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//===- AArch64LongBranchStub.cpp ------------------------------------------===//
//
// The MCLinker Project
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "AArch64LongBranchStub.h"
#include "AArch64LDBackend.h"
#include "AArch64RelocationHelpers.h"
#include "mcld/Fragment/Relocation.h"
#include "mcld/LD/BranchIsland.h"
#include "mcld/LD/LDSymbol.h"
#include "mcld/LD/ResolveInfo.h"
#include <llvm/Support/ELF.h>
#include <cassert>
namespace mcld {
//===----------------------------------------------------------------------===//
// AArch64LongBranchStub
//===----------------------------------------------------------------------===//
const uint32_t AArch64LongBranchStub::PIC_TEMPLATE[] = {
0x58000090, // ldr ip0, 0x10
0x10000011, // adr ip1, #0
0x8b110210, // add ip0, ip0, ip1
0xd61f0200, // br ip0
0x00000000, // .xword <-- R_AARCH64_PREL64(X+12)
0x00000000,
};
const uint32_t AArch64LongBranchStub::TEMPLATE[] = {
0x58000050, // ldr ip0, 0x8
0xd61f0200, // br ip0
0x00000000, // .xword <-- R_AARCH64_PREL64(X)
0x00000000,
};
const uint32_t AArch64LongBranchStub::ADRP_TEMPLATE[] = {
0x90000010, // adrp ip0, X <-- R_AARCH64_ADR_PREL_PG_HI21(X)
0x91000210, // add ip0, ip0, :lo12:X <-- R_AARCH64_ADD_ABS_LO12_NC(X)
0xd61f0200, // br ip0
};
AArch64LongBranchStub::AArch64LongBranchStub(bool pIsOutputPIC)
: m_pData(NULL),
m_Name("ljmp_prototype"),
m_Size(0x0) {
if (pIsOutputPIC) {
m_pData = PIC_TEMPLATE;
m_Size = sizeof(PIC_TEMPLATE);
addFixup(0x10, 12, llvm::ELF::R_AARCH64_PREL64);
} else {
m_pData = TEMPLATE;
m_Size = sizeof(TEMPLATE);
addFixup(0x8, 0, llvm::ELF::R_AARCH64_PREL64);
}
}
/// for doClone
AArch64LongBranchStub::AArch64LongBranchStub(const uint32_t* pData,
size_t pSize,
const_fixup_iterator pBegin,
const_fixup_iterator pEnd)
: m_pData(pData),
m_Name("ljmp_veneer"),
m_Size(pSize) {
for (const_fixup_iterator it = pBegin, ie = pEnd; it != ie; ++it) {
addFixup(**it);
}
}
AArch64LongBranchStub::~AArch64LongBranchStub() {
}
bool AArch64LongBranchStub::isMyDuty(const Relocation& pReloc,
uint64_t pSource,
uint64_t pTargetSymValue) const {
assert((pReloc.type() == llvm::ELF::R_AARCH64_CALL26) ||
(pReloc.type() == llvm::ELF::R_AARCH64_JUMP26));
int64_t dest = pTargetSymValue + pReloc.addend();
int64_t branch_offset = dest - pSource;
if ((branch_offset > AArch64GNULDBackend::MAX_FWD_BRANCH_OFFSET) ||
(branch_offset < AArch64GNULDBackend::MAX_BWD_BRANCH_OFFSET)) {
return true;
}
return false;
}
static bool isValidForADRP(uint64_t pSource, uint64_t pDest) {
int64_t imm = static_cast<int64_t>((helper_get_page_address(pDest) -
helper_get_page_address(pSource))) >> 12;
return ((imm <= AArch64GNULDBackend::MAX_ADRP_IMM) &&
(imm >= AArch64GNULDBackend::MIN_ADRP_IMM));
}
void AArch64LongBranchStub::applyFixup(Relocation& pSrcReloc,
IRBuilder& pBuilder,
BranchIsland& pIsland) {
// Try to relax the stub itself.
LDSymbol* symbol = pSrcReloc.symInfo()->outSymbol();
uint64_t dest = symbol->fragRef()->frag()->getParent()->getSection().addr() +
symbol->fragRef()->getOutputOffset();
uint64_t src = pIsland.getParent()->getSection().addr() +
pIsland.offset() +
pIsland.size();
if (isValidForADRP(src, dest)) {
m_pData = ADRP_TEMPLATE;
m_Name = "adrp_veneer";
m_Size = sizeof(ADRP_TEMPLATE);
getFixupList().clear();
addFixup(0x0, 0, llvm::ELF::R_AARCH64_ADR_PREL_PG_HI21);
addFixup(0x4, 0, llvm::ELF::R_AARCH64_ADD_ABS_LO12_NC);
}
Stub::applyFixup(pSrcReloc, pBuilder, pIsland);
}
const std::string& AArch64LongBranchStub::name() const {
return m_Name;
}
const uint8_t* AArch64LongBranchStub::getContent() const {
return reinterpret_cast<const uint8_t*>(m_pData);
}
size_t AArch64LongBranchStub::size() const {
return m_Size;
}
size_t AArch64LongBranchStub::alignment() const {
return 8;
}
Stub* AArch64LongBranchStub::doClone() {
return new AArch64LongBranchStub(m_pData, m_Size, fixup_begin(), fixup_end());
}
} // namespace mcld