType(ISD::ATOMIC_SWAP, VT, IntVT);
589     }
590   }
591 
592   // Set default actions for various operations.
593   for (MVT VT : MVT::all_valuetypes()) {
594     // Default all indexed load / store to expand.
595     for (unsigned IM = (unsigned)ISD::PRE_INC;
596          IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
597       setIndexedLoadAction(IM, VT, Expand);
598       setIndexedStoreAction(IM, VT, Expand);
599     }
600 
601     // Most backends expect to see the node which just returns the value loaded.
602     setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, VT, Expand);
603 
604     // These operations default to expand.
605     setOperationAction(ISD::FGETSIGN, VT, Expand);
606     setOperationAction(ISD::CONCAT_VECTORS, VT, Expand);
607     setOperationAction(ISD::FMINNUM, VT, Expand);
608     setOperationAction(ISD::FMAXNUM, VT, Expand);
609     setOperationAction(ISD::FMINNUM_IEEE, VT, Expand);
610     setOperationAction(ISD::FMAXNUM_IEEE, VT, Expand);
611     setOperationAction(ISD::FMINIMUM, VT, Expand);
612     setOperationAction(ISD::FMAXIMUM, VT, Expand);
613     setOperationAction(ISD::FMAD, VT, Expand);
614     setOperationAction(ISD::SMIN, VT, Expand);
615     setOperationAction(ISD::SMAX, VT, Expand);
616     setOperationAction(ISD::UMIN, VT, Expand);
617     setOperationAction(ISD::UMAX, VT, Expand);
618     setOperationAction(ISD::ABS, VT, Expand);
619     setOperationAction(ISD::FSHL, VT, Expand);
620     setOperationAction(ISD::FSHR, VT, Expand);
621     setOperationAction(ISD::SADDSAT, VT, Expand);
622     setOperationAction(ISD::UADDSAT, VT, Expand);
623     setOperationAction(ISD::SSUBSAT, VT, Expand);
624     setOperationAction(ISD::USUBSAT, VT, Expand);
625     setOperationAction(ISD::SMULFIX, VT, Expand);
626     setOperationAction(ISD::SMULFIXSAT, VT, Expand);
627     setOperationAction(ISD::UMULFIX, VT, Expand);
628 
629     // Overflow operations default to expand
630     setOperationAction(ISD::SADDO, VT, Expand);
631     setOperationAction(ISD::SSUBO, VT, Expand);
632     setOperationAction(ISD::UADDO, VT, Expand);
633     setOperationAction(ISD::USUBO, VT, Expand);
634     setOperationAction(ISD::SMULO, VT, Expand);
635     setOperationAction(ISD::UMULO, VT, Expand);
636 
637     // ADDCARRY operations default to expand
638     setOperationAction(ISD::ADDCARRY, VT, Expand);
639     setOperationAction(ISD::SUBCARRY, VT, Expand);
640     setOperationAction(ISD::SETCCCARRY, VT, Expand);
641 
642     // ADDC/ADDE/SUBC/SUBE default to expand.
643     setOperationAction(ISD::ADDC, VT, Expand);
644     setOperationAction(ISD::ADDE, VT, Expand);
645     setOperationAction(ISD::SUBC, VT, Expand);
646     setOperationAction(ISD::SUBE, VT, Expand);
647 
648     // These default to Expand so they will be expanded to CTLZ/CTTZ by default.
649     setOperationAction(ISD::CTLZ_ZERO_UNDEF, VT, Expand);
650     setOperationAction(ISD::CTTZ_ZERO_UNDEF, VT, Expand);
651 
652     setOperationAction(ISD::BITREVERSE, VT, Expand);
653 
654     // These library functions default to expand.
655     setOperationAction(ISD::FROUND, VT, Expand);
656     setOperationAction(ISD::FPOWI, VT, Expand);
657 
658     // These operations default to expand for vector types.
659     if (VT.isVector()) {
660       setOperationAction(ISD::FCOPYSIGN, VT, Expand);
661       setOperationAction(ISD::ANY_EXTEND_VECTOR_INREG, VT, Expand);
662       setOperationAction(ISD::SIGN_EXTEND_VECTOR_INREG, VT, Expand);
663       setOperationAction(ISD::ZERO_EXTEND_VECTOR_INREG, VT, Expand);
664     }
665 
666     // Constrained floating-point operations default to expand.
667     setOperationAction(ISD::STRICT_FADD, VT, Expand);
668     setOperationAction(ISD::STRICT_FSUB, VT, Expand);
669     setOperationAction(ISD::STRICT_FMUL, VT, Expand);
670     setOperationAction(ISD::STRICT_FDIV, VT, Expand);
671     setOperationAction(ISD::STRICT_FREM, VT, Expand);
672     setOperationAction(ISD::STRICT_FMA, VT, Expand);
673     setOperationAction(ISD::STRICT_FSQRT, VT, Expand);
674     setOperationAction(ISD::STRICT_FPOW, VT, Expand);
675     setOperationAction(ISD::STRICT_FPOWI, VT, Expand);
676     setOperationAction(ISD::STRICT_FSIN, VT, Expand);
677     setOperationAction(ISD::STRICT_FCOS, VT, Expand);
678     setOperationAction(ISD::STRICT_FEXP, VT, Expand);
679     setOperationAction(ISD::STRICT_FEXP2, VT, Expand);
680     setOperationAction(ISD::STRICT_FLOG, VT, Expand);
681     setOperationAction(ISD::STRICT_FLOG10, VT, Expand);
682     setOperationAction(ISD::STRICT_FLOG2, VT, Expand);
683     setOperationAction(ISD::STRICT_FRINT, VT, Expand);
684     setOperationAction(ISD::STRICT_FNEARBYINT, VT, Expand);
685     setOperationAction(ISD::STRICT_FCEIL, VT, Expand);
686     setOperationAction(ISD::STRICT_FFLOOR, VT, Expand);
687     setOperationAction(ISD::STRICT_FROUND, VT, Expand);
688     setOperationAction(ISD::STRICT_FTRUNC, VT, Expand);
689     setOperationAction(ISD::STRICT_FMAXNUM, VT, Expand);
690     setOperationAction(ISD::STRICT_FMINNUM, VT, Expand);
691     setOperationAction(ISD::STRICT_FP_ROUND, VT, Expand);
692     setOperationAction(ISD::STRICT_FP_EXTEND, VT, Expand);
693 
694     // For most targets @llvm.get.dynamic.area.offset just returns 0.
695     setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, VT, Expand);
696 
697     // Vector reduction default to expand.
698     setOperationAction(ISD::VECREDUCE_FADD, VT, Expand);
699     setOperationAction(ISD::VECREDUCE_FMUL, VT, Expand);
700     setOperationAction(ISD::VECREDUCE_ADD, VT, Expand);
701     setOperationAction(ISD::VECREDUCE_MUL, VT, Expand);
702     setOperationAction(ISD::VECREDUCE_AND, VT, Expand);
703     setOperationAction(ISD::VECREDUCE_OR, VT, Expand);
704     setOperationAction(ISD::VECREDUCE_XOR, VT, Expand);
705     setOperationAction(ISD::VECREDUCE_SMAX, VT, Expand);
706     setOperationAction(ISD::VECREDUCE_SMIN, VT, Expand);
707     setOperationAction(ISD::VECREDUCE_UMAX, VT, Expand);
708     setOperationAction(ISD::VECREDUCE_UMIN, VT, Expand);
709     setOperationAction(ISD::VECREDUCE_FMAX, VT, Expand);
710     setOperationAction(ISD::VECREDUCE_FMIN, VT, Expand);
711   }
712 
713   // Most targets ignore the @llvm.prefetch intrinsic.
