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105 lines
3.8 KiB
105 lines
3.8 KiB
//===- BranchIslandFactory.cpp --------------------------------------------===//
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//
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// The MCLinker Project
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "mcld/LD/BranchIslandFactory.h"
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#include "mcld/Fragment/Fragment.h"
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#include "mcld/LD/LDSection.h"
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#include "mcld/LD/SectionData.h"
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#include "mcld/Module.h"
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namespace mcld {
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//===----------------------------------------------------------------------===//
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// BranchIslandFactory
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//===----------------------------------------------------------------------===//
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/// ctor
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/// @param pMaxFwdBranchRange - the max forward branch range of the target
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/// @param pMaxBwdBranchRange - the max backward branch range of the target
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/// @param pMaxIslandSize - the predefined value for the max size of a island
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BranchIslandFactory::BranchIslandFactory(int64_t pMaxFwdBranchRange,
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int64_t pMaxBwdBranchRange,
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size_t pMaxIslandSize)
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: GCFactory<BranchIsland, 0>(1u), // magic number
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m_MaxFwdBranchRange(pMaxFwdBranchRange - pMaxIslandSize),
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m_MaxBwdBranchRange(pMaxBwdBranchRange + pMaxIslandSize),
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m_MaxIslandSize(pMaxIslandSize) {
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}
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BranchIslandFactory::~BranchIslandFactory() {
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}
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/// group - group fragments and create islands when needed
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/// @param pSectionData - the SectionData holds fragments need to be grouped
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void BranchIslandFactory::group(Module& pModule) {
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for (Module::iterator sect = pModule.begin(), sectEnd = pModule.end();
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sect != sectEnd; ++sect) {
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if (((*sect)->kind() == LDFileFormat::TEXT) && (*sect)->hasSectionData()) {
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SectionData& sd = *((*sect)->getSectionData());
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uint64_t group_end = m_MaxFwdBranchRange;
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for (SectionData::iterator it = sd.begin(), ie = sd.end(); it != ie;
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++it) {
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if ((*it).getOffset() + (*it).size() > group_end) {
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Fragment* frag = (*it).getPrevNode();
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while (frag != NULL && frag->getKind() == Fragment::Alignment) {
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frag = frag->getPrevNode();
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}
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if (frag != NULL) {
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produce(*frag);
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group_end = (*it).getOffset() + m_MaxFwdBranchRange;
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}
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}
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}
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if (getIslands(sd.back()).first == NULL)
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produce(sd.back());
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}
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}
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}
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/// produce - produce a island for the given fragment
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/// @param pFragment - the fragment needs a branch island
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BranchIsland* BranchIslandFactory::produce(Fragment& pFragment) {
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BranchIsland* island = allocate();
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new (island) BranchIsland(pFragment, // entry fragment to the island
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m_MaxIslandSize, // the max size of the island
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size() - 1u); // index in the island factory
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return island;
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}
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/// getIsland - find fwd and bwd islands for the fragment
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/// @param pFragment - the fragment needs a branch island
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std::pair<BranchIsland*, BranchIsland*> BranchIslandFactory::getIslands(
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const Fragment& pFragment) {
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BranchIsland* fwd = NULL;
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BranchIsland* bwd = NULL;
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for (iterator it = begin(), ie = end(), prev = ie; it != ie;
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prev = it, ++it) {
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if (pFragment.getParent() != (*it).getParent()) {
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continue;
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}
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if ((pFragment.getOffset() < (*it).offset()) &&
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((pFragment.getOffset() + m_MaxFwdBranchRange) >= (*it).offset())) {
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fwd = &*it;
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if ((prev != ie) && (pFragment.getParent() == (*prev).getParent())) {
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int64_t bwd_off = (int64_t)pFragment.getOffset() + m_MaxBwdBranchRange;
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if ((pFragment.getOffset() > (*prev).offset()) &&
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(bwd_off <= (int64_t)(*prev).offset())) {
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bwd = &*prev;
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}
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}
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break;
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}
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}
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return std::make_pair(fwd, bwd);
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}
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} // namespace mcld
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