/
AArch64AsmPrinter.cpp
1398 lines (1220 loc) · 49.6 KB
/
AArch64AsmPrinter.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
//===- AArch64AsmPrinter.cpp - AArch64 LLVM assembly writer ---------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains a printer that converts from our internal representation
// of machine-dependent LLVM code to the AArch64 assembly language.
//
//===----------------------------------------------------------------------===//
#include "AArch64.h"
#include "AArch64MCInstLower.h"
#include "AArch64MachineFunctionInfo.h"
#include "AArch64RegisterInfo.h"
#include "AArch64Subtarget.h"
#include "AArch64TargetObjectFile.h"
#include "MCTargetDesc/AArch64AddressingModes.h"
#include "MCTargetDesc/AArch64InstPrinter.h"
#include "MCTargetDesc/AArch64MCExpr.h"
#include "MCTargetDesc/AArch64MCTargetDesc.h"
#include "MCTargetDesc/AArch64TargetStreamer.h"
#include "TargetInfo/AArch64TargetInfo.h"
#include "Utils/AArch64BaseInfo.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/FaultMaps.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfoImpls.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <map>
#include <memory>
using namespace llvm;
#define DEBUG_TYPE "asm-printer"
namespace {
class AArch64AsmPrinter : public AsmPrinter {
AArch64MCInstLower MCInstLowering;
StackMaps SM;
FaultMaps FM;
const AArch64Subtarget *STI;
public:
AArch64AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
: AsmPrinter(TM, std::move(Streamer)), MCInstLowering(OutContext, *this),
SM(*this), FM(*this) {}
StringRef getPassName() const override { return "AArch64 Assembly Printer"; }
/// Wrapper for MCInstLowering.lowerOperand() for the
/// tblgen'erated pseudo lowering.
bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp) const {
return MCInstLowering.lowerOperand(MO, MCOp);
}
void emitStartOfAsmFile(Module &M) override;
void emitJumpTableInfo() override;
void LowerJumpTableDest(MCStreamer &OutStreamer, const MachineInstr &MI);
void LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI);
void LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI);
void LowerSTATEPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI);
void LowerFAULTING_OP(const MachineInstr &MI);
void LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI);
void LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI);
void LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI);
typedef std::tuple<unsigned, bool, uint32_t> HwasanMemaccessTuple;
std::map<HwasanMemaccessTuple, MCSymbol *> HwasanMemaccessSymbols;
void LowerHWASAN_CHECK_MEMACCESS(const MachineInstr &MI);
void EmitHwasanMemaccessSymbols(Module &M);
void EmitSled(const MachineInstr &MI, SledKind Kind);
/// tblgen'erated driver function for lowering simple MI->MC
/// pseudo instructions.
bool emitPseudoExpansionLowering(MCStreamer &OutStreamer,
const MachineInstr *MI);
void emitInstruction(const MachineInstr *MI) override;
void emitFunctionHeaderComment() override;
void getAnalysisUsage(AnalysisUsage &AU) const override {
AsmPrinter::getAnalysisUsage(AU);
AU.setPreservesAll();
}
bool runOnMachineFunction(MachineFunction &MF) override {
AArch64FI = MF.getInfo<AArch64FunctionInfo>();
STI = static_cast<const AArch64Subtarget*>(&MF.getSubtarget());
SetupMachineFunction(MF);
if (STI->isTargetCOFF()) {
bool Internal = MF.getFunction().hasInternalLinkage();
COFF::SymbolStorageClass Scl = Internal ? COFF::IMAGE_SYM_CLASS_STATIC
: COFF::IMAGE_SYM_CLASS_EXTERNAL;
int Type =
COFF::IMAGE_SYM_DTYPE_FUNCTION << COFF::SCT_COMPLEX_TYPE_SHIFT;
OutStreamer->BeginCOFFSymbolDef(CurrentFnSym);
OutStreamer->EmitCOFFSymbolStorageClass(Scl);
OutStreamer->EmitCOFFSymbolType(Type);
OutStreamer->EndCOFFSymbolDef();
}
// Emit the rest of the function body.
emitFunctionBody();
// Emit the XRay table for this function.
emitXRayTable();
// We didn't modify anything.