714   setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
715 
716   // Most targets also ignore the @llvm.readcyclecounter intrinsic.
717   setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Expand);
718 
719   // ConstantFP nodes default to expand.  Targets can either change this to
720   // Legal, in which case all fp constants are legal, or use isFPImmLegal()
721   // to optimize expansions for certain constants.
722   setOperationAction(ISD::ConstantFP, MVT::f16, Expand);
723   setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
724   setOperationAction(ISD::ConstantFP, MVT::f64, Expand);
725   setOperationAction(ISD::ConstantFP, MVT::f80, Expand);
726   setOperationAction(ISD::ConstantFP, MVT::f128, Expand);
727 
728   // These library functions default to expand.
729   for (MVT VT : {MVT::f32, MVT::f64, MVT::f128}) {
730     setOperationAction(ISD::FCBRT,      VT, Expand);
731     setOperationAction(ISD::FLOG ,      VT, Expand);
732     setOperationAction(ISD::FLOG2,      VT, Expand);
733     setOperationAction(ISD::FLOG10,     VT, Expand);
734     setOperationAction(ISD::FEXP ,      VT, Expand);
735     setOperationAction(ISD::FEXP2,      VT, Expand);
736     setOperationAction(ISD::FFLOOR,     VT, Expand);
737     setOperationAction(ISD::FNEARBYINT, VT, Expand);
738     setOperationAction(ISD::FCEIL,      VT, Expand);
739     setOperationAction(ISD::FRINT,      VT, Expand);
740     setOperationAction(ISD::FTRUNC,     VT, Expand);
741     setOperationAction(ISD::FROUND,     VT, Expand);
742     setOperationAction(ISD::LROUND,     VT, Expand);
743     setOperationAction(ISD::LLROUND,    VT, Expand);
744     setOperationAction(ISD::LRINT,      VT, Expand);
745     setOperationAction(ISD::LLRINT,     VT, Expand);
746   }
747 
748   // Default ISD::TRAP to expand (which turns it into abort).
749   setOperationAction(ISD::TRAP, MVT::Other, Expand);
750 
751   // On most systems, DEBUGTRAP and TRAP have no difference. The "Expand"
752   // here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP.
753   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand);
754 }
755 
756 MVT TargetLoweringBase::getScalarShiftAmountTy(const DataLayout &DL,
757                                                EVT) const {
758   return MVT::getIntegerVT(DL.getPointerSizeInBits(0));
759 }
760 
761 EVT TargetLoweringBase::getShiftAmountTy(EVT LHSTy, const DataLayout &DL,
762                                          bool LegalTypes) const {
763   assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
764   if (LHSTy.isVector())
765     return LHSTy;
766   return LegalTypes ? getScalarShiftAmountTy(DL, LHSTy)
767                     : getPointerTy(DL);
768 }
769 
770 bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
771   assert(isTypeLegal(VT));
772   switch (Op) {
773   default:
774     return false;
775   case ISD::SDIV:
776   case ISD::UDIV:
777   case ISD::SREM:
778   case ISD::UREM:
779     return true;
780   }
781 }
782 
783 void TargetLoweringBase::setJumpIsExpensive(bool isExpensive) {
784   // If the command-line option was specified, ignore this request.
785   if (!JumpIsExpensiveOverride.getNumOccurrences())
786     JumpIsExpensive = isExpensive;
787 }
788 
789 TargetLoweringBase::LegalizeKind
790 TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
791   // If this is a simple type, use the ComputeRegisterProp mechanism.
792   if (VT.isSimple()) {
793     MVT SVT = VT.getSimpleVT();
794     assert((unsigned)SVT.SimpleTy < array_lengthof(TransformToType));
795     MVT NVT = TransformToType[SVT.SimpleTy];
796     LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
797 
798     assert((LA == TypeLegal || LA == TypeSoftenFloat ||
799             ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger) &&
800            "Promote may not follow Expand or Promote");
801 
802     if (LA == TypeSplitVector)
803       return LegalizeKind(LA,
804                           EVT::getVectorVT(Context, SVT.getVectorElementType(),
805                                            SVT.getVectorNumElements() / 2));
806     if (LA == TypeScalarizeVector)
807       return LegalizeKind(LA, SVT.getVectorElementType());
808     return LegalizeKind(LA, NVT);
809   }
810 
811   // Handle Extended Scalar Types.
812   if (!VT.isVector()) {
813     assert(VT.isInteger() && "Float types must be simple");
814     unsigned BitSize = VT.getSizeInBits();
815     // First promote to a power-of-two size, then expand if necessary.
816     if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
817       EVT NVT = VT.getRoundIntegerType(Context);
818       assert(NVT != VT && "Unable to round integer VT");
819       LegalizeKind NextStep = getTypeConversion(Context, NVT);
820       // Avoid multi-step promotion.
821       if (NextStep.first == TypePromoteInteger)
822         return NextStep;
823       // Return rounded integer type.
824       return LegalizeKind(TypePromoteInteger, NVT);
825     }
826 
827     return LegalizeKind(TypeExpandInteger,
828                         EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
829   }
830 
831   // Handle vector types.
832   unsigned NumElts = VT.getVectorNumElements();
833   EVT EltVT = VT.getVectorElementType();
834 
835   // Vectors with only one element are always scalarized.
836   if (NumElts == 1)
837     return LegalizeKind(TypeScalarizeVector, EltVT);
838 
839   // Try to widen vector elements until the element type is a power of two and
840   // promote it to a legal type later on, for example:
841   // <3 x i8> -> <4 x i8> -> <4 x i32>
842   if (EltVT.isInteger()) {
843     // Vectors with a number of elements that is not a power of two are always
844     // widened, for example <3 x i8> -> <4 x i8>.
845     if (!VT.isPow2VectorType()) {
846       NumElts = (unsigned)NextPowerOf2(NumElts);
847       EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
848       return LegalizeKind(TypeWidenVector, NVT);
849     }
850 
851     // Examine the element type.
852     LegalizeKind LK = getTypeConversion(Context, EltVT);
853 
854     // If type is to be expanded, split the vector.
855     //  <4 x i140> -> <2 x i140>
856     if (LK.first == TypeExpandInteger)
857       return LegalizeKind(TypeSplitVector,
858                           EVT::getVectorVT(Context, EltVT, NumElts / 2));
859 
860     // Promote the integer element types until a legal vector type is found
861     // or until the element integer type is too big. If a legal type was not
862     // found, fallback to the usual mechanism of widening/splitting the
863     // vector.
864     EVT OldEltVT = EltVT;
865     while (true) {
866       // Increase the bitwidth of the element to the next pow-of-two
867       // (which is greater than 8 bits).
868       EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
869                   .getRoundIntegerType(Context);
870 
871       // Stop trying when getting a non-simple element type.
872       // Note that vector elements may be greater than legal vector element
873       // types. Example: X86 XMM registers hold 64bit element on 32bit
874       // systems.
875       if (!EltVT.isSimple())
876         break;
877 
878       // Build a new vector type and check if it is legal.
879       MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
880       // Found a legal promoted vector type.
881       if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
882         return LegalizeKind(TypePromoteInteger,
883                             EVT::getVectorVT(Context, EltVT, NumElts));
884     }
885 
886     // Reset the type to the unexpanded type if we did not find a legal vector
887     // type with a promoted vector element type.
888     EltVT = OldEltVT;
889   }
890 
891   // Try to widen the vector until a legal type is found.
892   // If there is no wider legal type, split the vector.
893   while (true) {
894     // Round up to the next power of 2.
