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
|
//===-- MBlazeAsmBackend.cpp - MBlaze Assembler Backend -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/MBlazeMCTargetDesc.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/MC/MCELFSymbolFlags.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCValue.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
static unsigned getFixupKindSize(unsigned Kind) {
switch (Kind) {
default: assert(0 && "invalid fixup kind!");
case FK_Data_1: return 1;
case FK_PCRel_2:
case FK_Data_2: return 2;
case FK_PCRel_4:
case FK_Data_4: return 4;
case FK_Data_8: return 8;
}
}
namespace {
class MBlazeAsmBackend : public MCAsmBackend {
public:
MBlazeAsmBackend(const Target &T)
: MCAsmBackend() {
}
unsigned getNumFixupKinds() const {
return 2;
}
bool mayNeedRelaxation(const MCInst &Inst) const;
bool fixupNeedsRelaxation(const MCFixup &Fixup,
uint64_t Value,
const MCInstFragment *DF,
const MCAsmLayout &Layout) const;
void relaxInstruction(const MCInst &Inst, MCInst &Res) const;
bool writeNopData(uint64_t Count, MCObjectWriter *OW) const;
unsigned getPointerSize() const {
return 4;
}
};
static unsigned getRelaxedOpcode(unsigned Op) {
switch (Op) {
default: return Op;
case MBlaze::ADDIK: return MBlaze::ADDIK32;
case MBlaze::ORI: return MBlaze::ORI32;
case MBlaze::BRLID: return MBlaze::BRLID32;
}
}
bool MBlazeAsmBackend::mayNeedRelaxation(const MCInst &Inst) const {
if (getRelaxedOpcode(Inst.getOpcode()) == Inst.getOpcode())
return false;
bool hasExprOrImm = false;
for (unsigned i = 0; i < Inst.getNumOperands(); ++i)
hasExprOrImm |= Inst.getOperand(i).isExpr();
return hasExprOrImm;
}
bool MBlazeAsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup,
uint64_t Value,
const MCInstFragment *DF,
const MCAsmLayout &Layout) const {
// FIXME: Is this right? It's what the "generic" code was doing before,
// but is X86 specific. Is it actually true for MBlaze also, or was it
// just close enough to not be a big deal?
//
// Relax if the value is too big for a (signed) i8.
return int64_t(Value) != int64_t(int8_t(Value));
}
void MBlazeAsmBackend::relaxInstruction(const MCInst &Inst, MCInst &Res) const {
Res = Inst;
Res.setOpcode(getRelaxedOpcode(Inst.getOpcode()));
}
bool MBlazeAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const {
if ((Count % 4) != 0)
return false;
for (uint64_t i = 0; i < Count; i += 4)
OW->Write32(0x00000000);
return true;
}
} // end anonymous namespace
namespace {
class ELFMBlazeAsmBackend : public MBlazeAsmBackend {
public:
uint8_t OSABI;
ELFMBlazeAsmBackend(const Target &T, uint8_t _OSABI)
: MBlazeAsmBackend(T), OSABI(_OSABI) { }
void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
uint64_t Value) const;
MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
return createMBlazeELFObjectWriter(OS, OSABI);
}
};
void ELFMBlazeAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
unsigned DataSize, uint64_t Value) const {
unsigned Size = getFixupKindSize(Fixup.getKind());
assert(Fixup.getOffset() + Size <= DataSize &&
"Invalid fixup offset!");
char *data = Data + Fixup.getOffset();
switch (Size) {
default: llvm_unreachable("Cannot fixup unknown value.");
case 1: llvm_unreachable("Cannot fixup 1 byte value.");
case 8: llvm_unreachable("Cannot fixup 8 byte value.");
case 4:
*(data+7) = uint8_t(Value);
*(data+6) = uint8_t(Value >> 8);
*(data+3) = uint8_t(Value >> 16);
*(data+2) = uint8_t(Value >> 24);
break;
case 2:
*(data+3) = uint8_t(Value >> 0);
*(data+2) = uint8_t(Value >> 8);
}
}
} // end anonymous namespace
MCAsmBackend *llvm::createMBlazeAsmBackend(const Target &T, StringRef TT) {
Triple TheTriple(TT);
if (TheTriple.isOSDarwin())
assert(0 && "Mac not supported on MBlaze");
if (TheTriple.isOSWindows())
assert(0 && "Windows not supported on MBlaze");
uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TheTriple.getOS());
return new ELFMBlazeAsmBackend(T, OSABI);
}
|
