1 //===- HexagonAbsoluteStub.cpp --------------------------------------------===//
2 //
3 // The MCLinker Project
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "HexagonAbsoluteStub.h"
11 #include "HexagonLDBackend.h"
12
13 #include "mcld/LD/ResolveInfo.h"
14 #include "mcld/LD/LDSymbol.h"
15 #include "mcld/Fragment/Relocation.h"
16
17 #include <llvm/Support/ELF.h>
18 #include <llvm/Support/MathExtras.h>
19
20 namespace mcld {
21
22 //===----------------------------------------------------------------------===//
23 // HexagonAbsoluteStub
24 //===----------------------------------------------------------------------===//
25
26 const uint32_t HexagonAbsoluteStub::TEMPLATE[] = {
27 0xbffd7f1d, /* { sp = add (sp, #-8) */
28 0xa79dfcfe, /* memw (sp + #-8) = r28 } */
29 0x723cc000, /* r28.h = #HI (foo) */
30 0x713cc000, /* r28.l = #LO (foo) */
31 0xb01d411d, /* { sp = add (sp, #8) */
32 0x529c4000, /* jumpr r28 */
33 0x919dc01c /* r28 = memw (sp) } */
34 };
35
36 #define FITS_IN_NBITS(D, B) \
37 (std::abs(D) < (~(~(int64_t)0 << ((B)-1)) & -(4 * 4)))
38
HexagonAbsoluteStub(bool pIsOutputPIC)39 HexagonAbsoluteStub::HexagonAbsoluteStub(bool pIsOutputPIC)
40 : Stub(), m_Name("HexagonTrampoline"), m_pData(NULL), m_Size(0x0) {
41 m_pData = TEMPLATE;
42 m_Size = sizeof(TEMPLATE);
43 addFixup(8u, 0x0, llvm::ELF::R_HEX_HI16);
44 addFixup(12u, 0x0, llvm::ELF::R_HEX_LO16);
45 }
46
47 /// for doClone
HexagonAbsoluteStub(const uint32_t * pData,size_t pSize,const_fixup_iterator pBegin,const_fixup_iterator pEnd)48 HexagonAbsoluteStub::HexagonAbsoluteStub(const uint32_t* pData,
49 size_t pSize,
50 const_fixup_iterator pBegin,
51 const_fixup_iterator pEnd)
52 : Stub(), m_Name("AbsVeneer"), m_pData(pData), m_Size(pSize) {
53 for (const_fixup_iterator it = pBegin, ie = pEnd; it != ie; ++it)
54 addFixup(**it);
55 }
56
~HexagonAbsoluteStub()57 HexagonAbsoluteStub::~HexagonAbsoluteStub() {
58 }
59
isMyDuty(const class Relocation & pReloc,uint64_t pSource,uint64_t pTargetSymValue) const60 bool HexagonAbsoluteStub::isMyDuty(const class Relocation& pReloc,
61 uint64_t pSource,
62 uint64_t pTargetSymValue) const {
63 int nbits = 0;
64 switch (pReloc.type()) {
65 case llvm::ELF::R_HEX_B22_PCREL:
66 nbits = 24;
67 break;
68 case llvm::ELF::R_HEX_B15_PCREL:
69 nbits = 17;
70 break;
71 case llvm::ELF::R_HEX_B7_PCREL:
72 nbits = 9;
73 break;
74 case llvm::ELF::R_HEX_B13_PCREL:
75 nbits = 15;
76 break;
77 case llvm::ELF::R_HEX_B9_PCREL:
78 nbits = 17;
79 break;
80 default:
81 return false;
82 }
83
84 int64_t offset = pTargetSymValue - pSource;
85 // if offset is going to fit in nbits then we dont
86 // need a stub to be created
87 if (FITS_IN_NBITS(offset, nbits))
88 return false;
89 return true;
90 }
91
name() const92 const std::string& HexagonAbsoluteStub::name() const {
93 return m_Name;
94 }
95
getContent() const96 const uint8_t* HexagonAbsoluteStub::getContent() const {
97 return reinterpret_cast<const uint8_t*>(m_pData);
98 }
99
size() const100 size_t HexagonAbsoluteStub::size() const {
101 return m_Size;
102 }
103
alignment() const104 size_t HexagonAbsoluteStub::alignment() const {
105 return 4u;
106 }
107
doClone()108 Stub* HexagonAbsoluteStub::doClone() {
109 return new HexagonAbsoluteStub(m_pData, m_Size, fixup_begin(), fixup_end());
110 }
111
112 } // namespace mcld
113