895     NumElts = (unsigned)NextPowerOf2(NumElts);
896 
897     // If there is no simple vector type with this many elements then there
898     // cannot be a larger legal vector type.  Note that this assumes that
899     // there are no skipped intermediate vector types in the simple types.
900     if (!EltVT.isSimple())
901       break;
902     MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
903     if (LargerVector == MVT())
904       break;
905 
906     // If this type is legal then widen the vector.
907     if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
908       return LegalizeKind(TypeWidenVector, LargerVector);
909   }
910 
911   // Widen odd vectors to next power of two.
912   if (!VT.isPow2VectorType()) {
913     EVT NVT = VT.getPow2VectorType(Context);
914     return LegalizeKind(TypeWidenVector, NVT);
915   }
916 
917   // Vectors with illegal element types are expanded.
918   EVT NVT = EVT::getVectorVT(Context, EltVT, VT.getVectorNumElements() / 2);
919   return LegalizeKind(TypeSplitVector, NVT);
920 }
921 
922 static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
923                                           unsigned &NumIntermediates,
924                                           MVT &RegisterVT,
925                                           TargetLoweringBase *TLI) {
926   // Figure out the right, legal destination reg to copy into.
927   unsigned NumElts = VT.getVectorNumElements();
928   MVT EltTy = VT.getVectorElementType();
929 
930   unsigned NumVectorRegs = 1;
931 
932   // FIXME: We don't support non-power-of-2-sized vectors for now.  Ideally we
933   // could break down into LHS/RHS like LegalizeDAG does.
934   if (!isPowerOf2_32(NumElts)) {
935     NumVectorRegs = NumElts;
936     NumElts = 1;
937   }
938 
939   // Divide the input until we get to a supported size.  This will always
940   // end with a scalar if the target doesn't support vectors.
941   while (NumElts > 1 && !TLI->isTypeLegal(MVT::getVectorVT(EltTy, NumElts))) {
942     NumElts >>= 1;
943     NumVectorRegs <<= 1;
944   }
945 
946   NumIntermediates = NumVectorRegs;
947 
948   MVT NewVT = MVT::getVectorVT(EltTy, NumElts);
949   if (!TLI->isTypeLegal(NewVT))
950     NewVT = EltTy;
951   IntermediateVT = NewVT;
952 
953   unsigned NewVTSize = NewVT.getSizeInBits();
954 
955   // Convert sizes such as i33 to i64.
956   if (!isPowerOf2_32(NewVTSize))
957     NewVTSize = NextPowerOf2(NewVTSize);
958 
959   MVT DestVT = TLI->getRegisterType(NewVT);
960   RegisterVT = DestVT;
961   if (EVT(DestVT).bitsLT(NewVT))    // Value is expanded, e.g. i64 -> i16.
962     return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
963 
964   // Otherwise, promotion or legal types use the same number of registers as
965   // the vector decimated to the appropriate level.
966   return NumVectorRegs;
967 }
968 
969 /// isLegalRC - Return true if the value types that can be represented by the
970 /// specified register class are all legal.
971 bool TargetLoweringBase::isLegalRC(const TargetRegisterInfo &TRI,
972                                    const TargetRegisterClass &RC) const {
973   for (auto I = TRI.legalclasstypes_begin(RC); *I != MVT::Other; ++I)
974     if (isTypeLegal(*I))
975       return true;
976   return false;
977 }
978 
979 /// Replace/modify any TargetFrameIndex operands with a targte-dependent
980 /// sequence of memory operands that is recognized by PrologEpilogInserter.
981 MachineBasicBlock *
982 TargetLoweringBase::emitPatchPoint(MachineInstr &InitialMI,
983                                    MachineBasicBlock *MBB) const {
984   MachineInstr *MI = &InitialMI;
985   MachineFunction &MF = *MI->getMF();
986   MachineFrameInfo &MFI = MF.getFrameInfo();
987 
988   // We're handling multiple types of operands here:
989   // PATCHPOINT MetaArgs - live-in, read only, direct
990   // STATEPOINT Deopt Spill - live-through, read only, indirect
991   // STATEPOINT Deopt Alloca - live-through, read only, direct
992   // (We're currently conservative and mark the deopt slots read/write in
993   // practice.)
994   // STATEPOINT GC Spill - live-through, read/write, indirect
995   // STATEPOINT GC Alloca - live-through, read/write, direct
996   // The live-in vs live-through is handled already (the live through ones are
997   // all stack slots), but we need to handle the different type of stackmap
998   // operands and memory effects here.
999 
1000   // MI changes inside this loop as we grow operands.
1001   for(unsigned OperIdx = 0; OperIdx != MI->getNumOperands(); ++OperIdx) {
1002     MachineOperand &MO = MI->getOperand(OperIdx);
1003     if (!MO.isFI())
1004       continue;
1005 
1006     // foldMemoryOperand builds a new MI after replacing a single FI operand
1007     // with the canonical set of five x86 addressing-mode operands.
1008     int FI = MO.getIndex();
1009     MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), MI->getDesc());
1010 
1011     // Copy operands before the frame-index.
1012     for (unsigned i = 0; i < OperIdx; ++i)
1013       MIB.add(MI->getOperand(i));
1014     // Add frame index operands recognized by stackmaps.cpp
1015     if (MFI.isStatepointSpillSlotObjectIndex(FI)) {
1016       // indirect-mem-ref tag, size, #FI, offset.
1017       // Used for spills inserted by StatepointLowering.  This codepath is not
1018       // used for patchpoints/stackmaps at all, for these spilling is done via
1019       // foldMemoryOperand callback only.
1020       assert(MI->getOpcode() == TargetOpcode::STATEPOINT && "sanity");
1021       MIB.addImm(StackMaps::IndirectMemRefOp);
1022       MIB.addImm(MFI.getObjectSize(FI));
1023       MIB.add(MI->getOperand(OperIdx));
1024       MIB.addImm(0);
1025     } else {
1026       // direct-mem-ref tag, #FI, offset.
1027       // Used by patchpoint, and direct alloca arguments to statepoints
1028       MIB.addImm(StackMaps::DirectMemRefOp);
1029       MIB.add(MI->getOperand(OperIdx));
1030       MIB.addImm(0);
1031     }
1032     // Copy the operands after the frame index.
1033     for (unsigned i = OperIdx + 1; i != MI->getNumOperands(); ++i)
1034       MIB.add(MI->getOperand(i));
1035 
1036     // Inherit previous memory operands.
1037     MIB.cloneMemRefs(*MI);
1038     assert(MIB->mayLoad() && "Folded a stackmap use to a non-load!");
1039 
1040     // Add a new memory operand for this FI.
1041     assert(MFI.getObjectOffset(FI) != -1);
1042 
1043     // Note: STATEPOINT MMOs are added during SelectionDAG.  STACKMAP, and
1044     // PATCHPOINT should be updated to do the same. (TODO)
1045     if (MI->getOpcode() != TargetOpcode::STATEPOINT) {
1046       auto Flags = MachineMemOperand::MOLoad;
1047       MachineMemOperand *MMO = MF.getMachineMemOperand(
1048           MachinePointerInfo::getFixedStack(MF, FI), Flags,
1049           MF.getDataLayout().getPointerSize(), MFI.getObjectAlignment(FI));
1050       MIB->addMemOperand(MF, MMO);
1051     }
1052 
1053     // Replace the instruction and update the operand index.
