LLVM  14.0.0git
SystemZMCObjectWriter.cpp
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1 //===-- SystemZMCObjectWriter.cpp - SystemZ ELF writer --------------------===//
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 
11 #include "llvm/BinaryFormat/ELF.h"
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/MC/MCFixup.h"
15 #include "llvm/MC/MCObjectWriter.h"
16 #include "llvm/MC/MCValue.h"
18 #include <cassert>
19 #include <cstdint>
20 
21 using namespace llvm;
22 
23 namespace {
24 
25 class SystemZObjectWriter : public MCELFObjectTargetWriter {
26 public:
27  SystemZObjectWriter(uint8_t OSABI);
28  ~SystemZObjectWriter() override = default;
29 
30 protected:
31  // Override MCELFObjectTargetWriter.
32  unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
33  const MCFixup &Fixup, bool IsPCRel) const override;
34 };
35 
36 } // end anonymous namespace
37 
38 SystemZObjectWriter::SystemZObjectWriter(uint8_t OSABI)
39  : MCELFObjectTargetWriter(/*Is64Bit_=*/true, OSABI, ELF::EM_S390,
40  /*HasRelocationAddend_=*/ true) {}
41 
42 // Return the relocation type for an absolute value of MCFixupKind Kind.
43 static unsigned getAbsoluteReloc(unsigned Kind) {
44  switch (Kind) {
45  case FK_Data_1: return ELF::R_390_8;
46  case FK_Data_2: return ELF::R_390_16;
47  case FK_Data_4: return ELF::R_390_32;
48  case FK_Data_8: return ELF::R_390_64;
49  case SystemZ::FK_390_12: return ELF::R_390_12;
50  case SystemZ::FK_390_20: return ELF::R_390_20;
51  }
52  llvm_unreachable("Unsupported absolute address");
53 }
54 
55 // Return the relocation type for a PC-relative value of MCFixupKind Kind.
56 static unsigned getPCRelReloc(unsigned Kind) {
57  switch (Kind) {
58  case FK_Data_2: return ELF::R_390_PC16;
59  case FK_Data_4: return ELF::R_390_PC32;
60  case FK_Data_8: return ELF::R_390_PC64;
61  case SystemZ::FK_390_PC12DBL: return ELF::R_390_PC12DBL;
62  case SystemZ::FK_390_PC16DBL: return ELF::R_390_PC16DBL;
63  case SystemZ::FK_390_PC24DBL: return ELF::R_390_PC24DBL;
64  case SystemZ::FK_390_PC32DBL: return ELF::R_390_PC32DBL;
65  }
66  llvm_unreachable("Unsupported PC-relative address");
67 }
68 
69 // Return the R_390_TLS_LE* relocation type for MCFixupKind Kind.
70 static unsigned getTLSLEReloc(unsigned Kind) {
71  switch (Kind) {
72  case FK_Data_4: return ELF::R_390_TLS_LE32;
73  case FK_Data_8: return ELF::R_390_TLS_LE64;
74  }
75  llvm_unreachable("Unsupported absolute address");
76 }
77 
78 // Return the R_390_TLS_LDO* relocation type for MCFixupKind Kind.
79 static unsigned getTLSLDOReloc(unsigned Kind) {
80  switch (Kind) {
81  case FK_Data_4: return ELF::R_390_TLS_LDO32;
82  case FK_Data_8: return ELF::R_390_TLS_LDO64;
83  }
84  llvm_unreachable("Unsupported absolute address");
85 }
86 
87 // Return the R_390_TLS_LDM* relocation type for MCFixupKind Kind.
88 static unsigned getTLSLDMReloc(unsigned Kind) {
89  switch (Kind) {
90  case FK_Data_4: return ELF::R_390_TLS_LDM32;
91  case FK_Data_8: return ELF::R_390_TLS_LDM64;
92  case SystemZ::FK_390_TLS_CALL: return ELF::R_390_TLS_LDCALL;
93  }
94  llvm_unreachable("Unsupported absolute address");
95 }
96 
97 // Return the R_390_TLS_GD* relocation type for MCFixupKind Kind.