return false;
}
private:
void printOperand(const MachineInstr *MI, unsigned OpNum, raw_ostream &O);
bool printAsmMRegister(const MachineOperand &MO, char Mode, raw_ostream &O);
bool printAsmRegInClass(const MachineOperand &MO,
const TargetRegisterClass *RC, unsigned AltName,
raw_ostream &O);
bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
const char *ExtraCode, raw_ostream &O) override;
bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
const char *ExtraCode, raw_ostream &O) override;
void PrintDebugValueComment(const MachineInstr *MI, raw_ostream &OS);
void emitFunctionBodyEnd() override;
MCSymbol *GetCPISymbol(unsigned CPID) const override;
void emitEndOfAsmFile(Module &M) override;
AArch64FunctionInfo *AArch64FI = nullptr;
/// Emit the LOHs contained in AArch64FI.
void EmitLOHs();
/// Emit instruction to set float register to zero.
void EmitFMov0(const MachineInstr &MI);
using MInstToMCSymbol = std::map<const MachineInstr *, MCSymbol *>;
MInstToMCSymbol LOHInstToLabel;
};
} // end anonymous namespace
void AArch64AsmPrinter::emitStartOfAsmFile(Module &M) {
if (!TM.getTargetTriple().isOSBinFormatELF())
return;
// Assemble feature flags that may require creation of a note section.
unsigned Flags = 0;
if (const auto *BTE = mdconst::extract_or_null<ConstantInt>(
M.getModuleFlag("branch-target-enforcement")))
if (BTE->getZExtValue())
Flags |= ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI;
if (const auto *Sign = mdconst::extract_or_null<ConstantInt>(
M.getModuleFlag("sign-return-address")))
if (Sign->getZExtValue())
Flags |= ELF::GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
if (Flags == 0)
return;
// Emit a .note.gnu.property section with the flags.
if (auto *TS = static_cast<AArch64TargetStreamer *>(
OutStreamer->getTargetStreamer()))
TS->emitNoteSection(Flags);
}
void AArch64AsmPrinter::emitFunctionHeaderComment() {
const AArch64FunctionInfo *FI = MF->getInfo<AArch64FunctionInfo>();
Optional<std::string> OutlinerString = FI->getOutliningStyle();
if (OutlinerString != None)
OutStreamer->GetCommentOS() << ' ' << OutlinerString;
}
void AArch64AsmPrinter::LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI)
{
const Function &F = MF->getFunction();
if (F.hasFnAttribute("patchable-function-entry")) {
unsigned Num;
if (F.getFnAttribute("patchable-function-entry")
.getValueAsString()
.getAsInteger(10, Num))
return;
emitNops(Num);
return;
}
EmitSled(MI, SledKind::FUNCTION_ENTER);
}
void AArch64AsmPrinter::LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI)
{
EmitSled(MI, SledKind::FUNCTION_EXIT);
}
void AArch64AsmPrinter::LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI)
{
EmitSled(MI, SledKind::TAIL_CALL);
}
void AArch64AsmPrinter::EmitSled(const MachineInstr &MI, SledKind Kind)
{
static const int8_t NoopsInSledCount = 7;
// We want to emit the following pattern:
//
// .Lxray_sled_N:
// ALIGN
// B #32
// ; 7 NOP instructions (28 bytes)
// .tmpN
//
// We need the 28 bytes (7 instructions) because at runtime, we'd be patching
// over the full 32 bytes (8 instructions) with the following pattern:
//
// STP X0, X30, [SP, #-16]! ; push X0 and the link register to the stack
// LDR W0, #12 ; W0 := function ID
// LDR X16,#12 ; X16 := addr of __xray_FunctionEntry or __xray_FunctionExit
// BLR X16 ; call the tracing trampoline
// ;DATA: 32 bits of function ID
// ;DATA: lower 32 bits of the address of the trampoline
// ;DATA: higher 32 bits of the address of the trampoline
// LDP X0, X30, [SP], #16 ; pop X0 and the link register from the stack
//
OutStreamer->emitCodeAlignment(4);
auto CurSled = OutContext.createTempSymbol("xray_sled_", true);
OutStreamer->emitLabel(CurSled);
auto Target = OutContext.createTempSymbol();
// Emit "B #32" instruction, which jumps over the next 28 bytes.
// The operand has to be the number of 4-byte instructions to jump over,
// including the current instruction.
EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::B).addImm(8));
for (int8_t I = 0; I < NoopsInSledCount; I++)
EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
OutStreamer->emitLabel(Target);
recordSled(CurSled, MI, Kind, 2);
}
void AArch64AsmPrinter::LowerHWASAN_CHECK_MEMACCESS(const MachineInstr &MI) {
Register Reg = MI.getOperand(0).getReg();
bool IsShort =
MI.getOpcode() == AArch64::HWASAN_CHECK_MEMACCESS_SHORTGRANULES;
uint32_t AccessInfo = MI.getOperand(1).getImm();
MCSymbol *&Sym =
HwasanMemaccessSymbols[HwasanMemaccessTuple(Reg, IsShort, AccessInfo)];
if (!Sym) {
// FIXME: Make this work on non-ELF.
if (!TM.getTargetTriple().isOSBinFormatELF())
report_fatal_error("llvm.hwasan.check.memaccess only supported on ELF");
std::string SymName = "__hwasan_check_x" + utostr(Reg - AArch64::X0) + "_" +
utostr(AccessInfo);
if (IsShort)
SymName += "_short";
Sym = OutContext.getOrCreateSymbol(SymName);
}
EmitToStreamer(*OutStreamer,
MCInstBuilder(AArch64::BL)
.addExpr(MCSymbolRefExpr::create(Sym, OutContext)));
}
void AArch64AsmPrinter::EmitHwasanMemaccessSymbols(Module &M) {
if (HwasanMemaccessSymbols.empty())
return;
const Triple &TT = TM.getTargetTriple();
assert(TT.isOSBinFormatELF());
std::unique_ptr<MCSubtargetInfo> STI(
TM.getTarget().createMCSubtargetInfo(TT.str(), "", ""));
MCSymbol *HwasanTagMismatchV1Sym =
OutContext.getOrCreateSymbol("__hwasan_tag_mismatch");
MCSymbol *HwasanTagMismatchV2Sym =
OutContext.getOrCreateSymbol("__hwasan_tag_mismatch_v2");
const MCSymbolRefExpr *HwasanTagMismatchV1Ref =
MCSymbolRefExpr::create(HwasanTagMismatchV1Sym, OutContext);
const MCSymbolRefExpr *HwasanTagMismatchV2Ref =
MCSymbolRefExpr::create(HwasanTagMismatchV2Sym, OutContext);
for (auto &P : HwasanMemaccessSymbols) {
unsigned Reg = std::get<0>(P.first);
bool IsShort = std::get<1>(P.first);
uint32_t AccessInfo = std::get<2>(P.first);
const MCSymbolRefExpr *HwasanTagMismatchRef =
IsShort ? HwasanTagMismatchV2Ref : HwasanTagMismatchV1Ref;
MCSymbol *Sym = P.second;
OutStreamer->SwitchSection(OutContext.getELFSection(
".text.hot", ELF::SHT_PROGBITS,
ELF::SHF_EXECINSTR | ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
Sym->getName()));
OutStreamer->emitSymbolAttribute(Sym, MCSA_ELF_TypeFunction);
OutStreamer->emitSymbolAttribute(Sym, MCSA_Weak);
OutStreamer->emitSymbolAttribute(Sym, MCSA_Hidden);
OutStreamer->emitLabel(Sym);
OutStreamer->emitInstruction(MCInstBuilder(AArch64::UBFMXri)
.addReg(AArch64::X16)
.addReg(Reg)
.addImm(4)
.addImm(55),
*STI);
OutStreamer->emitInstruction(MCInstBuilder(AArch64::LDRBBroX)
.addReg(AArch64::W16)
.addReg(AArch64::X9)
.addReg(AArch64::X16)
.addImm(0)
.addImm(0),
*STI);
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::SUBSXrs)
.addReg(AArch64::XZR)
.addReg(AArch64::X16)
.addReg(Reg)
.addImm(AArch64_AM::getShifterImm(AArch64_AM::LSR, 56)),
*STI);
MCSymbol *HandleMismatchOrPartialSym = OutContext.createTempSymbol();
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::Bcc)
.addImm(AArch64CC::NE)
.addExpr(MCSymbolRefExpr::create(HandleMismatchOrPartialSym,
OutContext)),
*STI);
MCSymbol *ReturnSym = OutContext.createTempSymbol();
OutStreamer->emitLabel(ReturnSym);
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::RET).addReg(AArch64::LR), *STI);
OutStreamer->emitLabel(HandleMismatchOrPartialSym);
if (IsShort) {
OutStreamer->emitInstruction(MCInstBuilder(AArch64::SUBSWri)