1054     MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1055     OperIdx += (MIB->getNumOperands() - MI->getNumOperands()) - 1;
1056     MI->eraseFromParent();
1057     MI = MIB;
1058   }
1059   return MBB;
1060 }
1061 
1062 MachineBasicBlock *
1063 TargetLoweringBase::emitXRayCustomEvent(MachineInstr &MI,
1064                                         MachineBasicBlock *MBB) const {
1065   assert(MI.getOpcode() == TargetOpcode::PATCHABLE_EVENT_CALL &&
1066          "Called emitXRayCustomEvent on the wrong MI!");
1067   auto &MF = *MI.getMF();
1068   auto MIB = BuildMI(MF, MI.getDebugLoc(), MI.getDesc());
1069   for (unsigned OpIdx = 0; OpIdx != MI.getNumOperands(); ++OpIdx)
1070     MIB.add(MI.getOperand(OpIdx));
1071 
1072   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1073   MI.eraseFromParent();
1074   return MBB;
1075 }
1076 
1077 MachineBasicBlock *
1078 TargetLoweringBase::emitXRayTypedEvent(MachineInstr &MI,
1079                                        MachineBasicBlock *MBB) const {
1080   assert(MI.getOpcode() == TargetOpcode::PATCHABLE_TYPED_EVENT_CALL &&
1081          "Called emitXRayTypedEvent on the wrong MI!");
1082   auto &MF = *MI.getMF();
1083   auto MIB = BuildMI(MF, MI.getDebugLoc(), MI.getDesc());
1084   for (unsigned OpIdx = 0; OpIdx != MI.getNumOperands(); ++OpIdx)
1085     MIB.add(MI.getOperand(OpIdx));
1086 
1087   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1088   MI.eraseFromParent();
1089   return MBB;
1090 }
1091 
1092 /// findRepresentativeClass - Return the largest legal super-reg register class
1093 /// of the register class for the specified type and its associated "cost".
1094 // This function is in TargetLowering because it uses RegClassForVT which would
1095 // need to be moved to TargetRegisterInfo and would necessitate moving
1096 // isTypeLegal over as well - a massive change that would just require
1097 // TargetLowering having a TargetRegisterInfo class member that it would use.
1098 std::pair<const TargetRegisterClass *, uint8_t>
1099 TargetLoweringBase::findRepresentativeClass(const TargetRegisterInfo *TRI,
1100                                             MVT VT) const {
1101   const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
1102   if (!RC)
1103     return std::make_pair(RC, 0);
1104 
1105   // Compute the set of all super-register classes.
1106   BitVector SuperRegRC(TRI->getNumRegClasses());
1107   for (SuperRegClassIterator RCI(RC, TRI); RCI.isValid(); ++RCI)
1108     SuperRegRC.setBitsInMask(RCI.getMask());
1109 
1110   // Find the first legal register class with the largest spill size.
1111   const TargetRegisterClass *BestRC = RC;
1112   for (unsigned i : SuperRegRC.set_bits()) {
1113     const TargetRegisterClass *SuperRC = TRI->getRegClass(i);
1114     // We want the largest possible spill size.
1115     if (TRI->getSpillSize(*SuperRC) <= TRI->getSpillSize(*BestRC))
1116       continue;
1117     if (!isLegalRC(*TRI, *SuperRC))
1118       continue;
1119     BestRC = SuperRC;
1120   }
1121   return std::make_pair(BestRC, 1);
1122 }
1123 
1124 /// computeRegisterProperties - Once all of the register classes are added,
1125 /// this allows us to compute derived properties we expose.
1126 void TargetLoweringBase::computeRegisterProperties(
1127     const TargetRegisterInfo *TRI) {
1128   static_assert(MVT::LAST_VALUETYPE <= MVT::MAX_ALLOWED_VALUETYPE,
1129                 "Too many value types for ValueTypeActions to hold!");
1130 
1131   // Everything defaults to needing one register.
1132   for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
1133     NumRegistersForVT[i] = 1;
1134     RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
1135   }
1136   // ...except isVoid, which doesn't need any registers.
1137   NumRegistersForVT[MVT::isVoid] = 0;
1138 
1139   // Find the largest integer register class.
1140   unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
1141   for (; RegClassForVT[LargestIntReg] == nullptr; --LargestIntReg)
1142     assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
1143 
1144   // Every integer value type larger than this largest register takes twice as
1145   // many registers to represent as the previous ValueType.
1146   for (unsigned ExpandedReg = LargestIntReg + 1;
1147        ExpandedReg <= MVT::LAST_INTEGER_VALUETYPE; ++ExpandedReg) {
1148     NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
1149     RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
1150     TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
1151     ValueTypeActions.setTypeAction((MVT::SimpleValueType)ExpandedReg,
1152                                    TypeExpandInteger);
1153   }
1154 
1155   // Inspect all of the ValueType's smaller than the largest integer
1156   // register to see which ones need promotion.
1157   unsigned LegalIntReg = LargestIntReg;
1158   for (unsigned IntReg = LargestIntReg - 1;
1159        IntReg >= (unsigned)MVT::i1; --IntReg) {
1160     MVT IVT = (MVT::SimpleValueType)IntReg;
1161     if (isTypeLegal(IVT)) {
1162       LegalIntReg = IntReg;
1163     } else {
1164       RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
1165         (MVT::SimpleValueType)LegalIntReg;
1166       ValueTypeActions.setTypeAction(IVT, TypePromoteInteger);
1167     }
1168   }
1169 
1170   // ppcf128 type is really two f64's.
1171   if (!isTypeLegal(MVT::ppcf128)) {
1172     if (isTypeLegal(MVT::f64)) {
1173       NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
1174       RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
1175       TransformToType[MVT::ppcf128] = MVT::f64;
1176       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat);
1177     } else {
1178       NumRegistersForVT[MVT::ppcf128] = NumRegistersForVT[MVT::i128];
1179       RegisterTypeForVT[MVT::ppcf128] = RegisterTypeForVT[MVT::i128];
1180       TransformToType[MVT::ppcf128] = MVT::i128;
1181       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeSoftenFloat);
1182     }
1183   }
1184 
1185   // Decide how to handle f128. If the target does not have native f128 support,
1186   // expand it to i128 and we will be generating soft float library calls.
1187   if (!isTypeLegal(MVT::f128)) {
1188     NumRegistersForVT[MVT::f128] = NumRegistersForVT[MVT::i128];
1189     RegisterTypeForVT[MVT::f128] = RegisterTypeForVT[MVT::i128];
1190     TransformToType[MVT::f128] = MVT::i128;
1191     ValueTypeActions.setTypeAction(MVT::f128, TypeSoftenFloat);
1192   }
1193 
1194   // Decide how to handle f64. If the target does not have native f64 support,
1195   // expand it to i64 and we will be generating soft float library calls.
1196   if (!isTypeLegal(MVT::f64)) {
1197     NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
1198     RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
1199     TransformToType[MVT::f64] = MVT::i64;
1200     ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat);
1201   }
1202 
1203   // Decide how to handle f32. If the target does not have native f32 support,
1204   // expand it to i32 and we will be generating soft float library calls.
1205   if (!isTypeLegal(MVT::f32)) {
1206     NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
1207     RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
1208     TransformToType[MVT::f32] = MVT::i32;
1209     ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat);
1210   }
1211 
1212   // Decide how to handle f16. If the target does not have native f16 support,
1213   // promote it to f32, because there are no f16 library calls (except for
1214   // conversions).
1215   if (!isTypeLegal(MVT::f16)) {
1216     NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::f32];
1217     RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::f32];
1218     TransformToType[MVT::f16] = MVT::f32;
1219     ValueTypeActions.setTypeAction(MVT::f16, TypePromoteFloat);
1220   }
1221 
1222   // Loop over all of the vector value types to see which need transformations.