98 static unsigned getTLSGDReloc(unsigned Kind) {
99  switch (Kind) {
100  case FK_Data_4: return ELF::R_390_TLS_GD32;
101  case FK_Data_8: return ELF::R_390_TLS_GD64;
102  case SystemZ::FK_390_TLS_CALL: return ELF::R_390_TLS_GDCALL;
103  }
104  llvm_unreachable("Unsupported absolute address");
105 }
106 
107 // Return the PLT relocation counterpart of MCFixupKind Kind.
108 static unsigned getPLTReloc(unsigned Kind) {
109  switch (Kind) {
110  case SystemZ::FK_390_PC12DBL: return ELF::R_390_PLT12DBL;
111  case SystemZ::FK_390_PC16DBL: return ELF::R_390_PLT16DBL;
112  case SystemZ::FK_390_PC24DBL: return ELF::R_390_PLT24DBL;
113  case SystemZ::FK_390_PC32DBL: return ELF::R_390_PLT32DBL;
114  }
115  llvm_unreachable("Unsupported absolute address");
116 }
117 
118 unsigned SystemZObjectWriter::getRelocType(MCContext &Ctx,
119  const MCValue &Target,
120  const MCFixup &Fixup,
121  bool IsPCRel) const {
122  unsigned Kind = Fixup.getKind();
125  MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
126  switch (Modifier) {
128  if (IsPCRel)
129  return getPCRelReloc(Kind);
130  return getAbsoluteReloc(Kind);
131 
133  assert(!IsPCRel && "NTPOFF shouldn't be PC-relative");
134  return getTLSLEReloc(Kind);
135 
137  if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)
138  return ELF::R_390_TLS_IEENT;
139  llvm_unreachable("Only PC-relative INDNTPOFF accesses are supported for now");
140 
142  assert(!IsPCRel && "DTPOFF shouldn't be PC-relative");
143  return getTLSLDOReloc(Kind);
144 
146  assert(!IsPCRel && "TLSLDM shouldn't be PC-relative");
147  return getTLSLDMReloc(Kind);
148 
150  assert(!IsPCRel && "TLSGD shouldn't be PC-relative");
151  return getTLSGDReloc(Kind);
152 
154  if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)
155  return ELF::R_390_GOTENT;
156  llvm_unreachable("Only PC-relative GOT accesses are supported for now");
157 
159  assert(IsPCRel && "@PLT shouldt be PC-relative");
160  return getPLTReloc(Kind);
161 
162  default:
163  llvm_unreachable("Modifier not supported");
164  }
165 }
166 
167 std::unique_ptr<MCObjectTargetWriter>
169  return std::make_unique<SystemZObjectWriter>(OSABI);
170 }
llvm::ELF::EM_S390
@ EM_S390
Definition: ELF.h:150
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AllocatorList.h:22
llvm::MCSymbolRefExpr::VK_GOT
@ VK_GOT
Definition: MCExpr.h:198
llvm::SystemZ::FK_390_20
@ FK_390_20
Definition: SystemZMCFixups.h:24
llvm::MCSymbolRefExpr::VK_INDNTPOFF
@ VK_INDNTPOFF
Definition: MCExpr.h:205
llvm::MCContext
Context object for machine code objects.
Definition: MCContext.h:72
llvm::Target
Target - Wrapper for Target specific information.
Definition: TargetRegistry.h:137
llvm::SystemZ::FK_390_PC16DBL
@ FK_390_PC16DBL
Definition: SystemZMCFixups.h:19
ErrorHandling.h
true
basic Basic Alias true
Definition: BasicAliasAnalysis.cpp:1886
SystemZMCTargetDesc.h
llvm::SystemZ::FK_390_PC12DBL
@ FK_390_PC12DBL
Definition: SystemZMCFixups.h:18
llvm::FirstLiteralRelocationKind
@ FirstLiteralRelocationKind
The range [FirstLiteralRelocationKind, MaxTargetFixupKind) is used for relocations coming from ....