.addReg(AArch64::WZR)
.addReg(AArch64::W16)
.addImm(15)
.addImm(0),
*STI);
MCSymbol *HandleMismatchSym = OutContext.createTempSymbol();
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::Bcc)
.addImm(AArch64CC::HI)
.addExpr(MCSymbolRefExpr::create(HandleMismatchSym, OutContext)),
*STI);
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::ANDXri)
.addReg(AArch64::X17)
.addReg(Reg)
.addImm(AArch64_AM::encodeLogicalImmediate(0xf, 64)),
*STI);
unsigned Size = 1 << (AccessInfo & 0xf);
if (Size != 1)
OutStreamer->emitInstruction(MCInstBuilder(AArch64::ADDXri)
.addReg(AArch64::X17)
.addReg(AArch64::X17)
.addImm(Size - 1)
.addImm(0),
*STI);
OutStreamer->emitInstruction(MCInstBuilder(AArch64::SUBSWrs)
.addReg(AArch64::WZR)
.addReg(AArch64::W16)
.addReg(AArch64::W17)
.addImm(0),
*STI);
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::Bcc)
.addImm(AArch64CC::LS)
.addExpr(MCSymbolRefExpr::create(HandleMismatchSym, OutContext)),
*STI);
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::ORRXri)
.addReg(AArch64::X16)
.addReg(Reg)
.addImm(AArch64_AM::encodeLogicalImmediate(0xf, 64)),
*STI);
OutStreamer->emitInstruction(MCInstBuilder(AArch64::LDRBBui)
.addReg(AArch64::W16)
.addReg(AArch64::X16)
.addImm(0),
*STI);
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::SUBSXrs)
.addReg(AArch64::XZR)
.addReg(AArch64::X16)
.addReg(Reg)
.addImm(AArch64_AM::getShifterImm(AArch64_AM::LSR, 56)),
*STI);
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::Bcc)
.addImm(AArch64CC::EQ)
.addExpr(MCSymbolRefExpr::create(ReturnSym, OutContext)),
*STI);
OutStreamer->emitLabel(HandleMismatchSym);
}
OutStreamer->emitInstruction(MCInstBuilder(AArch64::STPXpre)
.addReg(AArch64::SP)
.addReg(AArch64::X0)
.addReg(AArch64::X1)
.addReg(AArch64::SP)
.addImm(-32),
*STI);
OutStreamer->emitInstruction(MCInstBuilder(AArch64::STPXi)
.addReg(AArch64::FP)
.addReg(AArch64::LR)
.addReg(AArch64::SP)
.addImm(29),
*STI);
if (Reg != AArch64::X0)
OutStreamer->emitInstruction(MCInstBuilder(AArch64::ORRXrs)
.addReg(AArch64::X0)
.addReg(AArch64::XZR)
.addReg(Reg)
.addImm(0),
*STI);
OutStreamer->emitInstruction(MCInstBuilder(AArch64::MOVZXi)
.addReg(AArch64::X1)
.addImm(AccessInfo)
.addImm(0),
*STI);
// Intentionally load the GOT entry and branch to it, rather than possibly
// late binding the function, which may clobber the registers before we have
// a chance to save them.
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::ADRP)
.addReg(AArch64::X16)
.addExpr(AArch64MCExpr::create(
HwasanTagMismatchRef, AArch64MCExpr::VariantKind::VK_GOT_PAGE,
OutContext)),
*STI);
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::LDRXui)
.addReg(AArch64::X16)
.addReg(AArch64::X16)
.addExpr(AArch64MCExpr::create(
HwasanTagMismatchRef, AArch64MCExpr::VariantKind::VK_GOT_LO12,
OutContext)),
*STI);
OutStreamer->emitInstruction(
MCInstBuilder(AArch64::BR).addReg(AArch64::X16), *STI);
}
}
void AArch64AsmPrinter::emitEndOfAsmFile(Module &M) {
EmitHwasanMemaccessSymbols(M);
const Triple &TT = TM.getTargetTriple();
if (TT.isOSBinFormatMachO()) {
// Funny Darwin hack: This flag tells the linker that no global symbols
// contain code that falls through to other global symbols (e.g. the obvious
// implementation of multiple entry points). If this doesn't occur, the
// linker can safely perform dead code stripping. Since LLVM never
// generates code that does this, it is always safe to set.