1223   for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
1224        i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
1225     MVT VT = (MVT::SimpleValueType) i;
1226     if (isTypeLegal(VT))
1227       continue;
1228 
1229     MVT EltVT = VT.getVectorElementType();
1230     unsigned NElts = VT.getVectorNumElements();
1231     bool IsLegalWiderType = false;
1232     LegalizeTypeAction PreferredAction = getPreferredVectorAction(VT);
1233     switch (PreferredAction) {
1234     case TypePromoteInteger:
1235       // Try to promote the elements of integer vectors. If no legal
1236       // promotion was found, fall through to the widen-vector method.
1237       for (unsigned nVT = i + 1; nVT <= MVT::LAST_INTEGER_VECTOR_VALUETYPE; ++nVT) {
1238         MVT SVT = (MVT::SimpleValueType) nVT;
1239         // Promote vectors of integers to vectors with the same number
1240         // of elements, with a wider element type.
1241         if (SVT.getScalarSizeInBits() > EltVT.getSizeInBits() &&
1242             SVT.getVectorNumElements() == NElts && isTypeLegal(SVT)) {
1243           TransformToType[i] = SVT;
1244           RegisterTypeForVT[i] = SVT;
1245           NumRegistersForVT[i] = 1;
1246           ValueTypeActions.setTypeAction(VT, TypePromoteInteger);
1247           IsLegalWiderType = true;
1248           break;
1249         }
1250       }
1251       if (IsLegalWiderType)
1252         break;
1253       LLVM_FALLTHROUGH;
1254 
1255     case TypeWidenVector:
1256       // Try to widen the vector.
1257       for (unsigned nVT = i + 1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
1258         MVT SVT = (MVT::SimpleValueType) nVT;
1259         if (SVT.getVectorElementType() == EltVT
1260             && SVT.getVectorNumElements() > NElts && isTypeLegal(SVT)) {
1261           TransformToType[i] = SVT;
1262           RegisterTypeForVT[i] = SVT;
1263           NumRegistersForVT[i] = 1;
1264           ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1265           IsLegalWiderType = true;
1266           break;
1267         }
1268       }
1269       if (IsLegalWiderType)
1270         break;
1271       LLVM_FALLTHROUGH;
1272 
1273     case TypeSplitVector:
1274     case TypeScalarizeVector: {
1275       MVT IntermediateVT;
1276       MVT RegisterVT;
1277       unsigned NumIntermediates;
1278       NumRegistersForVT[i] = getVectorTypeBreakdownMVT(VT, IntermediateVT,
1279           NumIntermediates, RegisterVT, this);
1280       RegisterTypeForVT[i] = RegisterVT;
1281 
1282       MVT NVT = VT.getPow2VectorType();
1283       if (NVT == VT) {
1284         // Type is already a power of 2.  The default action is to split.
1285         TransformToType[i] = MVT::Other;
1286         if (PreferredAction == TypeScalarizeVector)
1287           ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
1288         else if (PreferredAction == TypeSplitVector)
1289           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1290         else
1291           // Set type action according to the number of elements.
1292           ValueTypeActions.setTypeAction(VT, NElts == 1 ? TypeScalarizeVector
1293                                                         : TypeSplitVector);
1294       } else {
1295         TransformToType[i] = NVT;
1296         ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1297       }
1298       break;
1299     }
1300     default:
1301       llvm_unreachable("Unknown vector legalization action!");
1302     }
1303   }
1304 
1305   // Determine the 'representative' register class for each value type.
1306   // An representative register class is the largest (meaning one which is
1307   // not a sub-register class / subreg register class) legal register class for
1308   // a group of value types. For example, on i386, i8, i16, and i32
1309   // representative would be GR32; while on x86_64 it's GR64.
1310   for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
1311     const TargetRegisterClass* RRC;
1312     uint8_t Cost;
1313     std::tie(RRC, Cost) = findRepresentativeClass(TRI, (MVT::SimpleValueType)i);
1314     RepRegClassForVT[i] = RRC;
1315     RepRegClassCostForVT[i] = Cost;
1316   }
1317 }
1318 
1319 EVT TargetLoweringBase::getSetCCResultType(const DataLayout &DL, LLVMContext &,
1320                                            EVT VT) const {
1321   assert(!VT.isVector() && "No default SetCC type for vectors!");
1322   return getPointerTy(DL).SimpleTy;
1323 }
1324 
1325 MVT::SimpleValueType TargetLoweringBase::getCmpLibcallReturnType() const {
1326   return MVT::i32; // return the default value
1327 }
1328 
1329 /// getVectorTypeBreakdown - Vector types are broken down into some number of
1330 /// legal first class types.  For example, MVT::v8f32 maps to 2 MVT::v4f32
1331 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
1332 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
1333 ///
1334 /// This method returns the number of registers needed, and the VT for each
1335 /// register.  It also returns the VT and quantity of the intermediate values
1336 /// before they are promoted/expanded.
1337 unsigned TargetLoweringBase::getVectorTypeBreakdown(LLVMContext &Context, EVT VT,
1338                                                 EVT &IntermediateVT,
1339                                                 unsigned &NumIntermediates,
1340                                                 MVT &RegisterVT) const {
1341   unsigned NumElts = VT.getVectorNumElements();
1342 
1343   // If there is a wider vector type with the same element type as this one,
1344   // or a promoted vector type that has the same number of elements which
1345   // are wider, then we should convert to that legal vector type.
1346   // This handles things like <2 x float> -> <4 x float> and
1347   // <4 x i1> -> <4 x i32>.
1348   LegalizeTypeAction TA = getTypeAction(Context, VT);
1349   if (NumElts != 1 && (TA == TypeWidenVector || TA == TypePromoteInteger)) {
1350     EVT RegisterEVT = getTypeToTransformTo(Context, VT);
1351     if (isTypeLegal(RegisterEVT)) {
1352       IntermediateVT = RegisterEVT;
1353       RegisterVT = RegisterEVT.getSimpleVT();
1354       NumIntermediates = 1;
1355       return 1;
1356     }
1357   }
1358 
1359   // Figure out the right, legal destination reg to copy into.
1360   EVT EltTy = VT.getVectorElementType();
1361 
1362   unsigned NumVectorRegs = 1;
1363 
1364   // FIXME: We don't support non-power-of-2-sized vectors for now.  Ideally we
1365   // could break down into LHS/RHS like LegalizeDAG does.
1366   if (!isPowerOf2_32(NumElts)) {
1367     NumVectorRegs = NumElts;
1368     NumElts = 1;
1369   }
1370 
1371   // Divide the input until we get to a supported size.  This will always
1372   // end with a scalar if the target doesn't support vectors.
1373   while (NumElts > 1 && !isTypeLegal(
1374                                    EVT::getVectorVT(Context, EltTy, NumElts))) {
1375     NumElts >>= 1;
1376     NumVectorRegs <<= 1;
1377   }
1378 
1379   NumIntermediates = NumVectorRegs;
1380 
1381   EVT NewVT = EVT::getVectorVT(Context, EltTy, NumElts);
1382   if (!isTypeLegal(NewVT))
1383     NewVT = EltTy;
1384   IntermediateVT = NewVT;
1385 
1386   MVT DestVT = getRegisterType(Context, NewVT);
1387   RegisterVT = DestVT;
1388   unsigned NewVTSize = NewVT.getSizeInBits();
1389 
1390   // Convert sizes such as i33 to i64.
1391   if (!isPowerOf2_32(NewVTSize))
1392     NewVTSize = NextPowerOf2(NewVTSize);
1393 
1394   if (EVT(DestVT).bitsLT(NewVT))   // Value is expanded, e.g. i64 -> i16.