Definition: MCFixup.h:50
llvm::MCSymbolRefExpr::VK_NTPOFF
@ VK_NTPOFF
Definition: MCExpr.h:206
llvm::FK_Data_4
@ FK_Data_4
A four-byte fixup.
Definition: MCFixup.h:25
ELF.h
llvm::SystemZ::FK_390_PC24DBL
@ FK_390_PC24DBL
Definition: SystemZMCFixups.h:20
llvm::SystemZ::FK_390_TLS_CALL
@ FK_390_TLS_CALL
Definition: SystemZMCFixups.h:22
llvm::MCSymbolRefExpr::VK_TLSLDM
@ VK_TLSLDM
Definition: MCExpr.h:211
llvm::MCELFObjectTargetWriter
Definition: MCELFObjectWriter.h:53
llvm::SystemZ::FK_390_12
@ FK_390_12
Definition: SystemZMCFixups.h:23
getPLTReloc
static unsigned getPLTReloc(unsigned Kind)
Definition: SystemZMCObjectWriter.cpp:108
getAbsoluteReloc
static unsigned getAbsoluteReloc(unsigned Kind)
Definition: SystemZMCObjectWriter.cpp:43
llvm::lltok::Kind
Kind
Definition: LLToken.h:18
getTLSLDMReloc
static unsigned getTLSLDMReloc(unsigned Kind)
Definition: SystemZMCObjectWriter.cpp:88
llvm::MCSymbolRefExpr::VariantKind
VariantKind
Definition: MCExpr.h:194
MCELFObjectWriter.h
llvm::MCSymbolRefExpr::VK_PLT
@ VK_PLT
Definition: MCExpr.h:208
assert
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
llvm::FK_Data_1
@ FK_Data_1
A one-byte fixup.
Definition: MCFixup.h:23
llvm::createSystemZObjectWriter
std::unique_ptr< MCObjectTargetWriter > createSystemZObjectWriter(uint8_t OSABI)
Definition: SystemZMCObjectWriter.cpp:168
llvm::SystemZ::FK_390_PC32DBL
@ FK_390_PC32DBL
Definition: SystemZMCFixups.h:21
Fixup
PowerPC TLS Dynamic Call Fixup
Definition: PPCTLSDynamicCall.cpp:233
getTLSGDReloc
static unsigned getTLSGDReloc(unsigned Kind)
Definition: SystemZMCObjectWriter.cpp:98
llvm_unreachable
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Definition: ErrorHandling.h:134
MCFixup.h
getTLSLDOReloc
static unsigned getTLSLDOReloc(unsigned Kind)
Definition: SystemZMCObjectWriter.cpp:79
MCObjectWriter.h
SystemZMCFixups.h
getTLSLEReloc
static unsigned getTLSLEReloc(unsigned Kind)
Definition: SystemZMCObjectWriter.cpp:70
llvm::MCSymbolRefExpr::VK_TLSGD
@ VK_TLSGD
Definition: MCExpr.h:209
MCValue.h
llvm::FK_Data_8
@ FK_Data_8
A eight-byte fixup.
Definition: MCFixup.h:26
getPCRelReloc
static unsigned getPCRelReloc(unsigned Kind)
Definition: SystemZMCObjectWriter.cpp:56
llvm::MCValue
This represents an "assembler immediate".
Definition: MCValue.h:37
llvm::MCSymbolRefExpr::VK_None
@ VK_None
Definition: MCExpr.h:195
llvm::FK_Data_2
@ FK_Data_2
A two-byte fixup.
Definition: MCFixup.h:24
MCExpr.h
llvm::MCFixup
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:71
llvm::MCSymbolRefExpr::VK_DTPOFF
@ VK_DTPOFF
Definition: MCExpr.h:213