OutStreamer->emitAssemblerFlag(MCAF_SubsectionsViaSymbols);
}
// Emit stack and fault map information.
emitStackMaps(SM);
FM.serializeToFaultMapSection();
}
void AArch64AsmPrinter::EmitLOHs() {
SmallVector<MCSymbol *, 3> MCArgs;
for (const auto &D : AArch64FI->getLOHContainer()) {
for (const MachineInstr *MI : D.getArgs()) {
MInstToMCSymbol::iterator LabelIt = LOHInstToLabel.find(MI);
assert(LabelIt != LOHInstToLabel.end() &&
"Label hasn't been inserted for LOH related instruction");
MCArgs.push_back(LabelIt->second);
}
OutStreamer->emitLOHDirective(D.getKind(), MCArgs);
MCArgs.clear();
}
}
void AArch64AsmPrinter::emitFunctionBodyEnd() {
if (!AArch64FI->getLOHRelated().empty())
EmitLOHs();
}
/// GetCPISymbol - Return the symbol for the specified constant pool entry.
MCSymbol *AArch64AsmPrinter::GetCPISymbol(unsigned CPID) const {
// Darwin uses a linker-private symbol name for constant-pools (to
// avoid addends on the relocation?), ELF has no such concept and
// uses a normal private symbol.
if (!getDataLayout().getLinkerPrivateGlobalPrefix().empty())
return OutContext.getOrCreateSymbol(
Twine(getDataLayout().getLinkerPrivateGlobalPrefix()) + "CPI" +
Twine(getFunctionNumber()) + "_" + Twine(CPID));
return AsmPrinter::GetCPISymbol(CPID);
}
void AArch64AsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNum,
raw_ostream &O) {
const MachineOperand &MO = MI->getOperand(OpNum);
switch (MO.getType()) {
default:
llvm_unreachable("<unknown operand type>");
case MachineOperand::MO_Register: {
Register Reg = MO.getReg();
assert(Register::isPhysicalRegister(Reg));
assert(!MO.getSubReg() && "Subregs should be eliminated!");
O << AArch64InstPrinter::getRegisterName(Reg);
break;
}
case MachineOperand::MO_Immediate: {
O << MO.getImm();
break;
}
case MachineOperand::MO_GlobalAddress: {
PrintSymbolOperand(MO, O);
break;
}
case MachineOperand::MO_BlockAddress: {
MCSymbol *Sym = GetBlockAddressSymbol(MO.getBlockAddress());
Sym->print(O, MAI);
break;
}
}
}
bool AArch64AsmPrinter::printAsmMRegister(const MachineOperand &MO, char Mode,
raw_ostream &O) {
Register Reg = MO.getReg();
switch (Mode) {
default:
return true; // Unknown mode.
case 'w':
Reg = getWRegFromXReg(Reg);
break;
case 'x':
Reg = getXRegFromWReg(Reg);
break;
}
O << AArch64InstPrinter::getRegisterName(Reg);
return false;
}
// Prints the register in MO using class RC using the offset in the
// new register class. This should not be used for cross class
// printing.
bool AArch64AsmPrinter::printAsmRegInClass(const MachineOperand &MO,
const TargetRegisterClass *RC,
unsigned AltName, raw_ostream &O) {
assert(MO.isReg() && "Should only get here with a register!");
const TargetRegisterInfo *RI = STI->getRegisterInfo();
Register Reg = MO.getReg();
unsigned RegToPrint = RC->getRegister(RI->getEncodingValue(Reg));
assert(RI->regsOverlap(RegToPrint, Reg));
O << AArch64InstPrinter::getRegisterName(RegToPrint, AltName);
return false;
}
bool AArch64AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
const char *ExtraCode, raw_ostream &O) {
const MachineOperand &MO = MI->getOperand(OpNum);
// First try the generic code, which knows about modifiers like 'c' and 'n'.
if (!AsmPrinter::PrintAsmOperand(MI, OpNum, ExtraCode, O))
return false;
// Does this asm operand have a single letter operand modifier?
if (ExtraCode && ExtraCode[0]) {
if (ExtraCode[1] != 0)
return true; // Unknown modifier.
switch (ExtraCode[0]) {
default:
return true; // Unknown modifier.