1395     return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
1396 
1397   // Otherwise, promotion or legal types use the same number of registers as
1398   // the vector decimated to the appropriate level.
1399   return NumVectorRegs;
1400 }
1401 
1402 /// Get the EVTs and ArgFlags collections that represent the legalized return
1403 /// type of the given function.  This does not require a DAG or a return value,
1404 /// and is suitable for use before any DAGs for the function are constructed.
1405 /// TODO: Move this out of TargetLowering.cpp.
1406 void llvm::GetReturnInfo(CallingConv::ID CC, Type *ReturnType,
1407                          AttributeList attr,
1408                          SmallVectorImpl<ISD::OutputArg> &Outs,
1409                          const TargetLowering &TLI, const DataLayout &DL) {
1410   SmallVector<EVT, 4> ValueVTs;
1411   ComputeValueVTs(TLI, DL, ReturnType, ValueVTs);
1412   unsigned NumValues = ValueVTs.size();
1413   if (NumValues == 0) return;
1414 
1415   for (unsigned j = 0, f = NumValues; j != f; ++j) {
1416     EVT VT = ValueVTs[j];
1417     ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
1418 
1419     if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::SExt))
1420       ExtendKind = ISD::SIGN_EXTEND;
1421     else if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::ZExt))
1422       ExtendKind = ISD::ZERO_EXTEND;
1423 
1424     // FIXME: C calling convention requires the return type to be promoted to
1425     // at least 32-bit. But this is not necessary for non-C calling
1426     // conventions. The frontend should mark functions whose return values
1427     // require promoting with signext or zeroext attributes.
1428     if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger()) {
1429       MVT MinVT = TLI.getRegisterType(ReturnType->getContext(), MVT::i32);
1430       if (VT.bitsLT(MinVT))
1431         VT = MinVT;
1432     }
1433 
1434     unsigned NumParts =
1435         TLI.getNumRegistersForCallingConv(ReturnType->getContext(), CC, VT);
1436     MVT PartVT =
1437         TLI.getRegisterTypeForCallingConv(ReturnType->getContext(), CC, VT);
1438 
1439     // 'inreg' on function refers to return value
1440     ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
1441     if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::InReg))
1442       Flags.setInReg();
1443 
1444     // Propagate extension type if any
1445     if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::SExt))
1446       Flags.setSExt();
1447     else if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::ZExt))
1448       Flags.setZExt();
1449 
1450     for (unsigned i = 0; i < NumParts; ++i)
1451       Outs.push_back(ISD::OutputArg(Flags, PartVT, VT, /*isFixed=*/true, 0, 0));
1452   }
1453 }
1454 
1455 /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
1456 /// function arguments in the caller parameter area.  This is the actual
1457 /// alignment, not its logarithm.
1458 unsigned TargetLoweringBase::getByValTypeAlignment(Type *Ty,
1459                                                    const DataLayout &DL) const {
1460   return DL.getABITypeAlignment(Ty);
1461 }
1462 
1463 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1464                                             const DataLayout &DL, EVT VT,
1465                                             unsigned AddrSpace,
1466                                             unsigned Alignment,
1467                                             MachineMemOperand::Flags Flags,
1468                                             bool *Fast) const {
1469   // Check if the specified alignment is sufficient based on the data layout.
1470   // TODO: While using the data layout works in practice, a better solution
1471   // would be to implement this check directly (make this a virtual function).
1472   // For example, the ABI alignment may change based on software platform while
1473   // this function should only be affected by hardware implementation.
1474   Type *Ty = VT.getTypeForEVT(Context);
1475   if (Alignment >= DL.getABITypeAlignment(Ty)) {
1476     // Assume that an access that meets the ABI-specified alignment is fast.
1477     if (Fast != nullptr)
1478       *Fast = true;
1479     return true;
1480   }
1481 
1482   // This is a misaligned access.
1483   return allowsMisalignedMemoryAccesses(VT, AddrSpace, Alignment, Flags, Fast);
1484 }
1485 
1486 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1487                                             const DataLayout &DL, EVT VT,
1488                                             const MachineMemOperand &MMO,
1489                                             bool *Fast) const {
1490   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(),
1491                             MMO.getAlignment(), MMO.getFlags(), Fast);
1492 }
1493 
1494 BranchProbability TargetLoweringBase::getPredictableBranchThreshold() const {
1495   return BranchProbability(MinPercentageForPredictableBranch, 100);
1496 }
1497 
1498 //===----------------------------------------------------------------------===//
1499 //  TargetTransformInfo Helpers
1500 //===----------------------------------------------------------------------===//
1501 
1502 int TargetLoweringBase::InstructionOpcodeToISD(unsigned Opcode) const {
1503   enum InstructionOpcodes {
1504 #define HANDLE_INST(NUM, OPCODE, CLASS) OPCODE = NUM,
1505 #define LAST_OTHER_INST(NUM) InstructionOpcodesCount = NUM
1506 #include "llvm/IR/Instruction.def"
1507   };
1508   switch (static_cast<InstructionOpcodes>(Opcode)) {
1509   case Ret:            return 0;
1510   case Br:             return 0;
1511   case Switch:         return 0;
1512   case IndirectBr:     return 0;
1513   case Invoke:         return 0;
1514   case CallBr:         return 0;
1515   case Resume:         return 0;
1516   case Unreachable:    return 0;
1517   case CleanupRet:     return 0;
1518   case CatchRet:       return 0;
1519   case CatchPad:       return 0;
1520   case CatchSwitch:    return 0;
1521   case CleanupPad:     return 0;
1522   case FNeg:           return ISD::FNEG;
1523   case Add:            return ISD::ADD;
1524   case FAdd:           return ISD::FADD;
1525   case Sub:            return ISD::SUB;
1526   case FSub:           return ISD::FSUB;
1527   case Mul:            return ISD::MUL;
1528   case FMul:           return ISD::FMUL;
1529   case UDiv:           return ISD::UDIV;
1530   case SDiv:           return ISD::SDIV;
1531   case FDiv:           return ISD::FDIV;
1532   case URem:           return ISD::UREM;
1533   case SRem:           return ISD::SREM;
1534   case FRem:           return ISD::FREM;
1535   case Shl:            return ISD::SHL;
1536   case LShr:           return ISD::SRL;
1537   case AShr:           return ISD::SRA;
1538   case And:            return ISD::AND;
1539   case Or:             return ISD::OR;
1540   case Xor:            return ISD::XOR;
1541   case Alloca:         return 0;
1542   case Load:           return ISD::LOAD;
1543   case Store:          return ISD::STORE;
1544   case GetElementPtr:  return 0;
1545   case Fence:          return 0;
1546   case AtomicCmpXchg:  return 0;
1547   case AtomicRMW:      return 0;
1548   case Trunc:          return ISD::TRUNCATE;
1549   case ZExt:           return ISD::ZERO_EXTEND;
1550   case SExt:           return ISD::SIGN_EXTEND;
1551   case FPToUI:         return ISD::FP_TO_UINT;
1552   case FPToSI:         return ISD::FP_TO_SINT;
1553   case UIToFP:         return ISD::UINT_TO_FP;
1554   case SIToFP:         return ISD::SINT_TO_FP;
1555   case FPTrunc:        return ISD::FP_ROUND;
1556   case FPExt:          return ISD::FP_EXTEND;
1557   case PtrToInt:       return ISD::BITCAST;
1558   case IntToPtr:       return ISD::BITCAST;
1559   case BitCast:        return ISD::BITCAST;
1560   case AddrSpaceCast:  return ISD::ADDRSPACECAST;
1561   case ICmp:           return ISD::SETCC;
1562   case FCmp:           return ISD::SETCC;
1563   case PHI:            return 0;
1564   case Call:           return 0;
1565   case Select:         return ISD::SELECT;
1566   case UserOp1:        return 0;
1567   case UserOp2:        return 0;
1568   case VAArg:          return 0;
1569   case ExtractElement: return ISD::EXTRACT_VECTOR_ELT;
1570   case InsertElement:  return ISD::INSERT_VECTOR_ELT;
1571   case ShuffleVector:  return ISD::VECTOR_SHUFFLE;
1572   case ExtractValue:   return ISD::MERGE_VALUES;
1573   case InsertValue:    return ISD::MERGE_VALUES;
1574   case LandingPad:     return 0;
1575   }
1576 
1577   llvm_unreachable("Unknown instruction type encountered!");
1578 }
1579 
1580 std::pair<int, MVT>
1581 TargetLoweringBase::getTypeLegalizationCost(const DataLayout &DL,
1582                                             Type *Ty) const {
1583   LLVMContext &C = Ty->getContext();
1584   EVT MTy = getValueType(DL, Ty);
1585 
1586   int Cost = 1;
1587   // We keep legalizing the type until we find a legal kind. We assume that
1588   // the only operation that costs anything is the split. After splitting
1589   // we need to handle two types.