case 'w': // Print W register
case 'x': // Print X register
if (MO.isReg())
return printAsmMRegister(MO, ExtraCode[0], O);
if (MO.isImm() && MO.getImm() == 0) {
unsigned Reg = ExtraCode[0] == 'w' ? AArch64::WZR : AArch64::XZR;
O << AArch64InstPrinter::getRegisterName(Reg);
return false;
}
printOperand(MI, OpNum, O);
return false;
case 'b': // Print B register.
case 'h': // Print H register.
case 's': // Print S register.
case 'd': // Print D register.
case 'q': // Print Q register.
case 'z': // Print Z register.
if (MO.isReg()) {
const TargetRegisterClass *RC;
switch (ExtraCode[0]) {
case 'b':
RC = &AArch64::FPR8RegClass;
break;
case 'h':
RC = &AArch64::FPR16RegClass;
break;
case 's':
RC = &AArch64::FPR32RegClass;
break;
case 'd':
RC = &AArch64::FPR64RegClass;
break;
case 'q':
RC = &AArch64::FPR128RegClass;
break;
case 'z':
RC = &AArch64::ZPRRegClass;
break;
default:
return true;
}
return printAsmRegInClass(MO, RC, AArch64::NoRegAltName, O);
}
printOperand(MI, OpNum, O);
return false;
}
}
// According to ARM, we should emit x and v registers unless we have a
// modifier.
if (MO.isReg()) {
Register Reg = MO.getReg();
// If this is a w or x register, print an x register.
if (AArch64::GPR32allRegClass.contains(Reg) ||
AArch64::GPR64allRegClass.contains(Reg))
return printAsmMRegister(MO, 'x', O);
unsigned AltName = AArch64::NoRegAltName;
const TargetRegisterClass *RegClass;
if (AArch64::ZPRRegClass.contains(Reg)) {
RegClass = &AArch64::ZPRRegClass;
} else if (AArch64::PPRRegClass.contains(Reg)) {
RegClass = &AArch64::PPRRegClass;
} else {
RegClass = &AArch64::FPR128RegClass;
AltName = AArch64::vreg;
}
// If this is a b, h, s, d, or q register, print it as a v register.
return printAsmRegInClass(MO, RegClass, AltName, O);
}
printOperand(MI, OpNum, O);
return false;
}
bool AArch64AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
unsigned OpNum,
const char *ExtraCode,
raw_ostream &O) {
if (ExtraCode && ExtraCode[0] && ExtraCode[0] != 'a')
return true; // Unknown modifier.
const MachineOperand &MO = MI->getOperand(OpNum);
assert(MO.isReg() && "unexpected inline asm memory operand");
O << "[" << AArch64InstPrinter::getRegisterName(MO.getReg()) << "]";
return false;
}
void AArch64AsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
raw_ostream &OS) {
unsigned NOps = MI->getNumOperands();
assert(NOps == 4);
OS << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
// cast away const; DIetc do not take const operands for some reason.
OS << MI->getDebugVariable()->getName();
OS << " <- ";
// Frame address. Currently handles register +- offset only.
assert(MI->getDebugOperand(0).isReg() && MI->isDebugOffsetImm());
OS << '[';
printOperand(MI, 0, OS);
OS << '+';
printOperand(MI, 1, OS);
OS << ']';
OS << "+";
printOperand(MI, NOps - 2, OS);
}
void AArch64AsmPrinter::emitJumpTableInfo() {
const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
if (!MJTI) return;
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
if (JT.empty()) return;
const Function &F = MF->getFunction();
const TargetLoweringObjectFile &TLOF = getObjFileLowering();
bool JTInDiffSection =
!STI->isTargetCOFF() ||
!TLOF.shouldPutJumpTableInFunctionSection(
MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
F);
if (JTInDiffSection) {
// Drop it in the readonly section.
MCSection *ReadOnlySec = TLOF.getSectionForJumpTable(F, TM);
OutStreamer->SwitchSection(ReadOnlySec);
}
auto AFI = MF->getInfo<AArch64FunctionInfo>();
for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
// If this jump table was deleted, ignore it.
if (JTBBs.empty()) continue;
unsigned Size = AFI->getJumpTableEntrySize(JTI);
emitAlignment(Align(Size));
OutStreamer->emitLabel(GetJTISymbol(JTI));
const MCSymbol *BaseSym = AArch64FI->getJumpTableEntryPCRelSymbol(JTI);
const MCExpr *Base = MCSymbolRefExpr::create(BaseSym, OutContext);
for (auto *JTBB : JTBBs) {
const MCExpr *Value =
MCSymbolRefExpr::create(JTBB->getSymbol(), OutContext);
// Each entry is:
// .byte/.hword (LBB - Lbase)>>2
// or plain:
// .word LBB - Lbase
Value = MCBinaryExpr::createSub(Value, Base, OutContext);
if (Size != 4)
Value = MCBinaryExpr::createLShr(
Value, MCConstantExpr::create(2, OutContext), OutContext);
OutStreamer->emitValue(Value, Size);
}
}
}
/// Small jump tables contain an unsigned byte or half, representing the offset
/// from the lowest-addressed possible destination to the desired basic
/// block. Since all instructions are 4-byte aligned, this is further compressed
/// by counting in instructions rather than bytes (i.e. divided by 4). So, to
/// materialize the correct destination we need:
///
/// adr xDest, .LBB0_0
/// ldrb wScratch, [xTable, xEntry] (with "lsl #1" for ldrh).
/// add xDest, xDest, xScratch (with "lsl #2" for smaller entries)
void AArch64AsmPrinter::LowerJumpTableDest(llvm::MCStreamer &OutStreamer,
const llvm::MachineInstr &MI) {
Register DestReg = MI.getOperand(0).getReg();
Register ScratchReg = MI.getOperand(1).getReg();
Register ScratchRegW =
STI->getRegisterInfo()->getSubReg(ScratchReg, AArch64::sub_32);
Register TableReg = MI.getOperand(2).getReg();
Register EntryReg = MI.getOperand(3).getReg();
int JTIdx = MI.getOperand(4).getIndex();
int Size = AArch64FI->getJumpTableEntrySize(JTIdx);
// This has to be first because the compression pass based its reachability
// calculations on the start of the JumpTableDest instruction.
auto Label =
MF->getInfo<AArch64FunctionInfo>()->getJumpTableEntryPCRelSymbol(JTIdx);
// If we don't already have a symbol to use as the base, use the ADR
// instruction itself.
if (!Label) {
Label = MF->getContext().createTempSymbol();
AArch64FI->setJumpTableEntryInfo(JTIdx, Size, Label);
OutStreamer.emitLabel(Label);
}
auto LabelExpr = MCSymbolRefExpr::create(Label, MF->getContext());
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::ADR)
.addReg(DestReg)
.addExpr(LabelExpr));
// Load the number of instruction-steps to offset from the label.
unsigned LdrOpcode;
switch (Size) {
case 1: LdrOpcode = AArch64::LDRBBroX; break;
case 2: LdrOpcode = AArch64::LDRHHroX; break;
case 4: LdrOpcode = AArch64::LDRSWroX; break;
default:
llvm_unreachable("Unknown jump table size");
}
EmitToStreamer(OutStreamer, MCInstBuilder(LdrOpcode)
.addReg(Size == 4 ? ScratchReg : ScratchRegW)
.addReg(TableReg)
.addReg(EntryReg)
.addImm(0)
.addImm(Size == 1 ? 0 : 1));
// Add to the already materialized base label address, multiplying by 4 if
// compressed.
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::ADDXrs)
.addReg(DestReg)
.addReg(DestReg)
.addReg(ScratchReg)
.addImm(Size == 4 ? 0 : 2));
}
void AArch64AsmPrinter::LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI) {
unsigned NumNOPBytes = StackMapOpers(&MI).getNumPatchBytes();
auto &Ctx = OutStreamer.getContext();
MCSymbol *MILabel = Ctx.createTempSymbol();
OutStreamer.emitLabel(MILabel);
SM.recordStackMap(*MILabel, MI);
assert(NumNOPBytes % 4 == 0 && "Invalid number of NOP bytes requested!");
// Scan ahead to trim the shadow.
const MachineBasicBlock &MBB = *MI.getParent();
MachineBasicBlock::const_iterator MII(MI);
++MII;
while (NumNOPBytes > 0) {
if (MII == MBB.end() || MII->isCall() ||
MII->getOpcode() == AArch64::DBG_VALUE ||
MII->getOpcode() == TargetOpcode::PATCHPOINT ||
MII->getOpcode() == TargetOpcode::STACKMAP)
break;
++MII;
NumNOPBytes -= 4;
}
// Emit nops.