1590   while (true) {
1591     LegalizeKind LK = getTypeConversion(C, MTy);
1592 
1593     if (LK.first == TypeLegal)
1594       return std::make_pair(Cost, MTy.getSimpleVT());
1595 
1596     if (LK.first == TypeSplitVector || LK.first == TypeExpandInteger)
1597       Cost *= 2;
1598 
1599     // Do not loop with f128 type.
1600     if (MTy == LK.second)
1601       return std::make_pair(Cost, MTy.getSimpleVT());
1602 
1603     // Keep legalizing the type.
1604     MTy = LK.second;
1605   }
1606 }
1607 
1608 Value *TargetLoweringBase::getDefaultSafeStackPointerLocation(IRBuilder<> &IRB,
1609                                                               bool UseTLS) const {
1610   // compiler-rt provides a variable with a magic name.  Targets that do not
1611   // link with compiler-rt may also provide such a variable.
1612   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1613   const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
1614   auto UnsafeStackPtr =
1615       dyn_cast_or_null<GlobalVariable>(M->getNamedValue(UnsafeStackPtrVar));
1616 
1617   Type *StackPtrTy = Type::getInt8PtrTy(M->getContext());
1618 
1619   if (!UnsafeStackPtr) {
1620     auto TLSModel = UseTLS ?
1621         GlobalValue::InitialExecTLSModel :
1622         GlobalValue::NotThreadLocal;
1623     // The global variable is not defined yet, define it ourselves.
1624     // We use the initial-exec TLS model because we do not support the
1625     // variable living anywhere other than in the main executable.
1626     UnsafeStackPtr = new GlobalVariable(
1627         *M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
1628         UnsafeStackPtrVar, nullptr, TLSModel);
1629   } else {
1630     // The variable exists, check its type and attributes.
1631     if (UnsafeStackPtr->getValueType() != StackPtrTy)
1632       report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
1633     if (UseTLS != UnsafeStackPtr->isThreadLocal())
1634       report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
1635                          (UseTLS ? "" : "not ") + "be thread-local");
1636   }
1637   return UnsafeStackPtr;
1638 }
1639 
1640 Value *TargetLoweringBase::getSafeStackPointerLocation(IRBuilder<> &IRB) const {
1641   if (!TM.getTargetTriple().isAndroid())
1642     return getDefaultSafeStackPointerLocation(IRB, true);
1643 
1644   // Android provides a libc function to retrieve the address of the current
1645   // thread's unsafe stack pointer.
1646   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1647   Type *StackPtrTy = Type::getInt8PtrTy(M->getContext());
1648   FunctionCallee Fn = M->getOrInsertFunction("__safestack_pointer_address",
1649                                              StackPtrTy->getPointerTo(0));
1650   return IRB.CreateCall(Fn);
1651 }
1652 
1653 //===----------------------------------------------------------------------===//
1654 //  Loop Strength Reduction hooks
1655 //===----------------------------------------------------------------------===//
1656 
1657 /// isLegalAddressingMode - Return true if the addressing mode represented
1658 /// by AM is legal for this target, for a load/store of the specified type.
1659 bool TargetLoweringBase::isLegalAddressingMode(const DataLayout &DL,
1660                                                const AddrMode &AM, Type *Ty,
1661                                                unsigned AS, Instruction *I) const {
1662   // The default implementation of this implements a conservative RISCy, r+r and
1663   // r+i addr mode.
1664 
1665   // Allows a sign-extended 16-bit immediate field.
1666   if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
1667     return false;
1668 
1669   // No global is ever allowed as a base.
1670   if (AM.BaseGV)
1671     return false;
1672 
1673   // Only support r+r,
1674   switch (AM.Scale) {
1675   case 0:  // "r+i" or just "i", depending on HasBaseReg.
1676     break;
1677   case 1:
1678     if (AM.HasBaseReg && AM.BaseOffs)  // "r+r+i" is not allowed.
1679       return false;
1680     // Otherwise we have r+r or r+i.
1681     break;
1682   case 2:
1683     if (AM.HasBaseReg || AM.BaseOffs)  // 2*r+r  or  2*r+i is not allowed.
1684       return false;
1685     // Allow 2*r as r+r.
1686     break;
1687   default: // Don't allow n * r
1688     return false;
1689   }
1690 
1691   return true;
1692 }
1693 
1694 //===----------------------------------------------------------------------===//
1695 //  Stack Protector
1696 //===----------------------------------------------------------------------===//
1697 
1698 // For OpenBSD return its special guard variable. Otherwise return nullptr,
1699 // so that SelectionDAG handle SSP.
1700 Value *TargetLoweringBase::getIRStackGuard(IRBuilder<> &IRB) const {
1701   if (getTargetMachine().getTargetTriple().isOSOpenBSD()) {
1702     Module &M = *IRB.GetInsertBlock()->getParent()->getParent();
1703     PointerType *PtrTy = Type::getInt8PtrTy(M.getContext());
1704     return M.getOrInsertGlobal("__guard_local", PtrTy);
1705   }
1706   return nullptr;
1707 }
1708 
1709 // Currently only support "standard" __stack_chk_guard.
1710 // TODO: add LOAD_STACK_GUARD support.
1711 void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
1712   if (!M.getNamedValue("__stack_chk_guard"))
1713     new GlobalVariable(M, Type::getInt8PtrTy(M.getContext()), false,
1714                        GlobalVariable::ExternalLinkage,
1715                        nullptr, "__stack_chk_guard");
1716 }
1717 
1718 // Currently only support "standard" __stack_chk_guard.
1719 // TODO: add LOAD_STACK_GUARD support.
1720 Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
1721   return M.getNamedValue("__stack_chk_guard");
1722 }
1723 
1724 Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
1725   return nullptr;
1726 }
1727 
1728 unsigned TargetLoweringBase::getMinimumJumpTableEntries() const {
1729   return MinimumJumpTableEntries;
1730 }
1731 
1732 void TargetLoweringBase::setMinimumJumpTableEntries(unsigned Val) {
1733   MinimumJumpTableEntries = Val;
1734 }
1735 
1736 unsigned TargetLoweringBase::getMinimumJumpTableDensity(bool OptForSize) const {
1737   return OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
1738 }
1739 
1740 unsigned TargetLoweringBase::getMaximumJumpTableSize() const {
1741   return MaximumJumpTableSize;
1742 }
1743 
1744 void TargetLoweringBase::setMaximumJumpTableSize(unsigned Val) {
1745   MaximumJumpTableSize = Val;
1746 }
1747 
1748 //===----------------------------------------------------------------------===//
1749 //  Reciprocal Estimates
1750 //===----------------------------------------------------------------------===//
1751 
1752 /// Get the reciprocal estimate attribute string for a function that will
1753 /// override the target defaults.