for (unsigned i = 0; i < NumNOPBytes; i += 4)
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
}
// Lower a patchpoint of the form:
// [<def>], <id>, <numBytes>, <target>, <numArgs>
void AArch64AsmPrinter::LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI) {
auto &Ctx = OutStreamer.getContext();
MCSymbol *MILabel = Ctx.createTempSymbol();
OutStreamer.emitLabel(MILabel);
SM.recordPatchPoint(*MILabel, MI);
PatchPointOpers Opers(&MI);
int64_t CallTarget = Opers.getCallTarget().getImm();
unsigned EncodedBytes = 0;
if (CallTarget) {
assert((CallTarget & 0xFFFFFFFFFFFF) == CallTarget &&
"High 16 bits of call target should be zero.");
Register ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
EncodedBytes = 16;
// Materialize the jump address:
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVZXi)
.addReg(ScratchReg)
.addImm((CallTarget >> 32) & 0xFFFF)
.addImm(32));
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm((CallTarget >> 16) & 0xFFFF)
.addImm(16));
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm(CallTarget & 0xFFFF)
.addImm(0));
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::BLR).addReg(ScratchReg));
}
// Emit padding.
unsigned NumBytes = Opers.getNumPatchBytes();
assert(NumBytes >= EncodedBytes &&
"Patchpoint can't request size less than the length of a call.");
assert((NumBytes - EncodedBytes) % 4 == 0 &&
"Invalid number of NOP bytes requested!");
for (unsigned i = EncodedBytes; i < NumBytes; i += 4)
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
}
void AArch64AsmPrinter::LowerSTATEPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI) {
StatepointOpers SOpers(&MI);
if (unsigned PatchBytes = SOpers.getNumPatchBytes()) {
assert(PatchBytes % 4 == 0 && "Invalid number of NOP bytes requested!");
for (unsigned i = 0; i < PatchBytes; i += 4)
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
} else {
// Lower call target and choose correct opcode
const MachineOperand &CallTarget = SOpers.getCallTarget();
MCOperand CallTargetMCOp;
unsigned CallOpcode;
switch (CallTarget.getType()) {
case MachineOperand::MO_GlobalAddress:
case MachineOperand::MO_ExternalSymbol:
MCInstLowering.lowerOperand(CallTarget, CallTargetMCOp);
CallOpcode = AArch64::BL;
break;
case MachineOperand::MO_Immediate:
CallTargetMCOp = MCOperand::createImm(CallTarget.getImm());
CallOpcode = AArch64::BL;
break;
case MachineOperand::MO_Register:
CallTargetMCOp = MCOperand::createReg(CallTarget.getReg());
CallOpcode = AArch64::BLR;
break;
default:
llvm_unreachable("Unsupported operand type in statepoint call target");
break;
}
EmitToStreamer(OutStreamer,
MCInstBuilder(CallOpcode).addOperand(CallTargetMCOp));
}
auto &Ctx = OutStreamer.getContext();
MCSymbol *MILabel = Ctx.createTempSymbol();
OutStreamer.emitLabel(MILabel);
SM.recordStatepoint(*MILabel, MI);
}
void AArch64AsmPrinter::LowerFAULTING_OP(const MachineInstr &FaultingMI) {
// FAULTING_LOAD_OP <def>, <faltinf type>, <MBB handler>,
// <opcode>, <operands>
Register DefRegister = FaultingMI.getOperand(0).getReg();
FaultMaps::FaultKind FK =
static_cast<FaultMaps::FaultKind>(FaultingMI.getOperand(1).getImm());
MCSymbol *HandlerLabel = FaultingMI.getOperand(2).getMBB()->getSymbol();
unsigned Opcode = FaultingMI.getOperand(3).getImm();
unsigned OperandsBeginIdx = 4;
auto &Ctx = OutStreamer->getContext();
MCSymbol *FaultingLabel = Ctx.createTempSymbol();
OutStreamer->emitLabel(FaultingLabel);
assert(FK < FaultMaps::FaultKindMax && "Invalid Faulting Kind!");
FM.recordFaultingOp(FK, FaultingLabel, HandlerLabel);
MCInst MI;
MI.setOpcode(Opcode);
if (DefRegister != (Register)0)
MI.addOperand(MCOperand::createReg(DefRegister));
for (auto I = FaultingMI.operands_begin() + OperandsBeginIdx,
E = FaultingMI.operands_end();
I != E; ++I) {
MCOperand Dest;
lowerOperand(*I, Dest);
MI.addOperand(Dest);
}