1754 static StringRef getRecipEstimateForFunc(MachineFunction &MF) {
1755   const Function &F = MF.getFunction();
1756   return F.getFnAttribute("reciprocal-estimates").getValueAsString();
1757 }
1758 
1759 /// Construct a string for the given reciprocal operation of the given type.
1760 /// This string should match the corresponding option to the front-end's
1761 /// "-mrecip" flag assuming those strings have been passed through in an
1762 /// attribute string. For example, "vec-divf" for a division of a vXf32.
1763 static std::string getReciprocalOpName(bool IsSqrt, EVT VT) {
1764   std::string Name = VT.isVector() ? "vec-" : "";
1765 
1766   Name += IsSqrt ? "sqrt" : "div";
1767 
1768   // TODO: Handle "half" or other float types?
1769   if (VT.getScalarType() == MVT::f64) {
1770     Name += "d";
1771   } else {
1772     assert(VT.getScalarType() == MVT::f32 &&
1773            "Unexpected FP type for reciprocal estimate");
1774     Name += "f";
1775   }
1776 
1777   return Name;
1778 }
1779 
1780 /// Return the character position and value (a single numeric character) of a
1781 /// customized refinement operation in the input string if it exists. Return
1782 /// false if there is no customized refinement step count.
1783 static bool parseRefinementStep(StringRef In, size_t &Position,
1784                                 uint8_t &Value) {
1785   const char RefStepToken = ':';
1786   Position = In.find(RefStepToken);
1787   if (Position == StringRef::npos)
1788     return false;
1789 
1790   StringRef RefStepString = In.substr(Position + 1);
1791   // Allow exactly one numeric character for the additional refinement
1792   // step parameter.
1793   if (RefStepString.size() == 1) {
1794     char RefStepChar = RefStepString[0];
1795     if (RefStepChar >= '0' && RefStepChar <= '9') {
1796       Value = RefStepChar - '0';
1797       return true;
1798     }
1799   }
1800   report_fatal_error("Invalid refinement step for -recip.");
1801 }
1802 
1803 /// For the input attribute string, return one of the ReciprocalEstimate enum
1804 /// status values (enabled, disabled, or not specified) for this operation on
1805 /// the specified data type.
1806 static int getOpEnabled(bool IsSqrt, EVT VT, StringRef Override) {
1807   if (Override.empty())
1808     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1809 
1810   SmallVector<StringRef, 4> OverrideVector;
1811   Override.split(OverrideVector, ',');
1812   unsigned NumArgs = OverrideVector.size();
1813 
1814   // Check if "all", "none", or "default" was specified.
1815   if (NumArgs == 1) {
1816     // Look for an optional setting of the number of refinement steps needed
1817     // for this type of reciprocal operation.
1818     size_t RefPos;
1819     uint8_t RefSteps;
1820     if (parseRefinementStep(Override, RefPos, RefSteps)) {
1821       // Split the string for further processing.
1822       Override = Override.substr(0, RefPos);
1823     }
1824 
1825     // All reciprocal types are enabled.
1826     if (Override == "all")
1827       return TargetLoweringBase::ReciprocalEstimate::Enabled;
1828 
1829     // All reciprocal types are disabled.
1830     if (Override == "none")
1831       return TargetLoweringBase::ReciprocalEstimate::Disabled;
1832 
1833     // Target defaults for enablement are used.
1834     if (Override == "default")
1835       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1836   }
1837 
1838   // The attribute string may omit the size suffix ('f'/'d').
1839   std::string VTName = getReciprocalOpName(IsSqrt, VT);
1840   std::string VTNameNoSize = VTName;
1841   VTNameNoSize.pop_back();
1842   static const char DisabledPrefix = '!';
1843 
1844   for (StringRef RecipType : OverrideVector) {
1845     size_t RefPos;
1846     uint8_t RefSteps;
1847     if (parseRefinementStep(RecipType, RefPos, RefSteps))
1848       RecipType = RecipType.substr(0, RefPos);
1849 
1850     // Ignore the disablement token for string matching.
1851     bool IsDisabled = RecipType[0] == DisabledPrefix;
1852     if (IsDisabled)
1853       RecipType = RecipType.substr(1);
1854 
1855     if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
1856       return IsDisabled ? TargetLoweringBase::ReciprocalEstimate::Disabled
1857                         : TargetLoweringBase::ReciprocalEstimate::Enabled;
1858   }
1859 
1860   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1861 }
1862 
1863 /// For the input attribute string, return the customized refinement step count
1864 /// for this operation on the specified data type. If the step count does not
1865 /// exist, return the ReciprocalEstimate enum value for unspecified.
1866 static int getOpRefinementSteps(bool IsSqrt, EVT VT, StringRef Override) {
1867   if (Override.empty())
1868     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1869 
1870   SmallVector<StringRef, 4> OverrideVector;
1871   Override.split(OverrideVector, ',');
1872   unsigned NumArgs = OverrideVector.size();
1873 
1874   // Check if "all", "default", or "none" was specified.
1875   if (NumArgs == 1) {
1876     // Look for an optional setting of the number of refinement steps needed
1877     // for this type of reciprocal operation.
1878     size_t RefPos;
1879     uint8_t RefSteps;
1880     if (!parseRefinementStep(Override, RefPos, RefSteps))
1881       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1882 
1883     // Split the string for further processing.
1884     Override = Override.substr(0, RefPos);
1885     assert(Override != "none" &&
1886            "Disabled reciprocals, but specifed refinement steps?");
1887 
1888     // If this is a general override, return the specified number of steps.
1889     if (Override == "all" || Override == "default")
1890       return RefSteps;
1891   }
1892 
1893   // The attribute string may omit the size suffix ('f'/'d').
1894   std::string VTName = getReciprocalOpName(IsSqrt, VT);
1895   std::string VTNameNoSize = VTName;
1896   VTNameNoSize.pop_back();
1897 
1898   for (StringRef RecipType : OverrideVector) {
1899     size_t RefPos;
1900     uint8_t RefSteps;
1901     if (!parseRefinementStep(RecipType, RefPos, RefSteps))
1902       continue;
1903 
1904     RecipType = RecipType.substr(0, RefPos);
1905     if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
1906       return RefSteps;
1907   }
1908 
1909   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1910 }
1911 
1912 int TargetLoweringBase::getRecipEstimateSqrtEnabled(EVT VT,
1913                                                     MachineFunction &MF) const {
1914   return getOpEnabled(true, VT, getRecipEstimateForFunc(MF));
1915 }
1916 
1917 int TargetLoweringBase::getRecipEstimateDivEnabled(EVT VT,
1918                                                    MachineFunction &MF) const {
1919   return getOpEnabled(false, VT, getRecipEstimateForFunc(MF));
1920 }
1921 
1922 int TargetLoweringBase::getSqrtRefinementSteps(EVT VT,
1923                                                MachineFunction &MF) const {
1924   return getOpRefinementSteps(true, VT, getRecipEstimateForFunc(MF));
1925 }
1926 
1927 int TargetLoweringBase::getDivRefinementSteps(EVT VT,
1928                                               MachineFunction &MF) const {
1929   return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
1930 }
1931 
1932 void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
1933   MF.getRegInfo().freezeReservedRegs(MF);
1934 }
1935